lib/ogl/basic.py

# -*- coding: utf-8 -*-
#----------------------------------------------------------------------------
# Name:         basic.py
# Purpose:      The basic OGL shapes
#
# Author:       Pierre Hjälm (from C++ original by Julian Smart)
#
# Created:      2004-05-08
# Copyright:    (c) 2004 Pierre Hjälm - 1998 Julian Smart
# Licence:      wxWindows license
# Tags:         phoenix-port, unittest, py3-port, documented
#----------------------------------------------------------------------------
"""
The basic shapes for OGL
"""

import wx
import math

from .oglmisc import *

DragOffsetX = 0.0
DragOffsetY = 0.0


def OGLInitialize():
    """Initialize OGL.

    :note: This creates some pens and brushes that the OGL library uses.
     It should be called after the app object has been created, but
     before OGL is used.
    """
    global WhiteBackgroundPen, WhiteBackgroundBrush, TransparentPen
    global BlackForegroundPen, NormalFont

    WhiteBackgroundPen = wx.Pen(wx.WHITE, 1, wx.PENSTYLE_SOLID)
    WhiteBackgroundBrush = wx.Brush(wx.WHITE, wx.BRUSHSTYLE_SOLID)

    TransparentPen = wx.Pen(wx.WHITE, 1, wx.PENSTYLE_TRANSPARENT)
    BlackForegroundPen = wx.Pen(wx.BLACK, 1, wx.PENSTYLE_SOLID)

    NormalFont = wx.Font(10, wx.FONTFAMILY_SWISS, wx.FONTSTYLE_NORMAL, wx.FONTWEIGHT_NORMAL)


def OGLCleanUp():
    """not implemented???"""
    pass


class ShapeTextLine(object):
    """The :class:`ShapeTextLine` class."""
    def __init__(self, the_x, the_y, the_line):
        """
        Default class constructor.

        :param int `the_x`: the x position
        :param int `the_y`: the y position
        :param str `the_line`: the text

        """
        self._x = the_x
        self._y = the_y
        self._line = the_line

    def GetX(self):
        """Get the x position."""
        return self._x

    def GetY(self):
        """Get the y position."""
        return self._y

    def SetX(self, x):
        """
        Set the x position.

        :param int `x`: the x position

        """
        self._x = x

    def SetY(self, y):
        """
        Set the y position.

        :param int `y`: the x position

        """
        self._y = y

    def SetText(self, text):
        """
        Set the text.

        :param str `text`: the text

        """
        self._line = text

    def GetText(self):
        """Get the text."""
        return self._line


class ShapeEvtHandler(object):
    """The :class:`ShapeEvtHandler` class."""
    def __init__(self, prev = None, shape = None):
        """
        Default class constructor.

        :param `pref`: the previous event handler, an instance of
         :class:`ShapeEvtHandler` ???
        :param `shape`: the shape, an instance of :class:`Shape`

        """
        self._previousHandler = prev
        self._handlerShape = shape

    def SetShape(self, sh):
        """
        Set associated shape

        :param `sh`:  the shape, an instance of :class:`Shape`

        """
        self._handlerShape = sh

    def GetShape(self):
        """Get associated shape."""
        return self._handlerShape

    def SetPreviousHandler(self, handler):
        """
        Set previous event handler.

        :param `handler`: the previous handler, an instance of
         :class:`ShapeEvtHandler` ???

        """
        self._previousHandler = handler

    def GetPreviousHandler(self):
        """Get previous event handler."""
        return self._previousHandler

    def OnDelete(self):
        """The delete handler."""
        if self!=self.GetShape():
            del self

    def OnDraw(self, dc):
        """The draw handler."""
        if self._previousHandler:
            self._previousHandler.OnDraw(dc)

    def OnMoveLinks(self, dc):
        """The move links handler."""
        if self._previousHandler:
            self._previousHandler.OnMoveLinks(dc)

    def OnMoveLink(self, dc, moveControlPoints = True):
        """The move link handler."""
        if self._previousHandler:
            self._previousHandler.OnMoveLink(dc, moveControlPoints)

    def OnDrawContents(self, dc):
        """The draw contents handler."""
        if self._previousHandler:
            self._previousHandler.OnDrawContents(dc)

    def OnDrawBranches(self, dc, erase = False):
        """The draw branches handler."""
        if self._previousHandler:
            self._previousHandler.OnDrawBranches(dc, erase = erase)

    def OnSize(self, x, y):
        """The size handler."""
        if self._previousHandler:
            self._previousHandler.OnSize(x, y)

    def OnMovePre(self, dc, x, y, old_x, old_y, display = True):
        """The pre move handler."""
        if self._previousHandler:
            return self._previousHandler.OnMovePre(dc, x, y, old_x, old_y, display)
        else:
            return True

    def OnMovePost(self, dc, x, y, old_x, old_y, display = True):
        """The post move handler."""
        if self._previousHandler:
            return self._previousHandler.OnMovePost(dc, x, y, old_x, old_y, display)
        else:
            return True

    def OnErase(self, dc):
        """The erase handler."""
        if self._previousHandler:
            self._previousHandler.OnErase(dc)

    def OnEraseContents(self, dc):
        """The erase contents handler."""
        if self._previousHandler:
            self._previousHandler.OnEraseContents(dc)

    def OnHighlight(self, dc):
        """The highlight handler."""
        if self._previousHandler:
            self._previousHandler.OnHighlight(dc)

    def OnLeftClick(self, x, y, keys, attachment):
        """The left click handler."""
        if self._previousHandler:
            self._previousHandler.OnLeftClick(x, y, keys, attachment)

    def OnLeftDoubleClick(self, x, y, keys = 0, attachment = 0):
        """The left double click handler."""
        if self._previousHandler:
            self._previousHandler.OnLeftDoubleClick(x, y, keys, attachment)

    def OnRightClick(self, x, y, keys = 0, attachment = 0):
        """The right click handler."""
        if self._previousHandler:
            self._previousHandler.OnRightClick(x, y, keys, attachment)

    def OnDragLeft(self, draw, x, y, keys = 0, attachment = 0):
        """The drag left handler."""
        if self._previousHandler:
            self._previousHandler.OnDragLeft(draw, x, y, keys, attachment)

    def OnBeginDragLeft(self, x, y, keys = 0, attachment = 0):
        """The begin drag left handler."""
        if self._previousHandler:
            self._previousHandler.OnBeginDragLeft(x, y, keys, attachment)

    def OnEndDragLeft(self, x, y, keys = 0, attachment = 0):
        """The end drag left handler."""
        if self._previousHandler:
            self._previousHandler.OnEndDragLeft(x, y, keys, attachment)

    def OnDragRight(self, draw, x, y, keys = 0, attachment = 0):
        """The drag right handler."""
        if self._previousHandler:
            self._previousHandler.OnDragRight(draw, x, y, keys, attachment)

    def OnBeginDragRight(self, x, y, keys = 0, attachment = 0):
        """The begin drag right handler."""
        if self._previousHandler:
            self._previousHandler.OnBeginDragRight(x, y, keys, attachment)

    def OnEndDragRight(self, x, y, keys = 0, attachment = 0):
        """The end drag right handler."""
        if self._previousHandler:
            self._previousHandler.OnEndDragRight(x, y, keys, attachment)

    # Control points ('handles') redirect control to the actual shape,
    # to make it easier to override sizing behaviour.
    def OnSizingDragLeft(self, pt, draw, x, y, keys = 0, attachment = 0):
        """The sizing drag left handler."""
        if self._previousHandler:
            self._previousHandler.OnSizingDragLeft(pt, draw, x, y, keys, attachment)

    def OnSizingBeginDragLeft(self, pt, x, y, keys = 0, attachment = 0):
        """The sizing begin drag left handler."""
        if self._previousHandler:
            self._previousHandler.OnSizingBeginDragLeft(pt, x, y, keys, attachment)

    def OnSizingEndDragLeft(self, pt, x, y, keys = 0, attachment = 0):
        """The sizing end drag left handler."""
        if self._previousHandler:
            self._previousHandler.OnSizingEndDragLeft(pt, x, y, keys, attachment)

    def OnBeginSize(self, w, h):
        """not implemented???"""
        pass

    def OnEndSize(self, w, h):
        """not implemented???"""
        pass

    def OnDrawOutline(self, dc, x, y, w, h):
        """The drag outline handler."""
        if self._previousHandler:
            self._previousHandler.OnDrawOutline(dc, x, y, w, h)

    def OnDrawControlPoints(self, dc):
        """The draw control points handler."""
        if self._previousHandler:
            self._previousHandler.OnDrawControlPoints(dc)

    def OnEraseControlPoints(self, dc):
        """The erase control points handler."""
        if self._previousHandler:
            self._previousHandler.OnEraseControlPoints(dc)

    # Can override this to prevent or intercept line reordering.
    def OnChangeAttachment(self, attachment, line, ordering):
        """The change attachment handler."""
        if self._previousHandler:
            self._previousHandler.OnChangeAttachment(attachment, line, ordering)


class Shape(ShapeEvtHandler):
    """
    The :class:`Shape` is the base class for OGL shapes.

    The :class:`Shape` is the top-level, abstract object that all other objects
    are derived from. All common functionality is represented by :class:`Shape`
    members, and overriden members that appear in derived classes and have
    behaviour as documented for :class:`Shape`, are not documented separately.
    """
    GraphicsInSizeToContents = False

    def __init__(self, canvas = None):
        """
        Default class constructor.

        :param `canvas`: an instance of :class:`~lib.ogl.Canvas`

        """
        ShapeEvtHandler.__init__(self)

        self._eventHandler = self
        self.SetShape(self)
        self._id = 0
        self._formatted = False
        self._canvas = canvas
        self._xpos = 0.0
        self._ypos = 0.0
        self._pen = BlackForegroundPen
        self._brush = wx.WHITE_BRUSH
        self._font = NormalFont
        self._textColour = wx.BLACK
        self._textColourName = wx.BLACK
        self._visible = False
        self._selected = False
        self._attachmentMode = ATTACHMENT_MODE_NONE
        self._spaceAttachments = True
        self._disableLabel = False
        self._fixedWidth = False
        self._fixedHeight = False
        self._drawHandles = True
        self._sensitivity = OP_ALL
        self._draggable = True
        self._parent = None
        self._formatMode = FORMAT_CENTRE_HORIZ | FORMAT_CENTRE_VERT
        self._shadowMode = SHADOW_NONE
        self._shadowOffsetX = 6
        self._shadowOffsetY = 6
        self._shadowBrush = wx.BLACK_BRUSH
        self._textMarginX = 5
        self._textMarginY = 5
        self._regionName = "0"
        self._centreResize = True
        self._maintainAspectRatio = False
        self._highlighted = False
        self._rotation = 0.0
        self._branchNeckLength = 10
        self._branchStemLength = 10
        self._branchSpacing = 10
        self._branchStyle = BRANCHING_ATTACHMENT_NORMAL

        self._regions = []
        self._lines = []
        self._controlPoints = []
        self._attachmentPoints = []
        self._text = []
        self._children = []

        # Set up a default region. Much of the above will be put into
        # the region eventually (the duplication is for compatibility)
        region = ShapeRegion()
        region.SetName("0")
        region.SetFont(NormalFont)
        region.SetFormatMode(FORMAT_CENTRE_HORIZ | FORMAT_CENTRE_VERT)
        region.SetColour("BLACK")
        self._regions.append(region)

    def __str__(self):
        return "<%s.%s>" % (self.__class__.__module__, self.__class__.__name__)

    def GetClassName(self):
        return str(self.__class__).split(".")[-1][:-2]

    def Delete(self):
        """
        Fully disconnect this shape from parents, children, the
        canvas, etc.
        """
        if self._parent:
            self._parent.GetChildren().remove(self)

        for child in self.GetChildren():
            child.Delete()

        self.ClearText()
        self.ClearRegions()
        self.ClearAttachments()

        self._handlerShape = None

        if self._canvas:
            self.RemoveFromCanvas(self._canvas)

        if self.GetEventHandler():
            self.GetEventHandler().OnDelete()
        self._eventHandler = None

    def Draggable(self):
        """
        Is shape draggable?

        :returns: `True` if the shape may be dragged by the user.
        """
        return True

    def SetShape(self, sh):
        """Set shape ???

        :param `sh`: an instance of :class:`Shape`

        """
        self._handlerShape = sh

    def GetCanvas(self):
        """Get the internal canvas."""
        return self._canvas

    def GetBranchStyle(self):
        """Get the branch style."""
        return self._branchStyle

    def GetRotation(self):
        """Return the angle of rotation in radians."""
        return self._rotation

    def SetRotation(self, rotation):
        """Set rotation

        :param int `rotation`: rotation

        """
        self._rotation = rotation

    def SetHighlight(self, hi, recurse = False):
        """Set the highlight for a shape. Shape highlighting is unimplemented."""
        self._highlighted = hi
        if recurse:
            for shape in self._children:
                shape.SetHighlight(hi, recurse)

    def SetSensitivityFilter(self, sens = OP_ALL, recursive = False):
        """
        Set the shape to be sensitive or insensitive to specific mouse
        operations.

        :param `sens`: is a bitlist of the following:

        ========================== ===================
        Mouse operation            Description
        ========================== ===================
        `OP_CLICK_LEFT`            left clicked
        `OP_CLICK_RIGHT`           right clicked
        `OP_DRAG_LEFT`             left drag
        `OP_DRAG_RIGHT`            right drag
        `OP_ALL`                   all of the above
        ========================== ===================

        :param `recursive`: if `True` recurse through children

        """
        self._draggable = sens & OP_DRAG_LEFT

        self._sensitivity = sens
        if recursive:
            for shape in self._children:
                shape.SetSensitivityFilter(sens, True)

    def SetDraggable(self, drag, recursive = False):
        """Set the shape to be draggable or not draggable.

        :param `drag`: if `True` make shape draggable
        :param `recursive`: if `True` recurse through children

        """
        self._draggable = drag
        if drag:
            self._sensitivity |= OP_DRAG_LEFT
        elif self._sensitivity & OP_DRAG_LEFT:
            self._sensitivity -= OP_DRAG_LEFT

        if recursive:
            for shape in self._children:
                shape.SetDraggable(drag, True)

    def SetDrawHandles(self, drawH):
        """
        Set the drawHandles flag for this shape and all descendants.

        :param `drawH`: if `True` (the default), any handles (control points)
         will be drawn. Otherwise, the handles will not be drawn.

        """
        self._drawHandles = drawH
        for shape in self._children:
            shape.SetDrawHandles(drawH)

    def SetShadowMode(self, mode, redraw = False):
        """
        Set the shadow mode (whether a shadow is drawn or not).

        :param `mode`: can be one of the following:

        =============================== ===========================
        Shadow mode                     Description
        =============================== ===========================
        `SHADOW_NONE`                   No shadow (the default)
        `SHADOW_LEFT`                   Shadow on the left side
        `SHADOW_RIGHT`                  Shadow on the right side
        =============================== ===========================

        """
        if redraw and self.GetCanvas():
            dc = wx.MemoryDC()
            dc.SelectObject(self.GetCanvas().GetBuffer())
            self.GetCanvas().PrepareDC(dc)
            self.Erase(dc)
            self._shadowMode = mode
            self.Draw(dc)
        else:
            self._shadowMode = mode

    def GetShadowMode(self):
        """Get the current shadow mode setting."""
        return self._shadowMode

    def SetCanvas(self, theCanvas):
        """
        Set the canvas, identical to Shape.Attach.

        :param `theCanvas`: an instance of :class:`~lib.ogl.Canvas`

        """
        self._canvas = theCanvas
        for shape in self._children:
            shape.SetCanvas(theCanvas)

    def AddToCanvas(self, theCanvas, addAfter = None):
        """
        Add the shape to the canvas's shape list.

        :param `theCanvas`: an instance of :class:`~lib.ogl.Canvas`
        :param `addAfter`: if non-NULL, will add the shape after this shape

        """
        theCanvas.AddShape(self, addAfter)

        lastImage = self
        for object in self._children:
            object.AddToCanvas(theCanvas, lastImage)
            lastImage = object

    def InsertInCanvas(self, theCanvas):
        """
        Insert the shape at the front of the shape list of canvas.

        :param `theCanvas`: an instance of :class:`~lib.ogl.Canvas`

        """
        theCanvas.InsertShape(self)

        lastImage = self
        for object in self._children:
            object.AddToCanvas(theCanvas, lastImage)
            lastImage = object

    def RemoveFromCanvas(self, theCanvas):
        """
        Remove the shape from the canvas.

        :param `theCanvas`: an instance of :class:`~lib.ogl.Canvas`

        """
        if self.Selected():
            self.Select(False)

        self._canvas = None
        theCanvas.RemoveShape(self)
        for object in self._children:
            object.RemoveFromCanvas(theCanvas)

    def ClearAttachments(self):
        """Clear internal custom attachment point shapes (of class
        :class:`~lib.ogl.AttachmentPoint`)
        """
        self._attachmentPoints = []

    def ClearText(self, regionId = 0):
        """
        Clear the text from the specified text region.

        :param `regionId`: the region identifier

        """
        if regionId == 0:
            self._text = ""
        if regionId < len(self._regions):
            self._regions[regionId].ClearText()

    def ClearRegions(self):
        """Clear the ShapeRegions from the shape."""
        self._regions = []

    def AddRegion(self, region):
        """Add a region to the shape."""
        self._regions.append(region)

    def SetDefaultRegionSize(self):
        """Set the default region to be consistent with the shape size."""
        if not self._regions:
            return
        w, h = self.GetBoundingBoxMax()
        self._regions[0].SetSize(w, h)

    def HitTest(self, x, y):
        """
        Given a point on a canvas, returns `True` if the point was on the
        shape, and returns the nearest attachment point and distance from
        the given point and target.

        :param `x`: the x position
        :param `y`: the y position

        """
        width, height = self.GetBoundingBoxMax()
        if abs(width) < 4:
            width = 4.0
        if abs(height) < 4:
            height = 4.0

        width += 4 # Allowance for inaccurate mousing
        height += 4

        left = self._xpos - width / 2.0
        top = self._ypos - height / 2.0
        right = self._xpos + width / 2.0
        bottom = self._ypos + height / 2.0

        nearest_attachment = 0

        # If within the bounding box, check the attachment points
        # within the object.
        if x >= left and x <= right and y >= top and y <= bottom:
            n = self.GetNumberOfAttachments()
            nearest = 999999

            # GetAttachmentPosition[Edge] takes a logical attachment position,
            # i.e. if it's rotated through 90%, position 0 is East-facing.

            for i in range(n):
                e = self.GetAttachmentPositionEdge(i)
                if e:
                    xp, yp = e
                    l = math.sqrt(((xp - x) * (xp - x)) + (yp - y) * (yp - y))
                    if l < nearest:
                        nearest = l
                        nearest_attachment = i

            return nearest_attachment, nearest
        return False

    # Format a text string according to the region size, adding
    # strings with positions to region text list

    def FormatText(self, dc, s, i = 0):
        """
        Reformat the given text region; defaults to formatting the
        default region.

        :param `dc`: the device contexr
        :param str `s`: the text string
        :param int `i`: the region identifier

        """
        self.ClearText(i)

        if not self._regions:
            return

        if i >= len(self._regions):
            return

        region = self._regions[i]
        region._regionText = s
        dc.SetFont(region.GetFont())

        w, h = region.GetSize()

        stringList = FormatText(dc, s, (w - 2 * self._textMarginX), (h - 2 * self._textMarginY), region.GetFormatMode())
        for s in stringList:
            line = ShapeTextLine(0.0, 0.0, s)
            region.GetFormattedText().append(line)

        actualW = w
        actualH = h
        # Don't try to resize an object with more than one image (this
        # case should be dealt with by overriden handlers)
        if (region.GetFormatMode() & FORMAT_SIZE_TO_CONTENTS) and \
           len(region.GetFormattedText()) and \
           len(self._regions) == 1 and \
           not Shape.GraphicsInSizeToContents:

            actualW, actualH = GetCentredTextExtent(dc, region.GetFormattedText())
            if actualW + 2 * self._textMarginX != w or actualH + 2 * self._textMarginY != h:
                # If we are a descendant of a composite, must make sure
                # the composite gets resized properly

                topAncestor = self.GetTopAncestor()
                if topAncestor != self:
                    Shape.GraphicsInSizeToContents = True

                    composite = topAncestor
                    composite.Erase(dc)
                    self.SetSize(actualW + 2 * self._textMarginX, actualH + 2 * self._textMarginY)
                    self.Move(dc, self._xpos, self._ypos)
                    composite.CalculateSize()
                    if composite.Selected():
                        composite.DeleteControlPoints(dc)
                        composite.MakeControlPoints()
                        composite.MakeMandatoryControlPoints()
                    # Where infinite recursion might happen if we didn't stop it
                    composite.Draw(dc)
                    Shape.GraphicsInSizeToContents = False
                else:
                    self.Erase(dc)

                self.SetSize(actualW + 2 * self._textMarginX, actualH + 2 * self._textMarginY)
                self.Move(dc, self._xpos, self._ypos)
                self.EraseContents(dc)
        CentreText(dc, region.GetFormattedText(), self._xpos, self._ypos, actualW - 2 * self._textMarginX, actualH - 2 * self._textMarginY, region.GetFormatMode())
        self._formatted = True

    def Recentre(self, dc):
        """
        Recentre (or other formatting) all the text regions for this shape.
        """
        w, h = self.GetBoundingBoxMin()
        for region in self._regions:
            CentreText(dc, region.GetFormattedText(), self._xpos, self._ypos, w - 2 * self._textMarginX, h - 2 * self._textMarginY, region.GetFormatMode())

    def GetPerimeterPoint(self, x1, y1, x2, y2):
        """
        Get the point at which the line from (x1, y1) to (x2, y2) hits
        the shape.

        :param `x1`: the x1 position
        :param `y1`: the y1 position
        :param `x2`: the x2 position
        :param `y2`: the y2 position

        :returns: `False` if the line doesn't hit the perimeter.

        """
        return False

    def SetPen(self, the_pen):
        """Set the pen for drawing the shape's outline."""
        self._pen = the_pen

    def SetBrush(self, the_brush):
        """Set the brush for filling the shape's shape."""
        self._brush = the_brush

    # Get the top - most (non-division) ancestor, or self
    def GetTopAncestor(self):
        """
        Return the top-most ancestor of this shape (the root of
        the composite).
        """
        if not self.GetParent():
            return self

        if isinstance(self.GetParent(), DivisionShape):
            return self
        return self.GetParent().GetTopAncestor()

    # Region functions
    def SetFont(self, the_font, regionId = 0):
        """
        Set the font for the specified text region.

        :param `the_font`: an instance of :class:`wx.Font` ???
        :param `regionId`: the region identifier

        """
        self._font = the_font
        if regionId < len(self._regions):
            self._regions[regionId].SetFont(the_font)

    def GetFont(self, regionId = 0):
        """
        Get the font for the specified text region.

        :param `regionId`: the region identifier

        """
        if regionId >= len(self._regions):
            return None
        return self._regions[regionId].GetFont()

    def SetFormatMode(self, mode, regionId = 0):
        """
        Set the format mode of the region.

        :param `mode`: can be a bit list of the following

        ============================== ==============================
        Format mode                    Description
        ============================== ==============================
        `FORMAT_NONE`                  No formatting
        `FORMAT_CENTRE_HORIZ`          Horizontal centring
        `FORMAT_CENTRE_VERT`           Vertical centring
        ============================== ==============================

        :param `regionId`: the region identifier, default=0

        """
        if regionId < len(self._regions):
            self._regions[regionId].SetFormatMode(mode)

    def GetFormatMode(self, regionId = 0):
        """
        Get the format mode.

        :param `regionId`: the region identifier, default=0

        """
        if regionId >= len(self._regions):
            return 0
        return self._regions[regionId].GetFormatMode()

    def SetTextColour(self, the_colour, regionId = 0):
        """
        Set the colour for the specified text region.

        :param str `the_colour`: a valid colour name,
         see :class:`wx.ColourDatabase`
        :param `regionId`: the region identifier

        """
        self._textColour = wx.TheColourDatabase.Find(the_colour)
        self._textColourName = the_colour

        if regionId < len(self._regions):
            self._regions[regionId].SetColour(the_colour)

    def GetTextColour(self, regionId = 0):
        """
        Get the colour for the specified text region.

        :param `regionId`: the region identifier

        """
        if regionId >= len(self._regions):
            return ""
        return self._regions[regionId].GetColour()

    def SetRegionName(self, name, regionId = 0):
        """
        Set the name for this region.

        :param str `name`: the name to set
        :param `regionId`: the region identifier

        :note: The name for a region is unique within the scope of the whole
         composite, whereas a region id is unique only for a single image.

        """
        if regionId < len(self._regions):
            self._regions[regionId].SetName(name)

    def GetRegionName(self, regionId = 0):
        """
        Get the region's name.

        :param `regionId`: the region identifier

        :note: A region's name can be used to uniquely determine a region within
         an entire composite image hierarchy. See also
         :meth:`~lib.ogl.Shape.SetRegionName`.

        """
        if regionId >= len(self._regions):
            return ""
        return self._regions[regionId].GetName()

    def GetRegionId(self, name):
        """
        Get the region's identifier by name.

        :param str `name`: the regions name

        :note: This is not unique for within an entire composite, but is unique
         for the image.

        """
        for i, r in enumerate(self._regions):
            if r.GetName() == name:
                return i
        return -1

    # Name all _regions in all subimages recursively
    def NameRegions(self, parentName=""):
        """
        Make unique names for all the regions in a shape or composite shape.

        :param str `parentName`: a prefix for the region names

        """
        n = self.GetNumberOfTextRegions()
        for i in range(n):
            if parentName:
                buff = parentName+"."+str(i)
            else:
                buff = str(i)
            self.SetRegionName(buff, i)

        for j, child in enumerate(self._children):
            if parentName:
                buff = parentName+"."+str(j)
            else:
                buff = str(j)
            child.NameRegions(buff)

    # Get a region by name, possibly looking recursively into composites
    def FindRegion(self, name):
        """
        Find the actual image ('this' if non-composite) and region id
        for the given region name.

        :param str `name`: the region name

        """
        id = self.GetRegionId(name)
        if id > -1:
            return self, id

        for child in self._children:
            actualImage, regionId = child.FindRegion(name)
            if actualImage:
                return actualImage, regionId

        return None, -1

    # Finds all region names for this image (composite or simple).
    def FindRegionNames(self):
        """Get a list of all region names for this image (composite or simple)."""
        list = []
        n = self.GetNumberOfTextRegions()
        for i in range(n):
            list.append(self.GetRegionName(i))

        for child in self._children:
            list += child.FindRegionNames()

        return list

    def AssignNewIds(self):
        """Assign new ids to this image and its children."""
        self._id = wx.NewIdRef()
        for child in self._children:
            child.AssignNewIds()

    def OnDraw(self, dc):
        """not implemented???"""
        pass

    def OnMoveLinks(self, dc):
        """The move links handler."""
        # Want to set the ends of all attached links
        # to point to / from this object

        for line in self._lines:
            line.GetEventHandler().OnMoveLink(dc)

    def OnDrawContents(self, dc):
        """The draw contents handler."""
        if not self._regions:
            return

        bound_x, bound_y = self.GetBoundingBoxMin()

        if self._pen:
            dc.SetPen(self._pen)

        for region in self._regions:
            if region.GetFont():
                dc.SetFont(region.GetFont())

            dc.SetTextForeground(region.GetActualColourObject())
            dc.SetBackgroundMode(wx.TRANSPARENT)
            if not self._formatted:
                CentreText(dc, region.GetFormattedText(), self._xpos, self._ypos, bound_x - 2 * self._textMarginX, bound_y - 2 * self._textMarginY, region.GetFormatMode())
                self._formatted = True

            if not self.GetDisableLabel():
                DrawFormattedText(dc, region.GetFormattedText(), self._xpos, self._ypos, bound_x - 2 * self._textMarginX, bound_y - 2 * self._textMarginY, region.GetFormatMode())

    def DrawContents(self, dc):
        """
        Draw the internal graphic of the shape (such as text).

        Do not override this function: override OnDrawContents, which
        is called by this function.
        """
        self.GetEventHandler().OnDrawContents(dc)

    def OnSize(self, x, y):
        """not implemented???"""
        pass

    def OnMovePre(self, dc, x, y, old_x, old_y, display = True):
        return True

    def OnErase(self, dc):
        """The erase handler."""
        if not self._visible:
            return

        # Erase links
        for line in self._lines:
            line.GetEventHandler().OnErase(dc)

        self.GetEventHandler().OnEraseContents(dc)

    def OnEraseContents(self, dc):
        """The erase contents handler."""
        if not self._visible:
            return

        xp, yp = self.GetX(), self.GetY()
        minX, minY = self.GetBoundingBoxMin()
        maxX, maxY = self.GetBoundingBoxMax()

        topLeftX = xp - maxX / 2.0 - 2
        topLeftY = yp - maxY / 2.0 - 2

        penWidth = 0
        if self._pen:
            penWidth = self._pen.GetWidth()

        dc.SetPen(self.GetBackgroundPen())
        dc.SetBrush(self.GetBackgroundBrush())

        dc.DrawRectangle(topLeftX - penWidth, topLeftY - penWidth, maxX + penWidth * 2 + 4, maxY + penWidth * 2 + 4)

    def EraseLinks(self, dc, attachment = -1, recurse = False):
        """
        Erase links attached to this shape, but do not repair damage
        caused to other shapes.

        :param `dc`: the device context
        :param `attachment`: ???
        :param `recurse`: if `True` recurse through the children

        """
        if not self._visible:
            return

        for line in self._lines:
            if attachment == -1 or (line.GetTo() == self and line.GetAttachmentTo() == attachment or line.GetFrom() == self and line.GetAttachmentFrom() == attachment):
                line.GetEventHandler().OnErase(dc)

        if recurse:
            for child in self._children:
                child.EraseLinks(dc, attachment, recurse)

    def DrawLinks(self, dc, attachment = -1, recurse = False):
        """
        Draws any lines linked to this shape.

        :param `dc`: the device context
        :param `attachment`: ???
        :param `recurse`: if `True` recurse through the children

        """
        if not self._visible:
            return

        for line in self._lines:
            if attachment == -1 or (line.GetTo() == self and line.GetAttachmentTo() == attachment or line.GetFrom() == self and line.GetAttachmentFrom() == attachment):
                line.Draw(dc)

        if recurse:
            for child in self._children:
                child.DrawLinks(dc, attachment, recurse)

    #  Returns TRUE if pt1 <= pt2 in the sense that one point comes before
    #  another on an edge of the shape.
    # attachmentPoint is the attachment point (= side) in question.

    # This is the default, rectangular implementation.
    def AttachmentSortTest(self, attachmentPoint, pt1, pt2):
        """
        Return TRUE if pt1 is less than or equal to pt2, in the sense
        that one point comes before another on an edge of the shape.

        attachment is the attachment point (side) in question.

        This function is used in Shape.MoveLineToNewAttachment to determine
        the new line ordering.
        """
        physicalAttachment = self.LogicalToPhysicalAttachment(attachmentPoint)
        if physicalAttachment in [0, 2]:
            return pt1[0] <= pt2[0]
        elif physicalAttachment in [1, 3]:
            return pt1[1] <= pt2[1]

        return False

    def MoveLineToNewAttachment(self, dc, to_move, x, y):
        """
        Move the given line (which must already be attached to the shape)
        to a different attachment point on the shape, or a different order
        on the same attachment.

        Calls Shape.AttachmentSortTest and then
        ShapeEvtHandler.OnChangeAttachment.
        """
        if self.GetAttachmentMode() == ATTACHMENT_MODE_NONE:
            return False

        # Is (x, y) on this object? If so, find the new attachment point
        # the user has moved the point to
        hit = self.HitTest(x, y)
        if not hit:
            return False

        newAttachment, distance = hit

        self.EraseLinks(dc)

        if to_move.GetTo() == self:
            oldAttachment = to_move.GetAttachmentTo()
        else:
            oldAttachment = to_move.GetAttachmentFrom()

        # The links in a new ordering
        # First, add all links to the new list
        newOrdering = self._lines[:]

        # Delete the line object from the list of links; we're going to move
        # it to another position in the list
        del newOrdering[newOrdering.index(to_move)]

        old_x = -99999.9
        old_y = -99999.9

        found = False

        for line in newOrdering:
            if line.GetTo() == self and oldAttachment == line.GetAttachmentTo() or \
               line.GetFrom() == self and oldAttachment == line.GetAttachmentFrom():
                startX, startY, endX, endY = line.GetEnds()
                if line.GetTo() == self:
                    xp = endX
                    yp = endY
                else:
                    xp = startX
                    yp = startY

                thisPoint = wx.RealPoint(xp, yp)
                lastPoint = wx.RealPoint(old_x, old_y)
                newPoint = wx.RealPoint(x, y)

                if self.AttachmentSortTest(newAttachment, newPoint, thisPoint) and self.AttachmentSortTest(newAttachment, lastPoint, newPoint):
                    found = True
                    newOrdering.insert(newOrdering.index(line), to_move)

                old_x = xp
                old_y = yp
            if found:
                break

        if not found:
            newOrdering.append(to_move)

        self.GetEventHandler().OnChangeAttachment(newAttachment, to_move, newOrdering)
        return True

    def OnChangeAttachment(self, attachment, line, ordering):
        """Change attachment handler."""
        if line.GetTo() == self:
            line.SetAttachmentTo(attachment)
        else:
            line.SetAttachmentFrom(attachment)

        self.ApplyAttachmentOrdering(ordering)

        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)
        self.MoveLinks(dc)

        if not self.GetCanvas().GetQuickEditMode():
            self.GetCanvas().Redraw(dc)

    # Reorders the lines according to the given list
    def ApplyAttachmentOrdering(self, linesToSort):
        """
        Apply the line ordering in linesToSort to the shape, to reorder
        the way lines are attached.
        """
        linesStore = self._lines[:]

        self._lines = []

        for line in linesToSort:
            if line in linesStore:
                del linesStore[linesStore.index(line)]
                self._lines.append(line)

        # Now add any lines that haven't been listed in linesToSort
        self._lines += linesStore

    def SortLines(self, attachment, linesToSort):
        """
        Reorder the lines coming into the node image at this attachment
        position, in the order in which they appear in linesToSort.

        Any remaining lines not in the list will be added to the end.
        """
        # This is a temporary store of all the lines at this attachment
        # point. We'll tick them off as we've processed them.
        linesAtThisAttachment = []

        for line in self._lines[:]:
            if line.GetTo() == self and line.GetAttachmentTo() == attachment or \
               line.GetFrom() == self and line.GetAttachmentFrom() == attachment:
                linesAtThisAttachment.append(line)
                del self._lines[self._lines.index(line)]

        for line in linesToSort:
            if line in linesAtThisAttachment:
                # Done this one
                del linesAtThisAttachment[linesAtThisAttachment.index(line)]
                self._lines.append(line)

        # Now add any lines that haven't been listed in linesToSort
        self._lines += linesAtThisAttachment

    def OnHighlight(self, dc):
        """not implemented???"""
        pass

    def OnLeftClick(self, x, y, keys = 0, attachment = 0):
        """The left click handler."""
        if self._sensitivity & OP_CLICK_LEFT != OP_CLICK_LEFT:
            if self._parent:
                attachment, dist = self._parent.HitTest(x, y)
                self._parent.GetEventHandler().OnLeftClick(x, y, keys, attachment)

    def OnRightClick(self, x, y, keys = 0, attachment = 0):
        """The right click handler."""
        if self._sensitivity & OP_CLICK_RIGHT != OP_CLICK_RIGHT:
            attachment, dist = self._parent.HitTest(x, y)
            self._parent.GetEventHandler().OnRightClick(x, y, keys, attachment)

    def OnDragLeft(self, draw, x, y, keys = 0, attachment = 0):
        """The drag left handler."""
        if self._sensitivity & OP_DRAG_LEFT != OP_DRAG_LEFT:
            if self._parent:
                hit = self._parent.HitTest(x, y)
                if hit:
                    attachment, dist = hit
                self._parent.GetEventHandler().OnDragLeft(draw, x, y, keys, attachment)
            return

        dc = wx.ClientDC(self.GetCanvas())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(OGLRBLF)

        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.PENSTYLE_DOT)

        dc.SetPen(dottedPen)
        dc.SetBrush(wx.TRANSPARENT_BRUSH)

        xx = x + DragOffsetX
        yy = y + DragOffsetY

        xx, yy = self._canvas.Snap(xx, yy)
        w, h = self.GetBoundingBoxMax()
        self.GetEventHandler().OnDrawOutline(dc, xx, yy, w, h)

    def OnBeginDragLeft(self, x, y, keys = 0, attachment = 0):
        """The begin drag left handler."""
        global DragOffsetX, DragOffsetY

        if self._sensitivity & OP_DRAG_LEFT != OP_DRAG_LEFT:
            if self._parent:
                hit = self._parent.HitTest(x, y)
                if hit:
                    attachment, dist = hit
                self._parent.GetEventHandler().OnBeginDragLeft(x, y, keys, attachment)
            return

        DragOffsetX = self._xpos - x
        DragOffsetY = self._ypos - y

        dc = wx.ClientDC(self.GetCanvas())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(OGLRBLF)

        # New policy: don't erase shape until end of drag.
        # self.Erase(dc)
        xx = x + DragOffsetX
        yy = y + DragOffsetY
        xx, yy = self._canvas.Snap(xx, yy)

        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.PENSTYLE_DOT)
        dc.SetPen(dottedPen)
        dc.SetBrush(wx.TRANSPARENT_BRUSH)

        w, h = self.GetBoundingBoxMax()
        self.GetEventHandler().OnDrawOutline(dc, xx, yy, w, h)
        self._canvas.CaptureMouse()

    def OnEndDragLeft(self, x, y, keys = 0, attachment = 0):
        """The end drag left handler."""
        if self._canvas.HasCapture():
            self._canvas.ReleaseMouse()
        if self._sensitivity & OP_DRAG_LEFT != OP_DRAG_LEFT:
            if self._parent:
                hit = self._parent.HitTest(x, y)
                if hit:
                    attachment, dist = hit
                self._parent.GetEventHandler().OnEndDragLeft(x, y, keys, attachment)
            return

        dc = wx.ClientDC(self.GetCanvas())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(wx.COPY)

        xx = x + DragOffsetX
        yy = y + DragOffsetY
        xx, yy = self._canvas.Snap(xx, yy)

        # New policy: erase shape at end of drag.
        self.Erase(dc)

        self.Move(dc, xx, yy)
        if self._canvas and not self._canvas.GetQuickEditMode():
            self._canvas.Redraw(dc)

    def OnDragRight(self, draw, x, y, keys = 0, attachment = 0):
        """The drag right handler."""
        if self._sensitivity & OP_DRAG_RIGHT != OP_DRAG_RIGHT:
            if self._parent:
                attachment, dist = self._parent.HitTest(x, y)
                self._parent.GetEventHandler().OnDragRight(draw, x, y, keys, attachment)
            return

    def OnBeginDragRight(self, x, y, keys = 0, attachment = 0):
        """The begin drag right handler."""
        if self._sensitivity & OP_DRAG_RIGHT != OP_DRAG_RIGHT:
            if self._parent:
                attachment, dist = self._parent.HitTest(x, y)
                self._parent.GetEventHandler().OnBeginDragRight(x, y, keys, attachment)
            return

    def OnEndDragRight(self, x, y, keys = 0, attachment = 0):
        """The end drag right handler."""
        if self._sensitivity & OP_DRAG_RIGHT != OP_DRAG_RIGHT:
            if self._parent:
                attachment, dist = self._parent.HitTest(x, y)
                self._parent.GetEventHandler().OnEndDragRight(x, y, keys, attachment)
            return

    def OnDrawOutline(self, dc, x, y, w, h):
        """The draw outline handler."""
        points = [[x - w / 2.0, y - h / 2.0],
                [x + w / 2.0, y - h / 2.0],
                [x + w / 2.0, y + h / 2.0],
                [x - w / 2.0, y + h / 2.0],
                [x - w / 2.0, y - h / 2.0],
                ]

        dc.DrawLines(points)

    def Attach(self, can):
        """Set the shape's internal canvas pointer to point to the given canvas."""
        self._canvas = can

    def Detach(self):
        """Disassociates the shape from its canvas."""
        self._canvas = None

    def Move(self, dc, x, y, display = True):
        """
        Move the shape to the given position.

        :param `dc`: the device context
        :param `x`: the x position
        :param `y`: the y position
        :param `display`: if `True` redraw

        """
        old_x = self._xpos
        old_y = self._ypos

        if not self.GetEventHandler().OnMovePre(dc, x, y, old_x, old_y, display):
            return

        self._xpos, self._ypos = x, y

        self.ResetControlPoints()

        if display:
            self.Draw(dc)

        self.MoveLinks(dc)

        self.GetEventHandler().OnMovePost(dc, x, y, old_x, old_y, display)

    def MoveLinks(self, dc):
        """Redraw all the lines attached to the shape."""
        self.GetEventHandler().OnMoveLinks(dc)

    def Draw(self, dc):
        """
        Draw the whole shape and any lines attached to it.

        Do not override this function: override OnDraw, which is called
        by this function.
        """
        if self._visible:
            self.GetEventHandler().OnDraw(dc)
            self.GetEventHandler().OnDrawContents(dc)
            self.GetEventHandler().OnDrawControlPoints(dc)
            self.GetEventHandler().OnDrawBranches(dc)

    def Flash(self):
        """Flash the shape."""
        if self.GetCanvas():
            dc = wx.MemoryDC()
            dc.SelectObject(self.GetCanvas().GetBuffer())
            self.GetCanvas().PrepareDC(dc)
            dc.SetLogicalFunction(OGLRBLF)
            self.Draw(dc)
            dc.SetLogicalFunction(wx.COPY)
            self.Draw(dc)

    def Show(self, show):
        """Set a flag indicating whether the shape should be drawn."""
        self._visible = show
        for child in self._children:
            child.Show(show)

    def Erase(self, dc):
        """
        Erase the shape.

        Does not repair damage caused to other shapes.
        """
        self.GetEventHandler().OnErase(dc)
        self.GetEventHandler().OnEraseControlPoints(dc)
        self.GetEventHandler().OnDrawBranches(dc, erase = True)

    def EraseContents(self, dc):
        """
        Erase the shape contents, that is, the area within the shape's
        minimum bounding box.
        """
        self.GetEventHandler().OnEraseContents(dc)

    def AddText(self, string):
        """Add a line of text to the shape's default text region."""
        if not self._regions:
            return

        region = self._regions[0]
        #region.ClearText()
        new_line = ShapeTextLine(0, 0, string)
        text = region.GetFormattedText()
        text.append(new_line)

        self._formatted = False

    def SetSize(self, x, y, recursive = True):
        """Set the shape's size.

        :param `x`: the x position
        :param `y`: the y position
        :param `recursive`: not used

        """
        self.SetAttachmentSize(x, y)
        self.SetDefaultRegionSize()

    def SetAttachmentSize(self, w, h):
        """
        Set the attachment size.

        :param `w`: width
        :param `h`: height

        """
        width, height = self.GetBoundingBoxMin()
        if width == 0:
            scaleX = 1.0
        else:
            scaleX = float(w) / width
        if height == 0:
            scaleY = 1.0
        else:
            scaleY = float(h) / height

        for point in self._attachmentPoints:
            point._x = point._x * scaleX
            point._y = point._y * scaleY

    # Add line FROM this object
    def AddLine(self, line, other, attachFrom = 0, attachTo = 0, positionFrom = -1, positionTo = -1):
        """
        Add a line between this shape and the given other shape, at the
        specified attachment points.

        :param `line`: the line an instance of :class:`~lib.ogl.LineShape`
        :param `other`: the other shape, an instance of :class:`Shape`
        :param `attachFrom`: the attachment from point ???
        :param `attachTo`: the attachment to point ???
        :param `positionFrom`: the from position
        :param `positionTo`: the to position

        :note: The position in the list of lines at each end can also be
         specified, so that the line will be drawn at a particular point on
         its attachment point.

        """
        if positionFrom == -1:
            if not line in self._lines:
                self._lines.append(line)
        else:
            # Don't preserve old ordering if we have new ordering instructions
            try:
                self._lines.remove(line)
            except ValueError:
                pass
            if positionFrom < len(self._lines):
                self._lines.insert(positionFrom, line)
            else:
                self._lines.append(line)

        if positionTo == -1:
            if not other in other._lines:
                other._lines.append(line)
        else:
            # Don't preserve old ordering if we have new ordering instructions
            try:
                other._lines.remove(line)
            except ValueError:
                pass
            if positionTo < len(other._lines):
                other._lines.insert(positionTo, line)
            else:
                other._lines.append(line)

        line.SetFrom(self)
        line.SetTo(other)
        line.SetAttachments(attachFrom, attachTo)

        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)
        self.MoveLinks(dc)

    def RemoveLine(self, line):
        """
        Remove the given line from the shape's list of attached lines.

        :param `line`: an instance of :class:`~lib.ogl.LineShape`

        """
        if line.GetFrom() == self:
            line.GetTo()._lines.remove(line)
        else:
            line.GetFrom()._lines.remove(line)

        self._lines.remove(line)

    # Default - make 6 control points
    def MakeControlPoints(self):
        """
        Make a list of control points (draggable handles) appropriate to
        the shape.
        """
        maxX, maxY = self.GetBoundingBoxMax()
        minX, minY = self.GetBoundingBoxMin()

        widthMin = minX + CONTROL_POINT_SIZE + 2
        heightMin = minY + CONTROL_POINT_SIZE + 2

        # Offsets from main object
        top = -heightMin / 2.0
        bottom = heightMin / 2.0 + (maxY - minY)
        left = -widthMin / 2.0
        right = widthMin / 2.0 + (maxX - minX)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, left, top, CONTROL_POINT_DIAGONAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, 0, top, CONTROL_POINT_VERTICAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, right, top, CONTROL_POINT_DIAGONAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, right, 0, CONTROL_POINT_HORIZONTAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, right, bottom, CONTROL_POINT_DIAGONAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, 0, bottom, CONTROL_POINT_VERTICAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, left, bottom, CONTROL_POINT_DIAGONAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

        control = ControlPoint(self._canvas, self, CONTROL_POINT_SIZE, left, 0, CONTROL_POINT_HORIZONTAL)
        self._canvas.AddShape(control)
        self._controlPoints.append(control)

    def MakeMandatoryControlPoints(self):
        """
        Make the mandatory control points.

        For example, the control point on a dividing line should appear even
        if the divided rectangle shape's handles should not appear (because
        it is the child of a composite, and children are not resizable).
        """
        for child in self._children:
            child.MakeMandatoryControlPoints()

    def ResetMandatoryControlPoints(self):
        """Reset the mandatory control points."""
        for child in self._children:
            child.ResetMandatoryControlPoints()

    def ResetControlPoints(self):
        """
        Reset the positions of the control points (for instance when the
        shape's shape has changed).
        """
        self.ResetMandatoryControlPoints()

        if len(self._controlPoints) == 0:
            return

        maxX, maxY = self.GetBoundingBoxMax()
        minX, minY = self.GetBoundingBoxMin()

        widthMin = minX + CONTROL_POINT_SIZE + 2
        heightMin = minY + CONTROL_POINT_SIZE + 2

        # Offsets from main object
        top = -heightMin / 2.0
        bottom = heightMin / 2.0 + (maxY - minY)
        left = -widthMin / 2.0
        right = widthMin / 2.0 + (maxX - minX)

        self._controlPoints[0]._xoffset = left
        self._controlPoints[0]._yoffset = top

        self._controlPoints[1]._xoffset = 0
        self._controlPoints[1]._yoffset = top

        self._controlPoints[2]._xoffset = right
        self._controlPoints[2]._yoffset = top

        self._controlPoints[3]._xoffset = right
        self._controlPoints[3]._yoffset = 0

        self._controlPoints[4]._xoffset = right
        self._controlPoints[4]._yoffset = bottom

        self._controlPoints[5]._xoffset = 0
        self._controlPoints[5]._yoffset = bottom

        self._controlPoints[6]._xoffset = left
        self._controlPoints[6]._yoffset = bottom

        self._controlPoints[7]._xoffset = left
        self._controlPoints[7]._yoffset = 0

    def DeleteControlPoints(self, dc = None):
        """
        Delete the control points (or handles) for the shape.

        Does not redraw the shape.
        """
        for control in self._controlPoints[:]:
            if dc:
                control.GetEventHandler().OnErase(dc)
            control.Delete()
            self._controlPoints.remove(control)
        self._controlPoints = []

        # Children of divisions are contained objects,
        # so stop here
        if not isinstance(self, DivisionShape):
            for child in self._children:
                child.DeleteControlPoints(dc)

    def OnDrawControlPoints(self, dc):
        """The draw control points handler."""
        if not self._drawHandles:
            return

        dc.SetBrush(wx.BLACK_BRUSH)
        dc.SetPen(wx.BLACK_PEN)

        for control in self._controlPoints:
            control.Draw(dc)

        # Children of divisions are contained objects,
        # so stop here.
        # This test bypasses the type facility for speed
        # (critical when drawing)

        if not isinstance(self, DivisionShape):
            for child in self._children:
                child.GetEventHandler().OnDrawControlPoints(dc)

    def OnEraseControlPoints(self, dc):
        """The erase control points handler."""
        for control in self._controlPoints:
            control.Erase(dc)

        if not isinstance(self, DivisionShape):
            for child in self._children:
                child.GetEventHandler().OnEraseControlPoints(dc)

    def Select(self, select, dc = None):
        """
        Select or deselect the given shape, drawing or erasing control points
        (handles) as necessary.

        :param `select`: `True` to select
        :param `dc`: the device context

        """
        self._selected = select
        if select:
            self.MakeControlPoints()
            # Children of divisions are contained objects,
            # so stop here
            if not isinstance(self, DivisionShape):
                for child in self._children:
                    child.MakeMandatoryControlPoints()
            if dc:
                self.GetEventHandler().OnDrawControlPoints(dc)
        else:
            self.DeleteControlPoints(dc)
            if not isinstance(self, DivisionShape):
                for child in self._children:
                    child.DeleteControlPoints(dc)

    def Selected(self):
        """`True` if the shape is currently selected."""
        return self._selected

    def AncestorSelected(self):
        """`True` if the shape's ancestor is currently selected."""
        if self._selected:
            return True
        if not self.GetParent():
            return False
        return self.GetParent().AncestorSelected()

    def GetNumberOfAttachments(self):
        """Get the number of attachment points for this shape."""
        # Should return the MAXIMUM attachment point id here,
        # so higher-level functions can iterate through all attachments,
        # even if they're not contiguous.

        if len(self._attachmentPoints) == 0:
            return 4
        else:
            maxN = 3
            for point in self._attachmentPoints:
                if point._id > maxN:
                    maxN = point._id
            return maxN + 1

    def AttachmentIsValid(self, attachment):
        """`True` if attachment is a valid attachment point."""
        if len(self._attachmentPoints) == 0:
            return attachment in range(4)

        for point in self._attachmentPoints:
            if point._id == attachment:
                return True
        return False

    def GetAttachmentPosition(self, attachment, nth = 0, no_arcs = 1, line = None):
        """
        Get the position at which the given attachment point should be drawn.

        :param `attachment`: the attachment ???
        :param `nth`: get nth attachment ???
        :param `no_arcs`: ???
        :param `line`: ???

        If attachment isn't found among the attachment points of the shape,
        returns None.
        """
        if self._attachmentMode == ATTACHMENT_MODE_NONE:
            return self._xpos, self._ypos
        elif self._attachmentMode == ATTACHMENT_MODE_BRANCHING:
            pt, stemPt = self.GetBranchingAttachmentPoint(attachment, nth)
            return pt[0], pt[1]
        elif self._attachmentMode == ATTACHMENT_MODE_EDGE:
            if len(self._attachmentPoints):
                for point in self._attachmentPoints:
                    if point._id == attachment:
                        return self._xpos + point._x, self._ypos + point._y
                return None
            else:
                # Assume is rectangular
                w, h = self.GetBoundingBoxMax()
                top = self._ypos + h / 2.0
                bottom = self._ypos - h / 2.0
                left = self._xpos - w / 2.0
                right = self._xpos + w / 2.0

                # wtf?
                line and line.IsEnd(self)

                physicalAttachment = self.LogicalToPhysicalAttachment(attachment)

                # Simplified code
                if physicalAttachment == 0:
                    pt = self.CalcSimpleAttachment((left, bottom), (right, bottom), nth, no_arcs, line)
                elif physicalAttachment == 1:
                    pt = self.CalcSimpleAttachment((right, bottom), (right, top), nth, no_arcs, line)
                elif physicalAttachment == 2:
                    pt = self.CalcSimpleAttachment((left, top), (right, top), nth, no_arcs, line)
                elif physicalAttachment == 3:
                    pt = self.CalcSimpleAttachment((left, bottom), (left, top), nth, no_arcs, line)
                else:
                    return None
                return pt[0], pt[1]
        return None

    def GetBoundingBoxMax(self):
        """
        Get the maximum bounding box for the shape, taking into account
        external features such as shadows.
        """
        ww, hh = self.GetBoundingBoxMin()
        if self._shadowMode != SHADOW_NONE:
            ww += self._shadowOffsetX
            hh += self._shadowOffsetY
        return ww, hh

    def GetBoundingBoxMin(self):
        """
        Get the minimum bounding box for the shape, that defines the area
        available for drawing the contents (such as text).

        Must be overridden.
        """
        return 0, 0

    def HasDescendant(self, image):
        """
        Is image a descendant of this composite.

        :param `image`: the image, is this a shape???
        :returns: `True` if it is a descendant

        """
        if image == self:
            return True
        for child in self._children:
            if child.HasDescendant(image):
                return True
        return False

    # Assuming the attachment lies along a vertical or horizontal line,
    # calculate the position on that point.
    def CalcSimpleAttachment(self, pt1, pt2, nth, noArcs, line):
        """
        Assuming the attachment lies along a vertical or horizontal line,
        calculate the position on that point.

        :param `pt1`: The first point of the line repesenting the edge of
         the shape
        :param `pt2`: The second point of the line representing the edge of
         the shape
        :param `nth`: The position on the edge (for example there may be 6
         lines at this attachment point, and this may be the 2nd line.
        :param `noArcs`: The number of lines at this edge.
        :param `line`: The line shape.

        :note: This function expects the line to be either vertical or horizontal,
         and determines which.

        """
        isEnd = line and line.IsEnd(self)

        # Are we horizontal or vertical?
        isHorizontal = RoughlyEqual(pt1[1], pt2[1])

        if isHorizontal:
            if pt1[0] > pt2[0]:
                firstPoint = pt2
                secondPoint = pt1
            else:
                firstPoint = pt1
                secondPoint = pt2

            if self._spaceAttachments:
                if line and line.GetAlignmentType(isEnd) == LINE_ALIGNMENT_TO_NEXT_HANDLE:
                    # Align line according to the next handle along
                    point = line.GetNextControlPoint(self)
                    if point[0] < firstPoint[0]:
                        x = firstPoint[0]
                    elif point[0] > secondPoint[0]:
                        x = secondPoint[0]
                    else:
                        x = point[0]
                else:
                    x = firstPoint[0] + (nth + 1) * (secondPoint[0] - firstPoint[0]) / (noArcs + 1.0)
            else:
                x = (secondPoint[0] - firstPoint[0]) / 2.0 # Midpoint
            y = pt1[1]
        else:
            assert RoughlyEqual(pt1[0], pt2[0])

            if pt1[1] > pt2[1]:
                firstPoint = pt2
                secondPoint = pt1
            else:
                firstPoint = pt1
                secondPoint = pt2

            if self._spaceAttachments:
                if line and line.GetAlignmentType(isEnd) == LINE_ALIGNMENT_TO_NEXT_HANDLE:
                    # Align line according to the next handle along
                    point = line.GetNextControlPoint(self)
                    if point[1] < firstPoint[1]:
                        y = firstPoint[1]
                    elif point[1] > secondPoint[1]:
                        y = secondPoint[1]
                    else:
                        y = point[1]
                else:
                    y = firstPoint[1] + (nth + 1) * (secondPoint[1] - firstPoint[1]) / (noArcs + 1.0)
            else:
                y = (secondPoint[1] - firstPoint[1]) / 2.0 # Midpoint
            x = pt1[0]

        return x, y

    def GetLinePosition(self, line):
        """
        Get the zero-based position of line in the list of lines
        for this shape.

        :param `line`: line to find position for

        """
        try:
            return self._lines.index(line)
        except:
            return 0


    #            |________|
    #                 | <- root
    #                 | <- neck
    # shoulder1 ->---------<- shoulder2
    #             | | | | |
    #                      <- branching attachment point N-1

    def GetBranchingAttachmentInfo(self, attachment):
        """
        Get information about where branching connections go.

        :param `attachment`: ???
        :returns: `False` if there are no lines at this attachment.
        """
        physicalAttachment = self.LogicalToPhysicalAttachment(attachment)

        # Number of lines at this attachment
        lineCount = self.GetAttachmentLineCount(attachment)

        if not lineCount:
            return False

        totalBranchLength = self._branchSpacing * (lineCount - 1)
        root = self.GetBranchingAttachmentRoot(attachment)

        neck = wx.RealPoint()
        shoulder1 = wx.RealPoint()
        shoulder2 = wx.RealPoint()

        # Assume that we have attachment points 0 to 3: top, right, bottom, left
        if physicalAttachment == 0:
            neck[0] = self.GetX()
            neck[1] = root[1] - self._branchNeckLength

            shoulder1[0] = root[0] - totalBranchLength / 2.0
            shoulder2[0] = root[0] + totalBranchLength / 2.0

            shoulder1[1] = neck[1]
            shoulder2[1] = neck[1]
        elif physicalAttachment == 1:
            neck[0] = root[0] + self._branchNeckLength
            neck[1] = root[1]

            shoulder1[0] = neck[0]
            shoulder2[0] = neck[0]

            shoulder1[1] = neck[1] - totalBranchLength / 2.0
            shoulder1[1] = neck[1] + totalBranchLength / 2.0
        elif physicalAttachment == 2:
            neck[0] = self.GetX()
            neck[1] = root[1] + self._branchNeckLength

            shoulder1[0] = root[0] - totalBranchLength / 2.0
            shoulder2[0] = root[0] + totalBranchLength / 2.0

            shoulder1[1] = neck[1]
            shoulder2[1] = neck[1]
        elif physicalAttachment == 3:
            neck[0] = root[0] - self._branchNeckLength
            neck[1] = root[1]

            shoulder1[0] = neck[0]
            shoulder2[0] = neck[0]

            shoulder1[1] = neck[1] - totalBranchLength / 2.0
            shoulder2[1] = neck[1] + totalBranchLength / 2.0
        else:
            raise ValueError("Unrecognised attachment point in GetBranchingAttachmentInfo")
        return root, neck, shoulder1, shoulder2

    def GetBranchingAttachmentPoint(self, attachment, n):
        """
        Get branching attachment point.

        :param `attachment`: ???
        :param `n`: ???

        """
        physicalAttachment = self.LogicalToPhysicalAttachment(attachment)

        root, neck, shoulder1, shoulder2 = self.GetBranchingAttachmentInfo(attachment)
        pt = wx.RealPoint()
        stemPt = wx.RealPoint()

        if physicalAttachment == 0:
            pt[1] = neck[1] - self._branchStemLength
            pt[0] = shoulder1[0] + n * self._branchSpacing

            stemPt[0] = pt[0]
            stemPt[1] = neck[1]
        elif physicalAttachment == 2:
            pt[1] = neck[1] + self._branchStemLength
            pt[0] = shoulder1[0] + n * self._branchStemLength

            stemPt[0] = pt[0]
            stemPt[1] = neck[1]
        elif physicalAttachment == 1:
            pt[0] = neck[0] + self._branchStemLength
            pt[1] = shoulder1[1] + n * self._branchSpacing

            stemPt[0] = neck[0]
            stemPt[1] = pt[1]
        elif physicalAttachment == 3:
            pt[0] = neck[0] - self._branchStemLength
            pt[1] = shoulder1[1] + n * self._branchSpacing

            stemPt[0] = neck[0]
            stemPt[1] = pt[1]
        else:
            raise ValueError("Unrecognised attachment point in GetBranchingAttachmentPoint")

        return pt, stemPt

    def GetAttachmentLineCount(self, attachment):
        """
        Get the number of lines at this attachment position.

        :param `attachment`: ???
        :returns: the count of lines at this position

        """
        count = 0
        for lineShape in self._lines:
            if lineShape.GetFrom() == self and lineShape.GetAttachmentFrom() == attachment:
                count += 1
            elif lineShape.GetTo() == self and lineShape.GetAttachmentTo() == attachment:
                count += 1
        return count

    def GetBranchingAttachmentRoot(self, attachment):
        """
        Get the root point at the given attachment.

        :param `attachment`: ???

        """
        physicalAttachment = self.LogicalToPhysicalAttachment(attachment)

        root = wx.RealPoint()

        width, height = self.GetBoundingBoxMax()

        # Assume that we have attachment points 0 to 3: top, right, bottom, left
        if physicalAttachment == 0:
            root[0] = self.GetX()
            root[1] = self.GetY() - height / 2.0
        elif physicalAttachment == 1:
            root[0] = self.GetX() + width / 2.0
            root[1] = self.GetY()
        elif physicalAttachment == 2:
            root[0] = self.GetX()
            root[1] = self.GetY() + height / 2.0
        elif physicalAttachment == 3:
            root[0] = self.GetX() - width / 2.0
            root[1] = self.GetY()
        else:
            raise ValueError("Unrecognised attachment point in GetBranchingAttachmentRoot")

        return root

    # Draw or erase the branches (not the actual arcs though)
    def OnDrawBranchesAttachment(self, dc, attachment, erase = False):
        """The draw branches attachment handler."""
        count = self.GetAttachmentLineCount(attachment)
        if count == 0:
            return

        root, neck, shoulder1, shoulder2 = self.GetBranchingAttachmentInfo(attachment)

        if erase:
            dc.SetPen(wx.WHITE_PEN)
            dc.SetBrush(wx.WHITE_BRUSH)
        else:
            dc.SetPen(wx.BLACK_PEN)
            dc.SetBrush(wx.BLACK_BRUSH)

        # Draw neck
        dc.DrawLine(root[0], root[1], neck[0], neck[1])

        if count > 1:
            # Draw shoulder-to-shoulder line
            dc.DrawLine(shoulder1[0], shoulder1[1], shoulder2[0], shoulder2[1])
        # Draw all the little branches
        for i in range(count):
            pt, stemPt = self.GetBranchingAttachmentPoint(attachment, i)
            dc.DrawLine(stemPt[0], stemPt[1], pt[0], pt[1])

            if self.GetBranchStyle() & BRANCHING_ATTACHMENT_BLOB and count > 1:
                blobSize = 6.0
                dc.DrawEllipse(stemPt[0] - blobSize / 2.0, stemPt[1] - blobSize / 2.0, blobSize, blobSize)

    def OnDrawBranches(self, dc, erase = False):
        """The draw branches handler."""
        if self._attachmentMode != ATTACHMENT_MODE_BRANCHING:
            return
        for i in range(self.GetNumberOfAttachments()):
            self.OnDrawBranchesAttachment(dc, i, erase)

    def GetAttachmentPositionEdge(self, attachment, nth = 0, no_arcs = 1, line = None):
        """
        Only get the attachment position at the _edge_ of the shape,
        ignoring branching mode. This is used e.g. to indicate the edge of
        interest, not the point on the attachment branch.

        :param `attachment`: the attachment ???
        :param `nth`: get nth attachment ???
        :param `no_arcs`: ???
        :param `line`: ???

        """
        oldMode = self._attachmentMode

        # Calculate as if to edge, not branch
        if self._attachmentMode == ATTACHMENT_MODE_BRANCHING:
            self._attachmentMode = ATTACHMENT_MODE_EDGE
        res = self.GetAttachmentPosition(attachment, nth, no_arcs, line)
        self._attachmentMode = oldMode

        return res

    def PhysicalToLogicalAttachment(self, physicalAttachment):
        """
        Rotate the standard attachment point from physical
        (0 is always North) to logical (0 -> 1 if rotated by 90 degrees)

        :param `physicalAttachment`: ???

        """
        if RoughlyEqual(self.GetRotation(), 0):
            i = physicalAttachment
        elif RoughlyEqual(self.GetRotation(), math.pi / 2.0):
            i = physicalAttachment - 1
        elif RoughlyEqual(self.GetRotation(), math.pi):
            i = physicalAttachment - 2
        elif RoughlyEqual(self.GetRotation(), 3 * math.pi / 2.0):
            i = physicalAttachment - 3
        else:
            # Can't handle -- assume the same
            return physicalAttachment

        if i < 0:
            i += 4

        return i

    def LogicalToPhysicalAttachment(self, logicalAttachment):
        """
        Rotate the standard attachment point from logical
        to physical (0 is always North).

        :param `logicalAttachment`: ???

        """
        if RoughlyEqual(self.GetRotation(), 0):
            i = logicalAttachment
        elif RoughlyEqual(self.GetRotation(), math.pi / 2.0):
            i = logicalAttachment + 1
        elif RoughlyEqual(self.GetRotation(), math.pi):
            i = logicalAttachment + 2
        elif RoughlyEqual(self.GetRotation(), 3 * math.pi / 2.0):
            i = logicalAttachment + 3
        else:
            return logicalAttachment

        if i > 3:
            i -= 4

        return i

    def Rotate(self, x, y, theta):
        """
        Rotate about the given axis by the given amount in radians.

        :param `x`: the x position
        :param `y`: the y position
        :param `theta`: the theta

        """
        self._rotation = theta
        if self._rotation < 0:
            self._rotation += 2 * math.pi
        elif self._rotation > 2 * math.pi:
            self._rotation -= 2 * math.pi

    def GetBackgroundPen(self):
        """Return pen of the right colour for the background."""
        if self.GetCanvas():
            return wx.Pen(self.GetCanvas().GetBackgroundColour(), 1, wx.PENSTYLE_SOLID)
        return WhiteBackgroundPen

    def GetBackgroundBrush(self):
        """Return brush of the right colour for the background."""
        if self.GetCanvas():
            return wx.Brush(self.GetCanvas().GetBackgroundColour(), wx.BRUSHSTYLE_SOLID)
        return WhiteBackgroundBrush

    def GetX(self):
        """Get the x position of the centre of the shape."""
        return self._xpos

    def GetY(self):
        """Get the y position of the centre of the shape."""
        return self._ypos

    def SetX(self, x):
        """
        Set the x position of the shape.

        :param `x`: the x position
        """
        self._xpos = x

    def SetY(self, y):
        """
        Set the y position of the shape.

        :param `y`: the y position

        """
        self._ypos = y

    def GetParent(self):
        """Get the parent of this shape, if it is part of a composite."""
        return self._parent

    def SetParent(self, p):
        """Set the parent

        :param `p`: the parent

        """
        self._parent = p

    def GetChildren(self):
        """Get the list of children for this shape."""
        return self._children

    def GetDrawHandles(self):
        """Get the list of drawhandles."""
        return self._drawHandles

    def GetEventHandler(self):
        """Get the event handler for this shape."""
        return self._eventHandler

    def SetEventHandler(self, handler):
        """Set the event handler for this shape.

        :param `handler`: an instance of :class:`ShapeEvtHandler`

        """
        self._eventHandler = handler

    def Recompute(self):
        """
        Recomputes any constraints associated with the shape.

        Normally applicable to CompositeShapes only, but harmless for
        other classes of Shape.
        """
        return True

    def IsHighlighted(self):
        """
        `True` if the shape is highlighted. Shape highlighting is unimplemented.
        """
        return self._highlighted

    def GetSensitivityFilter(self):
        """
        Get the sensitivity filter, a bitlist of values.

        See :meth:`Shape.SetSensitivityFilter`

        """
        return self._sensitivity

    def SetFixedSize(self, x, y):
        """
        Set the shape to be fixed size.

        :param `x`: the width
        :param `y`: the height

        """
        self._fixedWidth = x
        self._fixedHeight = y

    def GetFixedSize(self):
        """
        Return flags indicating whether the shape is of fixed size in
        either direction.
        """
        return self._fixedWidth, self._fixedHeight

    def GetFixedWidth(self):
        """`True` if the shape cannot be resized in the horizontal plane."""
        return self._fixedWidth

    def GetFixedHeight(self):
        """`True` if the shape cannot be resized in the vertical plane."""
        return self._fixedHeight

    def SetSpaceAttachments(self, sp):
        """
        Indicate whether lines should be spaced out evenly at the point
        they touch the node.

        :param `sp`: if `True` space out evently, else they should join at a
         single point.

        """
        self._spaceAttachments = sp

    def GetSpaceAttachments(self):
        """
        Get whether lines should be spaced out evenly at the point they
        touch the node (True), or whether they should join at a single point
        (False).
        """
        return self._spaceAttachments

    def SetCentreResize(self, cr):
        """
        Specify whether the shape is to be resized from the centre (the
        centre stands still) or from the corner or side being dragged (the
        other corner or side stands still).
        """
        self._centreResize = cr

    def GetCentreResize(self):
        """
        `True` if the shape is to be resized from the centre (the centre stands
        still), or `False` if from the corner or side being dragged (the other
        corner or side stands still)

        """
        return self._centreResize

    def SetMaintainAspectRatio(self, ar):
        """
        Set whether a shape that resizes should not change the aspect ratio
        (width and height should be in the original proportion).

        """
        self._maintainAspectRatio = ar

    def GetMaintainAspectRatio(self):
        """`True` if shape keeps aspect ratio during resize."""
        return self._maintainAspectRatio

    def GetLines(self):
        """Return the list of lines connected to this shape."""
        return self._lines

    def SetDisableLabel(self, flag):
        """Set flag to `True` to stop the default region being shown."""
        self._disableLabel = flag

    def GetDisableLabel(self):
        """`True` if the default region will not be shown, `False` otherwise."""
        return self._disableLabel

    def SetAttachmentMode(self, mode):
        """
        Set the attachment mode.

        :param `mode`: if `True` attachment points will be significant when
         drawing lines to and from this shape. If `False` lines will be drawn
         as if to the centre of the shape.

        """
        self._attachmentMode = mode

    def GetAttachmentMode(self):
        """
        Get the attachment mode.

        See :meth:`Shape.SetAttachmentMode`
        """
        return self._attachmentMode

    def SetId(self, i):
        """Set the integer identifier for this shape."""
        self._id = i

    def GetId(self):
        """Get the integer identifier for this shape."""
        return self._id

    def IsShown(self):
        """
        `True` if the shape is in a visible state, `False` otherwise.

        :note: That this has nothing to do with whether the window is hidden
         or the shape has scrolled off the canvas; it refers to the internal
         visibility flag.

        """
        return self._visible

    def GetPen(self):
        """Get the pen used for drawing the shape's outline."""
        return self._pen

    def GetBrush(self):
        """Get the brush used for filling the shape."""
        return self._brush

    def GetNumberOfTextRegions(self):
        """Get the number of text regions for this shape."""
        return len(self._regions)

    def GetRegions(self):
        """Get the list of ShapeRegions."""
        return self._regions

    # Control points ('handles') redirect control to the actual shape, to
    # make it easier to override sizing behaviour.
    def OnSizingDragLeft(self, pt, draw, x, y, keys = 0, attachment = 0):
        """The sizing drag left handler."""
        bound_x, bound_y = self.GetBoundingBoxMin()

        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(OGLRBLF)

        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.PENSTYLE_DOT)
        dc.SetPen(dottedPen)
        dc.SetBrush(wx.TRANSPARENT_BRUSH)

        if self.GetCentreResize():
            # Maintain the same centre point
            new_width = 2.0 * abs(x - self.GetX())
            new_height = 2.0 * abs(y - self.GetY())

            # Constrain sizing according to what control point you're dragging
            if pt._type == CONTROL_POINT_HORIZONTAL:
                if self.GetMaintainAspectRatio():
                    new_height = bound_y * (new_width / bound_x)
                else:
                    new_height = bound_y
            elif pt._type == CONTROL_POINT_VERTICAL:
                if self.GetMaintainAspectRatio():
                    new_width = bound_x * (new_height / bound_y)
                else:
                    new_width = bound_x
            elif pt._type == CONTROL_POINT_DIAGONAL and (keys & KEY_SHIFT):
                new_height = bound_y * (new_width / bound_x)

            if self.GetFixedWidth():
                new_width = bound_x

            if self.GetFixedHeight():
                new_height = bound_y

            pt._controlPointDragEndWidth = new_width
            pt._controlPointDragEndHeight = new_height

            self.GetEventHandler().OnDrawOutline(dc, self.GetX(), self.GetY(), new_width, new_height)
        else:
            # Don't maintain the same centre point
            newX1 = min(pt._controlPointDragStartX, x)
            newY1 = min(pt._controlPointDragStartY, y)
            newX2 = max(pt._controlPointDragStartX, x)
            newY2 = max(pt._controlPointDragStartY, y)
            if pt._type == CONTROL_POINT_HORIZONTAL:
                newY1 = pt._controlPointDragStartY
                newY2 = newY1 + pt._controlPointDragStartHeight
            elif pt._type == CONTROL_POINT_VERTICAL:
                newX1 = pt._controlPointDragStartX
                newX2 = newX1 + pt._controlPointDragStartWidth
            elif pt._type == CONTROL_POINT_DIAGONAL and (keys & KEY_SHIFT or self.GetMaintainAspectRatio()):
                newH = (newX2 - newX1) * (float(pt._controlPointDragStartHeight) / pt._controlPointDragStartWidth)
                if self.GetY() > pt._controlPointDragStartY:
                    newY2 = newY1 + newH
                else:
                    newY1 = newY2 - newH

            newWidth = float(newX2 - newX1)
            newHeight = float(newY2 - newY1)

            if pt._type == CONTROL_POINT_VERTICAL and self.GetMaintainAspectRatio():
                newWidth = bound_x * (newHeight / bound_y)

            if pt._type == CONTROL_POINT_HORIZONTAL and self.GetMaintainAspectRatio():
                newHeight = bound_y * (newWidth / bound_x)

            pt._controlPointDragPosX = newX1 + newWidth / 2.0
            pt._controlPointDragPosY = newY1 + newHeight / 2.0
            if self.GetFixedWidth():
                newWidth = bound_x

            if self.GetFixedHeight():
                newHeight = bound_y

            pt._controlPointDragEndWidth = newWidth
            pt._controlPointDragEndHeight = newHeight
            self.GetEventHandler().OnDrawOutline(dc, pt._controlPointDragPosX, pt._controlPointDragPosY, newWidth, newHeight)

    def OnSizingBeginDragLeft(self, pt, x, y, keys = 0, attachment = 0):
        """The sizing begin drag left handler."""
        self._canvas.CaptureMouse()

        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(OGLRBLF)

        bound_x, bound_y = self.GetBoundingBoxMin()
        self.GetEventHandler().OnBeginSize(bound_x, bound_y)

        # Choose the 'opposite corner' of the object as the stationary
        # point in case this is non-centring resizing.
        if pt.GetX() < self.GetX():
            pt._controlPointDragStartX = self.GetX() + bound_x / 2.0
        else:
            pt._controlPointDragStartX = self.GetX() - bound_x / 2.0

        if pt.GetY() < self.GetY():
            pt._controlPointDragStartY = self.GetY() + bound_y / 2.0
        else:
            pt._controlPointDragStartY = self.GetY() - bound_y / 2.0

        if pt._type == CONTROL_POINT_HORIZONTAL:
            pt._controlPointDragStartY = self.GetY() - bound_y / 2.0
        elif pt._type == CONTROL_POINT_VERTICAL:
            pt._controlPointDragStartX = self.GetX() - bound_x / 2.0

        # We may require the old width and height
        pt._controlPointDragStartWidth = bound_x
        pt._controlPointDragStartHeight = bound_y

        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.PENSTYLE_DOT)
        dc.SetPen(dottedPen)
        dc.SetBrush(wx.TRANSPARENT_BRUSH)

        if self.GetCentreResize():
            new_width = 2.0 * abs(x - self.GetX())
            new_height = 2.0 * abs(y - self.GetY())

            # Constrain sizing according to what control point you're dragging
            if pt._type == CONTROL_POINT_HORIZONTAL:
                if self.GetMaintainAspectRatio():
                    new_height = bound_y * (new_width / bound_x)
                else:
                    new_height = bound_y
            elif pt._type == CONTROL_POINT_VERTICAL:
                if self.GetMaintainAspectRatio():
                    new_width = bound_x * (new_height / bound_y)
                else:
                    new_width = bound_x
            elif pt._type == CONTROL_POINT_DIAGONAL and (keys & KEY_SHIFT):
                new_height = bound_y * (new_width / bound_x)

            if self.GetFixedWidth():
                new_width = bound_x

            if self.GetFixedHeight():
                new_height = bound_y

            pt._controlPointDragEndWidth = new_width
            pt._controlPointDragEndHeight = new_height
            self.GetEventHandler().OnDrawOutline(dc, self.GetX(), self.GetY(), new_width, new_height)
        else:
            # Don't maintain the same centre point
            newX1 = min(pt._controlPointDragStartX, x)
            newY1 = min(pt._controlPointDragStartY, y)
            newX2 = max(pt._controlPointDragStartX, x)
            newY2 = max(pt._controlPointDragStartY, y)
            if pt._type == CONTROL_POINT_HORIZONTAL:
                newY1 = pt._controlPointDragStartY
                newY2 = newY1 + pt._controlPointDragStartHeight
            elif pt._type == CONTROL_POINT_VERTICAL:
                newX1 = pt._controlPointDragStartX
                newX2 = newX1 + pt._controlPointDragStartWidth
            elif pt._type == CONTROL_POINT_DIAGONAL and (keys & KEY_SHIFT or self.GetMaintainAspectRatio()):
                newH = (newX2 - newX1) * (float(pt._controlPointDragStartHeight) / pt._controlPointDragStartWidth)
                if pt.GetY() > pt._controlPointDragStartY:
                    newY2 = newY1 + newH
                else:
                    newY1 = newY2 - newH

            newWidth = float(newX2 - newX1)
            newHeight = float(newY2 - newY1)

            if pt._type == CONTROL_POINT_VERTICAL and self.GetMaintainAspectRatio():
                newWidth = bound_x * (newHeight / bound_y)

            if pt._type == CONTROL_POINT_HORIZONTAL and self.GetMaintainAspectRatio():
                newHeight = bound_y * (newWidth / bound_x)

            pt._controlPointDragPosX = newX1 + newWidth / 2.0
            pt._controlPointDragPosY = newY1 + newHeight / 2.0
            if self.GetFixedWidth():
                newWidth = bound_x

            if self.GetFixedHeight():
                newHeight = bound_y

            pt._controlPointDragEndWidth = newWidth
            pt._controlPointDragEndHeight = newHeight
            self.GetEventHandler().OnDrawOutline(dc, pt._controlPointDragPosX, pt._controlPointDragPosY, newWidth, newHeight)

    def OnSizingEndDragLeft(self, pt, x, y, keys = 0, attachment = 0):
        """The sizing end drag left handler."""
        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)

        if self._canvas.HasCapture():
            self._canvas.ReleaseMouse()
        dc.SetLogicalFunction(wx.COPY)
        self.Recompute()
        self.ResetControlPoints()

        self.Erase(dc)

        self.SetSize(pt._controlPointDragEndWidth, pt._controlPointDragEndHeight)

        # The next operation could destroy this control point (it does for
        # label objects, via formatting the text), so save all values we're
        # going to use, or we'll be accessing garbage.

        #return

        if self.GetCentreResize():
            self.Move(dc, self.GetX(), self.GetY())
        else:
            self.Move(dc, pt._controlPointDragPosX, pt._controlPointDragPosY)

        # Recursively redraw links if we have a composite
        if len(self.GetChildren()):
            self.DrawLinks(dc, -1, True)

        width, height = self.GetBoundingBoxMax()
        self.GetEventHandler().OnEndSize(width, height)

        if not self._canvas.GetQuickEditMode() and pt._eraseObject:
            self._canvas.Redraw(dc)


class RectangleShape(Shape):
    """
    The :class:`wx.RectangleShape` class has rounded or square corners.
    """
    def __init__(self, w = 0.0, h = 0.0):
        """
        Default class constructor

        :param float `w`: the width
        :param float `h`: the height

        """
        Shape.__init__(self)
        self._width = w
        self._height = h
        self._cornerRadius = 0.0
        self.SetDefaultRegionSize()

    def OnDraw(self, dc):
        """The draw handler."""
        x1 = self._xpos - self._width / 2.0
        y1 = self._ypos - self._height / 2.0

        if self._shadowMode != SHADOW_NONE:
            if self._shadowBrush:
                dc.SetBrush(self._shadowBrush)
            dc.SetPen(TransparentPen)

            if self._cornerRadius:
                dc.DrawRoundedRectangle(x1 + self._shadowOffsetX, y1 + self._shadowOffsetY, self._width, self._height, self._cornerRadius)
            else:
                dc.DrawRectangle(x1 + self._shadowOffsetX, y1 + self._shadowOffsetY, self._width, self._height)

        if self._pen:
            if self._pen.GetWidth() == 0:
                dc.SetPen(TransparentPen)
            else:
                dc.SetPen(self._pen)
        if self._brush:
            dc.SetBrush(self._brush)

        if self._cornerRadius:
            dc.DrawRoundedRectangle(x1, y1, self._width, self._height, self._cornerRadius)
        else:
            dc.DrawRectangle(x1, y1, self._width, self._height)

    def GetBoundingBoxMin(self):
        """Get the bounding box minimum."""
        return self._width, self._height

    def SetSize(self, x, y, recursive = False):
        """
        Set the size.

        :param `x`: the width
        :param `y`: the height
        :param `recursive`: not used

        """
        self.SetAttachmentSize(x, y)
        self._width = max(x, 1)
        self._height = max(y, 1)
        self.SetDefaultRegionSize()

    def GetCornerRadius(self):
        """Get the radius of the rectangle's rounded corners."""
        return self._cornerRadius

    def SetCornerRadius(self, rad):
        """
        Set the radius of the rectangle's rounded corners.

        :param `rad`: If the radius is zero, a non-rounded rectangle will be
         drawn. If the radius is negative, the value is the proportion of the
         smaller dimension of the rectangle.

        """
        self._cornerRadius = rad

    # Assume (x1, y1) is centre of box (most generally, line end at box)
    def GetPerimeterPoint(self, x1, y1, x2, y2):
        """
        Get the perimeter point.

        :param `x1`: ???
        :param `y1`: ???
        :param `x2`: ???
        :param `y2`: ???

        """
        bound_x, bound_y = self.GetBoundingBoxMax()
        return FindEndForBox(bound_x, bound_y, self._xpos, self._ypos, x2, y2)

    def GetWidth(self):
        """Get the width."""
        return self._width

    def GetHeight(self):
        """Get the height."""
        return self._height

    def SetWidth(self, w):
        """
        Set the width.

        :param `w`: width to be set

        """
        self._width = w

    def SetHeight(self, h):
        """
        Set the heigth.

        :param `h`: heigth to be set

        """
        self._height = h


class PolygonShape(Shape):
    """
    The :class:`PolygonShape` class shape is defined by a number of points
    passed to the object's constructor. It can be used to create new shapes
    such as diamonds and triangles.
    """
    def __init__(self):
        """
        Default class constructor

        Does not follow above statement, should it? or is Create called
        automagically?

        """
        Shape.__init__(self)

        self._points = None
        self._originalPoints = None

    def Create(self, the_points = None):
        """
        Takes a list of :class:`wx.Points` or tuples; each point is an offset
        from the centre.
        """
        self.ClearPoints()

        if not the_points:
            self._originalPoints = []
            self._points = []
        else:
            self._originalPoints = the_points

            # Duplicate the list of points
            self._points = []
            for point in the_points:
                new_point = wx.Point(point[0], point[1])
                self._points.append(new_point)
            self.CalculateBoundingBox()
            self._originalWidth = self._boundWidth
            self._originalHeight = self._boundHeight
            self.SetDefaultRegionSize()

    def ClearPoints(self):
        """Clear the points."""
        self._points = []
        self._originalPoints = []

    # Width and height. Centre of object is centre of box
    def GetBoundingBoxMin(self):
        """Get minimum bounding box."""
        return self._boundWidth, self._boundHeight

    def GetPoints(self):
        """Return the internal list of polygon vertices."""
        return self._points

    def GetOriginalPoints(self):
        """Get the original points."""
        return self._originalPoints

    def GetOriginalWidth(self):
        """Get the original width."""
        return self._originalWidth

    def GetOriginalHeight(self):
        """Get the original height."""
        return self._originalHeight

    def SetOriginalWidth(self, w):
        """
        Set the original width.

        :param `w`: the width

        """
        self._originalWidth = w

    def SetOriginalHeight(self, h):
        """
        Set the original height.

        :param `w`: the height

        """
        self._originalHeight = h

    def CalculateBoundingBox(self):
        """Calculate the bounding box."""
        left = 10000
        right = -10000
        top = 10000
        bottom = -10000

        for point in self._points:
            if point[0] < left:
                left = point[0]
            if point[0] > right:
                right = point[0]

            if point[1] < top:
                top = point[1]
            if point[1] > bottom:
                bottom = point[1]

        self._boundWidth = right - left
        self._boundHeight = bottom - top

    def CalculatePolygonCentre(self):
        """
        Recalculates the centre of the polygon, and
        readjusts the point offsets accordingly.
        Necessary since the centre of the polygon
        is expected to be the real centre of the bounding
        box.
        """
        left = 10000
        right = -10000
        top = 10000
        bottom = -10000

        for point in self._points:
            if point[0] < left:
                left = point[0]
            if point[0] > right:
                right = point[0]

            if point[1] < top:
                top = point[1]
            if point[1] > bottom:
                bottom = point[1]

        bwidth = right - left
        bheight = bottom - top

        newCentreX = left + bwidth / 2.0
        newCentreY = top + bheight / 2.0

        for i in range(len(self._points)):
            self._points[i] = self._points[i][0] - newCentreX, self._points[i][1] - newCentreY
        self._xpos += newCentreX
        self._ypos += newCentreY

    def HitTest(self, x, y):
        """Hit text

        :param `x`: the x position
        :param `y`: the y position

        """
        # Imagine four lines radiating from this point. If all of these lines
        # hit the polygon, we're inside it, otherwise we're not. Obviously
        # we'd need more radiating lines to be sure of correct results for
        # very strange (concave) shapes.
        endPointsX = [x, x + 1000, x, x - 1000]
        endPointsY = [y - 1000, y, y + 1000, y]

        xpoints = []
        ypoints = []

        for point in self._points:
            xpoints.append(point[0] + self._xpos)
            ypoints.append(point[1] + self._ypos)

        # We assume it's inside the polygon UNLESS one or more
        # lines don't hit the outline.
        isContained = True

        for i in range(4):
            if not PolylineHitTest(xpoints, ypoints, x, y, endPointsX[i], endPointsY[i]):
                isContained = False

        if not isContained:
            return False

        nearest_attachment = 0

        # If a hit, check the attachment points within the object
        nearest = 999999

        for i in range(self.GetNumberOfAttachments()):
            e = self.GetAttachmentPositionEdge(i)
            if e:
                xp, yp = e
                l = math.sqrt((xp - x) * (xp - x) + (yp - y) * (yp - y))
                if l < nearest:
                    nearest = l
                    nearest_attachment = i

        return nearest_attachment, nearest

    # Really need to be able to reset the shape! Otherwise, if the
    # points ever go to zero, we've lost it, and can't resize.
    def SetSize(self, new_width, new_height, recursive = True):
        """
        Set the size

        :param `new_width`: the width
        :param `new_height`: the height
        :param `recursive`: not used

        """
        self.SetAttachmentSize(new_width, new_height)

        # Multiply all points by proportion of new size to old size
        x_proportion = abs(float(new_width) / self._originalWidth)
        y_proportion = abs(float(new_height) / self._originalHeight)

        for i in range(max(len(self._points), len(self._originalPoints))):
            self._points[i] = wx.Point(self._originalPoints[i][0] * x_proportion, self._originalPoints[i][1] * y_proportion)

        self._boundWidth = abs(new_width)
        self._boundHeight = abs(new_height)
        self.SetDefaultRegionSize()

    # Make the original points the same as the working points
    def UpdateOriginalPoints(self):
        """
        If we've changed the shape, must make the original points match the
        working points with this function.

        """
        self._originalPoints = []

        for point in self._points:
            original_point = wx.RealPoint(point[0], point[1])
            self._originalPoints.append(original_point)

        self.CalculateBoundingBox()
        self._originalWidth = self._boundWidth
        self._originalHeight = self._boundHeight

    def AddPolygonPoint(self, pos):
        """
        Add a control point after the given point.

        :param `pos`: position of point

        """
        try:
            firstPoint = self._points[pos]
        except ValueError:
            firstPoint = self._points[0]

        try:
            secondPoint = self._points[pos + 1]
        except ValueError:
            secondPoint = self._points[0]

        x = (secondPoint[0] - firstPoint[0]) / 2.0 + firstPoint[0]
        y = (secondPoint[1] - firstPoint[1]) / 2.0 + firstPoint[1]
        point = wx.RealPoint(x, y)

        if pos >= len(self._points) - 1:
            self._points.append(point)
        else:
            self._points.insert(pos + 1, point)

        self.UpdateOriginalPoints()

        if self._selected:
            self.DeleteControlPoints()
            self.MakeControlPoints()

    def DeletePolygonPoint(self, pos):
        """

        Delete the given control point.

        :param `pos`: position of point

        """
        if pos < len(self._points):
            del self._points[pos]
            self.UpdateOriginalPoints()
            if self._selected:
                self.DeleteControlPoints()
                self.MakeControlPoints()

    # Assume (x1, y1) is centre of box (most generally, line end at box)
    def GetPerimeterPoint(self, x1, y1, x2, y2):
        """
        Get the perimeter point.

        :param `x1`: the x1 position
        :param `y1`: the y1 position
        :param `x2`: the x2 position
        :param `y2`: the y2 position

        """
        # First check for situation where the line is vertical,
        # and we would want to connect to a point on that vertical --
        # oglFindEndForPolyline can't cope with this (the arrow
        # gets drawn to the wrong place).
        if self._attachmentMode == ATTACHMENT_MODE_NONE and x1 == x2:
            # Look for the point we'd be connecting to. This is
            # a heuristic...
            for point in self._points:
                if point[0] == 0:
                    if y2 > y1 and point[1] > 0:
                        return point[0] + self._xpos, point[1] + self._ypos
                    elif y2 < y1 and point[1] < 0:
                        return point[0] + self._xpos, point[1] + self._ypos

        xpoints = []
        ypoints = []
        for point in self._points:
            xpoints.append(point[0] + self._xpos)
            ypoints.append(point[1] + self._ypos)

        return FindEndForPolyline(xpoints, ypoints, x1, y1, x2, y2)

    def OnDraw(self, dc):
        """The draw handler."""
        if self._shadowMode != SHADOW_NONE:
            if self._shadowBrush:
                dc.SetBrush(self._shadowBrush)
            dc.SetPen(TransparentPen)

            dc.DrawPolygon(self._points, self._xpos + self._shadowOffsetX, self._ypos, self._shadowOffsetY)

        if self._pen:
            if self._pen.GetWidth() == 0:
                dc.SetPen(TransparentPen)
            else:
                dc.SetPen(self._pen)
        if self._brush:
            dc.SetBrush(self._brush)
        dc.DrawPolygon(self._points, self._xpos, self._ypos)

    def OnDrawOutline(self, dc, x, y, w, h):
        """The draw outline handler."""
        dc.SetBrush(wx.TRANSPARENT_BRUSH)
        # Multiply all points by proportion of new size to old size
        x_proportion = abs(float(w) / self._originalWidth)
        y_proportion = abs(float(h) / self._originalHeight)

        intPoints = []
        for point in self._originalPoints:
            intPoints.append(wx.Point(x_proportion * point[0], y_proportion * point[1]))
        dc.DrawPolygon(intPoints, x, y)

    # Make as many control points as there are vertices
    def MakeControlPoints(self):
        """Make control points."""
        for point in self._points:
            control = PolygonControlPoint(self._canvas, self, CONTROL_POINT_SIZE, point, point[0], point[1])
            self._canvas.AddShape(control)
            self._controlPoints.append(control)

    def ResetControlPoints(self):
        """Reset control points."""
        for i in range(min(len(self._points), len(self._controlPoints))):
            point = self._points[i]
            self._controlPoints[i]._xoffset = point[0]
            self._controlPoints[i]._yoffset = point[1]
            self._controlPoints[i].polygonVertex = point

    def GetNumberOfAttachments(self):
        """Get number of attachments."""
        maxN = max(len(self._points) - 1, 0)
        for point in self._attachmentPoints:
            if point._id > maxN:
                maxN = point._id
        return maxN + 1

    def GetAttachmentPosition(self, attachment, nth = 0, no_arcs = 1, line = None):
        """
        Get attachment position.

        :param `attachment`: the attachment ???
        :param `nth`: get nth attachment ???
        :param `no_arcs`: ???
        :param `line`: ???

        """
        if self._attachmentMode == ATTACHMENT_MODE_EDGE and self._points and attachment < len(self._points):
            point = self._points[0]
            return point[0] + self._xpos, point[1] + self._ypos
        return Shape.GetAttachmentPosition(self, attachment, nth, no_arcs, line)

    def AttachmentIsValid(self, attachment):
        """
        Is attachment valid?

        :param `attachment`: ???

        """
        if not self._points:
            return False

        if attachment >= 0 and attachment < len(self._points):
            return True

        for point in self._attachmentPoints:
            if point._id == attachment:
                return True

        return False

    def Rotate(self, x, y, theta):
        """
        Rotate about the given axis by the given amount in radians.

        :param `x`: the x position
        :param `y`: the y position
        :param `theta`: the theta

        """

        actualTheta = theta - self._rotation

        # Rotate attachment points
        sinTheta = math.sin(actualTheta)
        cosTheta = math.cos(actualTheta)

        for point in self._attachmentPoints:
            x1 = point._x
            y1 = point._y

            point._x = x1 * cosTheta - y1 * sinTheta + x * (1 - cosTheta) + y * sinTheta
            point._y = x1 * sinTheta + y1 * cosTheta + y * (1 - cosTheta) + x * sinTheta

        for i in range(len(self._points)):
            x1, y1 = self._points[i]

            self._points[i] = x1 * cosTheta - y1 * sinTheta + x * (1 - cosTheta) + y * sinTheta, x1 * sinTheta + y1 * cosTheta + y * (1 - cosTheta) + x * sinTheta

        for i in range(len(self._originalPoints)):
            x1, y1 = self._originalPoints[i]

            self._originalPoints[i] = x1 * cosTheta - y1 * sinTheta + x * (1 - cosTheta) + y * sinTheta, x1 * sinTheta + y1 * cosTheta + y * (1 - cosTheta) + x * sinTheta

        # Added by Pierre Hjälm. If we don't do this the outline will be
        # the wrong size. Hopefully it won't have any ill effects.
        self.UpdateOriginalPoints()

        self._rotation = theta

        self.CalculatePolygonCentre()
        self.CalculateBoundingBox()
        self.ResetControlPoints()

    # Control points ('handles') redirect control to the actual shape, to
    # make it easier to override sizing behaviour.
    def OnSizingDragLeft(self, pt, draw, x, y, keys = 0, attachment = 0):
        """The sizing drag left handler."""
        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(OGLRBLF)

        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.PENSTYLE_DOT)
        dc.SetPen(dottedPen)
        dc.SetBrush(wx.TRANSPARENT_BRUSH)

        # Code for CTRL-drag in C++ version commented out

        pt.CalculateNewSize(x, y)

        self.GetEventHandler().OnDrawOutline(dc, self.GetX(), self.GetY(), pt.GetNewSize()[0], pt.GetNewSize()[1])

    def OnSizingBeginDragLeft(self, pt, x, y, keys = 0, attachment = 0):
        """The sizing begin drag left handler."""
        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)
        dc.SetLogicalFunction(OGLRBLF)

        self.Erase(dc)

        bound_x, bound_y = self.GetBoundingBoxMin()

        dist = math.sqrt((x - self.GetX()) * (x - self.GetX()) + (y - self.GetY()) * (y - self.GetY()))

        pt._originalDistance = dist
        pt._originalSize[0] = bound_x
        pt._originalSize[1] = bound_y

        if pt._originalDistance == 0:
            pt._originalDistance = 0.0001

        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.PENSTYLE_DOT)
        dc.SetPen(dottedPen)
        dc.SetBrush(wx.TRANSPARENT_BRUSH)

        # Code for CTRL-drag in C++ version commented out

        pt.CalculateNewSize(x, y)

        self.GetEventHandler().OnDrawOutline(dc, self.GetX(), self.GetY(), pt.GetNewSize()[0], pt.GetNewSize()[1])

        self._canvas.CaptureMouse()

    def OnSizingEndDragLeft(self, pt, x, y, keys = 0, attachment = 0):
        """The sizing end drag left handler."""
        dc = wx.MemoryDC()
        dc.SelectObject(self.GetCanvas().GetBuffer())
        self.GetCanvas().PrepareDC(dc)

        if self._canvas.HasCapture():
            self._canvas.ReleaseMouse()
        dc.SetLogicalFunction(wx.COPY)

        # If we're changing shape, must reset the original points
        if keys & KEY_CTRL:
            self.CalculateBoundingBox()
            self.CalculatePolygonCentre()
        else:
            self.SetSize(pt.GetNewSize()[0], pt.GetNewSize()[1])

        self.Recompute()
        self.ResetControlPoints()
        self.Move(dc, self.GetX(), self.GetY())
        if not self._canvas.GetQuickEditMode():
            self._canvas.Redraw(dc)


class EllipseShape(Shape):
    """
    The :class:`EllipseShape` class behaves similarly to the
    :class`RectangleShape` but is elliptical.

    """
    def __init__(self, w, h):
        """
        Default class constructor

        :param `w`: the width
        :param `h`: the height

        """
        Shape.__init__(self)
        self._width = w
        self._height = h
        self.SetDefaultRegionSize()

    def GetBoundingBoxMin(self):
        """Get the minimum bounding box."""
        return self._width, self._height

    def GetPerimeterPoint(self, x1, y1, x2, y2):
        """
        Get the perimeter point.

        :param `x1`: the x1 position
        :param `y1`: the y1 position
        :param `x2`: the x2 position
        :param `y2`: the y2 position

        """
        bound_x, bound_y = self.GetBoundingBoxMax()

        return DrawArcToEllipse(self._xpos, self._ypos, bound_x, bound_y, x2, y2, x1, y1)

    def GetWidth(self):
        """Get the width."""
        return self._width

    def GetHeight(self):
        """Get the height."""
        return self._height

    def SetWidth(self, w):
        """
        Set the width.

        :param `w`: the width

        """
        self._width = w

    def SetHeight(self, h):
        """
        Set the height.

        :param `h`: the height

        """
        self._height = h

    def OnDraw(self, dc):
        """The draw handler."""
        if self._shadowMode != SHADOW_NONE:
            if self._shadowBrush:
                dc.SetBrush(self._shadowBrush)
            dc.SetPen(TransparentPen)
            dc.DrawEllipse(self._xpos - self.GetWidth() / 2.0 + self._shadowOffsetX,
                           self._ypos - self.GetHeight() / 2.0 + self._shadowOffsetY,
                           self.GetWidth(), self.GetHeight())

        if self._pen:
            if self._pen.GetWidth() == 0:
                dc.SetPen(TransparentPen)
            else:
                dc.SetPen(self._pen)
        if self._brush:
            dc.SetBrush(self._brush)
        dc.DrawEllipse(self._xpos - self.GetWidth() / 2.0, self._ypos - self.GetHeight() / 2.0, self.GetWidth(), self.GetHeight())

    def SetSize(self, x, y, recursive = True):
        """
        Set the size.

        :param `x`: the width
        :param `y`: the height
        :recursive: not used

        """
        self.SetAttachmentSize(x, y)
        self._width = x
        self._height = y
        self.SetDefaultRegionSize()

    def GetNumberOfAttachments(self):
        """Get number of attachments."""
        return Shape.GetNumberOfAttachments(self)

    # There are 4 attachment points on an ellipse - 0 = top, 1 = right,
    # 2 = bottom, 3 = left.
    def GetAttachmentPosition(self, attachment, nth = 0, no_arcs = 1, line = None):
        """
        Get attachment position.

        :param `attachment`: the attachment ???
        :param `nth`: get nth attachment ???
        :param `no_arcs`: ???
        :param `line`: ???

        """
        if self._attachmentMode == ATTACHMENT_MODE_BRANCHING:
            return Shape.GetAttachmentPosition(self, attachment, nth, no_arcs, line)

        if self._attachmentMode != ATTACHMENT_MODE_NONE:
            top = self._ypos + self._height / 2.0
            bottom = self._ypos - self._height / 2.0
            left = self._xpos - self._width / 2.0
            right = self._xpos + self._width / 2.0

            physicalAttachment = self.LogicalToPhysicalAttachment(attachment)

            if physicalAttachment == 0:
                if self._spaceAttachments:
                    x = left + (nth + 1) * self._width / (no_arcs + 1.0)
                else:
                    x = self._xpos
                y = top
                # We now have the point on the bounding box: but get the point
                # on the ellipse by imagining a vertical line from
                # (x, self._ypos - self._height - 500) to (x, self._ypos) intersecting
                # the ellipse.

                return DrawArcToEllipse(self._xpos, self._ypos, self._width, self._height, x, self._ypos - self._height - 500, x, self._ypos)
            elif physicalAttachment == 1:
                x = right
                if self._spaceAttachments:
                    y = bottom + (nth + 1) * self._height / (no_arcs + 1.0)
                else:
                    y = self._ypos
                return DrawArcToEllipse(self._xpos, self._ypos, self._width, self._height, self._xpos + self._width + 500, y, self._xpos, y)
            elif physicalAttachment == 2:
                if self._spaceAttachments:
                    x = left + (nth + 1) * self._width / (no_arcs + 1.0)
                else:
                    x = self._xpos
                y = bottom
                return DrawArcToEllipse(self._xpos, self._ypos, self._width, self._height, x, self._ypos + self._height + 500, x, self._ypos)
            elif physicalAttachment == 3:
                x = left
                if self._spaceAttachments:
                    y = bottom + (nth + 1) * self._height / (no_arcs + 1.0)
                else:
                    y = self._ypos
                return DrawArcToEllipse(self._xpos, self._ypos, self._width, self._height, self._xpos - self._width - 500, y, self._xpos, y)
            else:
                return Shape.GetAttachmentPosition(self, attachment, x, y, nth, no_arcs, line)
        else:
            return self._xpos, self._ypos


class CircleShape(EllipseShape):
    """
    The :class:`CircleShape` class is an :class:`EllipseShape` whose width
    and height are the same.
    """
    def __init__(self, diameter):
        """
        Default class constructor

        :param `diameter`: the diameter

        """
        EllipseShape.__init__(self, diameter, diameter)
        self.SetMaintainAspectRatio(True)

    def GetPerimeterPoint(self, x1, y1, x2, y2):
        """
        Get the perimeter point.

        :param `x1`: ???
        :param `y1`: ???
        :param `x2`: ???
        :param `y2`: ???
        :returns: ???

        """
        return FindEndForCircle(self._width / 2.0, self._xpos, self._ypos, x2, y2)


class TextShape(RectangleShape):
    """
    The :class:`TextShape` class like :class:`wx.RectangleShape` but only the
    text is displayed.
    """
    def __init__(self, width, height):
        """
        Default class constructor

        :param `width`: the width
        :param `height`: the height

        """
        RectangleShape.__init__(self, width, height)

    def OnDraw(self, dc):
        """not implemented???"""
        pass


class ShapeRegion(object):
    """The :class:`ShapeRegion` class."""
    def __init__(self, region = None):
        """
        Default class constructor

        :param `region`: a parent region or None???

        """
        if region:
            self._regionText = region._regionText
            self._regionName = region._regionName
            self._textColour = region._textColour

            self._font = region._font
            self._minHeight = region._minHeight
            self._minWidth = region._minWidth
            self._width = region._width
            self._height = region._height
            self._x = region._x
            self._y = region._y

            self._regionProportionX = region._regionProportionX
            self._regionProportionY = region._regionProportionY
            self._formatMode = region._formatMode
            self._actualColourObject = region._actualColourObject
            self._actualPenObject = None
            self._penStyle = region._penStyle
            self._penColour = region._penColour

            self.ClearText()
            for line in region._formattedText:
                new_line = ShapeTextLine(line.GetX(), line.GetY(), line.GetText())
                self._formattedText.append(new_line)
        else:
            self._regionText = ""
            self._font = NormalFont
            self._minHeight = 5.0
            self._minWidth = 5.0
            self._width = 0.0
            self._height = 0.0
            self._x = 0.0
            self._y = 0.0

            self._regionProportionX = -1.0
            self._regionProportionY = -1.0
            self._formatMode = FORMAT_CENTRE_HORIZ | FORMAT_CENTRE_VERT
            self._regionName = ""
            self._textColour = "BLACK"
            self._penColour = "BLACK"
            self._penStyle = wx.PENSTYLE_SOLID
            self._actualColourObject = wx.TheColourDatabase.Find("BLACK")
            self._actualPenObject = None

            self._formattedText = []

    def ClearText(self):
        """Clear the text."""
        self._formattedText = []

    def SetFont(self, f):
        """
        Set the font.

        :param `f`: an instance of :class:`wx.Font`
        """
        self._font = f

    def SetMinSize(self, w, h):
        """
        Set the minumum size.

        :param `w`: the minimum width
        :Param `h`: the minimum height

        """
        self._minWidth = w
        self._minHeight = h

    def SetSize(self, w, h):
        """
        Set the size.

        :param `w`: the width
        :Param `h`: the jeight

        """
        self._width = w
        self._height = h

    def SetPosition(self, xp, yp):
        """
        Set the position.

        :param `xp`: the x position
        :Param `yp`: the y position

        """
        self._x = xp
        self._y = yp

    def SetProportions(self, xp, yp):
        """
        Set the proportions.

        :param `xp`: the x region proportion
        :Param `yp`: the y region proportion

        """
        self._regionProportionX = xp
        self._regionProportionY = yp

    def SetFormatMode(self, mode):
        """
        Set the format mode of the region.

        :param `mode`: can be a bit list of the following

        ============================== ==============================
        Format mode                    Description
        ============================== ==============================
        `FORMAT_NONE`                  No formatting
        `FORMAT_CENTRE_HORIZ`          Horizontal centring
        `FORMAT_CENTRE_VERT`           Vertical centring
        ============================== ==============================

        """
        self._formatMode = mode

    def SetColour(self, col):
        """
        Set the colour.

        :param str `col`: a valid colour name,
         see :class:`wx.ColourDatabase`

        """
        self._textColour = col
        self._actualColourObject = col

    def GetActualColourObject(self):
        """Get the actual colour object from the :class:`wx.ColourDatabase`."""
        self._actualColourObject = wx.TheColourDatabase.Find(self.GetColour())
        return self._actualColourObject

    def SetPenColour(self, col):
        """
        Set the pen colour.

        :param str `col`: a valid colour name,
         see :class:`wx.ColourDatabase`

        """
        self._penColour = col
        self._actualPenObject = None

    def GetActualPen(self):
        """
        Get actual pen.

        :note: Returns NULL if the pen is invisible
         (different to pen being transparent; indicates that
         region boundary should not be drawn.)

         """
        if self._actualPenObject:
            return self._actualPenObject

        if not self._penColour:
            return None
        if self._penColour=="Invisible":
            return None
        self._actualPenObject = wx.Pen(self._penColour, 1, self._penStyle)
        return self._actualPenObject

    def SetText(self, s):
        """
        Set the text.

        :param str `s`: the text

        """
        self._regionText = s

    def SetName(self, s):
        """
        Set the name.

        :param str `s`: the name

        """
        self._regionName = s

    def GetText(self):
        """Get the text."""
        return self._regionText

    def GetFont(self):
        """Get the font."""
        return self._font

    def GetMinSize(self):
        """Get the minimum size."""
        return self._minWidth, self._minHeight

    def GetProportion(self):
        """Get the proportion."""
        return self._regionProportionX, self._regionProportionY

    def GetSize(self):
        """Get the size."""
        return self._width, self._height

    def GetPosition(self):
        """Get the position."""
        return self._x, self._y

    def GetFormatMode(self):
        """Get the format mode."""
        return self._formatMode

    def GetName(self):
        """Get the name."""
        return self._regionName

    def GetColour(self):
        """Get the colour."""
        return self._textColour

    def GetFormattedText(self):
        """Get the formatted text."""
        return self._formattedText

    def GetPenColour(self):
        """Get the pen colour"""
        return self._penColour

    def GetPenStyle(self):
        """Get the pen style."""
        return self._penStyle

    def SetPenStyle(self, style):
        """
        Set the pen style.

        :param `style`: the style, see :class:`wx.Pen`

        """
        self._penStyle = style
        self._actualPenObject = None

    def GetWidth(self):
        """Get the width."""
        return self._width

    def GetHeight(self):
        """Get the height."""
        return self._height


class ControlPoint(RectangleShape):
    """The :class:`wx.ControlPoint` class."""
    def __init__(self, theCanvas, object, size, the_xoffset, the_yoffset, the_type):
        """
        Default class constructor

        :param `theCanvas`: a :class:`~lib.ogl.Canvas`
        :param `object`: the shape, instance of :class:`~lib.ogl.Shape`
        :param float `size`: the size
        :param float `the_xoffset`: the x position
        :param float `the_yoffset`: the y position
        :param int `the_type`: one of the following types ???

         ======================================== ==================================
         Control point type                       Description
         ======================================== ==================================
         `CONTROL_POINT_VERTICAL`                 Vertical
         `CONTROL_POINT_HORIZONTAL`               Horizontal
         `CONTROL_POINT_DIAGONAL`                 Diagonal
         ======================================== ==================================

        """
        RectangleShape.__init__(self, size, size)

        self._canvas = theCanvas
        self._shape = object
        self._xoffset = the_xoffset
        self._yoffset = the_yoffset
        self._type = the_type
        self.SetPen(BlackForegroundPen)
        self.SetBrush(wx.BLACK_BRUSH)
        self._oldCursor = None
        self._visible = True
        self._eraseObject = True

    # Don't even attempt to draw any text - waste of time
    def OnDrawContents(self, dc):
        """not implemented???"""
        pass

    def OnDraw(self, dc):
        """The draw handler."""
        self._xpos = self._shape.GetX() + self._xoffset
        self._ypos = self._shape.GetY() + self._yoffset
        RectangleShape.OnDraw(self, dc)

    def OnErase(self, dc):
        """The erase handler."""
        RectangleShape.OnErase(self, dc)

    # Implement resizing of canvas object
    def OnDragLeft(self, draw, x, y, keys = 0, attachment = 0):
        """The drag left handler."""
        self._shape.GetEventHandler().OnSizingDragLeft(self, draw, x, y, keys, attachment)

    def OnBeginDragLeft(self, x, y, keys = 0, attachment = 0):
        """The begin drag left handler."""
        self._shape.GetEventHandler().OnSizingBeginDragLeft(self, x, y, keys, attachment)

    def OnEndDragLeft(self, x, y, keys = 0, attachment = 0):
        """The end drag left handler."""
        self._shape.GetEventHandler().OnSizingEndDragLeft(self, x, y, keys, attachment)

    def GetNumberOfAttachments(self):
        """Get the number of attachments."""
        return 1

    def GetAttachmentPosition(self, attachment, nth = 0, no_arcs = 1, line = None):
        """
        Get the attachment position.

        :param `attachment`: the attachment ???
        :param `nth`: get nth attachment ???
        :param `no_arcs`: ???
        :param `line`: ???

        """
        return self._xpos, self._ypos

    def SetEraseObject(self, er):
        """
        Set the erase object ???

        :param `er`: the object

        """
        self._eraseObject = er


class PolygonControlPoint(ControlPoint):
    """The :class:`PolygonControlPoint` class."""
    def __init__(self, theCanvas, object, size, vertex, the_xoffset, the_yoffset):
        """
        Default class constructor

        :param `theCanvas`: a :class:`~lib.ogl.Canvas`
        :param `object`: the shape, instance of :class:`~lib.ogl.Shape`
        :param float `size`: the size
        :param `vertext`: the vertex
        :param float `the_xoffset`: the x position
        :param float `the_yoffset`: the y position
        :param int `the_type`: one of the following types ???

         ======================================== ==================================
         Control point type                       Description
         ======================================== ==================================
         `CONTROL_POINT_VERTICAL`                 Vertical
         `CONTROL_POINT_HORIZONTAL`               Horizontal
         `CONTROL_POINT_DIAGONAL`                 Diagonal
         ======================================== ==================================

        """
        ControlPoint.__init__(self, theCanvas, object, size, the_xoffset, the_yoffset, 0)
        self._polygonVertex = vertex
        self._originalDistance = 0.0
        self._newSize = wx.RealPoint()
        self._originalSize = wx.RealPoint()

    def GetNewSize(self):
        """Get the new size."""
        return self._newSize

    def CalculateNewSize(self, x, y):
        """
        Calculate what new size would be, at end of resize.

        :param `x`: x ???
        :param `y`: y ???

        """
        bound_x, bound_y = self.GetShape().GetBoundingBoxMax()
        dist = math.sqrt((x - self._shape.GetX()) * (x - self._shape.GetX()) + (y - self._shape.GetY()) * (y - self._shape.GetY()))

        self._newSize[0] = dist / self._originalDistance * self._originalSize[0]
        self._newSize[1] = dist / self._originalDistance * self._originalSize[1]

    # Implement resizing polygon or moving the vertex
    def OnDragLeft(self, draw, x, y, keys = 0, attachment = 0):
        """The drag left handler."""
        self._shape.GetEventHandler().OnSizingDragLeft(self, draw, x, y, keys, attachment)

    def OnBeginDragLeft(self, x, y, keys = 0, attachment = 0):
        """The begin drag left handler."""
        self._shape.GetEventHandler().OnSizingBeginDragLeft(self, x, y, keys, attachment)

    def OnEndDragLeft(self, x, y, keys = 0, attachment = 0):
        """The end drag left handler."""
        self._shape.GetEventHandler().OnSizingEndDragLeft(self, x, y, keys, attachment)

from .canvas import *
from .lines import *
from .composit import *