1 /*
2   ==============================================================================
3 
4    This file is part of the JUCE library.
5    Copyright (c) 2020 - Raw Material Software Limited
6 
7    JUCE is an open source library subject to commercial or open-source
8    licensing.
9 
10    By using JUCE, you agree to the terms of both the JUCE 6 End-User License
11    Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
12 
13    End User License Agreement: www.juce.com/juce-6-licence
14    Privacy Policy: www.juce.com/juce-privacy-policy
15 
16    Or: You may also use this code under the terms of the GPL v3 (see
17    www.gnu.org/licenses).
18 
19    JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
20    EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
21    DISCLAIMED.
22 
23   ==============================================================================
24 */
25 
26 namespace juce
27 {
28 
29 //==============================================================================
30 /**
31     A component that resizes its parent component when dragged.
32 
33     This component forms a frame around the edge of a component, allowing it to
34     be dragged by the edges or corners to resize it - like the way windows are
35     resized in MSWindows or Linux.
36 
37     To use it, just add it to your component, making it fill the entire parent component
38     (there's a mouse hit-test that only traps mouse-events which land around the
39     edge of the component, so it's even ok to put it on top of any other components
40     you're using). Make sure you rescale the resizer component to fill the parent
41     each time the parent's size changes.
42 
43     @see ResizableCornerComponent
44 
45     @tags{GUI}
46 */
47 class JUCE_API  ResizableBorderComponent  : public Component
48 {
49 public:
50     //==============================================================================
51     /** Creates a resizer.
52 
53         Pass in the target component which you want to be resized when this one is
54         dragged.
55 
56         The target component will usually be a parent of the resizer component, but this
57         isn't mandatory.
58 
59         Remember that when the target component is resized, it'll need to move and
60         resize this component to keep it in place, as this won't happen automatically.
61 
62         If the constrainer parameter is not a nullptr, then this object will be used to
63         enforce limits on the size and position that the component can be stretched to.
64         Make sure that the constrainer isn't deleted while still in use by this object.
65 
66         @see ComponentBoundsConstrainer
67     */
68     ResizableBorderComponent (Component* componentToResize,
69                               ComponentBoundsConstrainer* constrainer);
70 
71     /** Destructor. */
72     ~ResizableBorderComponent() override;
73 
74 
75     //==============================================================================
76     /** Specifies how many pixels wide the draggable edges of this component are.
77 
78         @see getBorderThickness
79     */
80     void setBorderThickness (BorderSize<int> newBorderSize);
81 
82     /** Returns the number of pixels wide that the draggable edges of this component are.
83 
84         @see setBorderThickness
85     */
86     BorderSize<int> getBorderThickness() const;
87 
88 
89     //==============================================================================
90     /** Represents the different sections of a resizable border, which allow it to
91         resized in different ways.
92     */
93     class Zone
94     {
95     public:
96         //==============================================================================
97         enum Zones
98         {
99             centre  = 0,
100             left    = 1,
101             top     = 2,
102             right   = 4,
103             bottom  = 8
104         };
105 
106         //==============================================================================
107         /** Creates a Zone from a combination of the flags in zoneFlags. */
108         explicit Zone (int zoneFlags) noexcept;
109 
110         Zone() noexcept;
111         Zone (const Zone&) noexcept;
112         Zone& operator= (const Zone&) noexcept;
113 
114         bool operator== (const Zone&) const noexcept;
115         bool operator!= (const Zone&) const noexcept;
116 
117         //==============================================================================
118         /** Given a point within a rectangle with a resizable border, this returns the
119             zone that the point lies within.
120         */
121         static Zone fromPositionOnBorder (Rectangle<int> totalSize,
122                                           BorderSize<int> border,
123                                           Point<int> position);
124 
125         /** Returns an appropriate mouse-cursor for this resize zone. */
126         MouseCursor getMouseCursor() const noexcept;
127 
128         /** Returns true if dragging this zone will move the enire object without resizing it. */
isDraggingWholeObject()129         bool isDraggingWholeObject() const noexcept     { return zone == centre; }
130         /** Returns true if dragging this zone will move the object's left edge. */
isDraggingLeftEdge()131         bool isDraggingLeftEdge() const noexcept        { return (zone & left) != 0; }
132         /** Returns true if dragging this zone will move the object's right edge. */
isDraggingRightEdge()133         bool isDraggingRightEdge() const noexcept       { return (zone & right) != 0; }
134         /** Returns true if dragging this zone will move the object's top edge. */
isDraggingTopEdge()135         bool isDraggingTopEdge() const noexcept         { return (zone & top) != 0; }
136         /** Returns true if dragging this zone will move the object's bottom edge. */
isDraggingBottomEdge()137         bool isDraggingBottomEdge() const noexcept      { return (zone & bottom) != 0; }
138 
139         /** Resizes this rectangle by the given amount, moving just the edges that this zone
140             applies to.
141         */
142         template <typename ValueType>
resizeRectangleBy(Rectangle<ValueType> original,const Point<ValueType> & distance)143         Rectangle<ValueType> resizeRectangleBy (Rectangle<ValueType> original,
144                                                 const Point<ValueType>& distance) const noexcept
145         {
146             if (isDraggingWholeObject())
147                 return original + distance;
148 
149             if (isDraggingLeftEdge())   original.setLeft (jmin (original.getRight(), original.getX() + distance.x));
150             if (isDraggingRightEdge())  original.setWidth (jmax (ValueType(), original.getWidth() + distance.x));
151             if (isDraggingTopEdge())    original.setTop (jmin (original.getBottom(), original.getY() + distance.y));
152             if (isDraggingBottomEdge()) original.setHeight (jmax (ValueType(), original.getHeight() + distance.y));
153 
154             return original;
155         }
156 
157         /** Returns the raw flags for this zone. */
getZoneFlags()158         int getZoneFlags() const noexcept               { return zone; }
159 
160     private:
161         //==============================================================================
162         int zone = centre;
163     };
164 
165     /** Returns the zone in which the mouse was last seen. */
getCurrentZone()166     Zone getCurrentZone() const noexcept                 { return mouseZone; }
167 
168 protected:
169     /** @internal */
170     void paint (Graphics&) override;
171     /** @internal */
172     void mouseEnter (const MouseEvent&) override;
173     /** @internal */
174     void mouseMove (const MouseEvent&) override;
175     /** @internal */
176     void mouseDown (const MouseEvent&) override;
177     /** @internal */
178     void mouseDrag (const MouseEvent&) override;
179     /** @internal */
180     void mouseUp (const MouseEvent&) override;
181     /** @internal */
182     bool hitTest (int x, int y) override;
183 
184 private:
185     WeakReference<Component> component;
186     ComponentBoundsConstrainer* constrainer;
187     BorderSize<int> borderSize;
188     Rectangle<int> originalBounds;
189     Zone mouseZone;
190 
191     void updateMouseZone (const MouseEvent&);
192 
193     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ResizableBorderComponent)
194 };
195 
196 } // namespace juce
197