src/msw/imaglist.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        src/msw/imaglist.cpp
// Purpose:     wxImageList implementation for Win32
// Author:      Julian Smart
// Modified by:
// Created:     04/01/98
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#ifndef WX_PRECOMP
    #include "wx/app.h"
    #include "wx/msw/wrapcctl.h" // include <commctrl.h> "properly"
    #include "wx/window.h"
    #include "wx/icon.h"
    #include "wx/dc.h"
    #include "wx/string.h"
    #include "wx/dcmemory.h"
    #include "wx/intl.h"
    #include "wx/log.h"
    #include "wx/image.h"
    #include <stdio.h>
#endif

#include "wx/imaglist.h"
#include "wx/dc.h"
#include "wx/msw/dc.h"
#include "wx/msw/dib.h"
#include "wx/msw/private.h"

// ----------------------------------------------------------------------------
// wxWin macros
// ----------------------------------------------------------------------------

IMPLEMENT_DYNAMIC_CLASS(wxImageList, wxObject)

#define GetHImageList()     ((HIMAGELIST)m_hImageList)

// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------

// returns the mask if it's valid, otherwise the bitmap mask and, if it's not
// valid neither, a "solid" mask (no transparent zones at all)
static HBITMAP GetMaskForImage(const wxBitmap& bitmap, const wxBitmap& mask);

// ============================================================================
// implementation
// ============================================================================

// ----------------------------------------------------------------------------
// wxImageList creation/destruction
// ----------------------------------------------------------------------------

wxImageList::wxImageList()
{
    m_hImageList = 0;
}

// Creates an image list
bool wxImageList::Create(int width, int height, bool mask, int initial)
{
    UINT flags = 0;

    // as we want to be able to use 32bpp bitmaps in the image lists, we always
    // use ILC_COLOR32, even if the display resolution is less -- the system
    // will make the best effort to show the bitmap if we do this resulting in
    // quite acceptable display while using a lower depth ILC_COLOR constant
    // (e.g. ILC_COLOR16) shows completely broken bitmaps
#ifdef __WXWINCE__
    flags |= ILC_COLOR;
#else
    flags |= ILC_COLOR32;
#endif

    // For comctl32.dll < 6 always use masks as it doesn't support alpha.
    if ( mask || wxApp::GetComCtl32Version() < 600 )
        flags |= ILC_MASK;

    // Grow by 1, I guess this is reasonable behaviour most of the time
    m_hImageList = (WXHIMAGELIST) ImageList_Create(width, height, flags,
                                                   initial, 1);
    if ( !m_hImageList )
    {
        wxLogLastError(wxT("ImageList_Create()"));
    }

    return m_hImageList != 0;
}

wxImageList::~wxImageList()
{
    if ( m_hImageList )
    {
        ImageList_Destroy(GetHImageList());
        m_hImageList = 0;
    }
}

// ----------------------------------------------------------------------------
// wxImageList attributes
// ----------------------------------------------------------------------------

// Returns the number of images in the image list.
int wxImageList::GetImageCount() const
{
    wxASSERT_MSG( m_hImageList, wxT("invalid image list") );

    return ImageList_GetImageCount(GetHImageList());
}

// Returns the size (same for all images) of the images in the list
bool wxImageList::GetSize(int WXUNUSED(index), int &width, int &height) const
{
    wxASSERT_MSG( m_hImageList, wxT("invalid image list") );

    return ImageList_GetIconSize(GetHImageList(), &width, &height) != 0;
}

// ----------------------------------------------------------------------------
// wxImageList operations
// ----------------------------------------------------------------------------

// Adds a bitmap, and optionally a mask bitmap.
// Note that wxImageList creates new bitmaps, so you may delete
// 'bitmap' and 'mask'.
int wxImageList::Add(const wxBitmap& bitmap, const wxBitmap& mask)
{
    HBITMAP hbmp;
    bool useMask;

#if wxUSE_WXDIB && wxUSE_IMAGE
    // wxBitmap normally stores alpha in pre-multiplied format but
    // ImageList_Draw() does pre-multiplication internally so we need to undo
    // the pre-multiplication here. Converting back and forth like this is, of
    // course, very inefficient but it's better than wrong appearance so we do
    // this for now until a better way can be found.
    AutoHBITMAP hbmpRelease;
    if ( bitmap.HasAlpha() )
    {
        wxImage img = bitmap.ConvertToImage();

        // For comctl32.dll < 6 remove alpha channel from image
        // to prevent possible interferences with the mask.
        if ( wxApp::GetComCtl32Version() < 600 )
        {
            img.ClearAlpha();
            useMask = true;
        }
        else
        {
            useMask = false;
        }

        hbmp = wxDIB(img, wxDIB::PixelFormat_NotPreMultiplied).Detach();
        hbmpRelease.Init(hbmp);
    }
    else
#endif // wxUSE_WXDIB && wxUSE_IMAGE
    {
        hbmp = GetHbitmapOf(bitmap);
        useMask = true;
    }

    // Use mask only if we don't have alpha, the bitmap isn't drawn correctly
    // if we use both.
    AutoHBITMAP hbmpMask;
    if ( useMask )
        hbmpMask.Init(GetMaskForImage(bitmap, mask));

    int index = ImageList_Add(GetHImageList(), hbmp, hbmpMask);
    if ( index == -1 )
    {
        wxLogError(_("Couldn't add an image to the image list."));
    }

    return index;
}

// Adds a bitmap, using the specified colour to create the mask bitmap
// Note that wxImageList creates new bitmaps, so you may delete
// 'bitmap'.
int wxImageList::Add(const wxBitmap& bitmap, const wxColour& maskColour)
{
    HBITMAP hbmp;

#if wxUSE_WXDIB && wxUSE_IMAGE
    // See the comment in overloaded Add() above.
    AutoHBITMAP hbmpRelease;
    if ( bitmap.HasAlpha() )
    {
        wxImage img = bitmap.ConvertToImage();

        if ( wxApp::GetComCtl32Version() < 600 )
        {
            img.ClearAlpha();
        }

        hbmp = wxDIB(img, wxDIB::PixelFormat_NotPreMultiplied).Detach();
        hbmpRelease.Init(hbmp);
    }
    else
#endif // wxUSE_WXDIB && wxUSE_IMAGE
        hbmp = GetHbitmapOf(bitmap);

    int index = ImageList_AddMasked(GetHImageList(),
                                    hbmp,
                                    wxColourToRGB(maskColour));
    if ( index == -1 )
    {
        wxLogError(_("Couldn't add an image to the image list."));
    }

    return index;
}

// Adds a bitmap and mask from an icon.
int wxImageList::Add(const wxIcon& icon)
{
    int index = ImageList_AddIcon(GetHImageList(), GetHiconOf(icon));
    if ( index == -1 )
    {
        wxLogError(_("Couldn't add an image to the image list."));
    }

    return index;
}

// Replaces a bitmap, optionally passing a mask bitmap.
// Note that wxImageList creates new bitmaps, so you may delete
// 'bitmap' and 'mask'.
bool wxImageList::Replace(int index,
                          const wxBitmap& bitmap,
                          const wxBitmap& mask)
{
    HBITMAP hbmp;
    bool useMask;

#if wxUSE_WXDIB && wxUSE_IMAGE
    // See the comment in Add() above.
    AutoHBITMAP hbmpRelease;
    if ( bitmap.HasAlpha() )
    {
        wxImage img = bitmap.ConvertToImage();

        if ( wxApp::GetComCtl32Version() < 600 )
        {
            img.ClearAlpha();
            useMask = true;
        }
        else
        {
            useMask = false;
        }

        hbmp = wxDIB(img, wxDIB::PixelFormat_NotPreMultiplied).Detach();
        hbmpRelease.Init(hbmp);
    }
    else
#endif // wxUSE_WXDIB && wxUSE_IMAGE
    {
        hbmp = GetHbitmapOf(bitmap);
        useMask = true;
    }

    AutoHBITMAP hbmpMask;
    if ( useMask )
        hbmpMask.Init(GetMaskForImage(bitmap, mask));

    if ( !ImageList_Replace(GetHImageList(), index, hbmp, hbmpMask) )
    {
        wxLogLastError(wxT("ImageList_Replace()"));
        return false;
    }

    return true;
}

// Replaces a bitmap and mask from an icon.
bool wxImageList::Replace(int i, const wxIcon& icon)
{
    bool ok = ImageList_ReplaceIcon(GetHImageList(), i, GetHiconOf(icon)) != -1;
    if ( !ok )
    {
        wxLogLastError(wxT("ImageList_ReplaceIcon()"));
    }

    return ok;
}

// Removes the image at the given index.
bool wxImageList::Remove(int index)
{
    bool ok = ImageList_Remove(GetHImageList(), index) != 0;
    if ( !ok )
    {
        wxLogLastError(wxT("ImageList_Remove()"));
    }

    return ok;
}

// Remove all images
bool wxImageList::RemoveAll()
{
    // don't use ImageList_RemoveAll() because mingw32 headers don't have it
    return Remove(-1);
}

// Draws the given image on a dc at the specified position.
// If 'solidBackground' is true, Draw sets the image list background
// colour to the background colour of the wxDC, to speed up
// drawing by eliminating masked drawing where possible.
bool wxImageList::Draw(int index,
                       wxDC& dc,
                       int x, int y,
                       int flags,
                       bool solidBackground)
{
    wxDCImpl *impl = dc.GetImpl();
    wxMSWDCImpl *msw_impl = wxDynamicCast( impl, wxMSWDCImpl );
    if (!msw_impl)
       return false;

    HDC hDC = GetHdcOf(*msw_impl);
    wxCHECK_MSG( hDC, false, wxT("invalid wxDC in wxImageList::Draw") );

    COLORREF clr = CLR_NONE;    // transparent by default
    if ( solidBackground )
    {
        const wxBrush& brush = dc.GetBackground();
        if ( brush.IsOk() )
        {
            clr = wxColourToRGB(brush.GetColour());
        }
    }

    ImageList_SetBkColor(GetHImageList(), clr);

    UINT style = 0;
    if ( flags & wxIMAGELIST_DRAW_NORMAL )
        style |= ILD_NORMAL;
    if ( flags & wxIMAGELIST_DRAW_TRANSPARENT )
        style |= ILD_TRANSPARENT;
    if ( flags & wxIMAGELIST_DRAW_SELECTED )
        style |= ILD_SELECTED;
    if ( flags & wxIMAGELIST_DRAW_FOCUSED )
        style |= ILD_FOCUS;

    bool ok = ImageList_Draw(GetHImageList(), index, hDC, x, y, style) != 0;
    if ( !ok )
    {
        wxLogLastError(wxT("ImageList_Draw()"));
    }

    return ok;
}

// Get the bitmap
wxBitmap wxImageList::GetBitmap(int index) const
{
    int bmp_width = 0, bmp_height = 0;
    GetSize(index, bmp_width, bmp_height);

    wxBitmap bitmap(bmp_width, bmp_height);
    wxMemoryDC dc;
    dc.SelectObject(bitmap);

#if wxUSE_WXDIB && wxUSE_IMAGE
    IMAGEINFO ii;
    ImageList_GetImageInfo(GetHImageList(), index, &ii);
    if ( ii.hbmMask )
    {
        // draw it the first time to find a suitable mask colour
        ((wxImageList*)this)->Draw(index, dc, 0, 0, wxIMAGELIST_DRAW_TRANSPARENT);
        dc.SelectObject(wxNullBitmap);

        // find the suitable mask colour
        wxImage image = bitmap.ConvertToImage();
        unsigned char r = 0, g = 0, b = 0;
        image.FindFirstUnusedColour(&r, &g, &b);

        // redraw whole image and bitmap in the mask colour
        image.Create(bmp_width, bmp_height);
        image.Replace(0, 0, 0, r, g, b);
        bitmap = wxBitmap(image);

        // redraw icon over the mask colour to actually draw it
        dc.SelectObject(bitmap);
        ((wxImageList*)this)->Draw(index, dc, 0, 0, wxIMAGELIST_DRAW_TRANSPARENT);
        dc.SelectObject(wxNullBitmap);

        // get the image, set the mask colour and convert back to get transparent bitmap
        image = bitmap.ConvertToImage();
        image.SetMaskColour(r, g, b);
        bitmap = wxBitmap(image);
    }
    else // no mask
    {
        // Just draw it normally.
        ((wxImageList*)this)->Draw(index, dc, 0, 0, wxIMAGELIST_DRAW_NORMAL);
        dc.SelectObject(wxNullBitmap);

        // And adjust its alpha flag as the destination bitmap would get it if
        // the source one had it.
        //
        // Note that perhaps we could just call UseAlpha() which would set the
        // "has alpha" flag unconditionally as it doesn't seem to do any harm,
        // but for now only do it if necessary, just to be on the safe side,
        // even if it requires more work (and takes more time).
        bitmap.MSWUpdateAlpha();
    }
#else
    wxBitmap bitmap;
#endif
    return bitmap;
}

// Get the icon
wxIcon wxImageList::GetIcon(int index) const
{
    HICON hIcon = ImageList_ExtractIcon(0, GetHImageList(), index);
    if (hIcon)
    {
        wxIcon icon;
        icon.SetHICON((WXHICON)hIcon);

        int iconW, iconH;
        GetSize(index, iconW, iconH);
        icon.SetSize(iconW, iconH);

        return icon;
    }
    else
        return wxNullIcon;
}

// ----------------------------------------------------------------------------
// helpers
// ----------------------------------------------------------------------------

static HBITMAP GetMaskForImage(const wxBitmap& bitmap, const wxBitmap& mask)
{
#if wxUSE_IMAGE
    wxBitmap bitmapWithMask;
#endif // wxUSE_IMAGE

    HBITMAP hbmpMask;
    wxMask *pMask;
    bool deleteMask = false;

    if ( mask.IsOk() )
    {
        hbmpMask = GetHbitmapOf(mask);
        pMask = NULL;
    }
    else
    {
        pMask = bitmap.GetMask();

#if wxUSE_IMAGE
        // check if we don't have alpha in this bitmap -- we can create a mask
        // from it (and we need to do it for the older systems which don't
        // support 32bpp bitmaps natively)
        if ( !pMask )
        {
            wxImage img(bitmap.ConvertToImage());
            if ( img.HasAlpha() )
            {
                img.ConvertAlphaToMask();
                bitmapWithMask = wxBitmap(img);
                pMask = bitmapWithMask.GetMask();
            }
        }
#endif // wxUSE_IMAGE

        if ( !pMask )
        {
            // use the light grey count as transparent: the trouble here is
            // that the light grey might have been changed by Windows behind
            // our back, so use the standard colour map to get its real value
            wxCOLORMAP *cmap = wxGetStdColourMap();
            wxColour col;
            wxRGBToColour(col, cmap[wxSTD_COL_BTNFACE].from);

            pMask = new wxMask(bitmap, col);

            deleteMask = true;
        }

        hbmpMask = (HBITMAP)pMask->GetMaskBitmap();
    }

    // windows mask convention is opposite to the wxWidgets one
    HBITMAP hbmpMaskInv = wxInvertMask(hbmpMask);

    if ( deleteMask )
    {
        delete pMask;
    }

    return hbmpMaskInv;
}