From 1b7c01c976a2fd8a6ca3e46aab827dbc0b0e8da9 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Tue, 31 Oct 2006 14:43:04 +0000
Subject: [PATCH] fix wxBitmap mask copying

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42850 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 include/wx/msw/bitmap.h |  3 +++
 src/msw/bitmap.cpp      | 54 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/include/wx/msw/bitmap.h b/include/wx/msw/bitmap.h
index 4a02193bed..3d5fc34156 100644
--- a/include/wx/msw/bitmap.h
+++ b/include/wx/msw/bitmap.h
@@ -198,6 +198,9 @@ class WXDLLEXPORT wxMask : public wxObject
 public:
     wxMask();
 
+    // Copy constructor
+    wxMask(const wxMask &mask);
+
     // Construct a mask from a bitmap and a colour indicating the transparent
     // area
     wxMask(const wxBitmap& bitmap, const wxColour& colour);
diff --git a/src/msw/bitmap.cpp b/src/msw/bitmap.cpp
index f182df3c2a..20a2aa22b9 100644
--- a/src/msw/bitmap.cpp
+++ b/src/msw/bitmap.cpp
@@ -205,8 +205,13 @@ wxBitmapRefData::wxBitmapRefData(const wxBitmapRefData& data)
     m_selectedInto = NULL;
 #endif
 
-    // can't copy the mask as the other bitmap destroys it
+    // (deep) copy the mask if present
     m_bitmapMask = NULL;
+    if (data.m_bitmapMask)
+        m_bitmapMask = new wxMask(*data.m_bitmapMask);
+
+    // FIXME: we don't copy m_hBitmap currently but we should, see wxBitmap::
+    //        CloneRefData()
 
     wxASSERT_MSG( !data.m_isDIB,
                     _T("can't copy bitmap locked for raw access!") );
@@ -252,6 +257,10 @@ wxObjectRefData *wxBitmap::CloneRefData(const wxObjectRefData *dataOrig) const
     if ( !data )
         return NULL;
 
+    // FIXME: this method is backwards, it should just create a new
+    //        wxBitmapRefData using its copy ctor but instead it modifies this
+    //        bitmap itself and then returns its m_refData -- which works, of
+    //        course (except in !wxUSE_WXDIB), but is completely illogical
     wxBitmap *self = wx_const_cast(wxBitmap *, this);
 
 #if wxUSE_WXDIB
@@ -264,10 +273,19 @@ wxObjectRefData *wxBitmap::CloneRefData(const wxObjectRefData *dataOrig) const
     else
 #endif // wxUSE_WXDIB
     {
-        // don't copy the bitmap data, but do copy the size, depth, ...
+        // copy the bitmap data
         self->m_refData = new wxBitmapRefData(*data);
     }
 
+    // copy also the mask
+    wxMask * const maskSrc = data->GetMask();
+    if ( maskSrc )
+    {
+        wxBitmapRefData *selfdata = wx_static_cast(wxBitmapRefData *, m_refData);
+
+        selfdata->SetMask(new wxMask(*maskSrc));
+    }
+
     return m_refData;
 }
 
@@ -1327,6 +1345,38 @@ wxMask::wxMask()
     m_maskBitmap = 0;
 }
 
+// Copy constructor
+wxMask::wxMask(const wxMask &mask)
+{
+    BITMAP bmp;
+
+    HDC srcDC = CreateCompatibleDC(0);
+    HDC destDC = CreateCompatibleDC(0);
+
+    // GetBitmapDimensionEx won't work if SetBitmapDimensionEx wasn't used
+    // so we'll use GetObject() API here:
+    if (::GetObject((HGDIOBJ)mask.m_maskBitmap, sizeof(bmp), &bmp) == 0)
+    {
+        wxFAIL_MSG(wxT("Cannot retrieve the dimensions of the wxMask to copy"));
+        return;
+    }
+
+    // create our HBITMAP
+    int w = bmp.bmWidth, h = bmp.bmHeight;
+    m_maskBitmap = (WXHBITMAP)CreateCompatibleBitmap(srcDC, w, h);
+
+    // copy the mask's HBITMAP into our HBITMAP
+    SelectObject(srcDC, (HBITMAP) mask.m_maskBitmap);
+    SelectObject(destDC, (HBITMAP) m_maskBitmap);
+
+    BitBlt(destDC, 0, 0, w, h, srcDC, 0, 0, SRCCOPY);
+    
+    SelectObject(srcDC, 0);
+    DeleteDC(srcDC);
+    SelectObject(destDC, 0);
+    DeleteDC(destDC);
+}
+
 // Construct a mask from a bitmap and a colour indicating
 // the transparent area
 wxMask::wxMask(const wxBitmap& bitmap, const wxColour& colour)
-- 
2.45.2