Fixed generic art provider to scale bitmaps down to client-specific best size if needed.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@52561 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -125,6 +125,8 @@ All (GUI):
 - Added wxSizer::ComputeFittingClientSize() and ComputeFittingWindowSize().
 - Fixed wxSizer::SetSizeHints() to work when the best size decreases.
 - Fixed crash in wxHtmlHelpController if the help window is still open.
+- Fixed generic art provider to scale bitmaps down to client-specific
+  best size if needed.
 
 All (Unix):
 

src/common/artstd.cpp

@@ -235,14 +235,26 @@ wxBitmap wxDefaultArtProvider::CreateBitmap(const wxArtID& id,
             {
                 int bmp_w = bmp.GetWidth();
                 int bmp_h = bmp.GetHeight();
-                // want default size but it's smaller, paste into transparent image
+
                 if ((bmp_h < bestSize.x) && (bmp_w < bestSize.y))
                 {
+                    // the caller wants default size, which is larger than 
+                    // the image we have; to avoid degrading it visually by
+                    // scaling it up, paste it into transparent image instead:
                     wxPoint offset((bestSize.x - bmp_w)/2, (bestSize.y - bmp_h)/2);
                     wxImage img = bmp.ConvertToImage();
                     img.Resize(bestSize, offset);
                     bmp = wxBitmap(img);
                 }
+                else // scale (down or mixed, but not up)
+                {
+                    wxImage img = bmp.ConvertToImage();
+                    bmp = wxBitmap
+                          (
+                              img.Scale(bestSize.x, bestSize.y,
+                                        wxIMAGE_QUALITY_HIGH)
+                          );
+                }
             }
         }
     }