Merge branch 'more-icon-fixes'

More icon fixes in wxMSW: fix transparency in wxImageList and size in
wxArtProvider.

See #22487.

src/common/artprov.cpp

@@ -304,6 +304,30 @@ void wxArtProvider::RescaleBitmap(wxBitmap& bmp, const wxSize& sizeNeeded)
 }
 #endif // WXWIN_COMPATIBILITY_3_0
 
+#if wxUSE_IMAGE
+
+namespace
+{
+
+bool CanUpscaleByInt(int w, int h, const wxSize& sizeNeeded)
+{
+    return !(sizeNeeded.x % w) && !(sizeNeeded.y % h);
+}
+
+void ExtendBitmap(wxBitmap& bmp, const wxSize& sizeNeeded)
+{
+    const wxSize size = bmp.GetSize();
+
+    wxPoint offset((sizeNeeded.x - size.x)/2, (sizeNeeded.y - size.y)/2);
+    wxImage img = bmp.ConvertToImage();
+    img.Resize(sizeNeeded, offset);
+    bmp = wxBitmap(img);
+}
+
+} // anonymous namespace
+
+#endif // wxUSE_IMAGE
+
 void
 wxArtProvider::RescaleOrResizeIfNeeded(wxBitmap& bmp, const wxSize& sizeNeeded)
 {
@@ -317,25 +341,42 @@ wxArtProvider::RescaleOrResizeIfNeeded(wxBitmap& bmp, const wxSize& sizeNeeded)
         return;
 
 #if wxUSE_IMAGE
-    // Allow upscaling by an integer factor: this looks not too horribly and is
-    // needed to use reasonably-sized bitmaps in the code not yet updated to
-    // use wxBitmapBundle but using custom art providers.
-    if ((bmp_w <= sizeNeeded.x) && (bmp_h <= sizeNeeded.y) &&
-            (sizeNeeded.x % bmp_w || sizeNeeded.y % bmp_h))
+    // Check if we need to increase or decrease the image size (mixed case is
+    // handled as decreasing).
+    if ((bmp_w <= sizeNeeded.x) && (bmp_h <= sizeNeeded.y))
     {
+        // Allow upscaling by an integer factor: this looks not too horribly and is
+        // needed to use reasonably-sized bitmaps in the code not yet updated to
+        // use wxBitmapBundle but using custom art providers.
+        bool shouldUpscale = CanUpscaleByInt(bmp_w, bmp_h, sizeNeeded);
+
+        // And account for the common case of 16x15 bitmaps used for many wxMSW
+        // images: those can be resized to 16x16 and then upscaled if possible
+        // (and if 16x16 is the required size, there is no need to upscale, so
+        // don't handle this sub-case specially at all).
+        if (!shouldUpscale && bmp_w == 16 && bmp_h == 15 && sizeNeeded.y != 16)
+        {
+            // If we can't upscale it with its current height, perhaps we can
+            // if we resize it to 16 first?
+            if (CanUpscaleByInt(bmp_w, 16, sizeNeeded))
+            {
+                ExtendBitmap(bmp, wxSize(16, 16));
+                shouldUpscale = true;
+            }
+        }
+
         // 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((sizeNeeded.x - bmp_w)/2, (sizeNeeded.y - bmp_h)/2);
-        wxImage img = bmp.ConvertToImage();
-        img.Resize(sizeNeeded, offset);
-        bmp = wxBitmap(img);
+        if (!shouldUpscale)
+        {
+            ExtendBitmap(bmp, sizeNeeded);
+            return;
+        }
     }
-    else // scale (down or mixed, but not up, or at least not by an int factor)
 #endif // wxUSE_IMAGE
-    {
-        wxBitmap::Rescale(bmp, sizeNeeded);
-    }
+
+    wxBitmap::Rescale(bmp, sizeNeeded);
 }
 
 /*static*/ wxBitmap wxArtProvider::GetBitmap(const wxArtID& id,

src/msw/imaglist.cpp

@@ -328,26 +328,11 @@ int wxImageList::Add(const wxBitmap& bitmap, const wxColour& maskColour)
 // Adds a bitmap and mask from an icon.
 int wxImageList::Add(const wxIcon& icon)
 {
-    // ComCtl32 prior 6.0 doesn't support images with alpha
-    // channel so if we have 32-bit icon with transparency
-    // we need to add it as a wxBitmap via dedicated method
-    // where alpha channel will be converted to the mask.
-    if ( wxApp::GetComCtl32Version() < 600 )
-    {
-        wxBitmap bmp(icon);
-        if ( bmp.HasAlpha() )
-        {
-            return Add(bmp);
-        }
-    }
-
-    int index = ImageList_AddIcon(GetHImageList(), GetHiconOf(icon));
-    if ( index == -1 )
-    {
-        wxLogError(_("Couldn't add an image to the image list."));
-    }
-
-    return index;
+    // We don't use ImageList_AddIcon() here as this only works for icons with
+    // masks when using ILC_MASK, which we usually don't do, so reuse the
+    // bitmap function instead -- even if it's slightly less efficient due to
+    // extra conversions, it's simpler than handling all the various cases here.
+    return Add(wxBitmap(icon));
 }
 
 // Replaces a bitmap, optionally passing a mask bitmap.
@@ -372,26 +357,9 @@ bool wxImageList::Replace(int index,
 // Replaces a bitmap and mask from an icon.
 bool wxImageList::Replace(int i, const wxIcon& icon)
 {
-    // ComCtl32 prior 6.0 doesn't support images with alpha
-    // channel so if we have 32-bit icon with transparency
-    // we need to replace it as a wxBitmap via dedicated method
-    // where alpha channel will be converted to the mask.
-    if ( wxApp::GetComCtl32Version() < 600 )
-    {
-        wxBitmap bmp(icon);
-        if ( bmp.HasAlpha() )
-        {
-            return Replace(i, bmp);
-        }
-    }
-
-    bool ok = ImageList_ReplaceIcon(GetHImageList(), i, GetHiconOf(icon)) != -1;
-    if ( !ok )
-    {
-        wxLogLastError(wxT("ImageList_ReplaceIcon()"));
-    }
-
-    return ok;
+    // Same as in Add() above, just reuse the existing function for simplicity
+    // even if it means an extra conversion.
+    return Replace(i, wxBitmap(icon));
 }
 
 // Removes the image at the given index.