HIThemeBrushCreateCGColor seems to have become very CPU-expensive, cache the results for better performance

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73208 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/utils_osx.cpp

@@ -245,11 +245,28 @@ CGColorSpaceRef wxMacGetGenericRGBColorSpace()
 #if wxOSX_USE_COCOA_OR_CARBON
 
 CGColorRef wxMacCreateCGColorFromHITheme( ThemeBrush brush )
+{
+    const int maxcachedbrush = 58+5; // negative indices are for metabrushes, cache down to -5)
+    int brushindex = brush+5;
+    if ( brushindex < 0 || brush > brushindex )
     {
         CGColorRef color ;
         HIThemeBrushCreateCGColor( brush, &color );
         return color;
     }
+    else
+    {
+        static bool inited = false;
+        static CGColorRef themecolors[maxcachedbrush+1];
+        if ( !inited )
+        {
+            for ( int i = 0 ; i <= maxcachedbrush ; ++i )
+                HIThemeBrushCreateCGColor( i-5, &themecolors[i] );
+            inited = true;
+        }
+        return CGColorRetain(themecolors[brushindex ]);
+    }
+}
 
 //---------------------------------------------------------------------------
 // Mac Specific string utility functions