Bug 1529: Toolbar icons are broken with Windows high contrast themes

https://winscp.net/tracker/1529

Source commit: ebe3c5e6a71bbb845c5555efe98dbac38ce8428f

source/packages/tbx/TBXOfficeXPTheme.pas

@@ -782,8 +782,6 @@ begin
     end;
 
 {$IFNDEF ALTERNATIVE_DISABLED_STYLE}
-    HiContrast := IsDarkColor(GetItemImageBackground(ItemInfo), 64);
-
     if not Enabled then
     begin
       DrawTBXIconFlatShadow(Canvas, ARect, ImageList, ImageIndex,
@@ -797,16 +795,16 @@ begin
         DrawTBXIconFullShadow(Canvas, ARect, ImageList, ImageIndex, IconShadowColor);
         OffsetRect(ARect, -2, -2);
       end;
-      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex, HiContrast);
+      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex);
     end
-    else if HiContrast or TBXHiContrast or TBXLoColor then
-      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex, HiContrast)
+    else if TBXLoColor then
+      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex)
     else
       HighlightTBXIcon(Canvas, ARect, ImageList, ImageIndex, clWindow, 178);
 {$ELSE}
-    HiContrast := ColorIntensity(GetItemImageBackground(ItemInfo)) < 80;
     if not Enabled then
     begin
+      HiContrast := ColorIntensity(GetItemImageBackground(ItemInfo)) < 80;
       if not HiContrast then
         DrawTBXIconShadow(Canvas, ARect, ImageList, ImageIndex, 0)
       else
@@ -821,13 +819,13 @@ begin
         DrawTBXIconShadow(Canvas, ARect, ImageList, ImageIndex, 1);
         OffsetRect(ARect, -2, -2);
       end;
-      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex, HiContrast);
+      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex);
     end
       else
 {$IFNDEF NO_IMAGE_DIMMING}
-    if HiContrast or TBXHiContrast or TBXLoColor then
+    if TBXLoColor then
 {$ENDIF}
-      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex, HiContrast)
+      DrawTBXIcon(Canvas, ARect, ImageList, ImageIndex)
 {$IFNDEF NO_IMAGE_DIMMING}
     else
       HighlightTBXIcon(Canvas, ARect, ImageList, ImageIndex, clWindow, 178)

source/packages/tbx/TBXThemes.pas

@@ -377,8 +377,6 @@ var
 
   { Auxiliary flags corresponding to the system color scheme }
   TBXLoColor: Boolean;
-  TBXHiContrast: Boolean; // this can me removed in future
-  TBXNoBlending: Boolean; // TBXNoColor or TBXHiContrast
 
 var
   USE_FLATMENUS: Boolean;
@@ -729,8 +727,6 @@ begin
   DC := GetDC(0);
   try
     TBXLoColor := GetDeviceCaps(DC, BITSPIXEL) * GetDeviceCaps(DC, PLANES) < 12;
-    TBXHiContrast := GetSysColor(COLOR_BTNFACE) = $00FFFFFF;
-    TBXNoBlending := TBXLoColor or TBXHiContrast;
   finally
     ReleaseDC(0, DC);
   end;

source/packages/tbx/TBXUtils.pas

@@ -84,7 +84,7 @@ procedure MoveLongword(const Source; var Dest; Count: Integer);
 
 { extended icon painting routines }
 procedure DrawTBXIcon(Canvas: TCanvas; const R: TRect;
-  ImageList: TCustomImageList; ImageIndex: Integer; HiContrast: Boolean);
+  ImageList: TCustomImageList; ImageIndex: Integer);
 procedure BlendTBXIcon(Canvas: TCanvas; const R: TRect;
   ImageList: TCustomImageList; ImageIndex: Integer; Opacity: Byte);
 procedure HighlightTBXIcon(Canvas: TCanvas; const R: TRect;
@@ -1002,66 +1002,9 @@ asm
 end;
 
 procedure DrawTBXIcon(Canvas: TCanvas; const R: TRect;
-  ImageList: TCustomImageList; ImageIndex: Integer; HiContrast: Boolean);
-{const
-  CWeirdColor = $00203241;} {vb -}
-var
-  ImageWidth, ImageHeight: Integer;
-  I, J: Integer;
-  Src, Dst: PColor;
-  S, C: TColor;
+  ImageList: TCustomImageList; ImageIndex: Integer);
 begin
-  if not HiContrast then
-  begin
-    ImageList.Draw(Canvas, R.Left, R.Top, ImageIndex);
-    Exit;
-  end;
-  ImageWidth := R.Right - R.Left;
-  ImageHeight := R.Bottom - R.Top;
-  with ImageList do
-  begin
-    if Width < ImageWidth then ImageWidth := Width;
-    if Height < ImageHeight then ImageHeight :=  Height;
-  end;
-
-  StockBitmap1.Width := ImageWidth;
-  StockBitmap1.Height := ImageHeight;
-  StockBitmap2.Width := ImageWidth;
-  StockBitmap2.Height := ImageHeight;
-
-  BitBlt(StockBitmap1.Canvas.Handle, 0, 0, ImageWidth, ImageHeight,
-    Canvas.Handle, R.Left, R.Top, SRCCOPY);
-  {for J := 0 to ImageHeight - 1 do
-    FillLongWord(StockBitmap2.ScanLine[J]^, ImageWidth, CWeirdColor);} {vb -}
-  BitBlt(StockBitmap2.Canvas.Handle, 0, 0, ImageWidth, ImageHeight,
-    Canvas.Handle, R.Left, R.Top, SRCCOPY); {vb +}
-  ImageList.Draw(StockBitmap2.Canvas, 0, 0, ImageIndex);
-
-  for J := 0 to ImageHeight - 1 do
-  begin
-    Src := StockBitmap2.ScanLine[J];
-    Dst := StockBitmap1.ScanLine[J];
-    for I := 0 to ImageWidth - 1 do
-    begin
-      {S := Src^ and $00FFFFFF;} {vb -}
-      S := Src^; {vb +}
-      {if S <> CWeirdColor then} {vb -}
-      if S <> Dst^ then {vb +}
-      begin
-        {C := (S and $FF0000) shr 16 * 76 + (S and $00FF00) shr 8 * 150 +
-          (S and $0000FF) * 29;} {vb -}
-        C := (S and $00FF0000) shr 16 * 76 + (S and $0000FF00) shr 8 * 150 +
-          (S and $000000FF) * 29; {vb +}
-        if C > $FD00 then S := $000000
-        else if C < $6400 then S := $FFFFFF;
-        Dst^ := Lighten(S, 32);
-      end;
-      Inc(Src);
-      Inc(Dst);
-    end;
-  end;
-  BitBlt(Canvas.Handle, R.Left, R.Top, ImageWidth, ImageHeight,
-    StockBitmap1.Canvas.Handle, 0, 0, SRCCOPY);
+  ImageList.Draw(Canvas, R.Left, R.Top, ImageIndex);
 end;
 
 procedure BlendTBXIcon(Canvas: TCanvas; const R: TRect;