lcl: add overlay support to imagelist and treeview (based on patch of David Jenkins, issue #0021754)

git-svn-id: trunk@36805 -

lcl/imglist.pp

@@ -103,6 +103,7 @@ type
 
   TDrawingStyle = (dsFocus, dsSelected, dsNormal, dsTransparent);
   TImageType = (itImage, itMask);
+  TOverlay = 0..14; // windows limitation
 
   TCustomImageList = class(TLCLReferenceComponent)
   private
@@ -123,6 +124,7 @@ type
     FBkColor: TColor;
     FChanged: boolean;
     FUpdateCount: integer;
+    FOverlays: array[TOverlay] of Integer;
 
     procedure AllocData(ACount: Integer);
     function  GetReference: TWSCustomImageListReference;
@@ -146,6 +148,7 @@ type
     procedure Initialize; virtual;
     procedure DefineProperties(Filer: TFiler); override;
     procedure SetWidthHeight(NewWidth, NewHeight: integer); virtual;
+    procedure ClearOverlays;
 
     class procedure WSRegisterClass; override;
     function WSCreateReference(AParams: TCreateParams): PWSReference; override;
@@ -177,6 +180,10 @@ type
       AEnabled: Boolean = True); overload;
     procedure Draw(ACanvas: TCanvas; AX, AY, AIndex: Integer; ADrawingStyle: TDrawingStyle; AImageType: TImageType;
       ADrawEffect: TGraphicsDrawEffect); overload; virtual;
+    procedure DrawOverlay(ACanvas: TCanvas; AX, AY, AIndex: Integer; AOverlay: TOverlay; AEnabled: Boolean = True);
+    procedure DrawOverlay(ACanvas: TCanvas; AX, AY, AIndex: Integer; AOverlay: TOverlay; ADrawEffect: TGraphicsDrawEffect);
+    procedure DrawOverlay(ACanvas: TCanvas; AX, AY, AIndex: Integer; AOverlay: TOverlay; ADrawingStyle:
+      TDrawingStyle; AImageType: TImageType; ADrawEffect: TGraphicsDrawEffect); virtual;
     procedure FillDescription(out ADesc: TRawImageDescription);
 
     procedure GetBitmap(Index: Integer; Image: TCustomBitmap); overload;
@@ -193,6 +200,7 @@ type
     procedure InsertIcon(AIndex: Integer; AIcon: TCustomIcon);
     procedure InsertMasked(Index: Integer; AImage: TCustomBitmap; MaskColor: TColor);
     procedure Move(ACurIndex, ANewIndex: Integer);
+    procedure Overlay(AIndex: Integer; Overlay: TOverlay);
     procedure Replace(AIndex: Integer; AImage, AMask: TCustomBitmap);
     procedure ReplaceMasked(Index: Integer; NewImage: TCustomBitmap; MaskColor: TColor);
     procedure RegisterChanges(Value: TChangeLink);

lcl/include/imglist.inc

@@ -376,6 +376,7 @@ begin
   then TWSCustomImageListClass(WidgetSetClass).Clear(Self);
   SetLength(FData, 0);
   FAllocCount := 0;
+  ClearOverlays;
 
   FCount := 0;
   Change;
@@ -519,6 +520,38 @@ begin
                           BkColor, BlendColor, ADrawEffect, ADrawingStyle, AImageType);
 end;
 
+procedure TCustomImageList.DrawOverlay(ACanvas: TCanvas; AX, AY, AIndex: Integer;
+  AOverlay: TOverlay; AEnabled: Boolean = True);
+begin
+  DrawOverlay(ACanvas, AX, AY, AIndex, AOverlay, EffectMap[AEnabled]);
+end;
+
+procedure TCustomImageList.DrawOverlay(ACanvas: TCanvas; AX, AY, AIndex: Integer;
+  AOverlay: TOverlay; ADrawEffect: TGraphicsDrawEffect);
+begin
+  DrawOverlay(ACanvas, AX, AY, AIndex, AOverlay, DrawingStyle, ImageType, ADrawEffect);
+end;
+
+procedure TCustomImageList.DrawOverlay(ACanvas: TCanvas; AX, AY, AIndex: Integer;
+  AOverlay: TOverlay; ADrawingStyle: TDrawingStyle; AImageType: TImageType;
+  ADrawEffect: TGraphicsDrawEffect);
+var
+  OverlayIndex: Integer;
+begin
+  if (AIndex < 0) or (AIndex >= FCount) then Exit;
+
+  ReferenceNeeded;
+  TWSCustomImageListClass(WidgetSetClass).Draw(Self, AIndex, ACanvas, Rect(AX, AY, FWidth, FHeight),
+                          BkColor, BlendColor, ADrawEffect, ADrawingStyle, AImageType);
+
+  OverlayIndex := FOverlays[AOverlay];
+  if (OverlayIndex < 0) or (OverlayIndex >= FCount) then Exit;
+
+  TWSCustomImageListClass(WidgetSetClass).Draw(Self, OverlayIndex, ACanvas, Rect(AX, AY, FWidth, FHeight),
+                          clNone, BlendColor, ADrawEffect, ADrawingStyle, AImageType);
+end;
+
+
 {------------------------------------------------------------------------------
   Method:  TCustomImageList.EndUpdate
   Params:  none
@@ -738,6 +771,7 @@ begin
   FBlendColor := clNone;
   FBkColor := clNone;
   FDrawingStyle := dsNormal;
+  ClearOverlays;
 
   if (Height < 1) or (Height > 32768) or (Width < 1) 
   then raise EInvalidOperation.Create(SInvalidImageSize);
@@ -751,6 +785,14 @@ begin
   Clear;
 end;
 
+procedure TCustomImageList.ClearOverlays;
+var
+  I: TOverlay;
+begin
+  for I := Low(TOverlay) to High(TOverlay) do
+    FOverlays[I] := -1;
+end;
+
 class procedure TCustomImageList.WSRegisterClass;
 begin
   inherited WSRegisterClass;
@@ -1321,6 +1363,11 @@ begin
     {$ENDIF}
 end;
 
+procedure TCustomImageList.Overlay(AIndex: Integer; Overlay: TOverlay);
+begin
+  FOverlays[Overlay] := AIndex;
+end;
+
 {------------------------------------------------------------------------------
   Method:  TCustomImageList.RegisterChanges
   Params:  Value: a reference to changelink object

lcl/include/treeview.inc

@@ -4884,8 +4884,12 @@ begin
         ImgIndex := Node.SelectedIndex;
       end;
       if (ImgIndex >= 0) and (ImgIndex < Images.Count) then
-        Images.Draw(Canvas, x + 1, (NodeRect.Top + NodeRect.Bottom - Images.Height) div 2,
+      	if Node.OverlayIndex < 0 then
-            ImgIndex, Node.FNodeEffect);
+          Images.Draw(Canvas, x + 1, (NodeRect.Top + NodeRect.Bottom - Images.Height) div 2,
+             ImgIndex, Node.FNodeEffect)
+      	else
+          Images.DrawOverlay(Canvas, x + 1, (NodeRect.Top + NodeRect.Bottom - Images.Height) div 2,
+             ImgIndex, Node.OverlayIndex, Node.FNodeEffect);
       inc(x, Images.Width + 2);
     end;