LCL: Support for TImage.AntialiasingMode (stretching). Implement Win32 and GTK2. Issue #22205, patch from Chronos

git-svn-id: trunk@39894 -

lcl/extctrls.pp

@@ -464,6 +464,7 @@ type
 
   TCustomImage = class(TGraphicControl)
   private
+    FAntialiasingMode: TAntialiasingMode;
     FOnPictureChanged: TNotifyEvent;
     FPicture: TPicture;
     FCenter: Boolean;
@@ -472,6 +473,7 @@ type
     FStretch: Boolean;
     FUseAncestorCanvas: boolean;
     function  GetCanvas: TCanvas;
+    procedure SetAntialiasingMode(AValue: TAntialiasingMode);
     procedure SetPicture(const AValue: TPicture);
     procedure SetCenter(const AValue : Boolean);
     procedure SetProportional(const AValue: Boolean);
@@ -491,6 +493,7 @@ type
     property Canvas: TCanvas read GetCanvas;
     function DestRect: TRect; virtual;
   public
+    property AntialiasingMode: TAntialiasingMode read FAntialiasingMode write SetAntialiasingMode default amDontCare;
     property Align;
     property AutoSize;
     property Center: Boolean read FCenter write SetCenter default False;
@@ -512,6 +515,7 @@ type
 
   TImage = class(TCustomImage)
   published
+    property AntialiasingMode;
     property Align;
     property Anchors;
     property AutoSize;

lcl/include/customimage.inc

@@ -65,6 +65,13 @@ begin
     Result := inherited Canvas;
 end;
 
+procedure TCustomImage.SetAntialiasingMode(AValue: TAntialiasingMode);
+begin
+  if FAntialiasingMode = AValue then Exit;
+  FAntialiasingMode := AValue;
+  PictureChanged(Self);
+end;
+
 procedure TCustomImage.SetPicture(const AValue: TPicture);
 begin
   if FPicture=AValue then exit;
@@ -206,6 +213,7 @@ begin
 
   C := inherited Canvas;
   R := DestRect;
+  C.AntialiasingMode := FAntialiasingMode;
   C.StretchDraw(R, Picture.Graphic);
 
   FUseAncestorCanvas := True;

lcl/interfaces/gtk2/gtk2def.pp

@@ -345,6 +345,7 @@ type
     DCTextMetric: TDevContextTextMetric; // only valid if dcfTextMetricsValid set
     PaintRectangle: TRect;// set during paint, BeginPaint/EndPaint
     SavedContext: TGtkDeviceContext; // linked list of saved DCs
+    Antialiasing: Boolean;
 
     constructor Create; virtual;
     procedure CreateGDIObject(AGDIType: TGDIType);

lcl/interfaces/gtk2/gtk2int.pas

@@ -251,6 +251,7 @@ type
     procedure AddDummyNoteBookPage(NoteBookWidget: PGtkNoteBook);
     {$ENDIF}
 
+    procedure DCSetAntialiasing(CanvasHandle: HDC; AEnabled: Boolean); override;
     function  DCGetPixel(CanvasHandle: HDC; X, Y: integer): TGraphicsColor; override;
     procedure DCSetPixel(CanvasHandle: HDC; X, Y: integer; AColor: TGraphicsColor); override;
     procedure DCRedraw(CanvasHandle: HDC); override;

lcl/interfaces/gtk2/gtk2widgetset.inc

@@ -3720,7 +3720,10 @@ var
       else
         if ShrinkWidth or ShrinkHeight
         then ScaleMethod := GDK_INTERP_BILINEAR//GDK_INTERP_HYPER
-        else ScaleMethod := GDK_INTERP_BILINEAR;
+        else begin
+          if DstDevContext.Antialiasing then ScaleMethod := GDK_INTERP_BILINEAR
+            else ScaleMethod := GDK_INTERP_NEAREST;
+        end;
 
       // Scale the src part to a temporary pixmap with the size of the
       // destination rectangle
@@ -5224,6 +5227,21 @@ begin
 end;
 
 
+procedure TGtk2WidgetSet.DCSetAntialiasing(CanvasHandle: HDC; AEnabled: Boolean
+  );
+var
+  DC: TGtk2DeviceContext;
+begin
+  if IsValidDC(CanvasHandle) then
+  begin
+    //if CanvasHandle = 1 then
+      //DC := Gtk2DefaultContext
+    //else
+      DC := TGtk2DeviceContext(CanvasHandle);
+    DC.Antialiasing := AEnabled;
+  end;
+end;
+
 
 {------------------------------------------------------------------------------
   Function: NewDC

lcl/interfaces/win32/win32int.pp

@@ -161,6 +161,7 @@ type
     { Destructor of the class }
     destructor Destroy; override;
 
+    procedure DCSetAntialiasing(CanvasHandle: HDC; AEnabled: Boolean); override;
     function LCLPlatform: TLCLPlatform; override;
     function GetLCLCapability(ACapability: TLCLCapability): PtrUInt; override;
 

lcl/interfaces/win32/win32object.inc

@@ -105,6 +105,12 @@ begin
   inherited Destroy;
 end;
 
+procedure TWin32WidgetSet.DCSetAntialiasing(CanvasHandle: HDC; AEnabled: Boolean);
+begin
+  if AEnabled then SetStretchBltMode(CanvasHandle, HALFTONE)
+    else SetStretchBltMode(CanvasHandle, COLORONCOLOR);
+end;
+
 {------------------------------------------------------------------------------
   Method: TWin32WidgetSet.AppInit
   Params:  None

lcl/interfaces/win32/win32winapi.inc

@@ -3567,7 +3567,6 @@ begin
     Blend.AlphaFormat := AC_SRC_ALPHA;
   end;
 
-  Windows.SetStretchBltMode(DestDC, STRETCH_HALFTONE);
   Windows.SetBrushOrgEx(DestDC, 0, 0, nil);
   if Mask = 0 then
   begin