{******************************************************************}
{ ImgUtil.pas                                                      }
{                                                                  }
{ Author    : A.Nasir Senturk                                      }
{ Home Page : http://www.shenturk.com                              }
{ Email     : shenturk@gmail.com                                   }
{                                                                  }
{ Date      : 28.11.2006                                           }
{                                                                  }
{ Sizden iki şey rica edicem:                                      }
{ 1. Lutfen bu baslik kismini kaldirmayiniz.                       }
{ 2. Mumkunse bagis yapiniz.                                       }
{ *****************************************************************}

unit ImgUtil;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, GdipApi, GdipObj, DirectDraw, TextUtil, ExtCtrls;

type
  TGdiImage = class(TWinControl)
  private
    FCanvas: TGPGraphics;
    FBuffer: TGPBitmap;
    FBitmap: TGPBitmap;
    FOpacity: Byte;
    procedure AllocateHandle;
    procedure ReleaseHandle;
  protected
    procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
    procedure WMWindowPosChanging(var Message: TWMWindowPosChanging); message WM_WINDOWPOSCHANGING;
    procedure WMEraseBkgnd(var Message: TWmEraseBkgnd); message WM_ERASEBKGND;
    procedure CreateWnd; override;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Paint(Canvas: TGPGraphics); virtual;
    property Bitmap: TGPBitmap read FBitmap write FBitmap;
    property Opacity: Byte read FOpacity write FOpacity;
    property Color;
  end;

implementation

{ TGdiImage }

procedure TGdiImage.AllocateHandle;
begin
  FBuffer := TGPBitmap.Create(Width, Height, PixelFormat32bppARGB);
  FCanvas := TGPGraphics.Create(FBuffer);
end;

constructor TGdiImage.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  DoubleBuffered := True;
  ControlStyle := ControlStyle - [csOpaque] + [csParentBackground];
  FOpacity := 255;
end;

procedure TGdiImage.CreateWnd;
begin
  inherited CreateWnd;
  SetWindowLong(Parent.Handle, GWL_STYLE, GetWindowLong(Parent.Handle,
    GWL_STYLE) and not WS_CLIPCHILDREN);
end;

destructor TGdiImage.Destroy;
begin
  ReleaseHandle;
  inherited Destroy;
end;

procedure TGdiImage.Paint(Canvas: TGPGraphics);
var
  SolidBrush: TGPSolidBrush;
begin
  SolidBrush := TGPSolidBrush.Create(ColorRefToARGB(ColorToRGB(Color)));
  try
    Canvas.FillRectangle(SolidBrush, 0, 0, Width, Height);
    if Assigned(FBitmap) then
      DrawImageTo(Canvas, 0, 0, Width, Height, FBitmap, Opacity);
  finally
    SolidBrush.Free;
  end;
end;

procedure TGdiImage.ReleaseHandle;
begin
  FreeAndNil(FBuffer);
  FreeAndNil(FCanvas);
end;

procedure TGdiImage.WMEraseBkgnd(var Message: TWmEraseBkgnd);
begin

end;

procedure TGdiImage.WMPaint(var Message: TWMPaint);
var
  DC: HDC;
  PS: TPaintStruct;
  Graphics: TGPGraphics;
begin
  ReleaseHandle;
  AllocateHandle;
  DC := BeginPaint(Handle, PS);
  if DC = 0 then;
  Graphics := TGPGraphics.Create(Handle, False);
  //Graphics := TGPGraphics.Create(DC);
  try
    Paint(FCanvas);
    Graphics.DrawImage(FBuffer, 0, 0, FBuffer.GetWidth, FBuffer.GetHeight);
  finally
    Graphics.Free;
  end;
  EndPaint(Handle, PS);
  Message.Result := 0;
end;

procedure TGdiImage.WMWindowPosChanging(var Message: TWMWindowPosChanging);
var
  R : TRect;
begin
  R := ClientRect;
  InvalidateRect(Handle, @R, False);
end;

end.