unit ScrnCap;

interface

uses
  WinTypes, WinProcs, Forms, Classes, Graphics, Controls;

{ Копирует прямоугольную область экрана }
function CaptureScreenRect(ARect : TRect) : TBitmap;
{ Копирование всего экрана }
function CaptureScreen : TBitmap;
{ Копирование клиентской области формы или элемента }
function CaptureClientImage(Control : TControl) : TBitmap;
{ Копирование всей формы элемента }
function CaptureControlImage(Control : TControl) : TBitmap;

implementation

function GetSystemPalette : HPalette;
var
  PaletteSize : integer;
  LogSize : integer;
  LogPalette : PLogPalette;
  DC : HDC;
  Focus : HWND;
begin
  result:=0;
  Focus:=GetFocus;
  DC:=GetDC(Focus);
  try
    PaletteSize:=GetDeviceCaps(DC, SIZEPALETTE);
    LogSize:=SizeOf(TLogPalette)+(PaletteSize-1)*SizeOf(TPaletteEntry);
    GetMem(LogPalette, LogSize);
    try
      with LogPalette^ do
      begin
        palVersion:=$0300;
        palNumEntries:=PaletteSize;
        GetSystemPaletteEntries(DC, 0, PaletteSize, palPalEntry);
      end;
      result:=CreatePalette(LogPalette^);
    finally
      FreeMem(LogPalette, LogSize);
    end;
  finally
    ReleaseDC(Focus, DC);
  end;
end;


function CaptureScreenRect(ARect : TRect) : TBitmap;
var
  ScreenDC : HDC;
begin
  Result:=TBitmap.Create;
  with result, ARect do
  begin
    Width:=Right-Left;
    Height:=Bottom-Top;
    ScreenDC:=GetDC(0);
    try
      BitBlt(Canvas.Handle, 0,0,Width,Height,ScreenDC, Left, Top, SRCCOPY );
    finally
      ReleaseDC(0, ScreenDC);
    end;
    Palette:=GetSystemPalette;
  end;
end;

function CaptureScreen : TBitmap;
begin
  with Screen do
    Result:=CaptureScreenRect(Rect(0,0,Width,Height));
end;

function CaptureClientImage(Control : TControl) : TBitmap;
begin
  with Control, Control.ClientOrigin do
    result:=CaptureScreenRect(Bounds(X,Y,ClientWidth,ClientHeight));
end;

function CaptureControlImage(Control : TControl) : TBitmap;
begin
  with Control do
    if Parent=nil then
      result:=CaptureScreenRect(Bounds(Left,Top,Width,Height))
    else
      with Parent.ClientToScreen(Point(Left, Top)) do
        result:=CaptureScreenRect(Bounds(X,Y,Width,Height));
end;

end.