Restrict drawing on a canvas into a rectangle?

Hi,
here an example of reading .lnk files:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls,shlobj,activex,comobj,commctrl,menus;

type
  TForm1 = class(TForm)
    Button1: TButton;
    OpenDialog1: TOpenDialog;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }

  public
    { Public declarations }
  end;

var
  Form1: TForm1;
   NeedToUninitialize : boolean = false;
implementation

{$R *.DFM}

function LoadShellLink(shellLinkFile: string;
                       var description, linkedObj, params: string;
                       var pidl: PItemIDList; var findData: TWin32FindData;
                       var iconPath: string; var iconIndex: integer;
                       var workingDir, hotKey: string;
                       var showCmd: integer) : boolean;
var sl  : IShellLink;
    w1  : word;
    s1  : string;
    wfd : TWin32FindData;
    i1  : integer;
begin
  NeedToUninitialize:=NeedToUninitialize or succeeded(CoInitialize(nil));
  sl:=CreateComObject(CLSID_ShellLink) as IShellLink;
  result:=(sl as IPersistFile).Load(PWideChar(wideString(ShellLinkFile)),0)=S_OK;
  if not result then exit;
  SetLength(description,MAX_PATH+1);
  if sl.GetDescription(PChar(description),MAX_PATH)=NOERROR then description:=string(PChar(description))
  else                                                           description:='';
  SetLength(s1,MAX_PATH+1);
  if sl.GetPath(PChar(s1),MAX_PATH,wfd,0)=NOERROR then begin
    linkedObj:=string(PChar(s1));
    findData :=wfd;
  end else begin
    linkedObj:='';
    ZeroMemory(@findData,sizeOf(TWin32FindData));
  end;
  SetLength(params,MAX_PATH+1);
  if sl.GetArguments(PChar(params),MAX_PATH)=NOERROR then params:=string(PChar(params))
  else                                                    params:='';
  if sl.GetIDList(pidl)<>NOERROR then pidl:=nil;
  SetLength(s1,MAX_PATH+1);
  if sl.GetIconLocation(pchar(s1),MAX_PATH,i1)=NOERROR then begin
    iconPath :=string(pchar(s1));
    iconIndex:=i1;
  end else begin
    iconPath :='';
    iconIndex:=-1;
  end;
  SetLength(workingDir,MAX_PATH+1);
  if sl.GetWorkingDirectory(PChar(workingDir),MAX_PATH)=NOERROR then workingDir:=string(PChar(workingDir))
  else                                                               workingDir:='';
  sl.GetHotKey(w1);
  if w1 and (HOTKEYF_ALT     shl 8)<>0 then w1:=(w1 and (not (HOTKEYF_ALT     shl 8))) or scAlt;
  if w1 and (HOTKEYF_CONTROL shl 8)<>0 then w1:=(w1 and (not (HOTKEYF_CONTROL shl 8))) or scCtrl;
  if w1 and (HOTKEYF_SHIFT   shl 8)<>0 then w1:=(w1 and (not (HOTKEYF_SHIFT   shl 8))) or scShift;
  hotKey:=ShortCutToText(w1);
  if sl.GetShowCmd(showCmd)<>NOERROR then showCmd:=-1;
end;

procedure FreePidl(var pidl: PItemIDList);
var malloc : IMalloc;
begin
  if (pidl<>nil) and (SHGetMalloc(malloc)=NOERROR) then begin
    malloc.Free(pidl);
    pidl:=nil;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  pi:PItemIDList;
  s1,Desc,s2:String;
  icon,workdir,htkey:string;
  Data: TWin32FindData;
  i,ii : integer;
begin
  opendialog1.execute;
  loadshelllink(opendialog1.filename,desc,s1,s2,pi,Data,icon,i,workdir,htkey,ii);
  ShowMessage('File ShortCut : '+opendialog1.filename+#13#10+'File TruePath : '+s1+#13#10+'Working Dir : '+workdir+#13#10
              +'HotKey : '+htkey+#13#10+'Show Command : '+inttostr(ii));
 FreePidl(pi);
end;


initialization
finalization
  if NeedToUninitialize then CoUninitialize;

end.


Regards Barry

opps silly me ,im sorry i pasted in wrong question :-)

For TPrinter :

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Image1: TImage;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
uses printers;
{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
  Var Region, OldRegion : HRgn;
      DC        : HDC;

begin
  Printer.BeginDoc;
  DC:=Printer.Canvas.Handle;
  Region:=CreateRectRgn(10,10,50,50);
  GetClipRgn(DC,OldRegion);
  SelectClipRgn(DC,Region);
  DeleteObject(Region);
  with Printer do
  begin
    Canvas.Pen.Color := Random(65535);
    Canvas.Pen.Style := psSolid;
    Canvas.Rectangle(5, 5, 20,20);
  end;
  Printer.EndDoc;
  SelectClipRgn(DC,OldRegion);
end;

end.

What you see printed is just the right-bottom corner of the rectangle. The rest is clipped.


Regards, Zif.