Using a PanWindow (Delphi 6.0)

1.

Start with the project that you created in Loading and Displaying an Image.

2.

Replace the FormCreate Procedure with the following:

procedure TForm1.FormCreate(Sender: TObject); 
begin
     //Set defaults for displaying the image. 
     //These are all persistent properties that can be set in the properties box. 
     LEADRasterView1.Appearance:= RASTERVIEW_APPEARANCE_FLAT; 
     LEADRasterView1.BorderStyle := 1; 
     LEADRasterView1.BackColor := RGB(255, 255, 125); 
     LEADRasterView1.PaintDither := PAINTDITHER_DIFFUSION; 
     LEADRasterView1.PaintPalette := PAINTPALETTE_AUTO; 
     LEADRasterView1.AutoRepaint := True; 
     LEADRasterView1.AutoSize := False; 
     LEADRasterView1.AutoSetRects := True; 
     LEADRasterView1.PaintSizeMode := PAINTSIZEMODE_NORMAL; 
end; 

3.

Add a Check Box control to your form and set the Name and Caption properties as follows:

 

Name

Caption

 

chkPanWin

Pan Window

4.

Add a Button to the form and set the Name and Caption properties as follows:

 

Name

Caption

 

btnPanWindow

Show Pan Window

5.

Code the btnPanWindow click’s procedure as the following:

procedure TForm1.btnPanWindowClick(Sender: TObject); 
begin
   With LEADRasterView1 do
   begin
      BackErase := False; 
      //set the location of the PanWindow
      PanWinX := 100; 
      PanWinY := 100; 
      //set the size of the PanWindow
      //requested width
      PanWinWidth:= 150; 
      //requested height
      PanWinHeight := 200; 

      LEADRasterView1.PanWinPointer:= 12; 
      PanWinTitle := 'PanWindow'; 
      PanWinRectColor:= RGB(0, 0, 255); 
      PanWinSysMenu := True; 
      //use the settings for LEADRasterView1. 
      PanWinPaintPalette := PaintPalette; 
      PanWinBitonalScaling := BitonalScaling; 
      PanWinPaintScaling := PaintScaling; 
      PanWinPaintDither := PaintDither; 
      //show the Pan Window
      ShowPanWin ( True ); 
   end; 
   chkPanWin.Checked := True; 
end; 

6.

Code the LEADRasterView1 OnPanWin event procedure as follows:

procedure TForm1.LEADRasterView1PanWin(Sender: TObject; hPanWin: Integer; 
  iFlag: Smallint); 
begin
   if (iFlag = PANWIN_DESTROYED) then
      chkPanWin.Checked := False ;//indicate no more Pan Window
end; 

7.

Run your program to test it.