LoadInfo... example for Delphi

Take the following steps to exercise the LoadInfo event and LoadInfo... properties. The example creates a raw FAX file, then loads the file it just created. (Getting format information from an unfamiliar file is beyond the scope of this example.)

1.	Start with the project that you created in Loading and Displaying an Image.
2.	On the Project pull-down menu, use the Import Type library… and select the LEAD Raster Process object library (14.5).
3.	At the beginning of the Unit1 file, add LTRASTERPROCLib_TLB to the uses section. For example:

Uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, LTRASTERPROCLib_TLB;

4.	If you didn’t install LEvntSnk, install it.
	On the Component pull-down menu, use install component …, and browse to LEADXX\Include\LEvntSnk.pas, and press Ok.
5.	From the ActiveX controls, Add the LEvntSnk control to your form.
6.	Add the following variables to Unit1 Private declaration section:

      MyInfoBits: Integer;
      MyInfoFlags: Longint;
      MyInfoFormat: Integer;
      MyInfoHeight: Single;
      MyInfoOffset: Longint;
      MyInfoWidth: Single;
      MyInfoXRes: Integer;
      MyInfoYRes: Integer;
       MyRasterIO: LEADRasterIO;

7.	Add the following to LoadLead Click’s Procedure:

MyRasterIO:= CreateComObject (CLASS_LEADRasterIO) as ILEADRasterIO;
LEADEventSink1.Connect (MyRasterIO, _LEADRasterIOEvents);

8.	$image\btncmd.gif$ Add a button to your form and name it as follows:
	Name	Caption
	Button1	Button1
9.	Code the Button1 click’s procedure as follows:

procedure TForm1.Button1Click(Sender: TObject);
var
   sRet: Smallint;
   RasterProc: LEADRasterProcess;
begin
   RasterProc:= CreateComObject (CLASS_LEADRasterProcess) as  LEADRasterProcess;
   LEADRasterView1.ScaleMode := 3; //Pixels
   //Make the image look OK as a 1-bit image.
   RasterProc.Size (LEADRasterView1.Raster,
                              LEADRasterView1.ScaleWidth,
                              LEADRasterView1.ScaleHeight, RESIZE_RESAMPLE);
   RasterProc.Halftone (LEADRasterView1.Raster, HALFTONE_VIEW, 45);
   //Set the form-level variables to the values we will use when loading.
   MyInfoBits := 1;
   MyInfoFlags := LOADINFO_TOPLEFT;
   MyInfoFormat := FILE_FAX_G3_2D;
   MyInfoHeight := LEADRasterView1.Raster.BitmapHeight;
   MyInfoOffset := 0;
   MyInfoWidth := LEADRasterView1.Raster.BitmapWidth;
   MyInfoXRes := LEADRasterView1.Raster.BitmapXRes;
   MyInfoYRes := LEADRasterView1.Raster.BitmapYRes;
   //Save the image as raw FAX; then load the saved file.
   //Format information will be supplied in the LoadInfo event.
   MyRasterIO.Save (LEADRasterView1.Raster, 'c:\temp\tmp.tif', FILE_FAX_G3_2D,
                 1, 1, SAVE_OVERWRITE);
   MyRasterIO.Load (LEADRasterView1.Raster, 'c:\temp\tmp.tif', 0, 0, 1);
   //Repaint the newly loaded image.
   LEADRasterView1.ForceRepaint (sRet);
end;

10.	Code the MyRasterIO object's LoadInfo event as follows:

procedure TForm1. LEADEventSink1Invoke(Sender: TObject; DispID: Integer;
  const IID: TGUID; LocaleID: Integer; Flags: Word; Params: tagDISPPARAMS;
  varResult, ExcepInfo, ArgErr: Pointer);
begin
   case (DispID) of
      LEADRASTERIOEVENTS_LOADINFO:
      begin
         MyRasterIO.LoadInfoBits := MyInfoBits;
         MyRasterIO.LoadInfoFlags := MyInfoFlags;
         MyRasterIO.LoadInfoFormat := MyInfoFormat;
         MyRasterIO.LoadInfoHeight := MyInfoHeight;
         MyRasterIO.LoadInfoOffset := MyInfoOffset;
         MyRasterIO.LoadInfoWidth := MyInfoWidth;
         MyRasterIO.LoadInfoXRes := MyInfoXRes;
         MyRasterIO.LoadInfoYRes := MyInfoYRes;
      end;
   end;
end;

11.	Run your program to test it.