isCOBOL Evolve : Appendices : Library Routines : W$CAPTURE
W$CAPTURE
The W$CAPTURE library routine allows you to take a screenshot of a window or the whole screen. Different actions are performed depending on the number of parameters.
The routine creates a new image resource and returns its handle.
Note - The newly created resource is not released automatically. It must be destroyed by the programmer with the WBITMAP-DESTROY function when it is no longer needed.
Syntax:
 CALL "W$CAPTURE"  USING [windowHandle ]
                         [fileName ] 
                         [fileFormat ] 
                  GIVING  bitmapHandle
Parameters:
windowHandle
USAGE HANDLE
Specifies the handle of the window to be captured. The window decorations are included in the screenshot. When this parameter is omitted or zero, the whole screen is captured.
fileName
PIC X(n) or alphanumeric literal
Specifies the name of the file where the image has to be stored. When this parameter is omitted, the image is just loaded into memory and it is not stored on disk.
 
In thin client environment, the file is created on the client disk.
fileFormat
PIC X(n) or alphanumeric literal
Specifies the format used to store the image. Possible values are:
 
 
"bmp"
"gif"
"png"
"jpg"
Windows and OS/2 bitmap format
CompuServe Graphics Interchange Format
Portable Network Graphics format
JPEG (Joint Photographic Experts Group) format
Return code:
bitmapHandle must be an USAGE HANDLE data item and receives the handle of the captured image. A value of 0 means that the routine is not supported in the current runtime environment.
Examples:
Example - Capture full desktop and save to a .png file
call "w$capture" using 0, "c:\tmp\screenshot.png", "png"
 
Example - Capture main program screen and save to a .jpg file
 
working-storage section.              
copy "isgui.def".
copy "iscrt.def".
77  crt-status              special-names crt status pic 9(5).
77  hWin                    handle of window.
77  hBmp                    pic s9(9) comp-4.
 
 
screen section.
01  main-screen.
    03 push-button  
       line 2 col 3 size 15 cells 
       title "Capture Window"
       exception-value 102
       .
    03 push-button  
       line 6 col 3 
       title "Exit"
       exception-value 27
       .
 
procedure division.
main.
  display independent graphical window
          color  65793
          with   system menu
          title  "W$CAPTURE Routine"
          handle hWin
          event  WIN-EVT
 
  display main-screen
 
  accept main-screen on exception continue 
  end-accept
 
  if crt-status = 102   
       call "w$capture" using hWin "c:\tmp\mainscr.jpg", "jpg"
            giving hBmp
  end-if.