L_CaptureWindowUnderCursor

Summary

Captures an image of the window under the cursor position.

Syntax

L_LTSCR_API L_INT L_CaptureWindowUnderCursor(pBitmap, uBitmapStructSize, pCaptureInfo, uInfoStructSize, pfnCaptureCallback, pUserData)

Parameters

pBITMAPHANDLE pBitmap

Pointer to a bitmap handle that references the captured data.

L_UINT uBitmapStructSize

Size in bytes, of the structure pointed to by pBitmap, for versioning. Use sizeof(BITMAPHANDLE).

pLEADCAPTUREINFO pCaptureInfo

Address of LEADCAPTUREINFO structure to be filled with information regarding the captured image's source. Pass NULL if you are not interested in extra information about the capture.

L_UINT uInfoStructSize

Size in bytes, of the structure pointed to by pCaptureInfo, for versioning. Use sizeof(LEADCAPTUREINFO).

CAPTURECALLBACK pfnCaptureCallback

Optional callback function for additional processing.

If you do not provide a callback function, use NULL as the value of this parameter. If you do provide a callback function, use the function pointer as the value of this parameter. The callback function must adhere to the function prototype described in CAPTURECALLBACK Function.

L_VOID * pUserData

Void pointer that you can use to pass one or more additional parameters that the callback function needs.

To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID ;*. The callback function, which receives the address in its own pUserData parameter, can cast it to a pointer of the appropriate data type to access your variable or structure. If the additional parameters are not needed, you can pass NULL in this parameter.

Returns

Comments

This function captures an image of the window under the mouse cursor.

The hot key needs to be pressed to complete the capture.

Required DLLs and Libraries

• LTSCR
• For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

See Also

Functions

• CAPTURECALLBACK

Topics

• Screen Capture C API Function Groups: Capture Functions
• Implementing Screen Capture

Example

static L_INT EXT_CALLBACK pfnCaptureCallback(pBITMAPHANDLE    pBitmap, 
                                             pLEADCAPTUREINFO pCaptureInfo, 
                                             L_VOID         * pUserData) 
{ 
   UNREFERENCED_PARAMETER(pCaptureInfo); 
   UNREFERENCED_PARAMETER(pUserData); 
 
   /* save the captured image */ 
   return(L_SaveBitmap (MAKE_IMAGE_PATH(TEXT("WindowUnderCursor.bmp")), pBitmap, FILE_BMP, 0, 0, NULL)); 
} 
 
L_INT CaptureWindowUnderCursorExample(L_VOID) 
{ 
   BITMAPHANDLE    Bitmap; 
   LEADCAPTUREINFO CaptureInfo; 
 
   memset(&CaptureInfo, 0, sizeof(LEADCAPTUREINFO)); 
   /* To call the L_CaptureWindowUnderCursor */ 
   L_INT nRet = L_CaptureWindowUnderCursor(&Bitmap, sizeof(BITMAPHANDLE), 
                                           &CaptureInfo, sizeof(LEADCAPTUREINFO), 
                                           pfnCaptureCallback, 
                                           NULL); 
 
   if (Bitmap.Flags.Allocated) 
      L_FreeBitmap (&Bitmap); 
   return nRet; 
}