Changing the Mouse Pointer

Once you create or load a mouse pointer, you can change its shape by calling WinSetPointer. Following are three typical situations in which an application changes the shape of the mouse pointer:

• When an application receives a WM_MOUSEMOVE message, there is an opportunity to change the mouse pointer based on its location in the window. If you want the standard arrow pointer, pass this message on to WinDefWindowProc. If you want to change the mouse pointer on a standard dialog window, you need to capture the WM_CONTROLPOINTER message and return a pointing-device pointer handle.

• When an application is about to start a time-consuming process during which it will not accept user input, the application displays the system-wait mouse pointer (SPTR_WAIT). Upon finishing the process, the application resets the mouse pointer to its former shape.

  The following code fragment shows how to save the current mouse pointer, set the hourglass pointer, and restore the original mouse pointer. Notice that the hourglass pointer also is saved in a global variable so that the application can return it when responding to a WM_MOUSEMOVE message during a time-consuming process.

          HPOINTER hptrOld, hptrWait, hptrCurrent;
  
          /* Get the current pointer.                   */
          hptrOld = WinQueryPointer(HWND_DESKTOP);
  
          /* Get the wait mouse pointer.                */
          hptrWait = WinQuerySysPointer(HWND_DESKTOP,
              SPTR_WAIT, FALSE);
  
          /* Save the wait pointer to use in WM_MOUSEMOVE processing.*/
          hptrCurrent = hptrWait;
  
          /* Set the mouse pointer to the wait pointer. */
          WinSetPointer(HWND_DESKTOP, hptrWait);
  
          /*
           * Do a time-consuming operation, then restore the
           * original mouse pointer.
           */
          WinSetPointer(HWND_DESKTOP, hptrOld);
  
  

• When an application needs to indicate its current operational mode, it changes the pointer shape. For example, a paint program with a palette of drawing tools should change the pointer shape to indicate which drawing tool is in use currently.