Override this function to keep OnIdle from being called after specific messages are generated.
The default implementation does not call OnIdle after redundant mouse messages and messages generated by blinking carets.
If an application has created a short timer, OnIdle will be called frequently, causing performance problems. To improve such an application's performance, override IsIdleMessage in the application's CWinApp-derived class to check for WM_TIMER messages as follows:
Handling WM_TIMER in this fashion will improve performance of applications that use short timers.