DefScreenSaverProc

DefScreenSaverProc

The DefScreenSaverProc function provides default processing for any messages that a screen saver application does not process.

LONG DefScreenSaverProc(

HWND hWnd,	// handle to screen saver window
UINT msg,	// message
WPARAM wParam,	// first message parameter
LPARAM lParam	// second message parameter
);

Parameters

hWnd

Identifies the screen saver window.

msg

Specifies the message to be processed. The DefScreenSaverProc function responds to messages that affect the screen saver's operation, as detailed in the Remarks section.

If a screen saver application must perform a different action in response to any of these messages, the application's ScreenSaverProc window procedure should process the message.

wParam

Specifies additional message-specific information.

lParam

Specifies additional message-specific information.

Return Values

The return value specifies the result of the message processing and depends on the message sent.

Remarks

A screen saver application's ScreenSaverProc window procedure should use DefScreenSaverProc instead of the DefWindowProc function to provide default message processing. The DefScreenSaverProc function passes any messages that do not affect screen saver operation to DefWindowProc.

The following table describes how the DefScreenSaverProc processes a variety of window messages:

Message	Action
WM_ACTIVATE, WM_ACTIVATEAPP, WM_NCACTIVATE	Closes the screen saver if the wParam parameter is FALSE. A wParam value of FALSE indicates that the screen saver is losing the input focus. The screen saver is closed by sending a WM_CLOSE message.
WM_SETCURSOR	Removes the cursor from the screen by setting the cursor to NULL.
WM_LBUTTONDOWN, WM_RBUTTONDOWN, WM_MBUTTONDOWN, WM_KEYDOWN, WM_KEYUP, WM_MOUSEMOVE	Calls the PostQuitMessage function to close the screen saver.
WM_DESTROY	Posts a WM_CLOSE message to close the screen saver window.
WM_SYSCOMMAND	Returns FALSE if the wParam parameter of WM_SYSCOMMAND is either SC_CLOSE or SC_SCREENSAVE.