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. |
See Also