MLM_RESETUNDO
This message resets the undo state to indicate that no undo operations are possible.
Syntax
param1 ULONG ulReserved; /* Reserved value, should be 0. */ param2 ULONG ulReserved; /* Reserved value, should be 0. */
Parameters
- ulReserved (ULONG) - input
- Reserved value, should be 0.
- ulReserved (ULONG) - input
- Reserved value, should be 0.
Returns
- usOperation (USHORT) - return
- Operation that can be undone or redone.
- 0: An undo or redo operation is not possible.
- WM_CHAR: A WM_CHAR message, or messages for a simple string of keystrokes, can
- be undone or redone.
- MLM_SETFONT: A MLM_SETFONT message can be undone or redone.
- MLM_SETTEXTCOLOR: A MLM_SETTEXTCOLOR message can be undone or redone for both
- background and foreground color.
- MLM_CUT: A MLM_CUT message can be undone or redone.
- MLM_PASTE: A MLM_PASTE message can be undone or redone.
- MLM_CLEAR: A MLM_CLEAR message can be undone or redone.
- rc (BOOL) - return
- Undo or redo indicator.
- TRUE: An undo is possible.
- FALSE: A redo is possible.
Remarks
This message resets the undo state of the MLE to indicate that the last operation cannot be undone (null return from MLM_QUERYUNDO). This can be used by the application when it performs an operation that it can undo, that supersedes the last MLE operation. The application can then reset its own undo state upon receipt of an MLN_ CHANGE, indicating that later changes have occurred through the MLE.
Default Processing
The default window procedure takes no action on this message, other than to set ReturnCode to 0.