Tk_CreateEventHandler, Tk_DeleteEventHandler - associate procedure callback with an X event
Tk_CreateEventHandler(tkwin, mask, proc, clientData)
Tk_DeleteEventHandler(tkwin, mask, proc, clientData)
Tk_EventProc *proc (in) Procedure to invoke whenever an event in mask occurs in the window given by tkwin.
Proc should have arguments and result that match the type Tk_EventProc:
typedef void Tk_EventProc(
The clientData parameter to proc is a copy of the clientData argument given to Tk_CreateEventHandler when the callback was created. Typically, clientData points to a data structure containing application-specific information about the window in which the event occurred. EventPtr is a pointer to the X event, which will be one of the ones specified in the mask argument to Tk_CreateEventHandler.
Tk_DeleteEventHandler may be called to delete a previouslycreated event handler: it deletes the first handler it finds that is associated with tkwin and matches the mask, proc, and clientData arguments. If no such handler exists, then Tk_EventHandler returns without doing anything. Although Tk supports it, it's probably a bad idea to have more than one callback with the same mask, proc, and client_Data arguments. When a window is deleted all of its handlers will be deleted automatically; in this case there is no need to call Tk_DeleteEventHandler.
If multiple handlers are declared for the same type of X event on the same window, then the handlers will be invoked in the order they were created.
bind, callback, event, handler
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