EZ_AddItemCallBack(3) EZWGL Functions EZ_AddItemCallBack(3)NAME
EZ_AddItemCallBack,EZ_RemoveItemCallBack, EZ_RemoveAllItemCallBacks -
register/remove callbacks associated to a display item
SYNOPSIS
#include <EZ.h>
void EZ_AddItemCallBack( EZ_Item *item,
int which, EZ_CallBack callback, void *clientdata, int location)
void EZ_RemoveItemCallBack( EZ_Item *item,
int which, EZ_CallBack callback, void *clientdata)
void EZ_RemoveAllItemCallBacks( EZ_Item *item, int which)
ARGUMENTS
item Specifies a display item.
callback Specifies a callback.
clientdata Specifies an clientdata to be passed to the callback.
which Specifies a callback list.
location Specifies when the callback is to be called relative to other
previously callbacks.
DESCRIPTION
An callback is a procedure of the following prototype:
void (* callback)(void *object, void *data)
EZ_AddItemCallBack registers a callback to a item. There are two call‐
back lists associated to a item: an EZ_CALLBACK list and an
EZ_DESTROY_CALLBACK list. Normal callbacks are called when a double
Button1 click occurs on a item. Destroy callbacks are invoked at the
time a item is destroyed. If location is 0, the callback will be put in
front of all previously registered callbacks. If location is 1, the
callback will be inserted at the end of all previousely registered
callbacks.
EZ_RemoveItemCallBack deletes a callback from the specified callback
list. The specified callback will be deleted only if both the procedure
and the client data match.
EZ_RemoveAllCallBacks deletes all callbacks from the specified callback
list.
SEE ALSOEZ_CreateItem(3), EZ_ConfigureItem(3), EZ_SetItemClientData(3)EZWGLEZ_AddItemCallBack(3)
