gsignal: use g_clear_signal_handler() macro to implement g_clear_signal_handler() function

We have a "good" implementation of g_clear_signal_handler() in
form of a macro. Use it, and don't duplicate the code.

Also add a comment to the documentation that "instance" in fact must
not point to a valid GObject instance -- if the handler ID is unset.

Also reword the documentation about the reasoning for why a macro
version exists. The reason is not to use the function "without
pointer cast". I don't think the non-macro version requires any
pointer cast, since "instance" is a void pointer. Was this referring
to the handler_id_ptr? That doesn't seem right either, because the
caller should always provide a "gulong *" pointer and nothing else.
This commit is contained in:
Thomas Haller 2021-01-26 14:16:26 +01:00
parent 7777f3bdbe
commit 8416211231

View File

@ -4012,6 +4012,7 @@ g_signal_accumulator_first_wins (GSignalInvocationHint *ihint,
* g_clear_signal_handler:
* @handler_id_ptr: A pointer to a handler ID (of type #gulong) of the handler to be disconnected.
* @instance: (type GObject.Object): The instance to remove the signal handler from.
* This pointer may be %NULL or invalid, if the handler ID is zero.
*
* Disconnects a handler from @instance so it will not be called during
* any future or currently ongoing emissions of the signal it has been
@ -4019,21 +4020,20 @@ g_signal_accumulator_first_wins (GSignalInvocationHint *ihint,
*
* If the handler ID is 0 then this function does nothing.
*
* A macro is also included that allows this function to be used without
* pointer casts.
* There is also a macro version of this function so that the code
* will be inlined.
*
* Since: 2.62
*/
#undef g_clear_signal_handler
void
g_clear_signal_handler (gulong *handler_id_ptr,
gpointer instance)
(g_clear_signal_handler) (gulong *handler_id_ptr,
gpointer instance)
{
g_return_if_fail (handler_id_ptr != NULL);
if (*handler_id_ptr != 0)
{
g_signal_handler_disconnect (instance, *handler_id_ptr);
*handler_id_ptr = 0;
}
#ifndef g_clear_signal_handler
#error g_clear_signal_handler() macro is not defined
#endif
g_clear_signal_handler (handler_id_ptr, instance);
}