With v1 of this function, it's unclear where exactly the data pointer
comes from or what it is. In fact, this is not determined by libobs, but
the consumer. libobs assumes that the caller of
obs_property_button_clicked passes an obs_context_data pointer, and then
passes the data pointer of that obs_context_data as the data pointer to
the callback.
In OBS Studio, this is always the private data of the associated object.
However, this assumes that there even is such an object (source/encoder/
etc), even though properties are meant to be free-standing. This is not
just philosophical, because with obs_get_source_properties you can
actually get an obs_properties_t that isn't associated with any specific
source, at which point you have no idea what the data pointer will be.
For this reason, obs_properties_add_button v1 needs to go.
obs_properties_add_button2 can be used as a drop-in replacement.
With v2, it's well-defined that the pointer you're passing as priv is
the pointer you get back in the callback as data. If you don't care
about it, simply pass NULL/nullptr.
Once v1 is removed in the future, obs_property_button_clicked should be
replaced with a variant that doesn't take a second argument, as that
argument will no longer be used anywhere.
The important point here is that "data" from the callback isn't defined
by libobs, but rather by the API consumer.
Additionally, it's not entirely clear from the documentation whether the
callback would still be called for button of type OBS_BUTTON_URL. There
should be no negatives to always calling it and the OBS Studio frontend
already behaves that way, so let's document that in libobs.
This reverts commit 58fb63030c.
This is not the ideal fix for the fact that scripts can use a deferred
update flag because it makes it so that filters in general cannot use
flags. We need to disable this via other means.
Deferring properties was only ever made for input and transition
sources. As other property dialogs do not have an "Ok" button that would
cause an update to happen, if the deferred flag was set the callback
would never be called.
Also clarifies the docs to reflect this.
Adds links to release functions for "new/incremented reference".
Extra info on signal handler.
Parameter description on `obs_property_list_add_*` functions, since
their parameter `name` can be confusing and it is unclear which value
is stored in obs_data_t.
Adds clarifications on calldata_ptr.
