In Blender buttons are recreated over redraws, except of the active
button which is kept alive, and replaces the new version of itself in
the new redraw. In order to do that, the button needs to be recognized.
This process of recognizing and matching buttons from different redraws
isn't always bullet-proof. That's okay-ish, but we have to make sure
that the relevant data of the old active button is updated with the
newest data.
Here the matching would go wrong, and the new active button was
recognized as the old active button, which was in fact removed when the
asset was cleared. This patch makes sure the image buffer attached to
the buttons is updated when buttons were recognized as matching.
Note that the dragging will still use the wrong data-block, this will be
fixed in the following commit.
Issue is that the operator acts on the active button, and also uses that in the
poll. So the actually active button would affect the poll of a different
button. For the superimposed icons we need to be able to execute these polls
properly for non-active buttons.
This enables temporarily overriding the active button for lookups via context.
While a bit of a hack it makes sense conceptually.
Reviewed By: Campbell Barton
Maniphest Tasks: T97518
Differential Revision: https://developer.blender.org/D14880
The code to compare buttons from the previous to the current frame, to
see if they match (an thus should keep the same state) was quite
generic, and didn't allow much flexibility/customization. For some
cases this isn't enough, and a more specific comparison is needed. Say
if some buttons don't actually store comparable data themselves, only
via the button context. This was the case in D14653.
It was possible to set context pointers for buttons via the layout, but
not for buttons in places where the layout system wasn't used (where
buttons are placed manually). This is needed for buttons in the
Outliner, see D14653.
