Allow to explicitly swap node links by pressing the alt-key while
reconnecting node links. This replaces the old auto-swapping based on
matching prefixes in socket names.
The new behavior works as follows:
* By default plugging links into already occupied (single input)
sockets will connect the dragged link and remove the existing one.
* Pressing the alt-key while dragging an existing node link from one
socket to another socket that is already connected will swap the
links' destinations.
* Pressing the alt-key while dragging a new node link into an already
linked socket will try to reconnect the existing links into another
socket of the same type and remove the links, if no matching socket
is found on the node. This is similar to the old auto-swapping.
Swapping links from or to multi input sockets is not supported.
This commit also makes the link drag tooltip better visible, when using
light themes by using the text theme color.
Reviewed By: Hans Goudey, Simon Thommes
Differential Revision: https://developer.blender.org/D16244
Since a year and a half ago we've been switching to a new way to
represent what sockets a node should have called "declarations"
that's easier to use, clearer, and more flexible for upcoming
features like dynamic socket counts or generic type sockets.
All builtin nodes with a static set of sockets have switched, but one
missing area has been group nodes and group input/output nodes. These
nodes have **dynamic** declarations which change based on their
properties or the group they're inside of. This patch addresses that,
in preparation for using the same dynamic declaration feature for
simulation nodes.
Generally there shouldn't be user-visible differences, but one benefit
is that user-created socket descriptions are now visible directly in
the node editor for group nodes and group input/output nodes.
The commit contains a few changes:
- Add a node type callback for building dynamic declarations with
different arguments
- Add an `Extend` socket declaration for the "virtual" sockets used
for connecting new links
- A similar `Custom` socket declaration is used for addon-defined socket
- Simplify the node update loop to use the declaration to build update
sockets
- Replace the "group update" functions with the declaration building
- Move the node group input/output link creation to link drag operator
- Make the field status part of group node declarations
(not for group input/output nodes though)
- Some fixes for declarations to make them update and build properly
Differential Revision: https://developer.blender.org/D16850
