Fix T94415: Nodes: poor selection behavior inside frame nodes

Previously, node selection made no distinction between a frame node and
other nodes. So a frame node would be selected by their whole rect or
center (depending on box/lasso/circle select). As a consequence of this,
box and lasso could not pratically be started inside a frame node (with
the intention to select a subset of contained child nodes) because the
frame would be selected immediately and tweak-transforming started.
Circle selecting would always contain the frame node as well (making
transforming a subset of nodes without also transforming the whole frame
impossible).

Now change selection behavior so that for all selection modes only the
border [the margin area that is automatically added around all nodes,
see note below] of a frame node is considered in selection. This makes
for a much more intuitive experience when arranging nodes inside frames.

note: to make the area of interest for selection/moving more obvious,
the cursor changes when hovering over (as is done for resizing).
note: this also makes the resize margin consistent with other nodes.
note: this also fixes right resize border (was exclusive instead of
inclusive as every other border)

Also fixes T46540.

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/editors/space_node/node_intern.hh b/source/blender/editors/space_node/node_intern.hh
index c161fc70402..95f771cc00b 100644
--- a/source/blender/editors/space_node/node_intern.hh
+++ b/source/blender/editors/space_node/node_intern.hh
@@ -119,6 +119,8 @@ float2 node_link_calculate_multi_input_position(const float2 &socket_position,
                                                 int index,
                                                 int total_inputs);
 
+rctf node_frame_rect_inside(const bNode &node);
+
 int node_get_resize_cursor(NodeResizeDirection directions);
 NodeResizeDirection node_get_resize_direction(const bNode *node, int x, int y);
 /**