UI: Add context menu support for tree-view items

Tree-view items can now easily define their own context menu. This works
by overriding the `ui::AbstractTreeViewItem::build_context_menu()`
function. See the documentation:
https://wiki.blender.org/wiki/Source/Interface/Views#Context_Menus

Consistently with the Outliner and File Browser, the right-clicked item
also gets activated. This makes sure the correct context is set for the
operators and makes it clear to the user which item is operated on.

An operator to rename the active item is also added, which is something
you'd typically want to put in the context menu as well.

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/editors/interface/interface_view.cc b/source/blender/editors/interface/interface_view.cc
index 8122b965892..fdd8eb0cc71 100644
--- a/source/blender/editors/interface/interface_view.cc
+++ b/source/blender/editors/interface/interface_view.cc
@@ -94,6 +94,16 @@ uiTreeViewItemHandle *UI_block_tree_view_find_item_at(const ARegion *region,
   return tree_row_but->tree_item;
 }
 
+uiTreeViewItemHandle *UI_block_tree_view_find_active_item(const ARegion *region)
+{
+  uiButTreeRow *tree_row_but = (uiButTreeRow *)ui_tree_row_find_active(region);
+  if (!tree_row_but) {
+    return nullptr;
+  }
+
+  return tree_row_but->tree_item;
+}
+
 static StringRef ui_block_view_find_idname(const uiBlock &block, const AbstractTreeView &view)
 {
   /* First get the idname the of the view we're looking for. */