Outliner: Synced selection and active element highlighting

Adds a toggle to the filter menu for outliner synced selection. Enabled
by default, this ensures selection is synced between objects, bones, and
sequences. An active outliner element theme color is added to indicate
which element is active.

Synced selection is controlled on the operator level. Each operator
that modifies selection for objects, bones, sequences, or outliner
elements needs to call the respective ED_outliner_select_sync_from..
function to tag outliners to be synced.

Syncing is done lazily on outliner draw.

1 files changed, 8 insertions, 0 deletions

diff --git a/release/scripts/startup/bl_ui/space_outliner.py b/release/scripts/startup/bl_ui/space_outliner.py
index 6832e3d463b..7bf203d8e39 100644
--- a/release/scripts/startup/bl_ui/space_outliner.py
+++ b/release/scripts/startup/bl_ui/space_outliner.py
@@ -46,6 +46,10 @@ class OUTLINER_HT_header(Header):
 
         layout.separator_spacer()
 
+        if display_mode == 'SEQUENCE':
+            row = layout.row(align=True)
+            row.prop(space, "use_sync_select", icon="UV_SYNC_SELECT", text="")
+
         row = layout.row(align=True)
         if display_mode in {'SCENES', 'VIEW_LAYER'}:
             row.popover(
@@ -328,6 +332,10 @@ class OUTLINER_PT_filter(Panel):
             col.prop(space, "use_sort_alpha")
             layout.separator()
 
+        row = layout.row(align=True)
+        row.prop(space, "use_sync_select", text="Sync Selection")
+        layout.separator()
+
         col = layout.column(align=True)
         col.label(text="Search:")
         col.prop(space, "use_filter_complete", text="Exact Match")