Outliner: walk navigation operator and openclose fixes

Adds a keyboard walk navigation and selection operator to the
outliner. Up and down arrow keys walk up and down the list of
elements, and left and right will open and close elements if
the elements are closed or opened respectively. Holding shift
while walking up and down the tree expands the selection.

Holding shift while clicking or pressing left and right arrows
will expand or collapse all children elements recursively.
Pressing enter to openclose the hovered element is removed.

Also allows click+drag for openclose of element subtrees.

This moves openclose toggling to the openclose operator to
remove duplicate code. The outliner tree building is tweaked
slightly to set the proper parents in scene display mode for walk
select to walk to parents without errors.

1 files changed, 14 insertions, 0 deletions

diff --git a/source/blender/editors/space_outliner/outliner_intern.h b/source/blender/editors/space_outliner/outliner_intern.h
index 72cd8dc6424..e37f3519653 100644
--- a/source/blender/editors/space_outliner/outliner_intern.h
+++ b/source/blender/editors/space_outliner/outliner_intern.h
@@ -50,6 +50,14 @@ typedef enum TreeElementInsertType {
   TE_INSERT_INTO,
 } TreeElementInsertType;
 
+/* Use generic walk select after D4771 is committed */
+typedef enum WalkSelectDirection {
+  OUTLINER_SELECT_WALK_UP,
+  OUTLINER_SELECT_WALK_DOWN,
+  OUTLINER_SELECT_WALK_LEFT,
+  OUTLINER_SELECT_WALK_RIGHT,
+} WalkSelectDirection;
+
 typedef enum TreeTraversalAction {
   /* Continue traversal regularly, don't skip children. */
   TRAVERSE_CONTINUE = 0,
@@ -346,6 +354,8 @@ void item_object_mode_exit_cb(struct bContext *C,
 
 void outliner_set_coordinates(struct ARegion *ar, struct SpaceOutliner *soops);
 
+void outliner_item_openclose(TreeElement *te, bool open, bool toggle_all);
+
 /* outliner_dragdrop.c */
 void outliner_dropboxes(void);
 
@@ -373,6 +383,7 @@ void OUTLINER_OT_show_active(struct wmOperatorType *ot);
 void OUTLINER_OT_show_hierarchy(struct wmOperatorType *ot);
 
 void OUTLINER_OT_select_box(struct wmOperatorType *ot);
+void OUTLINER_OT_select_walk(struct wmOperatorType *ot);
 
 void OUTLINER_OT_select_all(struct wmOperatorType *ot);
 void OUTLINER_OT_expanded_toggle(struct wmOperatorType *ot);
@@ -470,6 +481,9 @@ bool outliner_tree_traverse(const SpaceOutliner *soops,
                             TreeTraversalFunc func,
                             void *customdata);
 float outliner_restrict_columns_width(const struct SpaceOutliner *soops);
+TreeElement *outliner_find_element_with_flag(const ListBase *lb, short flag);
+bool outliner_is_element_visible(const TreeElement *te);
+void outliner_scroll_view(struct ARegion *ar, int delta_y);
 
 /* outliner_sync.c ---------------------------------------------- */