UI: Add shortcuts for modifier panels

The shortcuts act on the modifier with its panel under the mouse.
The following shortcuts are enabled by default:
  - Remove modifier: X, Delete
  - Apply modifier: Ctrl A
  - Duplicate modifier: Shift D
More shortcuts can be added in the keymap.

Each panel can now store a custom data RNA pointer, and a new
function is added to get the custom data for the panel under the
cursor. This custom data could be used to refactor the "List Panel
System" to generalize it and integrate it further with RNA.

The same functionality will be added  in further commits where it
applies to constraints, grease pencil modifiers, and effects.

Differential Revision: https://developer.blender.org/D8031

1 files changed, 17 insertions, 9 deletions

diff --git a/source/blender/blenkernel/intern/screen.c b/source/blender/blenkernel/intern/screen.c
index bfc0d437994..c510b3a2dfb 100644
--- a/source/blender/blenkernel/intern/screen.c
+++ b/source/blender/blenkernel/intern/screen.c
@@ -393,6 +393,7 @@ static void panel_list_copy(ListBase *newlb, const ListBase *lb)
   Panel *panel = lb->first;
   for (; new_panel; new_panel = new_panel->next, panel = panel->next) {
     new_panel->activedata = NULL;
+    new_panel->runtime.custom_data_ptr = NULL;
     panel_list_copy(&new_panel->children, &panel->children);
   }
 }
@@ -575,18 +576,25 @@ void BKE_region_callback_free_gizmomap_set(void (*callback)(struct wmGizmoMap *)
   region_free_gizmomap_callback = callback;
 }
 
-void BKE_area_region_panels_free(ListBase *lb)
+static void area_region_panels_free_recursive(Panel *panel)
 {
-  Panel *panel, *panel_next;
-  for (panel = lb->first; panel; panel = panel_next) {
-    panel_next = panel->next;
-    if (panel->activedata) {
-      MEM_freeN(panel->activedata);
-    }
-    BKE_area_region_panels_free(&panel->children);
+  MEM_SAFE_FREE(panel->activedata);
+
+  LISTBASE_FOREACH_MUTABLE (Panel *, child_panel, &panel->children) {
+    area_region_panels_free_recursive(child_panel);
   }
 
-  BLI_freelistN(lb);
+  MEM_freeN(panel);
+}
+
+void BKE_area_region_panels_free(ListBase *lb)
+{
+  LISTBASE_FOREACH_MUTABLE (Panel *, panel, lb) {
+    /* Free custom data just for parent panels to avoid a double free. */
+    MEM_SAFE_FREE(panel->runtime.custom_data_ptr);
+    area_region_panels_free_recursive(panel);
+  }
+  BLI_listbase_clear(lb);
 }
 
 /* not region itself */