UI: Properties editor popover and outliner sync

This adds a popover to the properties editor. Currently the only setting
is for controlling outliner to properties syncing.

Because we cannot define a perfect heuristic to determine when
properties editors should change tabs based on outliner icon selection,
we need an option to enable or disable this behavior per properties
editor.

There are 3 options for controlling the syncing. Auto uses the heuristic
to only allow tab switching when a properties editor and outliner share
a border. On and off enable and disable syncing respectively.

Differential Revision: https://developer.blender.org/D9758

3 files changed, 43 insertions, 19 deletions

diff --git a/source/blender/editors/include/ED_buttons.h b/source/blender/editors/include/ED_buttons.h
index 1ff160b2ca8..af0643f0d64 100644
--- a/source/blender/editors/include/ED_buttons.h
+++ b/source/blender/editors/include/ED_buttons.h
@@ -26,6 +26,7 @@
 extern "C" {
 #endif
 
+struct ScrArea;
 struct SpaceProperties;
 struct bContext;
 
@@ -36,7 +37,13 @@ void ED_buttons_search_string_set(struct SpaceProperties *sbuts, const char *val
 int ED_buttons_search_string_length(struct SpaceProperties *sbuts);
 const char *ED_buttons_search_string_get(struct SpaceProperties *sbuts);
 
-void ED_buttons_set_context(const struct bContext *C, PointerRNA *ptr, const int context);
+bool ED_buttons_should_sync_with_outliner(const struct bContext *C,
+                                          const struct SpaceProperties *sbuts,
+                                          struct ScrArea *area);
+void ED_buttons_set_context(const struct bContext *C,
+                            struct SpaceProperties *sbuts,
+                            PointerRNA *ptr,
+                            const int context);
 
 #ifdef __cplusplus
 }
diff --git a/source/blender/editors/space_buttons/buttons_context.c b/source/blender/editors/space_buttons/buttons_context.c
index c1f29231f96..e2b889bece1 100644
--- a/source/blender/editors/space_buttons/buttons_context.c
+++ b/source/blender/editors/space_buttons/buttons_context.c
@@ -752,26 +752,25 @@ static bool is_pointer_in_path(ButsContextPath *path, PointerRNA *ptr)
   return false;
 }
 
-void ED_buttons_set_context(const bContext *C, PointerRNA *ptr, const int context)
+bool ED_buttons_should_sync_with_outliner(const bContext *C,
+                                          const SpaceProperties *sbuts,
+                                          ScrArea *area)
 {
   ScrArea *active_area = CTX_wm_area(C);
-  bScreen *screen = CTX_wm_screen(C);
-
-  LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
-    /* Only update for properties editors that are visible and share a border. */
-    if (area->spacetype != SPACE_PROPERTIES) {
-      continue;
-    }
-    if (!ED_area_has_shared_border(active_area, area)) {
-      continue;
-    }
+  const bool auto_sync = ED_area_has_shared_border(active_area, area) &&
+                         sbuts->outliner_sync == PROPERTIES_SYNC_AUTO;
+  return auto_sync || sbuts->outliner_sync == PROPERTIES_SYNC_ON;
+}
 
-    SpaceProperties *sbuts = (SpaceProperties *)area->spacedata.first;
-    ButsContextPath path;
-    if (buttons_context_path(C, sbuts, &path, context, 0) && is_pointer_in_path(&path, ptr)) {
-      sbuts->mainbuser = context;
-      sbuts->mainb = sbuts->mainbuser;
-    }
+void ED_buttons_set_context(const bContext *C,
+                            SpaceProperties *sbuts,
+                            PointerRNA *ptr,
+                            const int context)
+{
+  ButsContextPath path;
+  if (buttons_context_path(C, sbuts, &path, context, 0) && is_pointer_in_path(&path, ptr)) {
+    sbuts->mainbuser = context;
+    sbuts->mainb = sbuts->mainbuser;
   }
 }
 
diff --git a/source/blender/editors/space_outliner/outliner_select.c b/source/blender/editors/space_outliner/outliner_select.c
index 6380bb9505e..f8812ff5970 100644
--- a/source/blender/editors/space_outliner/outliner_select.c
+++ b/source/blender/editors/space_outliner/outliner_select.c
@@ -1105,6 +1105,24 @@ bPoseChannel *outliner_find_parent_bone(TreeElement *te, TreeElement **r_bone_te
   return NULL;
 }
 
+static void outliner_sync_to_properties_editors(const bContext *C,
+                                                PointerRNA *ptr,
+                                                const int context)
+{
+  bScreen *screen = CTX_wm_screen(C);
+
+  LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
+    if (area->spacetype != SPACE_PROPERTIES) {
+      continue;
+    }
+
+    SpaceProperties *sbuts = (SpaceProperties *)area->spacedata.first;
+    if (ED_buttons_should_sync_with_outliner(C, sbuts, area)) {
+      ED_buttons_set_context(C, sbuts, ptr, context);
+    }
+  }
+}
+
 static void outliner_set_properties_tab(bContext *C, TreeElement *te, TreeStoreElem *tselem)
 {
   PointerRNA ptr = {0};
@@ -1285,7 +1303,7 @@ static void outliner_set_properties_tab(bContext *C, TreeElement *te, TreeStoreE
   }
 
   if (ptr.data) {
-    ED_buttons_set_context(C, &ptr, context);
+    outliner_sync_to_properties_editors(C, &ptr, context);
   }
 }