Cleanup: Move outliner types to namespace, avoid C-style type definition

With C++ we should transition towards namespaces to avoid naming
collisions. Having the namespace in place is the first step for that
transition.

Plus, the `typedef` isn't necessary for struct/class/enum definitions
in C++, so avoid the verbosity it adds.

source/blender/editors/space_outliner/outliner_collections.cc

@@ -38,6 +38,8 @@
 
 #include "outliner_intern.hh" /* own include */
 
+namespace blender::ed::outliner {
+
 /* -------------------------------------------------------------------- */
 /** \name Utility API
  * \{ */
@@ -122,8 +124,12 @@ TreeTraversalAction outliner_find_selected_objects(TreeElement *te, void *custom
   return TRAVERSE_CONTINUE;
 }
 
+}  // namespace blender::ed::outliner
+
 void ED_outliner_selected_objects_get(const bContext *C, ListBase *objects)
 {
+  using namespace blender::ed::outliner;
+
   SpaceOutliner *space_outliner = CTX_wm_space_outliner(C);
   struct IDsSelectedData data = {{nullptr}};
   outliner_tree_traverse(space_outliner,
@@ -140,12 +146,16 @@ void ED_outliner_selected_objects_get(const bContext *C, ListBase *objects)
   BLI_freelistN(&data.selected_array);
 }
 
+namespace blender::ed::outliner {
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
 /** \name Poll Functions
  * \{ */
 
+}  // namespace blender::ed::outliner
+
 bool ED_outliner_collections_editor_poll(bContext *C)
 {
   SpaceOutliner *space_outliner = CTX_wm_space_outliner(C);
@@ -153,6 +163,8 @@ bool ED_outliner_collections_editor_poll(bContext *C)
          ELEM(space_outliner->outlinevis, SO_VIEW_LAYER, SO_SCENES, SO_LIBRARIES);
 }
 
+namespace blender::ed::outliner {
+
 static bool outliner_view_layer_collections_editor_poll(bContext *C)
 {
   SpaceOutliner *space_outliner = CTX_wm_space_outliner(C);
@@ -1636,3 +1648,5 @@ void OUTLINER_OT_collection_color_tag_set(wmOperatorType *ot)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_context.cc

@@ -14,7 +14,7 @@
 #include "outliner_intern.hh"
 #include "tree/tree_iterator.hh"
 
-using namespace blender::ed::outliner;
+namespace blender::ed::outliner {
 
 static void outliner_context_selected_ids_recursive(const SpaceOutliner &space_outliner,
                                                     bContextDataResult *result)
@@ -55,3 +55,5 @@ int /*eContextResult*/ outliner_context(const bContext *C,
 
   return CTX_RESULT_MEMBER_NOT_FOUND;
 }
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_dragdrop.cc

@@ -45,6 +45,8 @@
 
 #include "outliner_intern.hh"
 
+namespace blender::ed::outliner {
+
 static Collection *collection_parent_from_ID(ID *id);
 
 /* -------------------------------------------------------------------- */
@@ -1592,3 +1594,5 @@ void outliner_dropboxes(void)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_draw.cc

@@ -74,8 +74,7 @@
 #include "tree/tree_element_rna.hh"
 #include "tree/tree_iterator.hh"
 
-using namespace blender;
-using namespace blender::ed::outliner;
+namespace blender::ed::outliner {
 
 /* -------------------------------------------------------------------- */
 /** \name Tree Size Functions
@@ -3994,3 +3993,5 @@ void draw_outliner(const bContext *C)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_edit.cc

@@ -65,6 +65,8 @@
 
 using namespace blender::ed::outliner;
 
+namespace blender::ed::outliner {
+
 static void outliner_show_active(SpaceOutliner *space_outliner,
                                  ARegion *region,
                                  TreeElement *te,
@@ -2230,3 +2232,5 @@ void OUTLINER_OT_orphans_purge(wmOperatorType *ot)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_intern.hh

@@ -14,10 +14,6 @@
 /* Needed for `tree_element_cast()`. */
 #include "tree/tree_element.hh"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* internal exports only */
 
 struct ARegion;
@@ -27,7 +23,6 @@ struct ListBase;
 struct Main;
 struct Object;
 struct Scene;
-struct TreeElement;
 struct TreeStoreElem;
 struct ViewLayer;
 struct bContext;
@@ -37,22 +32,23 @@ struct View2D;
 struct wmKeyConfig;
 struct wmOperatorType;
 
-namespace blender::ed::outliner {
-class AbstractTreeDisplay;
-class AbstractTreeElement;
-}  // namespace blender::ed::outliner
-
 namespace blender::bke::outliner::treehash {
 class TreeHash;
 }
 
-namespace outliner = blender::ed::outliner;
+namespace blender::ed::outliner {
+
+class AbstractTreeDisplay;
+class AbstractTreeElement;
+
 namespace treehash = blender::bke::outliner::treehash;
 
+struct TreeElement;
+
 struct SpaceOutliner_Runtime {
   /** Object to create and manage the tree for a specific display type (View Layers, Scenes,
    * Blender File, etc.). */
-  std::unique_ptr<outliner::AbstractTreeDisplay> tree_display;
+  std::unique_ptr<AbstractTreeDisplay> tree_display;
 
   /* Hash table for tree-store elements, using `(id, type, index)` as key. */
   std::unique_ptr<treehash::TreeHash> tree_hash;
@@ -63,25 +59,25 @@ struct SpaceOutliner_Runtime {
   ~SpaceOutliner_Runtime() = default;
 };
 
-typedef enum TreeElementInsertType {
+enum TreeElementInsertType {
   TE_INSERT_BEFORE,
   TE_INSERT_AFTER,
   TE_INSERT_INTO,
-} TreeElementInsertType;
+};
 
-typedef enum TreeTraversalAction {
+enum TreeTraversalAction {
   /** Continue traversal regularly, don't skip children. */
   TRAVERSE_CONTINUE = 0,
   /** Stop traversal. */
   TRAVERSE_BREAK,
   /** Continue traversal, but skip children of traversed element. */
   TRAVERSE_SKIP_CHILDS,
-} TreeTraversalAction;
+};
 
-typedef TreeTraversalAction (*TreeTraversalFunc)(struct TreeElement *te, void *customdata);
+typedef TreeTraversalAction (*TreeTraversalFunc)(TreeElement *te, void *customdata);
 
-typedef struct TreeElement {
-  struct TreeElement *next, *prev, *parent;
+struct TreeElement {
+  TreeElement *next, *prev, *parent;
 
   /**
    * The new inheritance based representation of the element (a derived type of base
@@ -89,7 +85,7 @@ typedef struct TreeElement {
    * be moved to it and operations based on the type should become virtual methods of the class
    * hierarchy.
    */
-  std::unique_ptr<outliner::AbstractTreeElement> abstract_element;
+  std::unique_ptr<AbstractTreeElement> abstract_element;
 
   ListBase subtree;
   int xs, ys;                /* Do selection. */
@@ -100,12 +96,12 @@ typedef struct TreeElement {
   short xend;                /* Width of item display, for select. */
   const char *name;
   void *directdata; /* Armature Bones, Base, ... */
-} TreeElement;
+};
 
-typedef struct TreeElementIcon {
+struct TreeElementIcon {
   struct ID *drag_id, *drag_parent;
   int icon;
-} TreeElementIcon;
+};
 
 #define TREESTORE_ID_TYPE(_id) \
   (ELEM(GS((_id)->name), \
@@ -172,17 +168,17 @@ enum {
 /* button events */
 #define OL_NAMEBUTTON 1
 
-typedef enum {
+enum eOLDrawState {
   OL_DRAWSEL_NONE = 0,   /* inactive (regular black text) */
   OL_DRAWSEL_NORMAL = 1, /* active object (draws white text) */
   OL_DRAWSEL_ACTIVE = 2, /* active obdata (draws a circle around the icon) */
-} eOLDrawState;
+};
 
-typedef enum {
+enum eOLSetState {
   OL_SETSEL_NONE = 0,   /* don't change the selection state */
   OL_SETSEL_NORMAL = 1, /* select the item */
   OL_SETSEL_EXTEND = 2, /* select the item and extend (also toggles selection) */
-} eOLSetState;
+};
 
 /* get TreeStoreElem associated with a TreeElement
  * < a: (TreeElement) tree element to find stored element for
@@ -232,7 +228,7 @@ typedef enum {
  * Container to avoid passing around these variables to many functions.
  * Also so we can have one place to assign these variables.
  */
-typedef struct TreeViewContext {
+struct TreeViewContext {
   /* Scene level. */
   struct Scene *scene;
   struct ViewLayer *view_layer;
@@ -245,16 +241,16 @@ typedef struct TreeViewContext {
    * The pose object may not be the active object (when in weight paint mode).
    * Checking this in draw loops isn't efficient, so set only once. */
   Object *ob_pose;
-} TreeViewContext;
+};
 
-typedef enum TreeItemSelectAction {
+enum TreeItemSelectAction {
   OL_ITEM_DESELECT = 0,           /* Deselect the item */
   OL_ITEM_SELECT = (1 << 0),      /* Select the item */
   OL_ITEM_SELECT_DATA = (1 << 1), /* Select object data */
   OL_ITEM_ACTIVATE = (1 << 2),    /* Activate the item */
   OL_ITEM_EXTEND = (1 << 3),      /* Extend the current selection */
   OL_ITEM_RECURSIVE = (1 << 4),   /* Select recursively */
-} TreeItemSelectAction;
+};
 
 /* outliner_tree.c ----------------------------------------------- */
 
@@ -277,9 +273,9 @@ void outliner_build_tree(struct Main *mainvar,
                          struct SpaceOutliner *space_outliner,
                          struct ARegion *region);
 
-struct TreeElement *outliner_add_collection_recursive(SpaceOutliner *space_outliner,
-                                                      struct Collection *collection,
-                                                      TreeElement *ten);
+TreeElement *outliner_add_collection_recursive(SpaceOutliner *space_outliner,
+                                               struct Collection *collection,
+                                               TreeElement *ten);
 
 bool outliner_requires_rebuild_on_select_or_active_change(
     const struct SpaceOutliner *space_outliner);
@@ -288,8 +284,8 @@ typedef struct IDsSelectedData {
   struct ListBase selected_array;
 } IDsSelectedData;
 
-TreeTraversalAction outliner_find_selected_collections(struct TreeElement *te, void *customdata);
-TreeTraversalAction outliner_find_selected_objects(struct TreeElement *te, void *customdata);
+TreeTraversalAction outliner_find_selected_collections(TreeElement *te, void *customdata);
+TreeTraversalAction outliner_find_selected_objects(TreeElement *te, void *customdata);
 
 /* outliner_draw.c ---------------------------------------------- */
 
@@ -351,7 +347,7 @@ struct bPoseChannel *outliner_find_parent_bone(TreeElement *te, TreeElement **r_
  */
 void outliner_item_select(struct bContext *C,
                           struct SpaceOutliner *space_outliner,
-                          struct TreeElement *te,
+                          TreeElement *te,
                           short select_flag);
 
 /**
@@ -381,7 +377,7 @@ void outliner_item_mode_toggle(struct bContext *C,
 typedef void (*outliner_operation_fn)(struct bContext *C,
                                       struct ReportList *,
                                       struct Scene *scene,
-                                      struct TreeElement *,
+                                      TreeElement *,
                                       struct TreeStoreElem *,
                                       TreeStoreElem *,
                                       void *);
@@ -410,12 +406,10 @@ int outliner_flag_is_any_test(ListBase *lb, short flag, int curlevel);
  * Set or unset \a flag for all outliner elements in \a lb and sub-trees.
  * \return if any flag was modified.
  */
-extern "C++" {
 bool outliner_flag_set(const SpaceOutliner &space_outliner, short flag, short set);
 bool outliner_flag_set(const ListBase &lb, short flag, short set);
 bool outliner_flag_flip(const SpaceOutliner &space_outliner, short flag);
 bool outliner_flag_flip(const ListBase &lb, short flag);
-}
 
 void item_rename_fn(struct bContext *C,
                     struct ReportList *reports,
@@ -427,14 +421,14 @@ void item_rename_fn(struct bContext *C,
 void lib_relocate_fn(struct bContext *C,
                      struct ReportList *reports,
                      struct Scene *scene,
-                     struct TreeElement *te,
+                     TreeElement *te,
                      struct TreeStoreElem *tsep,
                      struct TreeStoreElem *tselem,
                      void *user_data);
 void lib_reload_fn(struct bContext *C,
                    struct ReportList *reports,
                    struct Scene *scene,
-                   struct TreeElement *te,
+                   TreeElement *te,
                    struct TreeStoreElem *tsep,
                    struct TreeStoreElem *tselem,
                    void *user_data);
@@ -442,14 +436,14 @@ void lib_reload_fn(struct bContext *C,
 void id_delete_tag_fn(struct bContext *C,
                       struct ReportList *reports,
                       struct Scene *scene,
-                      struct TreeElement *te,
+                      TreeElement *te,
                       struct TreeStoreElem *tsep,
                       struct TreeStoreElem *tselem,
                       void *user_data);
 void id_remap_fn(struct bContext *C,
                  struct ReportList *reports,
                  struct Scene *scene,
-                 struct TreeElement *te,
+                 TreeElement *te,
                  struct TreeStoreElem *tsep,
                  struct TreeStoreElem *tselem,
                  void *user_data);
@@ -686,12 +680,6 @@ int outliner_context(const struct bContext *C,
                      const char *member,
                      struct bContextDataResult *result);
 
-#ifdef __cplusplus
-}
-#endif
-
-namespace blender::ed::outliner {
-
 /**
  * Helper to safely "cast" a #TreeElement to its new C++ #AbstractTreeElement, if possible.
  * \return nullptr if the tree-element doesn't match the requested type \a TreeElementT or the

source/blender/editors/space_outliner/outliner_ops.cc

@@ -11,6 +11,7 @@
 
 #include "outliner_intern.hh"
 
+namespace blender::ed::outliner {
 /* -------------------------------------------------------------------- */
 /** \name Registration
  * \{ */
@@ -103,3 +104,5 @@ void outliner_keymap(wmKeyConfig *keyconf)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_query.cc

@@ -13,7 +13,7 @@
 #include "outliner_intern.hh"
 #include "tree/tree_display.hh"
 
-using namespace blender::ed::outliner;
+namespace blender::ed::outliner {
 
 bool outliner_shows_mode_column(const SpaceOutliner &space_outliner)
 {
@@ -46,3 +46,5 @@ bool outliner_has_element_warnings(const SpaceOutliner &space_outliner)
 
   return recursive_fn(space_outliner.tree);
 }
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_select.cc

@@ -70,7 +70,7 @@
 #include "tree/tree_element_seq.hh"
 #include "tree/tree_iterator.hh"
 
-using namespace blender::ed::outliner;
+namespace blender::ed::outliner {
 
 /* -------------------------------------------------------------------- */
 /** \name Internal Utilities
@@ -2040,3 +2040,5 @@ void OUTLINER_OT_select_walk(wmOperatorType *ot)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_sync.cc

@@ -94,6 +94,8 @@ void ED_outliner_select_sync_flag_outliners(const bContext *C)
   wm->outliner_sync_select_dirty = 0;
 }
 
+namespace blender::ed::outliner {
+
 /**
  * Outliner sync select dirty flags are not enough to determine which types to sync,
  * outliner display mode also needs to be considered. This stores the types of data
@@ -335,8 +337,12 @@ static void outliner_sync_selection_from_outliner(Scene *scene,
   }
 }
 
+}  // namespace blender::ed::outliner
+
 void ED_outliner_select_sync_from_outliner(bContext *C, SpaceOutliner *space_outliner)
 {
+  using namespace blender::ed::outliner;
+
   /* Don't sync if not checked or in certain outliner display modes */
   if (!(space_outliner->flag & SO_SYNC_SELECT) || ELEM(space_outliner->outlinevis,
                                                        SO_LIBRARIES,
@@ -380,6 +386,8 @@ void ED_outliner_select_sync_from_outliner(bContext *C, SpaceOutliner *space_out
   }
 }
 
+namespace blender::ed::outliner {
+
 static void outliner_select_sync_from_object(ViewLayer *view_layer,
                                              Object *obact,
                                              TreeElement *te,
@@ -561,3 +569,5 @@ void outliner_sync_selection(const bContext *C, SpaceOutliner *space_outliner)
     }
   }
 }
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_tools.cc

@@ -89,6 +89,8 @@
 #include "tree/tree_element_seq.hh"
 #include "tree/tree_iterator.hh"
 
+namespace blender::ed::outliner {
+
 static CLG_LogRef LOG = {"ed.outliner.tools"};
 
 using namespace blender::ed::outliner;
@@ -3459,3 +3461,5 @@ void OUTLINER_OT_operation(wmOperatorType *ot)
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_tree.cc

@@ -70,7 +70,7 @@
 #  include "BLI_math_base.h" /* M_PI */
 #endif
 
-using namespace blender::ed::outliner;
+namespace blender::ed::outliner {
 
 /* prototypes */
 static int outliner_exclude_filter_get(const SpaceOutliner *space_outliner);
@@ -786,8 +786,6 @@ static void outliner_add_id_contents(SpaceOutliner *space_outliner,
   }
 }
 
-namespace blender::ed::outliner {
-
 TreeElement *outliner_add_element(SpaceOutliner *space_outliner,
                                   ListBase *lb,
                                   void *idv,
@@ -924,8 +922,6 @@ TreeElement *outliner_add_element(SpaceOutliner *space_outliner,
   return te;
 }
 
-}  // namespace blender::ed::outliner
-
 /* ======================================================= */
 
 BLI_INLINE void outliner_add_collection_init(TreeElement *te, Collection *collection)
@@ -1727,3 +1723,5 @@ void outliner_build_tree(Main *mainvar,
 }
 
 /** \} */
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/outliner_utils.cc

@@ -30,7 +30,7 @@
 #include "tree/tree_display.hh"
 #include "tree/tree_iterator.hh"
 
-using namespace blender::ed::outliner;
+namespace blender::ed::outliner {
 
 /* -------------------------------------------------------------------- */
 /** \name Tree View Context
@@ -445,6 +445,10 @@ void outliner_tag_redraw_avoid_rebuild_on_open_change(const SpaceOutliner *space
   }
 }
 
+}  // namespace blender::ed::outliner
+
+using namespace blender::ed::outliner;
+
 Base *ED_outliner_give_base_under_cursor(bContext *C, const int mval[2])
 {
   ARegion *region = CTX_wm_region(C);

source/blender/editors/space_outliner/space_outliner.cc

@@ -37,6 +37,8 @@
 #include "outliner_intern.hh"
 #include "tree/tree_display.hh"
 
+namespace blender::ed::outliner {
+
 SpaceOutliner_Runtime::SpaceOutliner_Runtime(const SpaceOutliner_Runtime & /*other*/)
     : tree_display(nullptr), tree_hash(nullptr)
 {
@@ -433,8 +435,12 @@ static void outliner_deactivate(struct ScrArea *area)
   ED_region_tag_redraw_no_rebuild(BKE_area_find_region_type(area, RGN_TYPE_WINDOW));
 }
 
+}  // namespace blender::ed::outliner
+
 void ED_spacetype_outliner(void)
 {
+  using namespace blender::ed::outliner;
+
   SpaceType *st = MEM_cnew<SpaceType>("spacetype time");
   ARegionType *art;
 

source/blender/editors/space_outliner/tree/common.cc

@@ -21,6 +21,8 @@
 #include "common.hh"
 #include "tree_display.hh"
 
+namespace blender::ed::outliner {
+
 /* -------------------------------------------------------------------- */
 /** \name ID Helpers.
  * \{ */
@@ -63,3 +65,5 @@ bool outliner_animdata_test(const AnimData *adt)
   }
   return false;
 }
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/tree/common.hh

@@ -8,7 +8,11 @@
 
 struct ListBase;
 
+namespace blender::ed::outliner {
+
 const char *outliner_idcode_to_plural(short idcode);
 
 void outliner_make_object_parent_hierarchy(ListBase *lb);
 bool outliner_animdata_test(const struct AnimData *adt);
+
+}  // namespace blender::ed::outliner

source/blender/editors/space_outliner/tree/tree_display.hh

@@ -30,11 +30,11 @@ struct Main;
 struct Scene;
 struct Sequence;
 struct SpaceOutliner;
-struct TreeElement;
 struct ViewLayer;
 
 namespace blender::ed::outliner {
 
+struct TreeElement;
 class TreeElementID;
 
 /**

source/blender/editors/space_outliner/tree/tree_element.hh

@@ -14,10 +14,11 @@
 
 struct ListBase;
 struct SpaceOutliner;
-struct TreeElement;
 
 namespace blender::ed::outliner {
 
+struct TreeElement;
+
 /* -------------------------------------------------------------------- */
 /* Tree-Display Interface */
 

source/blender/editors/space_outliner/tree/tree_element_anim_data.hh

@@ -8,8 +8,6 @@
 
 #include "tree_element.hh"
 
-struct TreeElement;
-
 namespace blender::ed::outliner {
 
 class TreeElementAnimData final : public AbstractTreeElement {

source/blender/editors/space_outliner/tree/tree_element_driver.hh

@@ -8,8 +8,6 @@
 
 #include "tree_element.hh"
 
-struct TreeElement;
-
 namespace blender::ed::outliner {
 
 class TreeElementDriverBase final : public AbstractTreeElement {

source/blender/editors/space_outliner/tree/tree_iterator.hh

@@ -10,9 +10,11 @@
 
 struct ListBase;
 struct SpaceOutliner;
-struct TreeElement;
 
 namespace blender::ed::outliner {
+
+struct TreeElement;
+
 namespace tree_iterator {
 
 using VisitorFn = FunctionRef<void(TreeElement *)>;

source/blender/makesdna/DNA_space_types.h

@@ -50,14 +50,19 @@ struct wmTimer;
 /** Defined in `buttons_intern.h`. */
 typedef struct SpaceProperties_Runtime SpaceProperties_Runtime;
 
-/** Defined in `node_intern.hh`. */
 #ifdef __cplusplus
 namespace blender::ed::space_node {
 struct SpaceNode_Runtime;
 }  // namespace blender::ed::space_node
 using SpaceNode_Runtime = blender::ed::space_node::SpaceNode_Runtime;
+
+namespace blender::ed::outliner {
+struct SpaceOutliner_Runtime;
+}  // namespace blender::ed::outliner
+using SpaceOutliner_Runtime = blender::ed::outliner::SpaceOutliner_Runtime;
 #else
 typedef struct SpaceNode_Runtime SpaceNode_Runtime;
+typedef struct SpaceOutliner_Runtime SpaceOutliner_Runtime;
 #endif
 
 /** Defined in `file_intern.h`. */
@@ -252,9 +257,6 @@ typedef enum eSpaceButtons_OutlinerSync {
 /** \name Outliner
  * \{ */
 
-/** Defined in `outliner_intern.hh`. */
-typedef struct SpaceOutliner_Runtime SpaceOutliner_Runtime;
-
 /** Outliner */
 typedef struct SpaceOutliner {
   SpaceLink *next, *prev;