UI: Improved Area Icon Using a SpaceType Callback

Centralized method to obtain ScrArea icons. Areas can add an optional
space_icon_get callback to provide an icon that differs by subtype. If
not defined then ED_area_icon will return RNA UI icon, which is correct
in cases without area subtypes.

Pull Request: https://projects.blender.org/blender/blender/pulls/124556

source/blender/blenkernel/BKE_screen.hh

@@ -128,6 +128,8 @@ struct SpaceType {
 
   /* Return a custom name, based on subtype or other reason. */
   blender::StringRefNull (*space_name_get)(ScrArea *area);
+  /* Return a custom icon, based on subtype or other reason. */
+  int (*space_icon_get)(const ScrArea *area);
 
   /**
    * Update pointers for all structs directly owned by this space.

source/blender/editors/include/ED_screen.hh

@@ -211,6 +211,7 @@ int ED_area_header_switchbutton(const bContext *C, uiBlock *block, int yco);
 void ED_area_init(wmWindowManager *wm, wmWindow *win, ScrArea *area);
 void ED_area_exit(bContext *C, ScrArea *area);
 blender::StringRefNull ED_area_name(ScrArea *area);
+int ED_area_icon(const ScrArea *area);
 int ED_screen_area_active(const bContext *C);
 void ED_screen_global_areas_refresh(wmWindow *win);
 void ED_screen_global_areas_sync(wmWindow *win);

source/blender/editors/screen/screen_edit.cc

@@ -916,6 +916,17 @@ blender::StringRefNull ED_area_name(ScrArea *area)
   return item.name;
 }
 
+int ED_area_icon(const ScrArea *area)
+{
+  if (area->type->space_icon_get) {
+    return area->type->space_icon_get(area);
+  }
+
+  const int index = RNA_enum_from_value(rna_enum_space_type_items, area->spacetype);
+  const EnumPropertyItem item = rna_enum_space_type_items[index];
+  return item.icon;
+}
+
 /* *********************************** */
 
 /* case when on area-edge or in azones, or outside window */

source/blender/editors/space_action/space_action.cc

@@ -874,6 +874,14 @@ static blender::StringRefNull action_space_name_get(ScrArea *area)
   return item.name;
 }
 
+static int action_space_icon_get(const ScrArea *area)
+{
+  SpaceAction *sact = static_cast<SpaceAction *>(area->spacedata.first);
+  const int index = RNA_enum_from_value(rna_enum_space_action_mode_items, sact->mode);
+  const EnumPropertyItem item = rna_enum_space_action_mode_items[index];
+  return item.icon;
+}
+
 static void action_space_blend_read_data(BlendDataReader * /*reader*/, SpaceLink *sl)
 {
   SpaceAction *saction = (SpaceAction *)sl;
@@ -907,6 +915,7 @@ void ED_spacetype_action()
   st->space_subtype_get = action_space_subtype_get;
   st->space_subtype_set = action_space_subtype_set;
   st->space_name_get = action_space_name_get;
+  st->space_icon_get = action_space_icon_get;
   st->blend_read_data = action_space_blend_read_data;
   st->blend_read_after_liblink = nullptr;
   st->blend_write = action_space_blend_write;

source/blender/editors/space_file/space_file.cc

@@ -839,6 +839,14 @@ static blender::StringRefNull file_space_name_get(ScrArea *area)
   return item.name;
 }
 
+static int file_space_icon_get(const ScrArea *area)
+{
+  SpaceFile *sfile = static_cast<SpaceFile *>(area->spacedata.first);
+  const int index = RNA_enum_from_value(rna_enum_space_file_browse_mode_items, sfile->browse_mode);
+  const EnumPropertyItem item = rna_enum_space_file_browse_mode_items[index];
+  return item.icon;
+}
+
 static void file_id_remap(ScrArea *area,
                           SpaceLink *sl,
                           const blender::bke::id::IDRemapper & /*mappings*/)
@@ -935,6 +943,7 @@ void ED_spacetype_file()
   st->space_subtype_get = file_space_subtype_get;
   st->space_subtype_set = file_space_subtype_set;
   st->space_name_get = file_space_name_get;
+  st->space_icon_get = file_space_icon_get;
   st->context = file_context;
   st->id_remap = file_id_remap;
   st->foreach_id = file_foreach_id;

source/blender/editors/space_graph/space_graph.cc

@@ -876,6 +876,14 @@ static blender::StringRefNull graph_space_name_get(ScrArea *area)
   return item.name;
 }
 
+static int graph_space_icon_get(const ScrArea *area)
+{
+  SpaceGraph *sgraph = static_cast<SpaceGraph *>(area->spacedata.first);
+  const int index = RNA_enum_from_value(rna_enum_space_graph_mode_items, sgraph->mode);
+  const EnumPropertyItem item = rna_enum_space_graph_mode_items[index];
+  return item.icon;
+}
+
 static void graph_space_blend_read_data(BlendDataReader *reader, SpaceLink *sl)
 {
   SpaceGraph *sipo = (SpaceGraph *)sl;
@@ -923,6 +931,7 @@ void ED_spacetype_ipo()
   st->space_subtype_get = graph_space_subtype_get;
   st->space_subtype_set = graph_space_subtype_set;
   st->space_name_get = graph_space_name_get;
+  st->space_icon_get = graph_space_icon_get;
   st->blend_read_data = graph_space_blend_read_data;
   st->blend_read_after_liblink = nullptr;
   st->blend_write = graph_space_blend_write;

source/blender/editors/space_image/space_image.cc

@@ -1085,6 +1085,14 @@ static blender::StringRefNull image_space_name_get(ScrArea *area)
   return item.name;
 }
 
+static int image_space_icon_get(const ScrArea *area)
+{
+  SpaceImage *sima = static_cast<SpaceImage *>(area->spacedata.first);
+  const int index = RNA_enum_from_value(rna_enum_space_image_mode_items, sima->mode);
+  const EnumPropertyItem item = rna_enum_space_image_mode_items[index];
+  return item.icon;
+}
+
 static void image_space_blend_read_data(BlendDataReader * /*reader*/, SpaceLink *sl)
 {
   SpaceImage *sima = (SpaceImage *)sl;
@@ -1141,6 +1149,7 @@ void ED_spacetype_image()
   st->space_subtype_get = image_space_subtype_get;
   st->space_subtype_set = image_space_subtype_set;
   st->space_name_get = image_space_name_get;
+  st->space_icon_get = image_space_icon_get;
   st->blend_read_data = image_space_blend_read_data;
   st->blend_read_after_liblink = nullptr;
   st->blend_write = image_space_blend_write;

source/blender/editors/space_node/space_node.cc

@@ -1341,6 +1341,13 @@ static blender::StringRefNull node_space_name_get(ScrArea *area)
   return tree_type->ui_name;
 }
 
+static int node_space_icon_get(const ScrArea *area)
+{
+  SpaceNode *snode = static_cast<SpaceNode *>(area->spacedata.first);
+  bke::bNodeTreeType *tree_type = bke::ntreeTypeFind(snode->tree_idname);
+  return tree_type->ui_icon;
+}
+
 static void node_space_blend_read_data(BlendDataReader *reader, SpaceLink *sl)
 {
   SpaceNode *snode = (SpaceNode *)sl;
@@ -1395,6 +1402,7 @@ void ED_spacetype_node()
   st->space_subtype_get = node_space_subtype_get;
   st->space_subtype_set = node_space_subtype_set;
   st->space_name_get = node_space_name_get;
+  st->space_icon_get = node_space_icon_get;
   st->blend_read_data = node_space_blend_read_data;
   st->blend_read_after_liblink = nullptr;
   st->blend_write = node_space_blend_write;