GPv3: Add operator to add new layer group

scripts/startup/bl_ui/properties_data_grease_pencil.py

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 import bpy
-from bpy.types import Panel
+from bpy.types import Panel, Menu
 
 
 class DataButtonsPanel:
@@ -32,6 +32,15 @@ class DATA_PT_context_grease_pencil(DataButtonsPanel, Panel):
             layout.template_ID(space, "pin_id")
 
 
+class GREASE_PENCIL_MT_grease_pencil_add_layer_extra(Menu):
+    bl_label = "Add Extra"
+
+    def draw(self, context):
+        layout = self.layout
+
+        layout.operator("grease_pencil.layer_group_add", text="Add Group")
+
+
 class DATA_PT_grease_pencil_layers(DataButtonsPanel, Panel):
     bl_label = "Layers"
 
@@ -42,13 +51,17 @@ class DATA_PT_grease_pencil_layers(DataButtonsPanel, Panel):
         row.template_grease_pencil_layer_tree()
 
         col = row.column()
-        col.operator("grease_pencil.layer_add", icon='ADD', text="")
+        sub = col.column(align=True)
+        sub.operator("grease_pencil.layer_add", icon='ADD', text="")
+        sub.menu("GREASE_PENCIL_MT_grease_pencil_add_layer_extra", icon='DOWNARROW_HLT', text="")
+
         col.operator("grease_pencil.layer_remove", icon='REMOVE', text="")
 
 
 classes = (
     DATA_PT_context_grease_pencil,
     DATA_PT_grease_pencil_layers,
+    GREASE_PENCIL_MT_grease_pencil_add_layer_extra,
 )
 
 if __name__ == "__main__":  # only for live edit.

source/blender/blenkernel/BKE_grease_pencil.hh

@@ -207,6 +207,12 @@ class Layer : public ::GreasePencilLayer {
    */
   LayerGroup &parent_group() const;
 
+  /**
+   * \returns the layer as a `TreeNode`.
+   */
+  const TreeNode &as_node() const;
+  TreeNode &as_node();
+
   /**
    * \returns the frames mapping.
    */
@@ -287,6 +293,12 @@ class LayerGroup : public ::GreasePencilLayerTreeGroup {
   LayerGroup &add_group(LayerGroup *group);
   LayerGroup &add_group(StringRefNull name);
 
+  /**
+   * Adds a layer group after \a link and returns it.
+   */
+  LayerGroup &add_group_after(LayerGroup *group, TreeNode *link);
+  LayerGroup &add_group_after(StringRefNull name, TreeNode *link);
+
   /**
    * Adds a layer at the end of this group and returns it.
    */
@@ -359,6 +371,15 @@ inline LayerGroup &Layer::parent_group() const
   return this->base.parent->wrap();
 }
 
+inline const TreeNode &Layer::as_node() const
+{
+  return *reinterpret_cast<const TreeNode *>(this);
+}
+inline TreeNode &Layer::as_node()
+{
+  return *reinterpret_cast<TreeNode *>(this);
+}
+
 namespace convert {
 
 void legacy_gpencil_frame_to_grease_pencil_drawing(const bGPDframe &gpf,

source/blender/blenkernel/intern/grease_pencil.cc

@@ -631,6 +631,23 @@ LayerGroup &LayerGroup::add_group(StringRefNull name)
   return this->add_group(new_group);
 }
 
+LayerGroup &LayerGroup::add_group_after(LayerGroup *group, TreeNode *link)
+{
+  BLI_assert(group != nullptr && link != nullptr);
+  BLI_insertlinkafter(&this->children,
+                      reinterpret_cast<GreasePencilLayerTreeNode *>(link),
+                      reinterpret_cast<GreasePencilLayerTreeNode *>(group));
+  group->base.parent = reinterpret_cast<GreasePencilLayerTreeGroup *>(this);
+  this->tag_nodes_cache_dirty();
+  return *group;
+}
+
+LayerGroup &LayerGroup::add_group_after(StringRefNull name, TreeNode *link)
+{
+  LayerGroup *new_group = MEM_new<LayerGroup>(__func__, name);
+  return this->add_group_after(new_group, link);
+}
+
 Layer &LayerGroup::add_layer(Layer *layer)
 {
   BLI_assert(layer != nullptr);
@@ -1245,7 +1262,7 @@ static blender::VectorSet<blender::StringRefNull> get_node_names(GreasePencil &g
   return names;
 }
 
-static bool check_unique_layer_cb(void *arg, const char *name)
+static bool check_unique_node_cb(void *arg, const char *name)
 {
   using namespace blender;
   VectorSet<StringRefNull> &names = *reinterpret_cast<VectorSet<StringRefNull> *>(arg);
@@ -1254,7 +1271,12 @@ static bool check_unique_layer_cb(void *arg, const char *name)
 
 static bool unique_layer_name(VectorSet<blender::StringRefNull> &names, char *name)
 {
-  return BLI_uniquename_cb(check_unique_layer_cb, &names, "GP_Layer", '.', name, MAX_NAME);
+  return BLI_uniquename_cb(check_unique_node_cb, &names, "GP_Layer", '.', name, MAX_NAME);
+}
+
+static bool unique_layer_group_name(VectorSet<blender::StringRefNull> &names, char *name)
+{
+  return BLI_uniquename_cb(check_unique_node_cb, &names, "GP_Group", '.', name, MAX_NAME);
 }
 
 blender::bke::greasepencil::Layer &GreasePencil::add_layer(
@@ -1284,6 +1306,34 @@ blender::bke::greasepencil::Layer &GreasePencil::add_layer(const blender::String
   return this->add_layer(this->root_group.wrap(), name);
 }
 
+blender::bke::greasepencil::LayerGroup &GreasePencil::add_layer_group(
+    blender::bke::greasepencil::LayerGroup &group, const blender::StringRefNull name)
+{
+  using namespace blender;
+  VectorSet<StringRefNull> names = get_node_names(*this);
+  std::string unique_name(name.c_str());
+  unique_layer_group_name(names, unique_name.data());
+  return group.add_group(unique_name);
+}
+
+blender::bke::greasepencil::LayerGroup &GreasePencil::add_layer_group_after(
+    blender::bke::greasepencil::LayerGroup &group,
+    blender::bke::greasepencil::TreeNode *node,
+    const blender::StringRefNull name)
+{
+  using namespace blender;
+  VectorSet<StringRefNull> names = get_node_names(*this);
+  std::string unique_name(name.c_str());
+  unique_layer_group_name(names, unique_name.data());
+  return group.add_group_after(unique_name, node);
+}
+
+blender::bke::greasepencil::LayerGroup &GreasePencil::add_layer_group(
+    const blender::StringRefNull name)
+{
+  return this->add_layer_group(this->root_group.wrap(), name);
+}
+
 const blender::bke::greasepencil::Layer *GreasePencil::find_layer_by_name(
     const blender::StringRefNull name) const
 {

source/blender/editors/grease_pencil/intern/grease_pencil_layers.cc

@@ -179,6 +179,57 @@ static void GREASE_PENCIL_OT_layer_reorder(wmOperatorType *ot)
       ot->srna, "location", prop_layer_reorder_location, LAYER_REORDER_ABOVE, "Location", "");
 }
 
+static int grease_pencil_layer_group_add_exec(bContext *C, wmOperator *op)
+{
+  using namespace blender::bke::greasepencil;
+  Object *object = CTX_data_active_object(C);
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(object->data);
+
+  int new_layer_group_name_length;
+  char *new_layer_group_name = RNA_string_get_alloc(
+      op->ptr, "new_layer_group_name", nullptr, 0, &new_layer_group_name_length);
+
+  if (grease_pencil.has_active_layer()) {
+    LayerGroup &active_group = grease_pencil.get_active_layer()->parent_group();
+    grease_pencil.add_layer_group_after(active_group,
+                                        &grease_pencil.get_active_layer_for_write()->as_node(),
+                                        new_layer_group_name);
+  }
+  else {
+    grease_pencil.add_layer_group(new_layer_group_name);
+  }
+
+  MEM_SAFE_FREE(new_layer_group_name);
+
+  DEG_id_tag_update(&grease_pencil.id, ID_RECALC_GEOMETRY);
+  WM_event_add_notifier(C, NC_GEOM | ND_DATA, &grease_pencil);
+
+  return OPERATOR_FINISHED;
+}
+
+static void GREASE_PENCIL_OT_layer_group_add(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Add New Layer Group";
+  ot->idname = "GREASE_PENCIL_OT_layer_group_add";
+  ot->description = "Add a new Grease Pencil layer group in the active object";
+
+  /* callbacks */
+  ot->exec = grease_pencil_layer_group_add_exec;
+  ot->poll = active_grease_pencil_poll;
+
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  PropertyRNA *prop = RNA_def_string(ot->srna,
+                                     "new_layer_group_name",
+                                     "GP_Group",
+                                     INT16_MAX,
+                                     "Name",
+                                     "Name of the new layer group");
+  RNA_def_property_flag(prop, PROP_SKIP_SAVE);
+  ot->prop = prop;
+}
+
 }  // namespace blender::ed::greasepencil
 
 void ED_operatortypes_grease_pencil_layers(void)
@@ -187,4 +238,6 @@ void ED_operatortypes_grease_pencil_layers(void)
   WM_operatortype_append(GREASE_PENCIL_OT_layer_add);
   WM_operatortype_append(GREASE_PENCIL_OT_layer_remove);
   WM_operatortype_append(GREASE_PENCIL_OT_layer_reorder);
+
+  WM_operatortype_append(GREASE_PENCIL_OT_layer_group_add);
 }

source/blender/makesdna/DNA_grease_pencil_types.h

@@ -450,6 +450,14 @@ typedef struct GreasePencil {
                                                      blender::bke::greasepencil::Layer *layer,
                                                      blender::StringRefNull name);
 
+  blender::bke::greasepencil::LayerGroup &add_layer_group(
+      blender::bke::greasepencil::LayerGroup &group, blender::StringRefNull name);
+  blender::bke::greasepencil::LayerGroup &add_layer_group(blender::StringRefNull name);
+  blender::bke::greasepencil::LayerGroup &add_layer_group_after(
+      blender::bke::greasepencil::LayerGroup &group,
+      blender::bke::greasepencil::TreeNode *node,
+      blender::StringRefNull name);
+
   const blender::bke::greasepencil::Layer *find_layer_by_name(blender::StringRefNull name) const;
   blender::bke::greasepencil::Layer *find_layer_by_name(blender::StringRefNull name);