scripts/presets/keyconfig/keymap_data/blender_default.py

@@ -4642,6 +4642,9 @@ def km_grease_pencil_edit_mode(params):
         # Active layer
         op_menu("GREASE_PENCIL_MT_layer_active", {"type": 'Y', "value": 'PRESS'}),
 
+        # Move to layer
+        op_menu("GREASE_PENCIL_MT_move_to_layer", {"type": 'M', "value": 'PRESS'}),
+
         # Context menu
         *_template_items_context_menu("VIEW3D_MT_greasepencil_edit_context_menu", params.context_menu_event),
 

scripts/startup/bl_ui/properties_data_grease_pencil.py

@@ -55,6 +55,7 @@ class DATA_PT_grease_pencil_layers(DataButtonsPanel, Panel):
 
         col = row.column()
         sub = col.column(align=True)
+        sub.operator_context = 'EXEC_DEFAULT'
         sub.operator("grease_pencil.layer_add", icon='ADD', text="")
         sub.menu("GREASE_PENCIL_MT_grease_pencil_add_layer_extra", icon='DOWNARROW_HLT', text="")
 

scripts/startup/bl_ui/properties_grease_pencil_common.py

@@ -274,6 +274,30 @@ class GPENCIL_MT_layer_active(Menu):
                 i -= 1
 
 
+class GREASE_PENCIL_MT_move_to_layer(Menu):
+    bl_label = "Move to Layer"
+
+    def draw(self, context):
+        layout = self.layout
+        layout.operator_context = 'INVOKE_REGION_WIN'
+        grease_pencil = context.active_object.data
+
+        layout.operator("grease_pencil.move_to_layer", text="New Layer", icon='ADD').add_new_layer = True
+
+        if not grease_pencil.layers:
+            return
+
+        layout.separator()
+
+        for i in range(len(grease_pencil.layers) - 1, -1, -1):
+            layer = grease_pencil.layers[i]
+            if layer == grease_pencil.layers.active:
+                icon = 'GREASEPENCIL'
+            else:
+                icon = 'NONE'
+            layout.operator("grease_pencil.move_to_layer", text=layer.name, icon=icon).target_layer_name = layer.name
+
+
 class GREASE_PENCIL_MT_layer_active(Menu):
     bl_label = "Change Active Layer"
 
@@ -942,6 +966,7 @@ classes = (
     GPENCIL_UL_layer,
     GPENCIL_UL_masks,
 
+    GREASE_PENCIL_MT_move_to_layer,
     GREASE_PENCIL_MT_layer_active,
 
     GreasePencilFlipTintColors,

scripts/startup/bl_ui/space_view3d.py

@@ -5855,6 +5855,7 @@ class VIEW3D_MT_edit_greasepencil_stroke(Menu):
 
         layout.separator()
 
+        layout.menu("GREASE_PENCIL_MT_move_to_layer")
         layout.menu("VIEW3D_MT_grease_pencil_assign_material")
         layout.operator("grease_pencil.set_active_material")
 

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

@@ -13,6 +13,7 @@
 #include "BLI_math_vector_types.hh"
 #include "BLI_span.hh"
 #include "BLI_stack.hh"
+#include "BLI_string.h"
 #include "BLT_translation.h"
 
 #include "DNA_material_types.h"
@@ -34,13 +35,13 @@
 
 #include "ED_curves.hh"
 #include "ED_grease_pencil.hh"
+#include "ED_screen.hh"
 
+#include "GEO_join_geometries.hh"
 #include "GEO_reorder.hh"
 #include "GEO_smooth_curves.hh"
 #include "GEO_subdivide_curves.hh"
 
-#include "WM_api.hh"
-
 #include "UI_resources.hh"
 
 namespace blender::ed::greasepencil {
@@ -1693,6 +1694,122 @@ static void GREASE_PENCIL_OT_stroke_reorder(wmOperatorType *ot)
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Move To Layer Operator
+ * \{ */
+
+static int grease_pencil_move_to_layer_exec(bContext *C, wmOperator *op)
+{
+  using namespace blender::bke;
+  using namespace bke::greasepencil;
+  const Scene *scene = CTX_data_scene(C);
+  bool changed = false;
+
+  Object *object = CTX_data_active_object(C);
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(object->data);
+
+  int target_layer_name_length;
+  char *target_layer_name = nullptr;
+  BLI_SCOPED_DEFER([&] { MEM_SAFE_FREE(target_layer_name); });
+  const bool add_new_layer = RNA_boolean_get(op->ptr, "add_new_layer");
+  if (add_new_layer) {
+    Layer &new_layer = grease_pencil.add_layer("Layer");
+    target_layer_name = BLI_strdup_null(new_layer.name().c_str());
+  }
+  else {
+    target_layer_name = RNA_string_get_alloc(
+        op->ptr, "target_layer_name", nullptr, 0, &target_layer_name_length);
+  }
+
+  TreeNode *target_node = grease_pencil.find_node_by_name(target_layer_name);
+  if (target_node == nullptr) {
+    BKE_reportf(op->reports, RPT_ERROR, "There is no layer '%s'", target_layer_name);
+    return OPERATOR_CANCELLED;
+  }
+
+  Layer *layer_dst = &target_node->as_layer();
+  if (layer_dst->is_locked()) {
+    BKE_reportf(op->reports, RPT_ERROR, "'%s' Layer is locked", target_layer_name);
+    return OPERATOR_CANCELLED;
+  }
+
+  /* Iterate through all the drawings at current scene frame. */
+  const Array<MutableDrawingInfo> drawings_src = retrieve_editable_drawings(*scene, grease_pencil);
+  for (const MutableDrawingInfo &info : drawings_src) {
+    bke::CurvesGeometry &curves_src = info.drawing.strokes_for_write();
+    IndexMaskMemory memory;
+    const IndexMask selected_strokes = ed::curves::retrieve_selected_curves(curves_src, memory);
+    if (selected_strokes.is_empty()) {
+      continue;
+    }
+
+    if (!layer_dst->has_drawing_at(info.frame_number)) {
+      /* Move geometry to a new drawing in target layer. */
+      grease_pencil.insert_blank_frame(*layer_dst, info.frame_number, 0, BEZT_KEYTYPE_KEYFRAME);
+      Drawing &drawing_dst = *grease_pencil.get_editable_drawing_at(*layer_dst, info.frame_number);
+      drawing_dst.strokes_for_write() = bke::curves_copy_curve_selection(
+          curves_src, selected_strokes, {});
+
+      curves_src.remove_curves(selected_strokes, {});
+
+      drawing_dst.tag_topology_changed();
+    }
+    else {
+      /* Append geometry to drawing in target layer. */
+      Drawing &drawing_dst = *grease_pencil.get_editable_drawing_at(*layer_dst, info.frame_number);
+      bke::CurvesGeometry selected_elems = curves_copy_curve_selection(
+          curves_src, selected_strokes, {});
+      Curves *selected_curves = bke::curves_new_nomain(std::move(selected_elems));
+      Curves *layer_curves = bke::curves_new_nomain(std::move(drawing_dst.strokes_for_write()));
+      std::array<GeometrySet, 2> geometry_sets{GeometrySet::from_curves(selected_curves),
+                                               GeometrySet::from_curves(layer_curves)};
+      GeometrySet joined = geometry::join_geometries(geometry_sets, {});
+      drawing_dst.strokes_for_write() = std::move(joined.get_curves_for_write()->geometry.wrap());
+
+      curves_src.remove_curves(selected_strokes, {});
+
+      drawing_dst.tag_topology_changed();
+    }
+
+    info.drawing.tag_topology_changed();
+    changed = true;
+  }
+
+  if (changed) {
+    /* updates */
+    DEG_id_tag_update(&grease_pencil.id, ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY);
+    WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, nullptr);
+  }
+
+  return OPERATOR_FINISHED;
+}
+
+static void GREASE_PENCIL_OT_move_to_layer(wmOperatorType *ot)
+{
+  PropertyRNA *prop;
+
+  /* identifiers. */
+  ot->name = "Move to Layer";
+  ot->idname = "GREASE_PENCIL_OT_move_to_layer";
+  ot->description = "Move selected strokes to another layer";
+
+  /* callbacks. */
+  ot->exec = grease_pencil_move_to_layer_exec;
+  ot->poll = editable_grease_pencil_poll;
+
+  /* flags. */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  prop = RNA_def_string(
+      ot->srna, "target_layer_name", "Layer", INT16_MAX, "Name", "Target Grease Pencil Layer");
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+  prop = RNA_def_boolean(
+      ot->srna, "add_new_layer", false, "New Layer", "Move selection to a new layer");
+  RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+}
+
+/** \} */
+
 }  // namespace blender::ed::greasepencil
 
 void ED_operatortypes_grease_pencil_edit()
@@ -1715,4 +1832,5 @@ void ED_operatortypes_grease_pencil_edit()
   WM_operatortype_append(GREASE_PENCIL_OT_clean_loose);
   WM_operatortype_append(GREASE_PENCIL_OT_stroke_subdivide);
   WM_operatortype_append(GREASE_PENCIL_OT_stroke_reorder);
+  WM_operatortype_append(GREASE_PENCIL_OT_move_to_layer);
 }

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

@@ -76,13 +76,14 @@ static void GREASE_PENCIL_OT_layer_add(wmOperatorType *ot)
   ot->description = "Add a new Grease Pencil layer in the active object";
 
   /* callbacks */
+  ot->invoke = WM_operator_props_popup_confirm;
   ot->exec = grease_pencil_layer_add_exec;
   ot->poll = active_grease_pencil_poll;
 
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 
   PropertyRNA *prop = RNA_def_string(
-      ot->srna, "new_layer_name", nullptr, INT16_MAX, "Name", "Name of the new layer");
+      ot->srna, "new_layer_name", "Layer", INT16_MAX, "Name", "Name of the new layer");
   RNA_def_property_flag(prop, PROP_SKIP_SAVE);
   ot->prop = prop;
 }

source/blender/editors/include/ED_grease_pencil.hh

@@ -16,6 +16,8 @@
 
 #include "ED_keyframes_edit.hh"
 
+#include "WM_api.hh"
+
 struct bContext;
 struct Main;
 struct Object;