GPv3: Material Isolate Operator

This ports the `gpencil.material_isolate` operator to GPv3.

Pull Request: https://projects.blender.org/blender/blender/pulls/128549

scripts/startup/bl_ui/properties_grease_pencil_common.py

@@ -610,8 +610,11 @@ class GreasePencilMaterialsPanel:
                 col.separator()
 
                 sub = col.column(align=True)
-                sub.operator("gpencil.material_isolate", icon='RESTRICT_VIEW_ON', text="").affect_visibility = True
-                sub.operator("gpencil.material_isolate", icon='LOCKED', text="").affect_visibility = False
+                sub.operator(
+                    "grease_pencil.material_isolate",
+                    icon='RESTRICT_VIEW_ON',
+                    text="").affect_visibility = True
+                sub.operator("grease_pencil.material_isolate", icon='LOCKED', text="").affect_visibility = False
 
             if show_full_ui:
                 row = layout.row()

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

@@ -401,6 +401,104 @@ static void GREASE_PENCIL_OT_material_copy_to_object(wmOperatorType *ot)
   RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
 }
 
+static int material_isolate_exec(bContext *C, wmOperator *op)
+{
+  Object *ob = CTX_data_active_object(C);
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(ob->data);
+  Material *active_ma = BKE_gpencil_material(ob, ob->actcol);
+  MaterialGPencilStyle *active_material = BKE_gpencil_material_settings(ob, ob->actcol);
+  MaterialGPencilStyle *gp_style;
+
+  int flags = GP_MATERIAL_LOCKED;
+  bool isolate = false;
+
+  if (RNA_boolean_get(op->ptr, "affect_visibility")) {
+    flags |= GP_MATERIAL_HIDE;
+  }
+
+  if (active_material == nullptr) {
+    return OPERATOR_CANCELLED;
+  }
+
+  /* Test whether to isolate or clear all flags */
+  Material *ma = nullptr;
+  short *totcol = BKE_object_material_len_p(ob);
+  for (short i = 0; i < *totcol; i++) {
+    ma = BKE_gpencil_material(ob, i + 1);
+    /* Skip if this is the active one */
+    if (ELEM(ma, nullptr, active_ma)) {
+      continue;
+    }
+
+    /* If the flags aren't set, that means that the color is
+     * not alone, so we have some colors to isolate still
+     */
+    gp_style = ma->gp_style;
+    if ((gp_style->flag & flags) == 0) {
+      isolate = true;
+      break;
+    }
+  }
+
+  /* Set/Clear flags as appropriate */
+  if (isolate) {
+    /* Set flags on all "other" colors */
+    for (short i = 0; i < *totcol; i++) {
+      ma = BKE_gpencil_material(ob, i + 1);
+      if (ma == nullptr) {
+        continue;
+      }
+      gp_style = ma->gp_style;
+      if (gp_style == active_material) {
+        continue;
+      }
+      gp_style->flag |= flags;
+      DEG_id_tag_update(&ma->id, ID_RECALC_SYNC_TO_EVAL);
+    }
+  }
+  else {
+    /* Clear flags - Restore everything else */
+    for (short i = 0; i < *totcol; i++) {
+      ma = BKE_gpencil_material(ob, i + 1);
+      if (ma == nullptr) {
+        continue;
+      }
+      gp_style = ma->gp_style;
+      gp_style->flag &= ~flags;
+      DEG_id_tag_update(&ma->id, ID_RECALC_SYNC_TO_EVAL);
+    }
+  }
+
+  DEG_id_tag_update(&grease_pencil.id, ID_RECALC_GEOMETRY);
+  WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_EDITED, nullptr);
+
+  return OPERATOR_FINISHED;
+}
+
+static void GREASE_PENCIL_OT_material_isolate(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Isolate Material";
+  ot->idname = "GREASE_PENCIL_OT_material_isolate";
+  ot->description =
+      "Toggle whether the active material is the only one that is editable and/or visible";
+
+  /* callbacks */
+  ot->exec = material_isolate_exec;
+  ot->poll = active_grease_pencil_material_poll;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  /* properties */
+  RNA_def_boolean(ot->srna,
+                  "affect_visibility",
+                  false,
+                  "Affect Visibility",
+                  "In addition to toggling "
+                  "the editability, also affect the visibility");
+}
+
 /** \} */
 
 }  // namespace blender::ed::greasepencil
@@ -415,4 +513,5 @@ void ED_operatortypes_grease_pencil_material()
   WM_operatortype_append(GREASE_PENCIL_OT_material_lock_unused);
   WM_operatortype_append(GREASE_PENCIL_OT_material_lock_unselected);
   WM_operatortype_append(GREASE_PENCIL_OT_material_copy_to_object);
+  WM_operatortype_append(GREASE_PENCIL_OT_material_isolate);
 }

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

@@ -7,6 +7,7 @@
  */
 
 #include "BKE_context.hh"
+#include "BKE_material.h"
 #include "BKE_paint.hh"
 
 #include "DNA_brush_enums.h"
@@ -33,6 +34,16 @@ bool active_grease_pencil_poll(bContext *C)
   return true;
 }
 
+bool active_grease_pencil_material_poll(bContext *C)
+{
+  Object *object = CTX_data_active_object(C);
+  if (object == nullptr || object->type != OB_GREASE_PENCIL) {
+    return false;
+  }
+  short *totcolp = BKE_object_material_len_p(object);
+  return *totcolp > 0;
+}
+
 bool editable_grease_pencil_poll(bContext *C)
 {
   Object *object = CTX_data_active_object(C);

source/blender/editors/include/ED_grease_pencil.hh

@@ -286,6 +286,7 @@ void create_keyframe_edit_data_selected_frames_list(KeyframeEditData *ked,
                                                     const bke::greasepencil::Layer &layer);
 
 bool active_grease_pencil_poll(bContext *C);
+bool active_grease_pencil_material_poll(bContext *C);
 bool editable_grease_pencil_poll(bContext *C);
 bool active_grease_pencil_layer_poll(bContext *C);
 bool editable_grease_pencil_point_selection_poll(bContext *C);