Geometry Nodes: active modifier + geometry nodes editor

This commit adds functions to set and get the object's active
modifier, which is stored as a flag in the ModifierData struct,
similar to constraints. This will be used to set the context in
the node editor. There are no visible changes in this commit.

Similar to how the node editor context works for materials, this commit
makes the node group displayed in the node editor depend on the active
object and its active modifier. To keep the node group from changing,
just pin the node group in the header.

* Shortcuts performed while there is an active modifier will affect
  only that modifier (the exception is the A to expand the modifiers).
* Clicking anywhere on the empty space in a modifier's panel will make it active.

These changes require some refactoring of object modifier code. First
is splitting up the modifier property invoke callback, which now needs
to be able to get the active modifier separately from the hovered
modifier for the different operators.

Second is a change to removing modifiers, where there is now a separate
function to remove a modifier from an object's list, in order to handle
changing the active.

Finally, the panel handler needs a small tweak so that this "click in panel"
event can be handled afterwards.

1 files changed, 149 insertions, 81 deletions

diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index 6bd95cd8e51..7d12fa1805b 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -36,6 +36,7 @@
 #include "DNA_meshdata_types.h"
 #include "DNA_object_force_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_space_types.h"
 
 #include "BLI_bitmap.h"
 #include "BLI_listbase.h"
@@ -239,6 +240,8 @@ ModifierData *ED_object_modifier_add(
     }
   }
 
+  BKE_object_modifier_set_active(ob, new_md);
+
   DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
   DEG_relations_tag_update(bmain);
 
@@ -384,7 +387,7 @@ static bool object_modifier_remove(
     ob->mode &= ~OB_MODE_PARTICLE_EDIT;
   }
 
-  BLI_remlink(&ob->modifiers, md);
+  BKE_modifier_remove_from_list(ob, md);
   BKE_modifier_free(md);
   BKE_object_free_derived_caches(ob);
 
@@ -444,8 +447,7 @@ bool ED_object_modifier_move_up(ReportList *reports, Object *ob, ModifierData *m
       }
     }
 
-    BLI_remlink(&ob->modifiers, md);
-    BLI_insertlinkbefore(&ob->modifiers, md->prev, md);
+    BLI_listbase_swaplinks(&ob->modifiers, md, md->prev);
   }
   else {
     BKE_report(reports, RPT_WARNING, "Cannot move modifier beyond the start of the list");
@@ -469,8 +471,7 @@ bool ED_object_modifier_move_down(ReportList *reports, Object *ob, ModifierData
       }
     }
 
-    BLI_remlink(&ob->modifiers, md);
-    BLI_insertlinkafter(&ob->modifiers, md->next, md);
+    BLI_listbase_swaplinks(&ob->modifiers, md, md->next);
   }
   else {
     BKE_report(reports, RPT_WARNING, "Cannot move modifier beyond the end of the list");
@@ -896,7 +897,7 @@ bool ED_object_modifier_apply(Main *bmain,
   md_eval->mode = prev_mode;
 
   if (!keep_modifier) {
-    BLI_remlink(&ob->modifiers, md);
+    BKE_modifier_remove_from_list(ob, md);
     BKE_modifier_free(md);
   }
 
@@ -914,6 +915,7 @@ int ED_object_modifier_copy(
     nmd = object_copy_particle_system(bmain, scene, ob, ((ParticleSystemModifierData *)md)->psys);
     BLI_remlink(&ob->modifiers, nmd);
     BLI_insertlinkafter(&ob->modifiers, md, nmd);
+    BKE_object_modifier_set_active(ob, nmd);
     return true;
   }
 
@@ -921,6 +923,7 @@ int ED_object_modifier_copy(
   BKE_modifier_copydata(md, nmd);
   BLI_insertlinkafter(&ob->modifiers, md, nmd);
   BKE_modifier_unique_name(&ob->modifiers, nmd);
+  BKE_object_modifier_set_active(ob, nmd);
 
   nmd->flag |= eModifierFlag_OverrideLibrary_Local;
 
@@ -1024,7 +1027,7 @@ void OBJECT_OT_modifier_add(wmOperatorType *ot)
 /** \} */
 
 /* ------------------------------------------------------------------- */
-/** \name Generic Functions For Operators
+/** \name Generic Poll Function and Properties
  *
  * Using modifier names and data context.
  * \{ */
@@ -1090,16 +1093,15 @@ static void edit_modifier_report_property(wmOperatorType *ot)
   RNA_def_property_flag(prop, PROP_HIDDEN);
 }
 
-/**
- * \param event: If this isn't NULL, the operator will also look for panels underneath
- * the cursor with customdata set to a modifier.
- * \param r_retval: This should be used if #event is used in order to to return
- * #OPERATOR_PASS_THROUGH to check other operators with the same key set.
- */
-bool edit_modifier_invoke_properties(bContext *C,
-                                     wmOperator *op,
-                                     const wmEvent *event,
-                                     int *r_retval)
+/** \} */
+
+/* ------------------------------------------------------------------- */
+/** \name Generic Invoke Functions
+ *
+ * Using modifier names and data context.
+ * \{ */
+
+bool edit_modifier_invoke_properties(bContext *C, wmOperator *op)
 {
   if (RNA_struct_property_is_set(op->ptr, "modifier")) {
     return true;
@@ -1112,27 +1114,6 @@ bool edit_modifier_invoke_properties(bContext *C,
     return true;
   }
 
-  /* Check the custom data of panels under the mouse for a modifier. */
-  if (event != NULL) {
-    PointerRNA *panel_ptr = UI_region_panel_custom_data_under_cursor(C, event);
-
-    if (!(panel_ptr == NULL || RNA_pointer_is_null(panel_ptr))) {
-      if (RNA_struct_is_a(panel_ptr->type, &RNA_Modifier)) {
-        ModifierData *md = panel_ptr->data;
-        RNA_string_set(op->ptr, "modifier", md->name);
-        return true;
-      }
-      BLI_assert(r_retval != NULL); /* We need the return value in this case. */
-      if (r_retval != NULL) {
-        *r_retval = (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
-      }
-      return false;
-    }
-  }
-
-  if (r_retval != NULL) {
-    *r_retval = OPERATOR_CANCELLED;
-  }
   return false;
 }
 
@@ -1195,13 +1176,14 @@ static int modifier_remove_exec(bContext *C, wmOperator *op)
   return OPERATOR_FINISHED;
 }
 
-static int modifier_remove_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_remove_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_remove_exec(C, op);
   }
-  return retval;
+
+  /* Work around multiple operators using the same shortcut. */
+  return (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
 }
 
 void OBJECT_OT_modifier_remove(wmOperatorType *ot)
@@ -1241,13 +1223,13 @@ static int modifier_move_up_exec(bContext *C, wmOperator *op)
   return OPERATOR_FINISHED;
 }
 
-static int modifier_move_up_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_move_up_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_move_up_exec(C, op);
   }
-  return retval;
+  /* Work around multiple operators using the same shortcut. */
+  return (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
 }
 
 void OBJECT_OT_modifier_move_up(wmOperatorType *ot)
@@ -1286,13 +1268,13 @@ static int modifier_move_down_exec(bContext *C, wmOperator *op)
   return OPERATOR_FINISHED;
 }
 
-static int modifier_move_down_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_move_down_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_move_down_exec(C, op);
   }
-  return retval;
+  /* Work around multiple operators using the same shortcut. */
+  return (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
 }
 
 void OBJECT_OT_modifier_move_down(wmOperatorType *ot)
@@ -1329,13 +1311,12 @@ static int modifier_move_to_index_exec(bContext *C, wmOperator *op)
   return OPERATOR_FINISHED;
 }
 
-static int modifier_move_to_index_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_move_to_index_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_move_to_index_exec(C, op);
   }
-  return retval;
+  return OPERATOR_CANCELLED;
 }
 
 void OBJECT_OT_modifier_move_to_index(wmOperatorType *ot)
@@ -1434,13 +1415,13 @@ static int modifier_apply_exec(bContext *C, wmOperator *op)
   return modifier_apply_exec_ex(C, op, MODIFIER_APPLY_DATA, false);
 }
 
-static int modifier_apply_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_apply_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_apply_exec(C, op);
   }
-  return retval;
+  /* Work around multiple operators using the same shortcut. */
+  return (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
 }
 
 void OBJECT_OT_modifier_apply(wmOperatorType *ot)
@@ -1478,13 +1459,15 @@ static int modifier_apply_as_shapekey_exec(bContext *C, wmOperator *op)
   return modifier_apply_exec_ex(C, op, MODIFIER_APPLY_SHAPE, keep);
 }
 
-static int modifier_apply_as_shapekey_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_apply_as_shapekey_invoke(bContext *C,
+                                             wmOperator *op,
+                                             const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_apply_as_shapekey_exec(C, op);
   }
-  return retval;
+  /* Work around multiple operators using the same shortcut. */
+  return (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
 }
 
 static char *modifier_apply_as_shapekey_get_description(struct bContext *UNUSED(C),
@@ -1546,7 +1529,7 @@ static int modifier_convert_exec(bContext *C, wmOperator *op)
 
 static int modifier_convert_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_convert_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -1590,13 +1573,13 @@ static int modifier_copy_exec(bContext *C, wmOperator *op)
   return OPERATOR_FINISHED;
 }
 
-static int modifier_copy_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+static int modifier_copy_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  int retval;
-  if (edit_modifier_invoke_properties(C, op, event, &retval)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return modifier_copy_exec(C, op);
   }
-  return retval;
+  /* Work around multiple operators using the same shortcut. */
+  return (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
 }
 
 void OBJECT_OT_modifier_copy(wmOperatorType *ot)
@@ -1617,6 +1600,91 @@ void OBJECT_OT_modifier_copy(wmOperatorType *ot)
 /** \} */
 
 /* ------------------------------------------------------------------- */
+/** \name Set Active Modifier Operator
+ * \{ */
+
+static int modifier_set_active_exec(bContext *C, wmOperator *op)
+{
+  Object *ob = ED_object_active_context(C);
+  ModifierData *md = edit_modifier_property_get(op, ob, 0);
+
+  /* If there is no modifier set for this operator, clear the active modifier field. */
+  BKE_object_modifier_set_active(ob, md);
+
+  WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
+
+  return OPERATOR_FINISHED;
+}
+
+/**
+ * Get the modifier below the mouse cursor modifier without checking the context pointer.
+ * Used in order to set the active modifier on mouse click. If this checked the context
+ * pointer then it would always set the active modifier to the already active modifier.
+ *
+ * \param event: If this isn't NULL, the operator will also look for panels underneath
+ * the cursor with customdata set to a modifier.
+ * \param r_retval: This should be used if #event is used in order to to return
+ * #OPERATOR_PASS_THROUGH to check other operators with the same key set.
+ */
+bool edit_modifier_invoke_properties_with_hover_no_active(bContext *C,
+                                                          wmOperator *op,
+                                                          const wmEvent *event,
+                                                          int *r_retval)
+{
+  if (RNA_struct_property_is_set(op->ptr, "modifier")) {
+    return true;
+  }
+
+  PointerRNA *panel_ptr = UI_region_panel_custom_data_under_cursor(C, event);
+
+  if (!(panel_ptr == NULL || RNA_pointer_is_null(panel_ptr))) {
+    if (RNA_struct_is_a(panel_ptr->type, &RNA_Modifier)) {
+      ModifierData *md = panel_ptr->data;
+      RNA_string_set(op->ptr, "modifier", md->name);
+      return true;
+    }
+    BLI_assert(r_retval != NULL); /* We need the return value in this case. */
+    if (r_retval != NULL) {
+      *r_retval = (OPERATOR_PASS_THROUGH | OPERATOR_CANCELLED);
+    }
+    return false;
+  }
+
+  if (r_retval != NULL) {
+    *r_retval = OPERATOR_CANCELLED;
+  }
+
+  return false;
+}
+
+static int modifier_set_active_invoke(bContext *C, wmOperator *op, const wmEvent *event)
+{
+  int retval;
+  if (edit_modifier_invoke_properties_with_hover_no_active(C, op, event, &retval)) {
+    return modifier_set_active_exec(C, op);
+  }
+
+  return retval;
+}
+
+void OBJECT_OT_modifier_set_active(wmOperatorType *ot)
+{
+  ot->name = "Set Active Modifier";
+  ot->description = "Activate the modifier to use as the context";
+  ot->idname = "OBJECT_OT_modifier_set_active";
+
+  ot->invoke = modifier_set_active_invoke;
+  ot->exec = modifier_set_active_exec;
+  ot->poll = edit_modifier_liboverride_allowed_poll;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
+  edit_modifier_properties(ot);
+}
+
+/** \} */
+
+/* ------------------------------------------------------------------- */
 /** \name Multires Delete Higher Levels Operator
  * \{ */
 
@@ -1650,7 +1718,7 @@ static int multires_higher_levels_delete_invoke(bContext *C,
                                                 wmOperator *op,
                                                 const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return multires_higher_levels_delete_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -1726,7 +1794,7 @@ static int multires_subdivide_exec(bContext *C, wmOperator *op)
 
 static int multires_subdivide_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return multires_subdivide_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -1801,7 +1869,7 @@ static int multires_reshape_exec(bContext *C, wmOperator *op)
 
 static int multires_reshape_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return multires_reshape_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -1862,7 +1930,7 @@ static int multires_external_save_invoke(bContext *C, wmOperator *op, const wmEv
   Mesh *me = ob->data;
   char path[FILE_MAX];
 
-  if (!edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (!edit_modifier_invoke_properties(C, op)) {
     return OPERATOR_CANCELLED;
   }
 
@@ -1980,7 +2048,7 @@ static int multires_base_apply_exec(bContext *C, wmOperator *op)
 
 static int multires_base_apply_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return multires_base_apply_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2032,7 +2100,7 @@ static int multires_unsubdivide_exec(bContext *C, wmOperator *op)
 
 static int multires_unsubdivide_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return multires_unsubdivide_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2088,7 +2156,7 @@ static int multires_rebuild_subdiv_invoke(bContext *C,
                                           wmOperator *op,
                                           const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return multires_rebuild_subdiv_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2451,7 +2519,7 @@ static int skin_armature_create_exec(bContext *C, wmOperator *op)
 
 static int skin_armature_create_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return skin_armature_create_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2527,7 +2595,7 @@ static int correctivesmooth_bind_exec(bContext *C, wmOperator *op)
 
 static int correctivesmooth_bind_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return correctivesmooth_bind_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2602,7 +2670,7 @@ static int meshdeform_bind_exec(bContext *C, wmOperator *op)
 
 static int meshdeform_bind_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return meshdeform_bind_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2656,7 +2724,7 @@ static int explode_refresh_exec(bContext *C, wmOperator *op)
 
 static int explode_refresh_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return explode_refresh_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2857,7 +2925,7 @@ static int ocean_bake_exec(bContext *C, wmOperator *op)
 
 static int ocean_bake_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return ocean_bake_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -2934,7 +3002,7 @@ static int laplaciandeform_bind_exec(bContext *C, wmOperator *op)
 
 static int laplaciandeform_bind_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return laplaciandeform_bind_exec(C, op);
   }
   return OPERATOR_CANCELLED;
@@ -3001,7 +3069,7 @@ static int surfacedeform_bind_exec(bContext *C, wmOperator *op)
 
 static int surfacedeform_bind_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
-  if (edit_modifier_invoke_properties(C, op, NULL, NULL)) {
+  if (edit_modifier_invoke_properties(C, op)) {
     return surfacedeform_bind_exec(C, op);
   }
   return OPERATOR_CANCELLED;