UI: Drag and Drop Constraints, Layout Updates

This patch implements the list panel system D7490 for constraints.
In this case the panels are still defined in Python.

The layouts are also updated to use subpanels and the a more organized
single column layout. There may be more tweaks necessary for the
layouts.

Reviewed By: Severin, billreynish, Mets

Differential Revision: https://developer.blender.org/D7499

3 files changed, 73 insertions, 0 deletions

diff --git a/source/blender/editors/object/object_constraint.c b/source/blender/editors/object/object_constraint.c
index a2d33ffe413..5746480e3f8 100644
--- a/source/blender/editors/object/object_constraint.c
+++ b/source/blender/editors/object/object_constraint.c
@@ -1557,6 +1557,77 @@ void CONSTRAINT_OT_move_up(wmOperatorType *ot)
 /** \} */
 
 /* ------------------------------------------------------------------- */
+/** \name Move Constraint To Index Operator
+ * \{ */
+
+static int constraint_move_to_index_exec(bContext *C, wmOperator *op)
+{
+  Object *ob = ED_object_active_context(C);
+  bConstraint *con = edit_constraint_property_get(op, ob, 0);
+
+  int new_index = RNA_int_get(op->ptr, "index");
+  if (new_index < 0) {
+    new_index = 0;
+  }
+
+  if (con) {
+    ListBase *conlist = ED_object_constraint_list_from_constraint(ob, con, NULL);
+    int current_index = BLI_findindex(conlist, con);
+    BLI_assert(current_index >= 0);
+
+    BLI_listbase_link_move(conlist, con, new_index - current_index);
+
+    WM_event_add_notifier(C, NC_OBJECT | ND_CONSTRAINT, ob);
+
+    return OPERATOR_FINISHED;
+  }
+
+  return OPERATOR_CANCELLED;
+}
+
+static int constraint_move_to_index_invoke(bContext *C,
+                                           wmOperator *op,
+                                           const wmEvent *UNUSED(event))
+{
+  if (edit_constraint_invoke_properties(C, op)) {
+    return constraint_move_to_index_exec(C, op);
+  }
+  else {
+    return OPERATOR_CANCELLED;
+  }
+}
+
+void CONSTRAINT_OT_move_to_index(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Move Constraint To Index";
+  ot->idname = "CONSTRAINT_OT_move_to_index";
+  ot->description =
+      "Change the constraint's position in the list so it evaluates after the set number of "
+      "others";
+
+  /* callbacks */
+  ot->exec = constraint_move_to_index_exec;
+  ot->invoke = constraint_move_to_index_invoke;
+  ot->poll = edit_constraint_poll;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+  edit_constraint_properties(ot);
+  RNA_def_int(ot->srna,
+              "index",
+              0,
+              0,
+              INT_MAX,
+              "Index",
+              "The index to move the constraint to",
+              0,
+              INT_MAX);
+}
+
+/** \} */
+
+/* ------------------------------------------------------------------- */
 /** \name Clear Pose Constraints Operator
  * \{ */
 
diff --git a/source/blender/editors/object/object_intern.h b/source/blender/editors/object/object_intern.h
index c5a6e38fbcb..1cd91f7c1f3 100644
--- a/source/blender/editors/object/object_intern.h
+++ b/source/blender/editors/object/object_intern.h
@@ -217,6 +217,7 @@ void POSE_OT_ik_clear(struct wmOperatorType *ot);
 void CONSTRAINT_OT_delete(struct wmOperatorType *ot);
 
 void CONSTRAINT_OT_move_up(struct wmOperatorType *ot);
+void CONSTRAINT_OT_move_to_index(struct wmOperatorType *ot);
 void CONSTRAINT_OT_move_down(struct wmOperatorType *ot);
 
 void CONSTRAINT_OT_stretchto_reset(struct wmOperatorType *ot);
diff --git a/source/blender/editors/object/object_ops.c b/source/blender/editors/object/object_ops.c
index 05f1ced8615..84bc10f8064 100644
--- a/source/blender/editors/object/object_ops.c
+++ b/source/blender/editors/object/object_ops.c
@@ -179,6 +179,7 @@ void ED_operatortypes_object(void)
   WM_operatortype_append(CONSTRAINT_OT_delete);
   WM_operatortype_append(CONSTRAINT_OT_move_up);
   WM_operatortype_append(CONSTRAINT_OT_move_down);
+  WM_operatortype_append(CONSTRAINT_OT_move_to_index);
   WM_operatortype_append(CONSTRAINT_OT_stretchto_reset);
   WM_operatortype_append(CONSTRAINT_OT_limitdistance_reset);
   WM_operatortype_append(CONSTRAINT_OT_childof_set_inverse);