[Bf-blender-cvs] [7979dff9dc7] master: UI: Let object drop operator display hint why it's disabled

[Julian Eisel]

Commit: 7979dff9dc7985cebb530c7490dc730d9c1acf1d
Author: Julian Eisel
Date:   Tue Oct 26 18:06:10 2021 +0200
Branches: master
https://developer.blender.org/rB7979dff9dc7985cebb530c7490dc730d9c1acf1d

UI: Let object drop operator display hint why it's disabled

When dragging an object in non-object mode into a 3D View, there will now be
red text explaining that this is only possible in object mode.
The previous commit enabled this.

===================================================================

M	source/blender/editors/include/ED_screen.h
M	source/blender/editors/object/object_add.c
M	source/blender/editors/screen/screen_ops.c

===================================================================

diff --git a/source/blender/editors/include/ED_screen.h b/source/blender/editors/include/ED_screen.h
index b90c7f27c57..08b6c02a8d0 100644
--- a/source/blender/editors/include/ED_screen.h
+++ b/source/blender/editors/include/ED_screen.h
@@ -317,6 +317,7 @@ bool ED_operator_regionactive(struct bContext *C);
 bool ED_operator_scene(struct bContext *C);
 bool ED_operator_scene_editable(struct bContext *C);
 bool ED_operator_objectmode(struct bContext *C);
+bool ED_operator_objectmode_poll_msg(struct bContext *C);
 
 bool ED_operator_view3d_active(struct bContext *C);
 bool ED_operator_region_view3d_active(struct bContext *C);
diff --git a/source/blender/editors/object/object_add.c b/source/blender/editors/object/object_add.c
index 58767d5f50f..917df0da868 100644
--- a/source/blender/editors/object/object_add.c
+++ b/source/blender/editors/object/object_add.c
@@ -3591,7 +3591,7 @@ void OBJECT_OT_add_named(wmOperatorType *ot)
   /* api callbacks */
   ot->invoke = object_add_drop_xy_generic_invoke;
   ot->exec = object_add_named_exec;
-  ot->poll = ED_operator_objectmode;
+  ot->poll = ED_operator_objectmode_poll_msg;
 
   /* flags */
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
diff --git a/source/blender/editors/screen/screen_ops.c b/source/blender/editors/screen/screen_ops.c
index 5acfc5ac681..fc1b0ed173e 100644
--- a/source/blender/editors/screen/screen_ops.c
+++ b/source/blender/editors/screen/screen_ops.c
@@ -219,6 +219,20 @@ bool ED_operator_objectmode(bContext *C)
   return true;
 }
 
+/**
+ * Same as #ED_operator_objectmode() but additionally sets a "disabled hint". That is, a message
+ * to be displayed to the user explaining why the operator can't be used in current context.
+ */
+bool ED_operator_objectmode_poll_msg(bContext *C)
+{
+  if (!ED_operator_objectmode(C)) {
+    CTX_wm_operator_poll_msg_set(C, "Only supported in object mode");
+    return false;
+  }
+
+  return true;
+}
+
 static bool ed_spacetype_test(bContext *C, int type)
 {
   if (ED_operator_areaactive(C)) {