UI: show gizmo while transforming

When interacting with translate/rotate/scale gizmo, show the gizmo while
it's in use. There are some exceptions to this, as showing all scale
gizmos while scaling causes the gizmos to become large & distracting so
in this case only the gizmo being dragged is shown.

Resolves T63743.

4 files changed, 27 insertions, 0 deletions

diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index dec1260ad1d..ac06ababfd4 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -388,6 +388,12 @@ struct wmEventHandler_UI *WM_event_add_ui_handler(const struct bContext *C,
                                                   wmUIHandlerRemoveFunc remove_fn,
                                                   void *user_data,
                                                   char flag);
+
+/**
+ * Return the first modal operator of type \a ot or NULL.
+ */
+wmOperator *WM_operator_find_modal_by_type(wmWindow *win, const wmOperatorType *ot);
+
 /**
  * \param postpone: Enable for `win->modalhandlers`,
  * this is in a running for () loop in wm_handlers_do().
diff --git a/source/blender/windowmanager/gizmo/WM_gizmo_api.h b/source/blender/windowmanager/gizmo/WM_gizmo_api.h
index 80d29bb8c40..663c8a0baed 100644
--- a/source/blender/windowmanager/gizmo/WM_gizmo_api.h
+++ b/source/blender/windowmanager/gizmo/WM_gizmo_api.h
@@ -388,6 +388,8 @@ void WM_gizmomap_message_subscribe(const struct bContext *C,
                                    struct ARegion *region,
                                    struct wmMsgBus *mbus);
 bool WM_gizmomap_is_any_selected(const struct wmGizmoMap *gzmap);
+struct wmGizmo *WM_gizmomap_get_modal(const struct wmGizmoMap *gzmap);
+
 /**
  * \note We could use a callback to define bounds, for now just use matrix location.
  */
diff --git a/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c b/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c
index f481f19045d..36faeab161f 100644
--- a/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c
+++ b/source/blender/windowmanager/gizmo/intern/wm_gizmo_map.c
@@ -229,6 +229,11 @@ bool WM_gizmomap_is_any_selected(const wmGizmoMap *gzmap)
   return gzmap->gzmap_context.select.len != 0;
 }
 
+wmGizmo *WM_gizmomap_get_modal(const wmGizmoMap *gzmap)
+{
+  return gzmap->gzmap_context.modal;
+}
+
 bool WM_gizmomap_minmax(const wmGizmoMap *gzmap,
                         bool UNUSED(use_hidden),
                         bool use_select,
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index 3ff3117dafe..b28ae16c5a1 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -4583,6 +4583,20 @@ void WM_event_remove_area_handler(ListBase *handlers, void *area)
   }
 }
 
+wmOperator *WM_operator_find_modal_by_type(wmWindow *win, const wmOperatorType *ot)
+{
+  LISTBASE_FOREACH (wmEventHandler *, handler_base, &win->modalhandlers) {
+    if (handler_base->type != WM_HANDLER_TYPE_OP) {
+      continue;
+    }
+    wmEventHandler_Op *handler = (wmEventHandler_Op *)handler_base;
+    if (handler->op && handler->op->type == ot) {
+      return handler->op;
+    }
+  }
+  return NULL;
+}
+
 #if 0
 static void WM_event_remove_handler(ListBase *handlers, wmEventHandler *handler)
 {