WindowManager: Support Dynamic tooltips when dragging.

Originally the operator name was drawn next to the dragging content.
After that there was an option to add custom, static text with the
dragging content. This patch allows dynamic text to be drawn.

The custom text was implemented as out parameter of the poll function
what made the code unclear. This patch introduces a tooltip function
that separates tooltip generation from the poll function.

NOTE: the text should always be returned in its own memory block. This
block will be freed after it is copied in the drag struct.

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D12104

1 files changed, 33 insertions, 44 deletions

diff --git a/source/blender/editors/space_view3d/space_view3d.c b/source/blender/editors/space_view3d/space_view3d.c
index 54f10e259f9..a2564469c16 100644
--- a/source/blender/editors/space_view3d/space_view3d.c
+++ b/source/blender/editors/space_view3d/space_view3d.c
@@ -513,49 +513,38 @@ static bool view3d_drop_id_in_main_region_poll(bContext *C,
   return WM_drag_is_ID_type(drag, id_type);
 }
 
-static bool view3d_ob_drop_poll(bContext *C,
-                                wmDrag *drag,
-                                const wmEvent *event,
-                                const char **UNUSED(r_tooltip))
+static bool view3d_ob_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
   return view3d_drop_id_in_main_region_poll(C, drag, event, ID_OB);
 }
 
-static bool view3d_collection_drop_poll(bContext *C,
-                                        wmDrag *drag,
-                                        const wmEvent *event,
-                                        const char **UNUSED(r_tooltip))
+static bool view3d_collection_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
   return view3d_drop_id_in_main_region_poll(C, drag, event, ID_GR);
 }
 
-static bool view3d_mat_drop_poll(bContext *C,
-                                 wmDrag *drag,
-                                 const wmEvent *event,
-                                 const char **UNUSED(r_tooltip))
+static bool view3d_mat_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
   return view3d_drop_id_in_main_region_poll(C, drag, event, ID_MA);
 }
 
-static bool view3d_object_data_drop_poll(bContext *C,
-                                         wmDrag *drag,
-                                         const wmEvent *event,
-                                         const char **r_tooltip)
+static bool view3d_object_data_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
   ID_Type id_type = view3d_drop_id_in_main_region_poll_get_id_type(C, drag, event);
-  if (id_type) {
-    if (OB_DATA_SUPPORT_ID(id_type)) {
-      *r_tooltip = TIP_("Create object instance from object-data");
-      return true;
-    }
+  if (id_type && OB_DATA_SUPPORT_ID(id_type)) {
+    return true;
   }
   return false;
 }
 
-static bool view3d_ima_drop_poll(bContext *C,
-                                 wmDrag *drag,
-                                 const wmEvent *event,
-                                 const char **UNUSED(r_tooltip))
+static char *view3d_object_data_drop_tooltip(bContext *UNUSED(C),
+                                             wmDrag *UNUSED(drag),
+                                             const wmEvent *UNUSED(event))
+{
+  return BLI_strdup(TIP_("Create object instance from object-data"));
+}
+
+static bool view3d_ima_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
   if (ED_region_overlap_isect_any_xy(CTX_wm_area(C), &event->x)) {
     return false;
@@ -580,12 +569,9 @@ static bool view3d_ima_bg_is_camera_view(bContext *C)
   return false;
 }
 
-static bool view3d_ima_bg_drop_poll(bContext *C,
-                                    wmDrag *drag,
-                                    const wmEvent *event,
-                                    const char **r_tooltip)
+static bool view3d_ima_bg_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
-  if (!view3d_ima_drop_poll(C, drag, event, r_tooltip)) {
+  if (!view3d_ima_drop_poll(C, drag, event)) {
     return false;
   }
 
@@ -596,12 +582,9 @@ static bool view3d_ima_bg_drop_poll(bContext *C,
   return view3d_ima_bg_is_camera_view(C);
 }
 
-static bool view3d_ima_empty_drop_poll(bContext *C,
-                                       wmDrag *drag,
-                                       const wmEvent *event,
-                                       const char **r_tooltip)
+static bool view3d_ima_empty_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
-  if (!view3d_ima_drop_poll(C, drag, event, r_tooltip)) {
+  if (!view3d_ima_drop_poll(C, drag, event)) {
     return false;
   }
 
@@ -620,8 +603,7 @@ static bool view3d_ima_empty_drop_poll(bContext *C,
 
 static bool view3d_volume_drop_poll(bContext *UNUSED(C),
                                     wmDrag *drag,
-                                    const wmEvent *UNUSED(event),
-                                    const char **UNUSED(r_tooltip))
+                                    const wmEvent *UNUSED(event))
 {
   return (drag->type == WM_DRAG_PATH) && (drag->icon == ICON_FILE_VOLUME);
 }
@@ -700,37 +682,44 @@ static void view3d_dropboxes(void)
                  "OBJECT_OT_add_named",
                  view3d_ob_drop_poll,
                  view3d_ob_drop_copy,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 NULL);
   WM_dropbox_add(lb,
                  "OBJECT_OT_drop_named_material",
                  view3d_mat_drop_poll,
                  view3d_id_drop_copy,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 NULL);
   WM_dropbox_add(lb,
                  "VIEW3D_OT_background_image_add",
                  view3d_ima_bg_drop_poll,
                  view3d_id_path_drop_copy,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 NULL);
   WM_dropbox_add(lb,
                  "OBJECT_OT_drop_named_image",
                  view3d_ima_empty_drop_poll,
                  view3d_id_path_drop_copy,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 NULL);
   WM_dropbox_add(lb,
                  "OBJECT_OT_volume_import",
                  view3d_volume_drop_poll,
                  view3d_id_path_drop_copy,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 NULL);
   WM_dropbox_add(lb,
                  "OBJECT_OT_collection_instance_add",
                  view3d_collection_drop_poll,
                  view3d_collection_drop_copy,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 NULL);
   WM_dropbox_add(lb,
                  "OBJECT_OT_data_instance_add",
                  view3d_object_data_drop_poll,
                  view3d_id_drop_copy_with_type,
-                 WM_drag_free_imported_drag_ID);
+                 WM_drag_free_imported_drag_ID,
+                 view3d_object_data_drop_tooltip);
 }
 
 static void view3d_widgets(void)