UI: Confirm dialog when closing an unsaved file

The complexity in this patch comes from the fact
that the current operator system does not support
multi-step user interactions well.

More specifically, for this to work, we need to show
a confirm dialog and a file browser afterwards.
We decided that it is easier to keep everything in
a single operator, instead of creating separate
operators that invoke each other.

So, now the `WM_OT_open_mainfile` operator invokes
itself in different states. It implements a simple
finite state machine to manage the states.

The dialog itself is expected to be improved in
a future commit. See D4829 for more details.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D4829

1 files changed, 5 insertions, 2 deletions

diff --git a/source/blender/editors/space_topbar/space_topbar.c b/source/blender/editors/space_topbar/space_topbar.c
index 8b290009a97..725a49e417e 100644
--- a/source/blender/editors/space_topbar/space_topbar.c
+++ b/source/blender/editors/space_topbar/space_topbar.c
@@ -213,12 +213,15 @@ static void recent_files_menu_draw(const bContext *UNUSED(C), Menu *menu)
 {
   struct RecentFile *recent;
   uiLayout *layout = menu->layout;
-  uiLayoutSetOperatorContext(layout, WM_OP_EXEC_REGION_WIN);
+  uiLayoutSetOperatorContext(layout, WM_OP_INVOKE_DEFAULT);
   if (!BLI_listbase_is_empty(&G.recent_files)) {
     for (recent = G.recent_files.first; (recent); recent = recent->next) {
       const char *file = BLI_path_basename(recent->filepath);
       const int icon = BLO_has_bfile_extension(file) ? ICON_FILE_BLEND : ICON_FILE_BACKUP;
-      uiItemStringO(layout, file, icon, "WM_OT_open_mainfile", "filepath", recent->filepath);
+      PointerRNA ptr;
+      uiItemFullO(layout, "WM_OT_open_mainfile", file, icon, NULL, WM_OP_INVOKE_DEFAULT, 0, &ptr);
+      RNA_string_set(&ptr, "filepath", recent->filepath);
+      RNA_boolean_set(&ptr, "display_file_selector", false);
     }
   }
   else {