Redraw window immediately on "live resizing"

laf

@@ -1 +1 @@
-Subproject commit 6ace65197891e0e0c79e0e96d7b39daacc56e364
+Subproject commit 39ff91256cc64808bcf735c6d755a1746f841b3a

src/app/console.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2018-2020  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -177,7 +177,9 @@ void Console::printf(const char* format, ...)
 // static
 void Console::showException(const std::exception& e)
 {
-  ui::assert_ui_thread();
+  // TODO called from Session::deleteBackup() which is run in background thread
+  //ui::assert_ui_thread();
+
   if (!ui::is_ui_thread()) {
     LOG(ERROR, "A problem has occurred.\n\nDetails:\n%s\n", e.what());
     return;

src/app/modules/gui.cpp

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2018-2020  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -203,6 +203,21 @@ int init_module_gui()
   if (maximized)
     main_display->maximize();
 
+  // Handle live resize too redraw the entire manager, dispatch the UI
+  // messages, and flip the display.
+  main_display->handleResize =
+    [](os::Display* display) {
+      manager->invalidate();
+
+      Message* msg = new Message(kResizeDisplayMessage);
+      msg->setRecipient(manager);
+      msg->setPropagateToChildren(true);
+      manager->enqueueMessage(msg);
+
+      manager->dispatchMessages();
+      manager->flipDisplay();
+    };
+
   // Set graphics options for next time
   save_gui_config();