From 45fbeda95b90f85ecd8b7a0c68d593f182b16286 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mart=C3=ADn=20Capello?= <martin@igara.com>
Date: Fri, 11 Apr 2025 15:16:09 -0300
Subject: [PATCH] Avoid enqueuing events directly to laf-os

---
 src/app/ui/timeline/timeline.cpp | 11 +++--------
 src/ui/manager.cpp               |  7 +++++++
 src/ui/manager.h                 |  4 ++++
 src/ui/widget.cpp                | 10 ++++++++++
 src/ui/widget.h                  |  4 ++++
 5 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/src/app/ui/timeline/timeline.cpp b/src/app/ui/timeline/timeline.cpp
index cd404a136..2719bce97 100644
--- a/src/app/ui/timeline/timeline.cpp
+++ b/src/app/ui/timeline/timeline.cpp
@@ -55,8 +55,6 @@
 #include "fmt/format.h"
 #include "gfx/point.h"
 #include "gfx/rect.h"
-#include "os/event.h"
-#include "os/event_queue.h"
 #include "os/surface.h"
 #include "os/system.h"
 #include "text/font.h"
@@ -4496,8 +4494,7 @@ void Timeline::onDragLeave(ui::DragEvent& e)
   m_dropRange.clearRange();
   invalidate();
   flushRedraw();
-  os::Event ev;
-  os::System::instance()->eventQueue()->queueEvent(ev);
+  flushMessages();
 }
 
 void Timeline::onDrag(ui::DragEvent& e)
@@ -4526,8 +4523,7 @@ void Timeline::onDrag(ui::DragEvent& e)
 
   updateDropRange(e.position());
   flushRedraw();
-  os::Event ev;
-  os::System::instance()->eventQueue()->queueEvent(ev);
+  flushMessages();
 }
 
 void Timeline::onDrop(ui::DragEvent& e)
@@ -4603,8 +4599,7 @@ void Timeline::onDrop(ui::DragEvent& e)
   m_dropRange.clearRange();
   invalidate();
   flushRedraw();
-  os::Event ev;
-  os::System::instance()->eventQueue()->queueEvent(ev);
+  flushMessages();
 }
 
 int Timeline::tagFramesDuration(const Tag* tag) const
diff --git a/src/ui/manager.cpp b/src/ui/manager.cpp
index d66c4d7af..0666e6b2d 100644
--- a/src/ui/manager.cpp
+++ b/src/ui/manager.cpp
@@ -881,6 +881,13 @@ void Manager::dispatchMessages()
   }
 }
 
+void Manager::flushMessages() const
+{
+  // Send a dummy event just to break the waiting loop.
+  os::Event evt;
+  m_eventQueue->queueEvent(evt);
+}
+
 void Manager::addToGarbage(Widget* widget)
 {
   ASSERT(widget);
diff --git a/src/ui/manager.h b/src/ui/manager.h
index 721efc341..ef4226078 100644
--- a/src/ui/manager.h
+++ b/src/ui/manager.h
@@ -63,6 +63,10 @@ public:
   bool generateMessages();
   void dispatchMessages();
 
+  // Wakes up the system's events queue to process the currently enqueued UI
+  // messages.
+  void flushMessages() const;
+
   // Makes the generateMessages() function to return immediately if
   // there is no user events in the OS queue. Useful only for tests
   // or benchmarks where we don't wait the user (or we don't even
diff --git a/src/ui/widget.cpp b/src/ui/widget.cpp
index a80a25392..b13850334 100644
--- a/src/ui/widget.cpp
+++ b/src/ui/widget.cpp
@@ -1176,6 +1176,16 @@ void Widget::flushRedraw()
   }
 }
 
+void Widget::flushMessages() const
+{
+  Manager* manager = this->manager();
+  ASSERT(manager);
+  if (!manager)
+    return;
+
+  manager->flushMessages();
+}
+
 void Widget::paint(Graphics* graphics, const gfx::Region& drawRegion, const bool isBg)
 {
   if (drawRegion.isEmpty())
diff --git a/src/ui/widget.h b/src/ui/widget.h
index c909f3d2b..44799dfb1 100644
--- a/src/ui/widget.h
+++ b/src/ui/widget.h
@@ -313,6 +313,10 @@ public:
   // Generates paint messages for the current update region.
   void flushRedraw();
 
+  // Wakes up the system's events queue to process the currently enqueued UI
+  // messages.
+  void flushMessages() const;
+
   GraphicsPtr getGraphics(const gfx::Rect& clip);
 
   // ===============================================================