mash: Repost mouse pressed event when closing Ash system tray

ui/views/mus/platform_window_mus.cc

Index: ui/views/mus/platform_window_mus.cc
diff --git a/ui/views/mus/platform_window_mus.cc b/ui/views/mus/platform_window_mus.cc
index 1ae09d182c134d3542b9eb0dfdeafe0a1f96e234..1323f307eb0631f4b92dc3671c9c46f4747cc547 100644
--- a/ui/views/mus/platform_window_mus.cc
+++ b/ui/views/mus/platform_window_mus.cc
@@ -4,6 +4,7 @@
 
 #include "ui/views/mus/platform_window_mus.h"
 
+#include "base/message_loop/message_loop.h"
 #include "build/build_config.h"
 #include "components/bitmap_uploader/bitmap_uploader.h"
 #include "components/mus/public/cpp/property_type_converters.h"
@@ -17,6 +18,7 @@
 namespace views {
 
 namespace {
+
 static uint32_t accelerated_widget_count = 1;
 
 }  // namespace
@@ -33,6 +35,7 @@ PlatformWindowMus::PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
   DCHECK(mus_window_);
   mus_window_->AddObserver(this);
   mus_window_->set_input_event_handler(this);
+  base::MessageLoop::current()->AddNestingObserver(this);
 
   // We need accelerated widget numbers to be different for each
   // window and fit in the smallest sizeof(AcceleratedWidget) uint32_t
@@ -55,6 +58,7 @@ PlatformWindowMus::PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
 }
 
 PlatformWindowMus::~PlatformWindowMus() {
+  base::MessageLoop::current()->RemoveNestingObserver(this);
   if (!mus_window_)
     return;
   mus_window_->RemoveObserver(this);
@@ -223,18 +227,49 @@ void PlatformWindowMus::OnRequestClose(mus::Window* window) {
 void PlatformWindowMus::OnWindowInputEvent(
     mus::Window* view,
     const ui::Event& event,
-    std::unique_ptr<base::Callback<void(bool)>>* ack_callback) {
-  // It's possible dispatching the event will spin a nested message loop. Ack
-  // the callback now, otherwise we appear unresponsive for the life of the
-  // nested message loop.
-  // TODO(jamescook): Only ack the event as handled if a nested message loop
-  // actually starts, perhaps through an observer on MessageLoop. Otherwise
-  // ack the event with the actual handled state below DispatchEvent().
-  (*ack_callback)->Run(true);
-  ack_callback->reset();
-  // TODO(moshayedi): Avoid cloning after updating PlatformWindowDelegate to
-  // accept constant pointers.
-  delegate_->DispatchEvent(ui::Event::Clone(event).get());
+    std::unique_ptr<base::Callback<void(mus::mojom::EventResult)>>*
+        ack_callback) {
+  event_ack_callback_ = std::move(*ack_callback);
+
+  bool had_capture = mus_window_->HasCapture();
+
+  // DispatchEvent requires a mutable event so flags like handled can be set.
+  scoped_ptr<ui::Event> mutable_event = ui::Event::Clone(event);
+  delegate_->DispatchEvent(mutable_event.get());
+
+  mus::mojom::EventResult result;
+  if (mutable_event->handled())
+    result = mus::mojom::EventResult::HANDLED;
+  else if (ShouldRepostEvent(*mutable_event.get(), had_capture))
+    result = mus::mojom::EventResult::REPOST;
+  else
+    result = mus::mojom::EventResult::UNHANDLED;
+
+  // If the event wasn't already handled by a nested message loop then ack it
+  // with the handled state.
+  if (event_ack_callback_) {
+    event_ack_callback_->Run(result);
+    event_ack_callback_.reset();
+  }
+}
+
+void PlatformWindowMus::OnBeginNestedMessageLoop() {
+  // It's possible dispatching an event will spin a nested message loop. If we
+  // are processing an event then ack the callback now, otherwise we appear
+  // unresponsive for the life of the nested message loop.
+  if (event_ack_callback_) {
+    event_ack_callback_->Run(mus::mojom::EventResult::HANDLED);
+    event_ack_callback_.reset();
+  }
+}
+
+bool PlatformWindowMus::ShouldRepostEvent(const ui::Event& event,
+                                          bool had_capture) {
+  // Repost mouse events that cause capture loss (e.g. a mouse press that closes
+  // a menu that had capture).
+  return had_capture && !mus_window_->HasCapture() &&
+         (event.type() == ui::ET_MOUSE_PRESSED ||
+          event.type() == ui::ET_MOUSE_RELEASED);
 }
 
 }  // namespace views