mus: Fix handled status in UI event ack, add MessageLoop::NestingObserver

ui/views/mus/platform_window_mus_unittest.cc

Index: ui/views/mus/platform_window_mus_unittest.cc
diff --git a/ui/views/mus/platform_window_mus_unittest.cc b/ui/views/mus/platform_window_mus_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e4d5a7b91feef2f4c20e41e971a2138b04716936
--- /dev/null
+++ b/ui/views/mus/platform_window_mus_unittest.cc
@@ -0,0 +1,154 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/mus/platform_window_mus.h"
+
+#include <memory>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/events/event.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/views/mus/native_widget_mus.h"
+#include "ui/views/mus/window_tree_host_mus.h"
+#include "ui/views/test/views_test_base.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_delegate.h"
+
+using mus::mojom::EventResult;
+
+namespace views {
+namespace {
+
+// A view that reports any mouse press as handled.
+class HandleMousePressView : public View {
+ public:
+  HandleMousePressView() {}
+  ~HandleMousePressView() override {}
+
+  // View:
+  bool OnMousePressed(const ui::MouseEvent& event) override { return true; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HandleMousePressView);
+};
+
+// A view that deletes a widget on mouse press.
+class DeleteWidgetView : public View {
+ public:
+  explicit DeleteWidgetView(std::unique_ptr<Widget>* widget_ptr)
+      : widget_ptr_(widget_ptr) {}
+  ~DeleteWidgetView() override {}
+
+  // View:
+  bool OnMousePressed(const ui::MouseEvent& event) override {
+    widget_ptr_->reset();
+    return true;
+  }
+
+ private:
+  std::unique_ptr<Widget>* widget_ptr_;
+  DISALLOW_COPY_AND_ASSIGN(DeleteWidgetView);
+};
+
+}  // namespace
+
+class PlatformWindowMusTest : public ViewsTestBase {
+ public:
+  PlatformWindowMusTest() {}
+  ~PlatformWindowMusTest() override {}
+
+  int ack_callback_count() { return ack_callback_count_; }
+
+  void AckCallback(mus::mojom::EventResult result) {
+    ack_callback_count_++;
+    EXPECT_EQ(mus::mojom::EventResult::HANDLED, result);
+  }
+
+  // testing::Test:
+  void SetUp() override {
+    ViewsTestBase::SetUp();
+    widget_.reset(new Widget);
+    Widget::InitParams params = CreateParams(Widget::InitParams::TYPE_WINDOW);
+    params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+    params.bounds = gfx::Rect(0, 0, 100, 100);
+    widget_->Init(params);
+    widget_->Show();
+    native_widget_ =
+        static_cast<NativeWidgetMus*>(widget_->native_widget_private());
+    platform_window_ = native_widget_->window_tree_host()->platform_window();
+    ASSERT_TRUE(platform_window_);
+  }
+
+  // Returns a mouse pressed event in the middle of the widget.
+  std::unique_ptr<ui::MouseEvent> CreateMouseEvent() {
+    return base::WrapUnique(new ui::MouseEvent(
+        ui::ET_MOUSE_PRESSED, gfx::Point(50, 50), gfx::Point(50, 50),
+        base::TimeDelta(), ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON));
+  }
+
+  // Simulates an input event to the PlatformWindow.
+  void OnWindowInputEvent(
+      const ui::Event& event,
+      std::unique_ptr<base::Callback<void(mus::mojom::EventResult)>>*
+          ack_callback) {
+    platform_window_->OnWindowInputEvent(native_widget_->window(), event,
+                                         ack_callback);
+  }
+
+ protected:
+  std::unique_ptr<Widget> widget_;
+
+ private:
+  NativeWidgetMus* native_widget_ = nullptr;
+  PlatformWindowMus* platform_window_ = nullptr;
+  int ack_callback_count_ = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformWindowMusTest);
+};
+
+// Tests that an incoming UI event is acked with the handled status.
+TEST_F(PlatformWindowMusTest, EventAcked) {
+  View* content = new HandleMousePressView;
+  content->SetBounds(0, 0, 100, 100);
+  widget_->GetContentsView()->AddChildView(content);
+
+  // Dispatch an input event to the window and view.
+  std::unique_ptr<ui::MouseEvent> event = CreateMouseEvent();
+  std::unique_ptr<base::Callback<void(EventResult)>> ack_callback(
+      new base::Callback<void(EventResult)>(base::Bind(
+          &PlatformWindowMusTest::AckCallback, base::Unretained(this))));
+  OnWindowInputEvent(*event, &ack_callback);
+
+  // The platform window took ownership of the callback and called it.
+  EXPECT_FALSE(ack_callback);
+  EXPECT_EQ(1, ack_callback_count());
+}
+
+// Tests that a window that is deleted during event handling properly acks the
+// event.
+TEST_F(PlatformWindowMusTest, EventAckedWithWindowDestruction) {
+  View* content = new DeleteWidgetView(&widget_);
+  content->SetBounds(0, 0, 100, 100);
+  widget_->GetContentsView()->AddChildView(content);
+
+  // Dispatch an input event to the window and view.
+  std::unique_ptr<ui::MouseEvent> event = CreateMouseEvent();
+  std::unique_ptr<base::Callback<void(EventResult)>> ack_callback(
+      new base::Callback<void(EventResult)>(base::Bind(
+          &PlatformWindowMusTest::AckCallback, base::Unretained(this))));
+  OnWindowInputEvent(*event, &ack_callback);
+
+  // The widget was deleted.
+  EXPECT_FALSE(widget_);
+
+  // The platform window took ownership of the callback and called it.
+  EXPECT_FALSE(ack_callback);
+  EXPECT_EQ(1, ack_callback_count());
+}
+
+}  // namespace views