mash: make Env::last_mouse_location() accurate for Mus

ui/aura/window_event_dispatcher_unittest.cc

Index: ui/aura/window_event_dispatcher_unittest.cc
diff --git a/ui/aura/window_event_dispatcher_unittest.cc b/ui/aura/window_event_dispatcher_unittest.cc
index ebec238f29dfcb9e996ae909f55013bc1288c2a0..ca48fb2d792765baa17ffcf7eea237184fa72651 100644
--- a/ui/aura/window_event_dispatcher_unittest.cc
+++ b/ui/aura/window_event_dispatcher_unittest.cc
@@ -20,6 +20,7 @@
 #include "ui/aura/client/event_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/env.h"
+#include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/test/aura_test_base.h"
 #include "ui/aura/test/env_test_helper.h"
 #include "ui/aura/test/test_cursor_client.h"
@@ -2690,4 +2691,139 @@ INSTANTIATE_TEST_CASE_P(/* no prefix */,
                         ::testing::Values(test::BackendType::CLASSIC,
                                           test::BackendType::MUS));
 
+using WindowEventDispatcherMusTest = test::AuraTestBaseMus;
+
+class LastEventLocationDelegate : public test::TestWindowDelegate {
+ public:
+  LastEventLocationDelegate() {}
+  ~LastEventLocationDelegate() override {}
+
+  int mouse_event_count() const { return mouse_event_count_; }
+  const gfx::Point& last_mouse_location() const { return last_mouse_location_; }
+
+  // TestWindowDelegate:
+  void OnMouseEvent(ui::MouseEvent* event) override {
+    ++mouse_event_count_;
+    last_mouse_location_ = event->root_location();
+    EXPECT_EQ(last_mouse_location_, Env::GetInstance()->last_mouse_location());
+  }
+
+ private:
+  int mouse_event_count_ = 0;
+  gfx::Point last_mouse_location_;
+
+  DISALLOW_COPY_AND_ASSIGN(LastEventLocationDelegate);
+};
+
+TEST_F(WindowEventDispatcherMusTest, LastEventLocation) {
+  LastEventLocationDelegate last_event_location_delegate;
+  std::unique_ptr<Window> window(
+      CreateTestWindowWithDelegate(&last_event_location_delegate, 123,
+                                   gfx::Rect(0, 0, 10, 20), root_window()));
+
+  // Enable fetching mouse location from mouse.
+  test::EnvTestHelper().SetAlwaysUseLastMouseLocation(false);
+  EXPECT_EQ(gfx::Point(0, 0),
+            window_tree_client_impl()->GetCursorScreenPoint());
+  EXPECT_EQ(gfx::Point(0, 0), Env::GetInstance()->last_mouse_location());
+
+  // Dispatch an event to |mouse_location|. While dispatching the event
+  // Env::last_mouse_location() should return |mouse_location|.
+  const gfx::Point mouse_location(1, 2);
+  ui::MouseEvent mouse(ui::ET_MOUSE_PRESSED, mouse_location, mouse_location,
+                       ui::EventTimeForNow(), ui::EF_LEFT_MOUSE_BUTTON,
+                       ui::EF_LEFT_MOUSE_BUTTON);
+  DispatchEventUsingWindowDispatcher(&mouse);
+  EXPECT_EQ(1, last_event_location_delegate.mouse_event_count());
+  EXPECT_EQ(mouse_location, last_event_location_delegate.last_mouse_location());
+
+  // After dispatch the location should fallback to that of the
+  // WindowTreeClient, which defaults to 0,0.
+  EXPECT_EQ(gfx::Point(0, 0), Env::GetInstance()->last_mouse_location());
+}
+
+class NestedLocationDelegate : public test::TestWindowDelegate {
+ public:
+  NestedLocationDelegate() {}
+  ~NestedLocationDelegate() override {}
+
+  int mouse_event_count() const { return mouse_event_count_; }
+  int nested_message_loop_count() const { return nested_message_loop_count_; }
+  const gfx::Point& last_mouse_location() const { return last_mouse_location_; }
+
+  // TestWindowDelegate:
+  void OnMouseEvent(ui::MouseEvent* event) override {
+    ++mouse_event_count_;
+    last_mouse_location_ = event->root_location();
+    EXPECT_EQ(last_mouse_location_, Env::GetInstance()->last_mouse_location());
+
+    // Start a RunLoop that in turn starts a RunLoop. We have to do this as the
+    // first RunLoop doesn't triggering nesting (the MessageLoop isn't running
+    // at this point). The second RunLoop (created in InInitialMessageLoop())
+    // is considered the first nested loop.
+    base::RunLoop run_loop;
+    base::MessageLoop::current()->task_runner()->PostTask(
+        FROM_HERE, base::Bind(&NestedLocationDelegate::InInitialMessageLoop,
+                              base::Unretained(this), &run_loop));
+    run_loop.Run();
+  }
+
+ private:
+  void InInitialMessageLoop(base::RunLoop* initial_run_loop) {
+    // See comments in OnMouseEvent() for details on which this creates another
+    // RunLoop.
+    base::MessageLoop::ScopedNestableTaskAllower allow_nestable_tasks(
+        base::MessageLoop::current());
+    base::RunLoop run_loop;
+    base::MessageLoop::current()->task_runner()->PostTask(
+        FROM_HERE, base::Bind(&NestedLocationDelegate::InRunMessageLoop,
+                              base::Unretained(this), &run_loop));
+    run_loop.Run();
+    initial_run_loop->Quit();
+  }
+
+  void InRunMessageLoop(base::RunLoop* run_loop) {
+    ++nested_message_loop_count_;
+    // Nested message loops trigger falling back to using the location from
+    // WindowTreeClient, which is 0,0.
+    EXPECT_EQ(gfx::Point(0, 0), Env::GetInstance()->last_mouse_location());
+    run_loop->Quit();
+  }
+
+  int mouse_event_count_ = 0;
+  // Incremented when the deepest message loop is encountered.
+  int nested_message_loop_count_ = 0;
+  gfx::Point last_mouse_location_;
+
+  DISALLOW_COPY_AND_ASSIGN(NestedLocationDelegate);
+};
+
+TEST_F(WindowEventDispatcherMusTest, EventDispatchTriggersNestedMessageLoop) {
+  NestedLocationDelegate last_event_location_delegate;
+  std::unique_ptr<Window> window(
+      CreateTestWindowWithDelegate(&last_event_location_delegate, 123,
+                                   gfx::Rect(0, 0, 10, 20), root_window()));
+
+  // Enable fetching mouse location from mouse.
+  test::EnvTestHelper().SetAlwaysUseLastMouseLocation(false);
+  EXPECT_EQ(gfx::Point(0, 0),
+            window_tree_client_impl()->GetCursorScreenPoint());
+  EXPECT_EQ(gfx::Point(0, 0), Env::GetInstance()->last_mouse_location());
+
+  // Dispatch an event to |mouse_location|. While dispatching the event
+  // Env::last_mouse_location() should return |mouse_location|.
+  const gfx::Point mouse_location(1, 2);
+  ui::MouseEvent mouse(ui::ET_MOUSE_PRESSED, mouse_location, mouse_location,
+                       ui::EventTimeForNow(), ui::EF_LEFT_MOUSE_BUTTON,
+                       ui::EF_LEFT_MOUSE_BUTTON);
+  DispatchEventUsingWindowDispatcher(&mouse);
+  EXPECT_EQ(1, last_event_location_delegate.mouse_event_count());
+  EXPECT_EQ(1, last_event_location_delegate.nested_message_loop_count());
+  EXPECT_EQ(mouse_location, last_event_location_delegate.last_mouse_location());
+
+  // After dispatch the location should fallback to that of the
+  // WindowTreeClient, which defaults to 0,0.
+  EXPECT_EQ(gfx::Point(0, 0), Env::GetInstance()->last_mouse_location());
+}
+
 }  // namespace aura