mus Window Server: implement event capture

components/mus/ws/window_tree_host_impl.cc

 // Copyright 2015 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 "components/mus/ws/window_tree_host_impl.h"
 
 #include "base/debug/debugger.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/mus/common/types.h"
 #include "components/mus/public/interfaces/input_event_constants.mojom.h"
@@ skipping 143 matching lines @@
   if (windows_needing_frame_destruction_.count(window))
     return;
   windows_needing_frame_destruction_.insert(window);
   window->AddObserver(this);
 }
 
 const mojom::ViewportMetrics& WindowTreeHostImpl::GetViewportMetrics() const {
   return display_manager_->GetViewportMetrics();
 }
 
+void WindowTreeHostImpl::SetCapture(ServerWindow* window,
+                                    bool in_nonclient_area) {
+  ServerWindow* capture_window = event_dispatcher_.capture_window();
+  if (capture_window == window)
+    return;
+  event_dispatcher_.SetCaptureWindow(window, in_nonclient_area);
+}
+
 mojom::Rotation WindowTreeHostImpl::GetRotation() const {
   return display_manager_->GetRotation();
 }
 
 void WindowTreeHostImpl::SetFocusedWindow(ServerWindow* new_focused_window) {
   ServerWindow* old_focused_window = focus_controller_->GetFocusedWindow();
   if (old_focused_window == new_focused_window)
     return;
   DCHECK(root_window()->Contains(new_focused_window));
   focus_controller_->SetFocusedWindow(new_focused_window);
@@ skipping 162 matching lines @@
       event_queue_.back()->event = CoalesceEvents(
           std::move(event_queue_.back()->event), std::move(mojo_event));
       return;
     }
     QueueEvent(std::move(mojo_event), nullptr);
     return;
   }
   event_dispatcher_.ProcessEvent(std::move(mojo_event));
 }
 
+void WindowTreeHostImpl::SetCapture(ServerWindow* window) {
+  if (window)

[sky, 2016/02/10 17:38:22]

This should never supply null, right? If I'm right, then DCHECK(window). If I'm
wrong, why would we supply null?

[jonross, 2016/02/10 19:45:49]

Window is no longer passed in. So removed.

+    display_manager_->SetCapture();
+}
+
+void WindowTreeHostImpl::ReleaseCapture(ServerWindow* window) {
+  display_manager_->ReleaseCapture();
+}
+
+void WindowTreeHostImpl::OnLostCapture() {
+  SetCapture(nullptr, false);
+}
+
 void WindowTreeHostImpl::OnDisplayClosed() {
   if (delegate_)
     delegate_->OnDisplayClosed();
 }
 
 void WindowTreeHostImpl::OnViewportMetricsChanged(
     const mojom::ViewportMetrics& old_metrics,
     const mojom::ViewportMetrics& new_metrics) {
   if (!root_) {
     root_.reset(connection_manager_->CreateServerWindow(
@@ skipping 111 matching lines @@
 
 void WindowTreeHostImpl::SetFocusedWindowFromEventDispatcher(
     ServerWindow* new_focused_window) {
   SetFocusedWindow(new_focused_window);
 }
 
 ServerWindow* WindowTreeHostImpl::GetFocusedWindowForEventDispatcher() {
   return GetFocusedWindow();
 }
 
+void WindowTreeHostImpl::OnLostCapture(ServerWindow* window) {
+  DCHECK(window);
+  connection_manager_->ProcessLostCapture(window);
+}
+
 void WindowTreeHostImpl::DispatchInputEventToWindow(ServerWindow* target,
                                                     bool in_nonclient_area,
                                                     mojom::EventPtr event) {
   if (event_ack_timer_.IsRunning()) {
     scoped_ptr<ProcessedEventTarget> processed_event_target(
         new ProcessedEventTarget(target, in_nonclient_area));
     QueueEvent(std::move(event), std::move(processed_event_target));
     return;
   }
 
   DispatchInputEventToWindowImpl(target, in_nonclient_area, std::move(event));
 }
 
 void WindowTreeHostImpl::OnWindowDestroyed(ServerWindow* window) {
   windows_needing_frame_destruction_.erase(window);
   window->RemoveObserver(this);
 }
 
 }  // namespace ws
 }  // namespace mus