mus: Implement Window Server Capture

components/mus/ws/window_tree_impl.cc

Index: components/mus/ws/window_tree_impl.cc
diff --git a/components/mus/ws/window_tree_impl.cc b/components/mus/ws/window_tree_impl.cc
index 3cdb88cf19897663b2a7a29fb11b56b442147dfb..4057398b8e947b7109aa07044f3b5492a137b3ab 100644
--- a/components/mus/ws/window_tree_impl.cc
+++ b/components/mus/ws/window_tree_impl.cc
@@ -590,6 +590,17 @@ bool WindowTreeImpl::ShouldRouteToWindowManager(
   return is_wm ? false : true;
 }
 
+void WindowTreeImpl::ProcessLostCapture(const ServerWindow* old_capture_window,
+                                        bool originated_change) {
+  if ((originated_change &&
+       connection_manager_->current_operation_type() ==
+           OperationType::RELEASE_CAPTURE) ||
+      !IsWindowKnown(old_capture_window)) {
+    return;
+  }
+  client()->OnLostCapture(WindowIdToTransportId(old_capture_window->id()));
+}
+
 ClientWindowId WindowTreeImpl::ClientWindowIdForWindow(
     const ServerWindow* window) const {
   auto iter = window_id_to_client_id_map_.find(window->id());
@@ -978,6 +989,36 @@ void WindowTreeImpl::GetWindowTree(
   callback.Run(WindowsToWindowDatas(windows));
 }
 
+void WindowTreeImpl::SetCapture(uint32_t change_id, Id window_id) {
+  ServerWindow* window = GetWindow(WindowIdFromTransportId(window_id));

[sky, 2016/01/29 20:47:00]

Sorry, I've changed things around. You want:

window = GetWindowByClientId(ClientWindowId(window_id));

[jonross, 2016/02/01 18:52:22]

Done.

+  WindowTreeHostImpl* host = GetHost(window);
+  ServerWindow* current_capture_window =
+      host ? host->GetCaptureWindow() : nullptr;
+  bool success = window && access_policy_->CanSetCapture(window) && host &&
+                 (!current_capture_window ||
+                  access_policy_->CanSetCapture(current_capture_window)) &&

[sky, 2016/01/29 20:47:00]

Can the condition in () ever hit? Why do we need it?

[jonross, 2016/02/01 18:52:22]

Yes this can be hit.

When a window tree has been created, and all capture is currently implicit
within EventDispatcher. This leads to the |current_capture_window| being null.

On subsequent runs the second portion should always be true, unless an access
policy can change at runtime.

+                 event_ack_id_;
+  if (success) {
+    Operation op(this, connection_manager_, OperationType::SET_CAPTURE);
+    host->SetCapture(window, !HasRoot(window));
+  }
+  client_->OnChangeCompleted(change_id, success);
+}
+
+void WindowTreeImpl::ReleaseCapture(uint32_t change_id, Id window_id) {
+  ServerWindow* window = GetWindow(WindowIdFromTransportId(window_id));

[sky, 2016/01/29 20:47:00]

Same comment about ids.

[jonross, 2016/02/01 18:52:22]

Done.

+  WindowTreeHostImpl* host = GetHost(window);
+  ServerWindow* capture_window = host ? host->GetCaptureWindow() : nullptr;
+  bool success = window && host &&
+                 access_policy_->CanSetCapture(capture_window) &&
+                 window == capture_window;
+  if (success) {
+    Operation op(this, connection_manager_, OperationType::RELEASE_CAPTURE);
+    host->SetCapture(nullptr, false);
+  }
+  client_->OnChangeCompleted(change_id, success);
+}
+
 void WindowTreeImpl::SetWindowBounds(uint32_t change_id,
                                      Id window_id,
                                      mojo::RectPtr bounds) {
@@ -1084,7 +1125,6 @@ void WindowTreeImpl::OnWindowInputEventAck(uint32_t event_id) {
     NOTIMPLEMENTED() << "Wrong event acked.";
   }
   event_ack_id_ = 0;
-
   WindowTreeHostImpl* event_source_host = event_source_host_;
   event_source_host_ = nullptr;
   if (event_source_host)