mus: Server-side implementation of modal windows

components/mus/ws/window_manager_state.cc

 // 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 "components/mus/ws/window_manager_state.h"
 
 #include "components/mus/ws/connection_manager.h"
 #include "components/mus/ws/display_manager.h"
 #include "components/mus/ws/platform_display.h"
 #include "components/mus/ws/server_window.h"
@@ skipping 88 matching lines @@
 
 void WindowManagerState::SetFrameDecorationValues(
     mojom::FrameDecorationValuesPtr values) {
   got_frame_decoration_values_ = true;
   frame_decoration_values_ = values.Clone();
   display_->display_manager()
       ->GetUserDisplayManager(user_id_)
       ->OnFrameDecorationValuesChanged(this);
 }
 
-void WindowManagerState::SetCapture(ServerWindow* window,
+bool WindowManagerState::SetCapture(ServerWindow* window,
                                     bool in_nonclient_area) {
   // TODO(sky): capture should be a singleton. Need to route to
   // ConnectionManager so that all other EventDispatchers are updated.
   DCHECK(IsActive());
   if (capture_window() == window)
+    return true;
+  DCHECK(!window || root_->Contains(window));
+  return event_dispatcher_.SetCaptureWindow(window, in_nonclient_area);
+}
+
+void WindowManagerState::ReleaseCaptureBlockedByModalWindow(
+    const ServerWindow* modal_window) {
+  if (!capture_window() || !modal_window->is_modal() ||
+      !modal_window->IsDrawn())
     return;
-  DCHECK(!window || root_->Contains(window));
-  event_dispatcher_.SetCaptureWindow(window, in_nonclient_area);
+
+  if (modal_window->transient_parent() &&
+      !modal_window->transient_parent()->Contains(capture_window())) {
+    return;
+  }
+
+  SetCapture(nullptr, false);
+}
+
+void WindowManagerState::ReleaseCaptureBlockedByAnyModalWindow() {
+  if (!capture_window() || !capture_window()->IsBlockedByModalWindow())
+    return;
+
+  SetCapture(nullptr, false);
 }
 
 mojom::DisplayPtr WindowManagerState::ToMojomDisplay() const {
   mojom::DisplayPtr display_ptr = display_->ToMojomDisplay();
   // TODO(sky): set work area.
   display_ptr->work_area = display_ptr->bounds.Clone();
   display_ptr->frame_decoration_values = frame_decoration_values_.Clone();
   return display_ptr;
 }
 
@@ skipping 182 matching lines @@
         new ProcessedEventTarget(target, in_nonclient_area));
     QueueEvent(event, std::move(processed_event_target));
     return;
   }
 
   DispatchInputEventToWindowImpl(target, in_nonclient_area, event);
 }
 
 }  // namespace ws
 }  // namespace mus