mus: Add debug key to print the server window hierarchy

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 "base/memory/weak_ptr.h"
+#include "components/mus/common/event_matcher_util.h"
 #include "components/mus/ws/accelerator.h"
 #include "components/mus/ws/display_manager.h"
 #include "components/mus/ws/platform_display.h"
 #include "components/mus/ws/server_window.h"
 #include "components/mus/ws/user_display_manager.h"
 #include "components/mus/ws/user_id_tracker.h"
 #include "components/mus/ws/window_server.h"
 #include "components/mus/ws/window_tree.h"
 #include "services/shell/public/interfaces/connector.mojom.h"
 #include "ui/events/event.h"
 
 namespace mus {
 namespace ws {
 namespace {
 
+// Debug accelerator IDs start far above the highest valid Windows command ID
+// (0xDFFF) and Chrome's highest IDC command ID.
+const uint32_t kPrintWindowsDebugAcceleratorId = 1 << 24;
+
 base::TimeDelta GetDefaultAckTimerDelay() {
 #if defined(NDEBUG)
   return base::TimeDelta::FromMilliseconds(100);
 #else
   return base::TimeDelta::FromMilliseconds(1000);
 #endif
 }
 
 bool EventsCanBeCoalesced(const ui::Event& one, const ui::Event& two) {
   if (one.type() != two.type() || one.flags() != two.flags())
@@ skipping 145 matching lines @@
       ServerWindow::Properties()));
   // Our root is always a child of the Display's root. Do this
   // before the WindowTree has been created so that the client doesn't get
   // notified of the add, bounds change and visibility change.
   root_->SetBounds(gfx::Rect(display->root_window()->bounds().size()));
   root_->SetVisible(true);
   display->root_window()->Add(root_.get());
 
   event_dispatcher_.set_root(root_.get());
   event_dispatcher_.set_surface_id(surface_id);
+
+  AddDebugAccelerators();
 }
 
 bool WindowManagerState::IsActive() const {
   return display()->GetActiveWindowManagerState() == this;
 }
 
 void WindowManagerState::Activate(const gfx::Point& mouse_location_on_screen) {
   root_->SetVisible(true);
   event_dispatcher_.Reset();
   event_dispatcher_.SetMousePointerScreenLocation(mouse_location_on_screen);
@@ skipping 124 matching lines @@
     event_awaiting_input_ack_ = ui::Event::Clone(event);
     post_target_accelerator_ = accelerator;
   }
 
   // Ignore |tree| because it will receive the event via normal dispatch.
   window_server()->SendToEventObservers(event, user_id_, tree);
 
   tree->DispatchInputEvent(target, event);
 }
 
+void WindowManagerState::AddDebugAccelerators() {
+  // Always register the accelerators, even if they only work in debug, so that
+  // keyboard behavior is the same in release and debug builds.
+  mojom::EventMatcherPtr matcher = CreateKeyMatcher(
+      mus::mojom::KeyboardCode::S,
+      mus::mojom::kEventFlagControlDown | mus::mojom::kEventFlagAltDown
+          | mus::mojom::kEventFlagShiftDown);
+  event_dispatcher_.AddAccelerator(kPrintWindowsDebugAcceleratorId,
+                                   std::move(matcher));
+}
+
+bool WindowManagerState::HandleDebugAccelerator(uint32_t accelerator_id) {
+#if !defined(NDEBUG)
+  if (accelerator_id == kPrintWindowsDebugAcceleratorId) {
+    // Error so it will be collected in system logs.
+    LOG(ERROR) << "ServerWindow hierarchy:\n"
+               << root()->GetDebugWindowHierarchy();
+    return true;
+  }
+#endif
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // EventDispatcherDelegate:
 
 void WindowManagerState::OnAccelerator(uint32_t accelerator_id,
                                        const ui::Event& event) {
   DCHECK(IsActive());
+  if (HandleDebugAccelerator(accelerator_id))
+    return;
   tree_->OnAccelerator(accelerator_id, event);
 }
 
 void WindowManagerState::SetFocusedWindowFromEventDispatcher(
     ServerWindow* new_focused_window) {
   DCHECK(IsActive());
   display_->SetFocusedWindow(new_focused_window);
 }
 
 ServerWindow* WindowManagerState::GetFocusedWindowForEventDispatcher() {
@@ skipping 40 matching lines @@
                                  weak_accelerator);
 }
 
 void WindowManagerState::OnEventTargetNotFound(const ui::Event& event) {
   window_server()->SendToEventObservers(event, user_id_,
                                         nullptr /* ignore_tree */);
 }
 
 }  // namespace ws
 }  // namespace mus