cros: Fix touch HUD application to support multiple displays

Create one touch hud views::Widget per display and open/close new
widgets as displays are added and removed.

Bug: 840380
Test: run chrome --show-taps-app and add/remove displays
Change-Id: I21c87b35ec520bd1501f0cbf02c073d030c7ff64
Reviewed-on: https://chromium-review.googlesource.com/1058591
Commit-Queue: James Cook <jamescook@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558731}

ash/components/touch_hud/DEPS

@@ -7,5 +7,6 @@ include_rules = [
   "+services/service_manager/public",
   "+services/ui/public",
   "+ui/aura",
+  "+ui/display",
   "+ui/views",
 ]

ash/components/touch_hud/touch_hud_application.cc

@@ -15,6 +15,8 @@
 #include "services/ui/public/cpp/property_type_converters.h"
 #include "services/ui/public/interfaces/window_manager_constants.mojom.h"
 #include "ui/aura/mus/property_converter.h"
+#include "ui/display/display.h"
+#include "ui/display/screen.h"
 #include "ui/views/mus/aura_init.h"
 #include "ui/views/mus/mus_client.h"
 #include "ui/views/mus/pointer_watcher_event_router.h"
@@ -23,6 +25,7 @@
 #include "ui/views/widget/widget_delegate.h"
 
 namespace touch_hud {
+namespace {
 
 // TouchHudUI handles events on the widget of the touch-hud app. After
 // receiving touch events from PointerWatcher, it calls ash::TouchHudRenderer to
@@ -31,7 +34,8 @@ class TouchHudUI : public views::WidgetDelegateView,
                    public views::PointerWatcher {
  public:
   explicit TouchHudUI(views::Widget* widget)
-      : touch_hud_renderer_(new ash::TouchHudRenderer(widget)) {
+      : touch_hud_renderer_(std::make_unique<ash::TouchHudRenderer>(widget)) {
+    // Watches moves so the user can drag around a touch point.
     views::MusClient::Get()->pointer_watcher_event_router()->AddPointerWatcher(
         this, true /* want_moves */);
   }
@@ -52,21 +56,31 @@ class TouchHudUI : public views::WidgetDelegateView,
   void OnPointerEventObserved(const ui::PointerEvent& event,
                               const gfx::Point& location_in_screen,
                               gfx::NativeView target) override {
-    if (event.IsTouchPointerEvent())
-      touch_hud_renderer_->HandleTouchEvent(event);
+    if (!event.IsTouchPointerEvent())
+      return;
+
+    // Ignore taps on other displays.
+    if (!GetWidget()->GetWindowBoundsInScreen().Contains(location_in_screen))
+      return;
+
+    touch_hud_renderer_->HandleTouchEvent(event);
   }
 
-  // TODO(jamescook): Don't leak this.
-  ash::TouchHudRenderer* touch_hud_renderer_;
+  std::unique_ptr<ash::TouchHudRenderer> touch_hud_renderer_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchHudUI);
 };
 
+}  // namespace
+
 TouchHudApplication::TouchHudApplication() : binding_(this) {
   registry_.AddInterface<mash::mojom::Launchable>(base::BindRepeating(
       &TouchHudApplication::Create, base::Unretained(this)));
 }
-TouchHudApplication::~TouchHudApplication() = default;
+
+TouchHudApplication::~TouchHudApplication() {
+  display::Screen::GetScreen()->RemoveObserver(this);
+}
 
 void TouchHudApplication::OnStart() {
   const bool register_path_provider = running_standalone_;
@@ -78,6 +92,7 @@ void TouchHudApplication::OnStart() {
     context()->QuitNow();
     return;
   }
+  display::Screen::GetScreen()->AddObserver(this);
   Launch(mash::mojom::kWindow, mash::mojom::LaunchMode::DEFAULT);
 }
 
@@ -89,25 +104,43 @@ void TouchHudApplication::OnBindInterface(
 }
 
 void TouchHudApplication::Launch(uint32_t what, mash::mojom::LaunchMode how) {
-  if (!widget_) {
-    widget_ = new views::Widget;
-    views::Widget::InitParams params(
-        views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
-    params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
-    params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
-    params.accept_events = false;
-    params.delegate = new TouchHudUI(widget_);
-    params.mus_properties[ui::mojom::WindowManager::kContainerId_InitProperty] =
-        mojo::ConvertTo<std::vector<uint8_t>>(
-            static_cast<int32_t>(ash::kShellWindowId_OverlayContainer));
-    params.show_state = ui::SHOW_STATE_FULLSCREEN;
-    widget_->Init(params);
-    widget_->Show();
-  } else {
-    widget_->Activate();
+  for (const display::Display& display :
+       display::Screen::GetScreen()->GetAllDisplays()) {
+    CreateWidgetForDisplay(display.id());
   }
 }
 
+void TouchHudApplication::OnDisplayAdded(const display::Display& new_display) {
+  CreateWidgetForDisplay(new_display.id());
+}
+
+void TouchHudApplication::OnDisplayRemoved(
+    const display::Display& old_display) {
+  // Deletes the widget.
+  display_id_to_widget_.erase(old_display.id());
+}
+
+void TouchHudApplication::CreateWidgetForDisplay(int64_t display_id) {
+  std::unique_ptr<views::Widget> widget = std::make_unique<views::Widget>();
+  views::Widget::InitParams params(
+      views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
+  params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
+  params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
+  params.accept_events = false;
+  params.delegate = new TouchHudUI(widget.get());
+  params.mus_properties[ui::mojom::WindowManager::kContainerId_InitProperty] =
+      mojo::ConvertTo<std::vector<uint8_t>>(
+          static_cast<int32_t>(ash::kShellWindowId_OverlayContainer));
+  params.mus_properties[ui::mojom::WindowManager::kDisplayId_InitProperty] =
+      mojo::ConvertTo<std::vector<uint8_t>>(display_id);
+  params.show_state = ui::SHOW_STATE_FULLSCREEN;
+  params.name = "TouchHud";
+  widget->Init(params);
+  widget->Show();
+  display_id_to_widget_[display_id] = std::move(widget);
+}
+
 void TouchHudApplication::Create(mash::mojom::LaunchableRequest request) {
   binding_.Close();
   binding_.Bind(std::move(request));

ash/components/touch_hud/touch_hud_application.h

@@ -5,11 +5,17 @@
 #ifndef ASH_COMPONENTS_TOUCH_HUD_TOUCH_HUD_APPLICATION_H_
 #define ASH_COMPONENTS_TOUCH_HUD_TOUCH_HUD_APPLICATION_H_
 
+#include <stdint.h>
+
+#include <map>
+#include <memory>
+
 #include "base/macros.h"
 #include "mash/public/mojom/launchable.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
 #include "services/service_manager/public/cpp/service.h"
+#include "ui/display/display_observer.h"
 
 namespace views {
 class AuraInit;
@@ -18,8 +24,11 @@ class Widget;
 
 namespace touch_hud {
 
+// Application that paints touch tap points as circles. Creates a fullscreen
+// transparent widget on each display to draw the taps.
 class TouchHudApplication : public service_manager::Service,
-                            public mash::mojom::Launchable {
+                            public mash::mojom::Launchable,
+                            public display::DisplayObserver {
  public:
   TouchHudApplication();
   ~TouchHudApplication() override;
@@ -36,11 +45,20 @@ class TouchHudApplication : public service_manager::Service,
   // mojom::Launchable:
   void Launch(uint32_t what, mash::mojom::LaunchMode how) override;
 
+  // display::DisplayObserver:
+  void OnDisplayAdded(const display::Display& new_display) override;
+  void OnDisplayRemoved(const display::Display& old_display) override;
+
+  // Creates the touch HUD widget for a display.
+  void CreateWidgetForDisplay(int64_t display_id);
+
   void Create(mash::mojom::LaunchableRequest request);
 
   service_manager::BinderRegistry registry_;
   mojo::Binding<mash::mojom::Launchable> binding_;
-  views::Widget* widget_ = nullptr;
+
+  // Maps display::Display::id() to the touch HUD widget for that display.
+  std::map<int64_t, std::unique_ptr<views::Widget>> display_id_to_widget_;
 
   std::unique_ptr<views::AuraInit> aura_init_;