mash: Make TouchSelectionControllerClientAura use ui::EventObserver

Close touch selection ui in Mash on events outside the browser window.
(global pre-target handlers are not supported in window service clients)
This follows and refines the new pattern in TouchSelectionControllerImpl.

Bug: 896973, 884394
Test: Text touch selection ui hides as expected in Views and Content.
Change-Id: Iedba63a7ce5d5f70f9763cf540d26ee69cee5f28
Reviewed-on: https://chromium-review.googlesource.com/c/1292274
Commit-Queue: Michael Wasserman <msw@chromium.org>
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602084}

content/browser/renderer_host/input/touch_selection_controller_client_aura.cc

@@ -16,6 +16,7 @@
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/base/clipboard/clipboard.h"
+#include "ui/events/event_observer.h"
 #include "ui/gfx/geometry/point_conversions.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/strings/grit/ui_strings.h"
@@ -47,78 +48,58 @@ gfx::Rect ConvertRectToScreen(aura::Window* window, const gfx::RectF& rect) {
 
 }  // namespace
 
-// A pre-target event handler for aura::Env which deactivates touch selection on
-// mouse and keyboard events.
-class TouchSelectionControllerClientAura::EnvPreTargetHandler
-    : public ui::EventHandler {
+// An aura::Env event observer that hides touch selection ui on mouse and
+// keyboard events, including those targeting windows outside the client.
+class TouchSelectionControllerClientAura::EnvEventObserver
+    : public ui::EventObserver {
  public:
-  EnvPreTargetHandler(ui::TouchSelectionController* selection_controller,
-                      aura::Window* window);
-  ~EnvPreTargetHandler() override;
-
- private:
-  // EventHandler:
-  void OnKeyEvent(ui::KeyEvent* event) override;
-  void OnMouseEvent(ui::MouseEvent* event) override;
-  void OnScrollEvent(ui::ScrollEvent* event) override;
-
-  ui::TouchSelectionController* selection_controller_;
-  aura::Window* window_;
-
-  DISALLOW_COPY_AND_ASSIGN(EnvPreTargetHandler);
-};
-
-TouchSelectionControllerClientAura::EnvPreTargetHandler::EnvPreTargetHandler(
-    ui::TouchSelectionController* selection_controller,
+  EnvEventObserver(ui::TouchSelectionController* selection_controller,
                    aura::Window* window)
       : selection_controller_(selection_controller), window_(window) {
-  aura::Env::GetInstance()->AddPreTargetHandler(this);
-}
-
-TouchSelectionControllerClientAura::EnvPreTargetHandler::
-    ~EnvPreTargetHandler() {
-  aura::Env::GetInstance()->RemovePreTargetHandler(this);
-}
-
-void TouchSelectionControllerClientAura::EnvPreTargetHandler::OnKeyEvent(
-    ui::KeyEvent* event) {
-  DCHECK_NE(ui::TouchSelectionController::INACTIVE,
-            selection_controller_->active_status());
+    // Observe certain event types sent to any event target, to hide this ui.
+    aura::Env* env = aura::Env::GetInstance();
+    std::set<ui::EventType> types = {ui::ET_MOUSE_PRESSED, ui::ET_MOUSE_MOVED,
+                                     ui::ET_KEY_PRESSED, ui::ET_MOUSEWHEEL};
+    env->AddEventObserver(this, env, types);
+  }
 
-  selection_controller_->HideAndDisallowShowingAutomatically();
-}
+  ~EnvEventObserver() override {
+    aura::Env::GetInstance()->RemoveEventObserver(this);
+  }
 
-void TouchSelectionControllerClientAura::EnvPreTargetHandler::OnMouseEvent(
-    ui::MouseEvent* event) {
+ private:
+  // ui::EventObserver:
+  void OnEvent(const ui::Event& event) override {
     DCHECK_NE(ui::TouchSelectionController::INACTIVE,
               selection_controller_->active_status());
 
-  // Avoid adjusting the handles on synthesized or events
-  // generated from touch as this can clear an active selection
-  // generated by the pen.
-  if (event->flags() & (ui::EF_IS_SYNTHESIZED | ui::EF_FROM_TOUCH))
+    if (event.IsMouseEvent()) {
+      // Check IsMouseEventsEnabled, except on Mus, where it's disabled on touch
+      // events in this client, but not re-enabled on mouse events elsewhere.
+      auto* cursor = aura::client::GetCursorClient(window_->GetRootWindow());
+      if (cursor && !cursor->IsMouseEventsEnabled() &&
+          aura::Env::GetInstance()->mode() != aura::Env::Mode::MUS) {
         return;
+      }
 
-  // Don't hide handles for pen input.
-  if (event->pointer_details().pointer_type ==
-      ui::EventPointerType::POINTER_TYPE_PEN)
+      // Windows OS unhandled WM_POINTER* may be redispatched as WM_MOUSE*.
+      // Avoid adjusting the handles on synthesized events or events generated
+      // from touch as this can clear an active selection generated by the pen.
+      if ((event.flags() & (ui::EF_IS_SYNTHESIZED | ui::EF_FROM_TOUCH)) ||
+          event.AsMouseEvent()->pointer_details().pointer_type ==
+              ui::EventPointerType::POINTER_TYPE_PEN) {
         return;
+      }
+    }
 
-  // If mouse events are not enabled, this mouse event is synthesized from a
-  // touch event in which case we don't want to deactivate touch selection.
-  aura::client::CursorClient* cursor_client =
-      aura::client::GetCursorClient(window_->GetRootWindow());
-  if (!cursor_client || cursor_client->IsMouseEventsEnabled())
     selection_controller_->HideAndDisallowShowingAutomatically();
-}
+  }
 
-void TouchSelectionControllerClientAura::EnvPreTargetHandler::OnScrollEvent(
-    ui::ScrollEvent* event) {
-  DCHECK_NE(ui::TouchSelectionController::INACTIVE,
-            selection_controller_->active_status());
+  ui::TouchSelectionController* selection_controller_;
+  aura::Window* window_;
 
-  selection_controller_->HideAndDisallowShowingAutomatically();
-}
+  DISALLOW_COPY_AND_ASSIGN(EnvEventObserver);
+};
 
 TouchSelectionControllerClientAura::TouchSelectionControllerClientAura(
     RenderWidgetHostViewAura* rwhva)
@@ -382,12 +363,12 @@ void TouchSelectionControllerClientAura::OnSelectionEvent(
       FALLTHROUGH;
     case ui::INSERTION_HANDLE_SHOWN:
       UpdateQuickMenu();
-      env_pre_target_handler_.reset(new EnvPreTargetHandler(
-          rwhva_->selection_controller(), rwhva_->GetNativeView()));
+      env_event_observer_ = std::make_unique<EnvEventObserver>(
+          rwhva_->selection_controller(), rwhva_->GetNativeView());
       break;
     case ui::SELECTION_HANDLES_CLEARED:
     case ui::INSERTION_HANDLE_CLEARED:
-      env_pre_target_handler_.reset();
+      env_event_observer_.reset();
       quick_menu_requested_ = false;
       UpdateQuickMenu();
       break;

content/browser/renderer_host/input/touch_selection_controller_client_aura.h

@@ -70,7 +70,7 @@ class CONTENT_EXPORT TouchSelectionControllerClientAura
 
  private:
   friend class TestTouchSelectionControllerClientAura;
-  class EnvPreTargetHandler;
+  class EnvEventObserver;
 
   bool IsQuickMenuAvailable() const;
   void ShowQuickMenu();
@@ -133,9 +133,8 @@ class CONTENT_EXPORT TouchSelectionControllerClientAura
 
   bool show_quick_menu_immediately_for_test_;
 
-  // A pre-target event handler for aura::Env which deactivates touch selection
-  // on mouse and keyboard events.
-  std::unique_ptr<EnvPreTargetHandler> env_pre_target_handler_;
+  // An event observer that deactivates touch selection on certain input events.
+  std::unique_ptr<EnvEventObserver> env_event_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchSelectionControllerClientAura);
 };

ui/views/touchui/touch_selection_controller_impl.cc

@@ -418,7 +418,7 @@ TouchSelectionControllerImpl::TouchSelectionControllerImpl(
   if (client_widget_)
     client_widget_->AddObserver(this);
 
-  // Observe certain event types sent to other event targets, to hide this ui.
+  // Observe certain event types sent to any event target, to hide this ui.
   aura::Env* env = aura::Env::GetInstance();
   std::set<ui::EventType> types = {ui::ET_MOUSE_PRESSED, ui::ET_MOUSE_MOVED,
                                    ui::ET_KEY_PRESSED, ui::ET_MOUSEWHEEL};
@@ -628,22 +628,27 @@ void TouchSelectionControllerImpl::OnWidgetBoundsChanged(
 }
 
 void TouchSelectionControllerImpl::OnEvent(const ui::Event& event) {
-  if (event.IsKeyEvent() || event.IsScrollEvent()) {
-    client_view_->DestroyTouchSelection();
-    return;
-  }
-
   if (event.IsMouseEvent()) {
-    aura::client::CursorClient* cursor_client = aura::client::GetCursorClient(
+    // Check IsMouseEventsEnabled, except on Mus, where it's disabled on touch
+    // events in this client, but not re-enabled on mouse events elsewhere.
+    auto* cursor = aura::client::GetCursorClient(
         client_view_->GetNativeView()->GetRootWindow());
-    // Disregard IsMouseEventsEnabled on Mus, it is disabled on touch events in
-    // this client, but not re-enabled when mouse events are sent elsewhere.
-    if ((cursor_client && cursor_client->IsMouseEventsEnabled()) ||
-        aura::Env::GetInstance()->mode() == aura::Env::Mode::MUS) {
-      client_view_->DestroyTouchSelection();
+    if (cursor && !cursor->IsMouseEventsEnabled() &&
+        aura::Env::GetInstance()->mode() != aura::Env::Mode::MUS) {
+      return;
     }
+
+    // Windows OS unhandled WM_POINTER* may be redispatched as WM_MOUSE*.
+    // Avoid adjusting the handles on synthesized events or events generated
+    // from touch as this can clear an active selection generated by the pen.
+    if ((event.flags() & (ui::EF_IS_SYNTHESIZED | ui::EF_FROM_TOUCH)) ||
+        event.AsMouseEvent()->pointer_details().pointer_type ==
+            ui::EventPointerType::POINTER_TYPE_PEN) {
       return;
     }
+  }
+
+  client_view_->DestroyTouchSelection();
 }
 
 void TouchSelectionControllerImpl::QuickMenuTimerFired() {