Autoclose tab strip container on events outside the container

Bug: 1009122
Change-Id: I64e48c638b403911a8879ff1fa7b290628373bd9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877454
Commit-Queue: Collin Baker <collinbaker@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709304}

chrome/browser/ui/views/frame/webui_tab_strip_container_view.cc

@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "base/logging.h"
+#include "base/scoped_observer.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/app/vector_icons/vector_icons.h"
 #include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
@@ -22,6 +23,7 @@
 #include "chrome/browser/ui/webui/tab_strip/tab_strip_ui_layout.h"
 #include "chrome/common/webui_url_constants.h"
 #include "chrome/grit/generated_resources.h"
+#include "ui/aura/window.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/paint_vector_icon.h"
@@ -31,6 +33,113 @@
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/layout/flex_layout.h"
 #include "ui/views/view_class_properties.h"
+#include "ui/views/view_observer.h"
+#include "ui/views/widget/widget.h"
+
+namespace {
+
+bool EventTypeCanCloseTabStrip(const ui::EventType& type) {
+  switch (type) {
+    case ui::ET_MOUSE_PRESSED:
+    case ui::ET_TOUCH_PRESSED:
+    case ui::ET_GESTURE_TAP:
+    case ui::ET_GESTURE_DOUBLE_TAP:
+      return true;
+    default:
+      return false;
+  }
+}
+
+}  // namespace
+
+// When enabled, closes the container upon any event in the window not
+// destined for the container and cancels the event. If an event is
+// destined for the container, it passes it through.
+class WebUITabStripContainerView::AutoCloser : public ui::EventHandler,
+                                               public views::ViewObserver {
+ public:
+  AutoCloser(views::View* container,
+             base::RepeatingClosure close_container_callback)
+      : container_(container),
+        close_container_callback_(std::move(close_container_callback)),
+        view_observer_(this) {
+    view_observer_.Add(container);
+    WidgetChanged();
+
+    // Our observed Widget's NativeView may be destroyed before us. We
+    // have no reasonable way of un-registering our pre-target handler
+    // from the NativeView while the Widget is destroying. This disables
+    // EventHandler's check that it has been removed from all
+    // EventTargets.
+    DisableCheckTargets();
+  }
+
+  ~AutoCloser() override {
+    // If |container_| was in a Widget and that Widget still has its
+    // NativeView, remove ourselves from it. Otherwise, the NativeView
+    // is already destroying so we don't need to do anything.
+    if (last_widget_ && last_widget_->GetNativeView())
+      last_widget_->GetNativeView()->RemovePreTargetHandler(this);
+  }
+
+  // Sets whether to inspect events. If not enabled, all events are
+  // ignored and passed through as usual.
+  void set_enabled(bool enabled) { enabled_ = enabled; }
+
+  // ui::EventHandler:
+  void OnEvent(ui::Event* event) override {
+    if (!enabled_)
+      return;
+    if (!event->IsLocatedEvent())
+      return;
+
+    ui::LocatedEvent* located_event = event->AsLocatedEvent();
+    // Let any events destined for |container_| pass through.
+    const gfx::Rect container_bounds_in_window =
+        container_->ConvertRectToWidget(container_->GetLocalBounds());
+    if (container_bounds_in_window.Contains(located_event->root_location()))
+      return;
+
+    // Upon any user action outside |container_|, cancel the event and close the
+    // container.
+    if (EventTypeCanCloseTabStrip(located_event->type())) {
+      located_event->StopPropagation();
+      close_container_callback_.Run();
+    }
+  }
+
+  // views::ViewObserver:
+  void OnViewAddedToWidget(views::View* observed_view) override {
+    DCHECK_EQ(container_, observed_view);
+    WidgetChanged();
+  }
+
+  void OnViewRemovedFromWidget(views::View* observed_view) override {
+    DCHECK_EQ(container_, observed_view);
+    WidgetChanged();
+  }
+
+ private:
+  // Handle when |container_| is added to a new Widget or removed from
+  // its Widget.
+  void WidgetChanged() {
+    views::Widget* new_widget = container_->GetWidget();
+    if (new_widget == last_widget_)
+      return;
+
+    if (last_widget_)
+      last_widget_->GetNativeView()->RemovePreTargetHandler(this);
+    if (new_widget)
+      new_widget->GetNativeView()->AddPreTargetHandler(this);
+    last_widget_ = new_widget;
+  }
+
+  views::View* const container_;
+  base::RepeatingClosure close_container_callback_;
+  views::Widget* last_widget_ = nullptr;
+  ScopedObserver<View, ViewObserver> view_observer_;
+  bool enabled_ = false;
+};
 
 WebUITabStripContainerView::WebUITabStripContainerView(
     Browser* browser,
@@ -38,7 +147,11 @@ WebUITabStripContainerView::WebUITabStripContainerView(
     : browser_(browser),
       web_view_(
           AddChildView(std::make_unique<views::WebView>(browser->profile()))),
-      tab_contents_container_(tab_contents_container) {
+      tab_contents_container_(tab_contents_container),
+      auto_closer_(std::make_unique<AutoCloser>(
+          this,
+          base::Bind(&WebUITabStripContainerView::CloseContainer,
+                     base::Unretained(this)))) {
   SetVisible(false);
   // TODO(crbug.com/1010589) WebContents are initially assumed to be visible by
   // default unless explicitly hidden. The WebContents need to be set to hidden
@@ -95,6 +208,7 @@ void WebUITabStripContainerView::CloseContainer() {
   if (!GetVisible())
     return;
   SetVisible(false);
+  auto_closer_->set_enabled(false);
   InvalidateLayout();
 }
 
@@ -125,6 +239,7 @@ void WebUITabStripContainerView::ButtonPressed(views::Button* sender,
   if (sender->GetID() == VIEW_ID_WEBUI_TAB_STRIP_TOGGLE_BUTTON) {
     // TODO(pbos): Trigger a slide animation here.
     SetVisible(!GetVisible());
+    auto_closer_->set_enabled(GetVisible());
     InvalidateLayout();
   } else if (sender->GetID() == VIEW_ID_WEBUI_TAB_STRIP_NEW_TAB_BUTTON) {
     chrome::ExecuteCommand(browser_, IDC_NEW_TAB);

chrome/browser/ui/views/frame/webui_tab_strip_container_view.h

@@ -11,6 +11,7 @@
 #include "chrome/browser/ui/views/toolbar/toolbar_button.h"
 #include "chrome/browser/ui/webui/tab_strip/tab_strip_ui.h"
 #include "chrome/common/buildflags.h"
+#include "ui/events/event_handler.h"
 #include "ui/views/view.h"
 
 #if !BUILDFLAG(ENABLE_WEBUI_TAB_STRIP)
@@ -45,6 +46,8 @@ class WebUITabStripContainerView : public TabStripUI::Embedder,
   std::unique_ptr<ToolbarButton> CreateToggleButton();
 
  private:
+  class AutoCloser;
+
   // TabStripUI::Embedder:
   void CloseContainer() override;
   void ShowContextMenuAtPoint(
@@ -67,6 +70,8 @@ class WebUITabStripContainerView : public TabStripUI::Embedder,
 
   int desired_height_ = 0;
 
+  std::unique_ptr<AutoCloser> auto_closer_;
+
   std::unique_ptr<views::MenuRunner> context_menu_runner_;
   std::unique_ptr<ui::MenuModel> context_menu_model_;