Add a delay to tab hover cards based on tab width.

Create a logarithmic scaled delay based on tab width for tab hover cards to show.

Bug: 910739
Change-Id: I00b4d4de57cea75b837b7cadc81dea4bb5023c6e
Reviewed-on: https://chromium-review.googlesource.com/c/1455057
Commit-Queue: Caroline Rising <corising@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630082}

chrome/browser/ui/views/tabs/tab_hover_card_bubble_view.cc

@@ -4,18 +4,29 @@
 
 #include "chrome/browser/ui/views/tabs/tab_hover_card_bubble_view.h"
 
+#include <algorithm>
+
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/views/chrome_typography.h"
+#include "chrome/browser/ui/views/tabs/tab.h"
 #include "chrome/browser/ui/views/tabs/tab_renderer_data.h"
+#include "chrome/browser/ui/views/tabs/tab_style.h"
 #include "components/url_formatter/url_formatter.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/layout_provider.h"
 #include "ui/views/widget/widget.h"
 
-TabHoverCardBubbleView::TabHoverCardBubbleView(views::View* anchor_view,
-                                               TabRendererData data)
-    : BubbleDialogDelegateView(anchor_view, views::BubbleBorder::TOP_LEFT) {
+namespace {
+
+constexpr base::TimeDelta kMinimumTriggerDelay =
+    base::TimeDelta::FromMilliseconds(50);
+constexpr base::TimeDelta kMaximumTriggerDelay =
+    base::TimeDelta::FromMilliseconds(1000);
+}  // namespace
+
+TabHoverCardBubbleView::TabHoverCardBubbleView(Tab* tab)
+    : BubbleDialogDelegateView(tab, views::BubbleBorder::TOP_LEFT) {
   SetLayoutManager(
       std::make_unique<views::BoxLayout>(views::BoxLayout::kVertical));
   // Set so that when hovering over a tab in a inactive window that window will
@@ -28,7 +39,6 @@ TabHoverCardBubbleView::TabHoverCardBubbleView(views::View* anchor_view,
                        views::style::STYLE_PRIMARY);
   domain_label_ = new views::Label(base::string16(), CONTEXT_BODY_TEXT_LARGE,
                                    ChromeTextStyle::STYLE_SECONDARY);
-  UpdateCardContent(data);
 
   title_label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
   title_label_->SetMultiLine(false);
@@ -42,14 +52,66 @@ TabHoverCardBubbleView::TabHoverCardBubbleView(views::View* anchor_view,
 
 TabHoverCardBubbleView::~TabHoverCardBubbleView() = default;
 
-void TabHoverCardBubbleView::Show() {
-  widget_->Show();
+void TabHoverCardBubbleView::UpdateAndShow(Tab* tab) {
+  UpdateCardContent(tab->data());
+
+  views::BubbleDialogDelegateView::SetAnchorView(tab);
+
+  // Start trigger timer if necessary.
+  if (widget_->IsVisible()) {
+    ShowImmediately();
+  } else {
+    // Note that this will restart the timer if it is already running. If the
+    // hover cards are not yet visible, moving the cursor within the tabstrip
+    // will not trigger the hover cards.
+    delayed_show_timer_.Start(FROM_HERE, GetDelay(tab->width()), this,
+                              &TabHoverCardBubbleView::ShowImmediately);
+  }
 }
 
 void TabHoverCardBubbleView::Hide() {
+  delayed_show_timer_.Stop();
   widget_->Hide();
 }
 
+int TabHoverCardBubbleView::GetDialogButtons() const {
+  return ui::DIALOG_BUTTON_NONE;
+}
+
+base::TimeDelta TabHoverCardBubbleView::GetDelay(int tab_width) const {
+  // Delay is calculated as a logarithmic scale and bounded by a minimum width
+  // based on the width of a pinned tab and a maximum of the standard width.
+  //
+  //  delay (ms)
+  //           |
+  // max delay-|                                    *
+  //           |                          *
+  //           |                    *
+  //           |                *
+  //           |            *
+  //           |         *
+  //           |       *
+  //           |     *
+  //           |    *
+  // min delay-|****
+  //           |___________________________________________ tab width
+  //               |                                |
+  //       pinned tab width               standard tab width
+  double logarithmic_fraction =
+      std::log(tab_width - TabStyle::GetPinnedWidth() + 1) /
+      std::log(TabStyle::GetStandardWidth() - TabStyle::GetPinnedWidth() + 1);
+  base::TimeDelta scaling_factor = kMaximumTriggerDelay - kMinimumTriggerDelay;
+  base::TimeDelta delay =
+      logarithmic_fraction * scaling_factor + kMinimumTriggerDelay;
+  if (delay < kMinimumTriggerDelay)
+    delay = kMinimumTriggerDelay;
+  return delay;
+}
+
+void TabHoverCardBubbleView::ShowImmediately() {
+  widget_->Show();
+}
+
 void TabHoverCardBubbleView::UpdateCardContent(TabRendererData data) {
   title_label_->SetText(data.title);
 
@@ -65,14 +127,6 @@ void TabHoverCardBubbleView::UpdateCardContent(TabRendererData data) {
   domain_label_->SetText(domain);
 }
 
-void TabHoverCardBubbleView::UpdateCardAnchor(View* tab) {
-  views::BubbleDialogDelegateView::SetAnchorView(tab);
-}
-
-int TabHoverCardBubbleView::GetDialogButtons() const {
-  return ui::DIALOG_BUTTON_NONE;
-}
-
 gfx::Size TabHoverCardBubbleView::CalculatePreferredSize() const {
   const gfx::Size size = BubbleDialogDelegateView::CalculatePreferredSize();
   return gfx::Size(240, size.height());

chrome/browser/ui/views/tabs/tab_hover_card_bubble_view.h

@@ -5,42 +5,50 @@
 #ifndef CHROME_BROWSER_UI_VIEWS_TABS_TAB_HOVER_CARD_BUBBLE_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_TABS_TAB_HOVER_CARD_BUBBLE_VIEW_H_
 
+#include "base/time/time.h"
+#include "base/timer/timer.h"
 #include "ui/views/bubble/bubble_dialog_delegate_view.h"
 
 namespace views {
 class Label;
 class Widget;
 }  // namespace views
+
+class Tab;
 struct TabRendererData;
 
 // Dialog that displays an informational hover card containing page information.
 class TabHoverCardBubbleView : public views::BubbleDialogDelegateView {
  public:
-  TabHoverCardBubbleView(views::View* anchor_view, TabRendererData data);
+  explicit TabHoverCardBubbleView(Tab* tab);
 
   ~TabHoverCardBubbleView() override;
 
-  // Creates (if not already created) and shows the widget.
-  void Show();
+  // Updates card content and anchoring and shows the tab hover card.
+  void UpdateAndShow(Tab* tab);
 
   void Hide();
 
-  // Updates and formats title and domain with given data.
-  void UpdateCardContent(TabRendererData data);
-
-  // Updates where the card should be anchored.
-  void UpdateCardAnchor(View* tab);
-
   // BubbleDialogDelegateView:
   int GetDialogButtons() const override;
 
  private:
   friend class TabHoverCardBubbleViewBrowserTest;
 
+  base::OneShotTimer delayed_show_timer_;
+
   views::Widget* widget_ = nullptr;
   views::Label* title_label_;
   views::Label* domain_label_;
 
+  // Get delay in milliseconds based on tab width.
+  base::TimeDelta GetDelay(int tab_width) const;
+
+  void ShowImmediately();
+
+  // Updates and formats title and domain with given data.
+  void UpdateCardContent(TabRendererData data);
+
   gfx::Size CalculatePreferredSize() const override;
 };
 

chrome/browser/ui/views/tabs/tab_hover_card_bubble_view_browsertest.cc

@@ -46,6 +46,32 @@ class WindowDeactivedWaiter : public views::WidgetObserver {
   base::RunLoop run_loop_;
 };
 
+// Helper to wait until the hover card widget is visible.
+class HoverCardVisibleWaiter : public views::WidgetObserver {
+ public:
+  explicit HoverCardVisibleWaiter(Widget* hover_card)
+      : hover_card_(hover_card) {
+    hover_card_->AddObserver(this);
+  }
+  ~HoverCardVisibleWaiter() override { hover_card_->RemoveObserver(this); }
+
+  void Wait() {
+    if (hover_card_->IsVisible())
+      return;
+    run_loop_.Run();
+  }
+
+  // WidgetObserver overrides:
+  void OnWidgetVisibilityChanged(Widget* widget, bool visible) override {
+    if (visible)
+      run_loop_.Quit();
+  }
+
+ private:
+  Widget* const hover_card_;
+  base::RunLoop run_loop_;
+};
+
 class TabHoverCardBubbleViewBrowserTest : public DialogBrowserTest {
  public:
   TabHoverCardBubbleViewBrowserTest() = default;
@@ -109,6 +135,10 @@ class TabHoverCardBubbleViewBrowserTest : public DialogBrowserTest {
     ui::MouseEvent hover_event(ui::ET_MOUSE_ENTERED, gfx::Point(), gfx::Point(),
                                base::TimeTicks(), ui::EF_NONE, 0);
     tab->OnMouseEntered(hover_event);
+    TabHoverCardBubbleView* hover_card = GetHoverCard(tab_strip);
+    Widget* widget = GetHoverCardWidget(hover_card);
+    HoverCardVisibleWaiter waiter(widget);
+    waiter.Wait();
   }
 
  private:

chrome/browser/ui/views/tabs/tab_strip.cc

@@ -1143,17 +1143,13 @@ void TabStrip::UpdateHoverCard(Tab* tab, bool should_show) {
     // not trying to show it.
     if (!should_show)
       return;
-    hover_card_ = new TabHoverCardBubbleView(tab, tab->data());
+    hover_card_ = new TabHoverCardBubbleView(tab);
     hover_card_->views::View::AddObserver(this);
   }
-
-  if (should_show) {
-    hover_card_->UpdateCardContent(tab->data());
-    hover_card_->UpdateCardAnchor(tab);
-    hover_card_->Show();
-  } else {
+  if (should_show)
+    hover_card_->UpdateAndShow(tab);
+  else
     hover_card_->Hide();
-  }
 }
 
 bool TabStrip::ShouldPaintTab(const Tab* tab, float scale, SkPath* clip) {