Add screen reader support for groups

- Tabs will read out their group membership.
- Group headers will read out their tab contents.

Tiny side bonus: Focusing on group headers will no longer show the wrong hovercard.

Bug: 1045844
Change-Id: I5fc98231a5c5a0372aa75e31a5c3a6e321ce24b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2025698
Commit-Queue: Connie Wan <connily@chromium.org>
Reviewed-by: Charlene Yan <cyan@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736582}

chrome/app/generated_resources.grd

@@ -9573,6 +9573,18 @@ Please help our engineers fix this problem. Tell us what happened right before y
           $1<ex>A VR-enabled website</ex>
         </ph> - VR presenting to headset
       </message>
+      <message name="IDS_TAB_AX_LABEL_UNNAMED_GROUP_FORMAT" desc="Accessibility label text for a tab, when it is in a group that has not been named by the user. Example: 'Google Search - Part of unnamed group'">
+        <ph name="WINDOW_TITLE">$1<ex>Google Search</ex></ph> - Part of unnamed group
+      </message>
+      <message name="IDS_TAB_AX_LABEL_NAMED_GROUP_FORMAT" desc="Accessibility label text for a tab, when it is in a group that has been named by the user. Example: 'Google Search - Part of group MyGroupName'">
+        <ph name="WINDOW_TITLE">$1<ex>Google Search</ex></ph> - Part of group <ph name="GROUP_NAME">$2</ph>
+      </message>
+      <message name="IDS_GROUP_AX_LABEL_UNNAMED_GROUP_FORMAT" desc="Accessibility label text for a tab group header, when it has not been named by the user. Example: 'Unnamed group - Google Search and 3 other tabs'">
+        Unnamed group - <ph name="GROUP_CONTENTS">$1<ex>Google Search and 3 other tabs</ex></ph>
+      </message>
+      <message name="IDS_GROUP_AX_LABEL_NAMED_GROUP_FORMAT" desc="Accessibility label text for a tab group header, when it has been named by the user. Example: 'Group MyGroupName - Google Search and 3 other tabs'">
+        Group <ph name="GROUP_NAME">$1</ph> - <ph name="GROUP_CONTENTS">$2<ex>Google Search and 3 other tabs</ex></ph>
+      </message>
 
       <!-- ProcessSingleton -->
       <message name="IDS_PROFILE_IN_USE_LINUX_QUIT" desc="Text of button in profile in use dialog to quit without doing anything.">

chrome/browser/ui/tabs/existing_tab_group_sub_menu_model.cc

@@ -88,8 +88,11 @@ void ExistingTabGroupSubMenuModel::Build() {
   for (tab_groups::TabGroupId group : GetOrderedTabGroups()) {
     if (ShouldShowGroup(model_, context_index_, group)) {
       const TabGroup* tab_group = model_->group_model()->GetTabGroup(group);
+      const base::string16 group_title = tab_group->visual_data()->title();
+      const base::string16 displayed_title =
+          group_title.empty() ? tab_group->GetContentString() : group_title;
       AddItemWithIcon(
-          group_index, tab_group->GetDisplayedTitle(),
+          group_index, displayed_title,
           gfx::ImageSkia(std::make_unique<TabGroupIconImageSource>(
                              tab_group->visual_data()),
                          gfx::Size(TabGroupIconImageSource::kIconSize,

chrome/browser/ui/tabs/tab_group.cc

@@ -34,23 +34,17 @@ void TabGroup::SetVisualData(
   controller_->ChangeTabGroupVisuals(id_);
 }
 
-base::string16 TabGroup::GetDisplayedTitle() const {
-  base::string16 title = visual_data_->title();
-  if (title.empty()) {
-    // Generate a descriptive placeholder title for the group.
-    std::vector<int> tabs_in_group = ListTabs();
-    TabUIHelper* const tab_ui_helper = TabUIHelper::FromWebContents(
-        controller_->GetWebContentsAt(tabs_in_group.front()));
-    constexpr size_t kContextMenuTabTitleMaxLength = 30;
-    base::string16 format_string = l10n_util::GetPluralStringFUTF16(
-        IDS_TAB_CXMENU_PLACEHOLDER_GROUP_TITLE, tabs_in_group.size() - 1);
-    base::string16 short_title;
-    gfx::ElideString(tab_ui_helper->GetTitle(), kContextMenuTabTitleMaxLength,
-                     &short_title);
-    title =
-        base::ReplaceStringPlaceholders(format_string, {short_title}, nullptr);
-  }
-  return title;
+base::string16 TabGroup::GetContentString() const {
+  std::vector<int> tabs_in_group = ListTabs();
+  TabUIHelper* const tab_ui_helper = TabUIHelper::FromWebContents(
+      controller_->GetWebContentsAt(tabs_in_group.front()));
+  constexpr size_t kContextMenuTabTitleMaxLength = 30;
+  base::string16 format_string = l10n_util::GetPluralStringFUTF16(
+      IDS_TAB_CXMENU_PLACEHOLDER_GROUP_TITLE, tabs_in_group.size() - 1);
+  base::string16 short_title;
+  gfx::ElideString(tab_ui_helper->GetTitle(), kContextMenuTabTitleMaxLength,
+                   &short_title);
+  return base::ReplaceStringPlaceholders(format_string, {short_title}, nullptr);
 }
 
 void TabGroup::AddTab() {

chrome/browser/ui/tabs/tab_group.h

@@ -36,10 +36,11 @@ class TabGroup {
   }
   void SetVisualData(const tab_groups::TabGroupVisualData& visual_data);
 
-  // Returns the user-visible group title that will be displayed in context
-  // menus and tooltips. Generates a descriptive placeholder if the user has
-  // not yet named the group, otherwise uses the group's name.
-  base::string16 GetDisplayedTitle() const;
+  // Returns a user-visible string describing the contents of the group, such as
+  // "Google Search and 3 other tabs". Used for accessibly describing the group,
+  // as well as for displaying in context menu items and tooltips when the group
+  // is unnamed.
+  base::string16 GetContentString() const;
 
   // Updates internal bookkeeping for group contents, and notifies the
   // controller that contents changed when a tab is added.

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

@@ -2046,6 +2046,19 @@ base::string16 BrowserView::GetAccessibleTabLabel(bool include_app_name,
   base::string16 title =
       browser_->GetWindowTitleForTab(include_app_name, index);
 
+  base::Optional<tab_groups::TabGroupId> group =
+      tabstrip_->tab_at(index)->group();
+  if (group.has_value()) {
+    base::string16 group_title = tabstrip_->GetGroupTitle(group.value());
+    if (group_title.empty()) {
+      title = l10n_util::GetStringFUTF16(IDS_TAB_AX_LABEL_UNNAMED_GROUP_FORMAT,
+                                         title);
+    } else {
+      title = l10n_util::GetStringFUTF16(IDS_TAB_AX_LABEL_NAMED_GROUP_FORMAT,
+                                         title, group_title);
+    }
+  }
+
   // Tab has crashed.
   if (tabstrip_->IsTabCrashed(index))
     return l10n_util::GetStringFUTF16(IDS_TAB_AX_LABEL_CRASHED_FORMAT, title);

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

@@ -458,6 +458,11 @@ base::string16 BrowserTabStripController::GetGroupTitle(
   return model_->group_model()->GetTabGroup(group)->visual_data()->title();
 }
 
+base::string16 BrowserTabStripController::GetGroupContentString(
+    const tab_groups::TabGroupId& group) const {
+  return model_->group_model()->GetTabGroup(group)->GetContentString();
+}
+
 tab_groups::TabGroupColorId BrowserTabStripController::GetGroupColorId(
     const tab_groups::TabGroupId& group) const {
   return model_->group_model()->GetTabGroup(group)->visual_data()->color();

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

@@ -84,6 +84,8 @@ class BrowserTabStripController : public TabStripController,
   void OnKeyboardFocusedTabChanged(base::Optional<int> index) override;
   base::string16 GetGroupTitle(
       const tab_groups::TabGroupId& group_id) const override;
+  base::string16 GetGroupContentString(
+      const tab_groups::TabGroupId& group_id) const override;
   tab_groups::TabGroupColorId GetGroupColorId(
       const tab_groups::TabGroupId& group_id) const override;
   void SetVisualDataForGroup(

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

@@ -72,6 +72,11 @@ base::string16 FakeBaseTabStripController::GetGroupTitle(
   return fake_group_data_.title();
 }
 
+base::string16 FakeBaseTabStripController::GetGroupContentString(
+    const tab_groups::TabGroupId& group_id) const {
+  return base::string16();
+}
+
 tab_groups::TabGroupColorId FakeBaseTabStripController::GetGroupColorId(
     const tab_groups::TabGroupId& group_id) const {
   return fake_group_data_.color();

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

@@ -61,6 +61,8 @@ class FakeBaseTabStripController : public TabStripController {
   void OnKeyboardFocusedTabChanged(base::Optional<int> index) override;
   base::string16 GetGroupTitle(
       const tab_groups::TabGroupId& group_id) const override;
+  base::string16 GetGroupContentString(
+      const tab_groups::TabGroupId& group_id) const override;
   tab_groups::TabGroupColorId GetGroupColorId(
       const tab_groups::TabGroupId& group_id) const override;
   void SetVisualDataForGroup(

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

@@ -19,11 +19,13 @@
 #include "chrome/browser/ui/views/tabs/tab_strip_controller.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_layout.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_types.h"
+#include "chrome/grit/generated_resources.h"
 #include "components/tab_groups/tab_group_color.h"
 #include "components/tab_groups/tab_group_id.h"
 #include "components/tab_groups/tab_group_visual_data.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPath.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/geometry/insets.h"
@@ -199,15 +201,25 @@ void TabGroupHeader::OnGestureEvent(ui::GestureEvent* event) {
   event->SetHandled();
 }
 
+void TabGroupHeader::OnFocus() {
+  View::OnFocus();
+  tab_strip_->UpdateHoverCard(nullptr);
+}
+
 void TabGroupHeader::GetAccessibleNodeData(ui::AXNodeData* node_data) {
   node_data->role = ax::mojom::Role::kTabList;
   node_data->AddState(ax::mojom::State::kEditable);
 
-  base::string16 name = tab_strip_->GetGroupTitle(group().value());
-  if (name.empty()) {
-    node_data->SetNameExplicitlyEmpty();
+  base::string16 title =
+      tab_strip_->controller()->GetGroupTitle(group().value());
+  base::string16 contents =
+      tab_strip_->controller()->GetGroupContentString(group().value());
+  if (title.empty()) {
+    node_data->SetName(l10n_util::GetStringFUTF16(
+        IDS_GROUP_AX_LABEL_UNNAMED_GROUP_FORMAT, contents));
   } else {
-    node_data->SetName(name);
+    node_data->SetName(l10n_util::GetStringFUTF16(
+        IDS_GROUP_AX_LABEL_NAMED_GROUP_FORMAT, title, contents));
   }
 }
 

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

@@ -33,6 +33,7 @@ class TabGroupHeader : public TabSlotView {
   void OnMouseReleased(const ui::MouseEvent& event) override;
   void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
+  void OnFocus() override;
   void OnThemeChanged() override;
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
   TabSlotView::ViewType GetTabSlotViewType() const override;

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

@@ -141,10 +141,14 @@ class TabStripController {
   // to |index|.
   virtual void OnKeyboardFocusedTabChanged(base::Optional<int> index) = 0;
 
-  // Returns the displayed title of the given |group|.
+  // Returns the title of the given |group|.
   virtual base::string16 GetGroupTitle(
       const tab_groups::TabGroupId& group) const = 0;
 
+  // Returns the string describing the contents of the given |group|.
+  virtual base::string16 GetGroupContentString(
+      const tab_groups::TabGroupId& group) const = 0;
+
   // Returns the color ID of the given |group|.
   virtual tab_groups::TabGroupColorId GetGroupColorId(
       const tab_groups::TabGroupId& group) const = 0;