localize a11y tab labels in the TabBar (#13714)

* localize a11y tab labels in the TabBar

* break import cycle

* test boilerplate

* fix German translation

* more test boilerplate fixes

packages/flutter/lib/src/material/material_localizations.dart

@@ -85,6 +85,14 @@ abstract class MaterialLocalizations {
   /// Title for the [PaginatedDataTable]'s "rows per page" footer.
   String get rowsPerPageTitle;
 
+  /// The accessibility label used on a tab in a [TabBar].
+  ///
+  /// This message describes the index of the selected tab and how many tabs
+  /// there are, e.g. 'Tab 1 of 2' in United States English.
+  ///
+  /// `tabIndex` and `tabCount` must be greater than or equal to one.
+  String tabLabel({int tabIndex, int tabCount});
+
   /// Title for the [PaginatedDataTable]'s selected row count header.
   String selectedRowCountTitle(int selectedRowCount);
 
@@ -517,6 +525,13 @@ class DefaultMaterialLocalizations implements MaterialLocalizations {
   @override
   String get rowsPerPageTitle => 'Rows per page:';
 
+  @override
+  String tabLabel({int tabIndex, int tabCount}) {
+    assert(tabIndex >= 1);
+    assert(tabCount >= 1);
+    return 'Tab $tabIndex of $tabCount';
+  }
+
   @override
   String selectedRowCountTitle(int selectedRowCount) {
     switch (selectedRowCount) {

packages/flutter/lib/src/material/tabs.dart

@@ -16,6 +16,7 @@ import 'constants.dart';
 import 'debug.dart';
 import 'ink_well.dart';
 import 'material.dart';
+import 'material_localizations.dart';
 import 'tab_controller.dart';
 import 'theme.dart';
 
@@ -747,6 +748,7 @@ class _TabBarState extends State<TabBar> {
 
   @override
   Widget build(BuildContext context) {
+    final MaterialLocalizations localizations = MaterialLocalizations.of(context);
     if (_controller.length == 0) {
       return new Container(
         height: _kTabHeight + widget.indicatorWeight,
@@ -811,8 +813,7 @@ class _TabBarState extends State<TabBar> {
               wrappedTabs[index],
               new Semantics(
                 selected: index == _currentIndex,
-                // TODO(goderbauer): I10N-ify
-                label: 'Tab ${index + 1} of $tabCount',
+                label: localizations.tabLabel(tabIndex: index + 1, tabCount: tabCount),
               ),
             ]
           ),

packages/flutter/test/material/app_bar_test.dart

@@ -8,7 +8,13 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 Widget buildSliverAppBarApp({ bool floating, bool pinned, double expandedHeight, bool snap: false }) {
-  return new Directionality(
+  return new Localizations(
+    locale: const Locale('en', 'US'),
+    delegates: <LocalizationsDelegate<dynamic>>[
+      DefaultMaterialLocalizations.delegate,
+      DefaultWidgetsLocalizations.delegate,
+    ],
+    child: new Directionality(
       textDirection: TextDirection.ltr,
       child: new MediaQuery(
         data: const MediaQueryData(),
@@ -39,6 +45,7 @@ Widget buildSliverAppBarApp({ bool floating, bool pinned, double expandedHeight,
           ),
         ),
       ),
+    ),
   );
 }
 

packages/flutter/test/material/tabs_test.dart

@@ -15,11 +15,18 @@ import '../rendering/recording_canvas.dart';
 import '../widgets/semantics_tester.dart';
 
 Widget boilerplate({ Widget child, TextDirection textDirection: TextDirection.ltr }) {
-  return new Directionality(
+  return new Localizations(
+    locale: const Locale('en', 'US'),
+    delegates: <LocalizationsDelegate<dynamic>>[
+      DefaultMaterialLocalizations.delegate,
+      DefaultWidgetsLocalizations.delegate,
+    ],
+    child: new Directionality(
       textDirection: textDirection,
       child: new Material(
         child: child,
       ),
+    ),
   );
 }
 

packages/flutter/test/widgets/nested_scroll_view_test.dart

@@ -21,7 +21,13 @@ class _CustomPhysics extends ClampingScrollPhysics {
 }
 
 Widget buildTest({ ScrollController controller, String title:'TTTTTTTT' }) {
-  return new Directionality(
+  return new Localizations(
+    locale: const Locale('en', 'US'),
+    delegates: <LocalizationsDelegate<dynamic>>[
+      DefaultMaterialLocalizations.delegate,
+      DefaultWidgetsLocalizations.delegate,
+    ],
+    child: new Directionality(
       textDirection: TextDirection.ltr,
       child: new MediaQuery(
         data: const MediaQueryData(),
@@ -95,6 +101,7 @@ Widget buildTest({ ScrollController controller, String title:'TTTTTTTT' }) {
           ),
         ),
       ),
+    ),
   );
 }
 

packages/flutter_localizations/lib/src/l10n/material_ar.arb

@@ -20,6 +20,7 @@
   "pageRowsInfoTitle": "من $firstRow إلى $lastRow من إجمالي $rowCount",
   "pageRowsInfoTitleApproximate": "من $firstRow إلى $lastRow من إجمالي $rowCount تقريبًا",
   "rowsPerPageTitle": "عدد الصفوف في الصفحة:",
+  "tabLabel": "من $tabIndex من إجمالي $tabCount",
   "selectedRowCountTitleOther": "تم اختيار $selectedRowCount عنصر",
   "cancelButtonLabel": "إلغاء",
   "closeButtonLabel": "إغلاق",

packages/flutter_localizations/lib/src/l10n/material_de.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow–$lastRow von $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow von etwa $rowCount",
   "rowsPerPageTitle": "Zeilen pro Seite:",
+  "tabLabel": "Tabulator $tabIndex von $tabCount",
   "selectedRowCountTitleZero": "Keine Objekte ausgewählt",
   "selectedRowCountTitleOne": "1 Element ausgewählt",
   "selectedRowCountTitleOther": "$selectedRowCount Elemente ausgewählt",

packages/flutter_localizations/lib/src/l10n/material_en.arb

@@ -82,6 +82,12 @@
     "description": "The caption for the drop-down button on a paginated data table's footer that allows the user to control the number of rows of data per page of the table."
   },
 
+  "tabLabel": "Tab $tabIndex of $tabCount",
+  "@tabLabel": {
+    "description": "The accessibility label used on a tab. This message describes the index of the selected tab and how many tabs there are, e.g. 'Tab 1 of 2'. All values are greater than or equal to one.",
+    "parameters": "tabIndex, tabCount"
+  },
+
   "selectedRowCountTitleZero": "No items selected",
   "selectedRowCountTitleOne": "1 item selected",
   "selectedRowCountTitleOther": "$selectedRowCount items selected",

packages/flutter_localizations/lib/src/l10n/material_es.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow‑$lastRow de $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow‑$lastRow de aproximadamente $rowCount",
   "rowsPerPageTitle": "Filas por página:",
+  "tabLabel": "$tabIndex de $tabCount",
   "selectedRowCountTitleZero": "No se han seleccionado elementos",
   "selectedRowCountTitleOne": "1 elemento seleccionado",
   "selectedRowCountTitleOther": "$selectedRowCount elementos seleccionados",

packages/flutter_localizations/lib/src/l10n/material_fa.arb

@@ -16,6 +16,7 @@
   "pageRowsInfoTitle": "$firstRow–$lastRow از $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow از حدود $rowCount",
   "rowsPerPageTitle": "ردیف در هر صفحه:",
+  "tabLabel": "$tabIndex از $tabCount",
   "selectedRowCountTitleOther": "$selectedRowCount مورد انتخاب شدند",
   "cancelButtonLabel": "لغو",
   "closeButtonLabel": "بستن",

packages/flutter_localizations/lib/src/l10n/material_fr.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow – $lastRow sur $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow – $lastRow sur environ $rowCount",
   "rowsPerPageTitle": "Lignes par page :",
+  "tabLabel": "$tabIndex sur $tabCount",
   "selectedRowCountTitleZero": "Aucun élément sélectionné",
   "selectedRowCountTitleOne": "1 élément sélectionné",
   "selectedRowCountTitleOther": "$selectedRowCount éléments sélectionnés",

packages/flutter_localizations/lib/src/l10n/material_he.arb

@@ -18,6 +18,7 @@
   "pageRowsInfoTitle": "$lastRow–$firstRow מתוך $rowCount",
   "pageRowsInfoTitleApproximate": "$lastRow–$firstRow מתוך כ-$rowCount",
   "rowsPerPageTitle": "שורות בכל דף:",
+  "tabLabel": "$tabIndex מתוך $tabCount",
   "selectedRowCountTitleOther": "$selectedRowCount פריטים נבחרו",
   "cancelButtonLabel": "ביטול",
   "closeButtonLabel": "סגירה",

packages/flutter_localizations/lib/src/l10n/material_it.arb

@@ -16,6 +16,7 @@
   "pageRowsInfoTitle": "$firstRow-$lastRow di $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow-$lastRow di circa $rowCount",
   "rowsPerPageTitle": "Righe per pagina:",
+  "tabLabel": "$tabIndex di $tabCount",
   "selectedRowCountTitleOther": "$selectedRowCount elementi selezionati",
   "cancelButtonLabel": "ANNULLA",
   "closeButtonLabel": "CHIUDI",

packages/flutter_localizations/lib/src/l10n/material_ja.arb

@@ -16,6 +16,7 @@
   "pageRowsInfoTitle": "$firstRow - $lastRow 行（合計 $rowCount 行）",
   "pageRowsInfoTitleApproximate": "$firstRow – $lastRow 行（合計約 $rowCount 行）",
   "rowsPerPageTitle": "ページあたりの行数:",
+  "tabLabel": "$tabIndex 行（合計 $tabCount 行）",
   "selectedRowCountTitleOther": "$selectedRowCount 件のアイテムを選択中",
   "cancelButtonLabel": "キャンセル",
   "closeButtonLabel": "閉じる",

packages/flutter_localizations/lib/src/l10n/material_ko.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$rowCount행 중 $firstRow~$lastRow행",
   "pageRowsInfoTitleApproximate": "약 $rowCount행 중 $firstRow~$lastRow행",
   "rowsPerPageTitle": "페이지당 행 수:",
+  "tabLabel": "$tabCount행 중 $tabIndex행",
   "selectedRowCountTitleOne": "항목 1개 선택됨",
   "selectedRowCountTitleOther": "항목 $selectedRowCount개 선택됨",
   "cancelButtonLabel": "취소",

packages/flutter_localizations/lib/src/l10n/material_nl.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow-$lastRow van $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow-$lastRow van ongeveer $rowCount",
   "rowsPerPageTitle": "Rijen per pagina:",
+  "tabLabel": "$tabIndex van $tabCount",
   "selectedRowCountTitleOne": "1 item geselecteerd",
   "selectedRowCountTitleOther": "$selectedRowCount items geselecteerd",
   "cancelButtonLabel": "ANNULEREN",

packages/flutter_localizations/lib/src/l10n/material_pl.arb

@@ -17,6 +17,7 @@
   "pageRowsInfoTitle": "$firstRow–$lastRow z $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow z około $rowCount",
   "rowsPerPageTitle": "Wiersze na stronie:",
+  "tabLabel": "$tabIndex z $tabCount",
   "selectedRowCountTitleOne": "1 wybrany element",
   "selectedRowCountTitleOther": "$selectedRowCount wybranego elementu",
   "cancelButtonLabel": "ANULUJ",

packages/flutter_localizations/lib/src/l10n/material_ps.arb

@@ -17,6 +17,7 @@
   "pageRowsInfoTitle": "$firstRow–$lastRow د $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow څخه $rowCount د",
   "rowsPerPageTitle": "د هرې پاڼې پاڼې:",
+  "tabLabel": "$tabIndex د $tabCount",
   "selectedRowCountTitleOther": "$selectedRowCount توکي غوره شوي",
   "cancelButtonLabel": "لغوه کول",
   "closeButtonLabel": "تړل",

packages/flutter_localizations/lib/src/l10n/material_pt.arb

@@ -20,6 +20,7 @@
   "pageRowsInfoTitle": "$firstRow – $lastRow de $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow – $lastRow de aproximadamente $rowCount",
   "rowsPerPageTitle": "Linhas por página:",
+  "tabLabel": "$tabIndex de $tabCount",
   "selectedRowCountTitleOther": "$selectedRowCount itens selecionados",
   "cancelButtonLabel": "CANCELAR",
   "closeButtonLabel": "FECHAR",

packages/flutter_localizations/lib/src/l10n/material_ru.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow–$lastRow из $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow из примерно $rowCount",
   "rowsPerPageTitle": "Строк на странице:",
+  "tabLabel": "Закладка $tabIndex из $tabCount",
   "aboutListTileTitle": "$applicationName: сведения",
   "licensesPageTitle": "Лицензии",
   "selectedRowCountTitleZero": "Строки не выбраны",

packages/flutter_localizations/lib/src/l10n/material_th.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow-$lastRow จาก $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow จากประมาณ $rowCount",
   "rowsPerPageTitle": "แถวต่อหน้า:",
+  "tabLabel": "$tabIndex จาก $tabCount",
   "selectedRowCountTitleOne": "เลือกแล้ว 1 รายการ",
   "selectedRowCountTitleOther": "เลือกแล้ว $selectedRowCount รายการ",
   "cancelButtonLabel": "ยกเลิก",

packages/flutter_localizations/lib/src/l10n/material_tr.arb

@@ -15,6 +15,7 @@
   "pageRowsInfoTitle": "$firstRow-$lastRow / $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow-$lastRow / $rowCount",
   "rowsPerPageTitle": "Sayfa başına satır sayısı:",
+  "tabLabel": "$tabIndex, $tabCount içinde",
   "selectedRowCountTitleOne": "1 öğe seçildi",
   "selectedRowCountTitleOther": "$selectedRowCount öğe seçildi",
   "cancelButtonLabel": "İPTAL",

packages/flutter_localizations/lib/src/l10n/material_ur.arb

@@ -16,6 +16,7 @@
   "pageRowsInfoTitle": "$firstRow–$lastRow از $rowCount",
   "pageRowsInfoTitleApproximate": "$firstRow–$lastRow $rowCount میں سے تقریباً",
   "rowsPerPageTitle": "قطاریں فی صفحہ:",
+  "tabLabel": "$tabIndex از $tabCount",
   "selectedRowCountTitleOther": "$selectedRowCount آئٹمز منتخب کیے گئے",
   "cancelButtonLabel": "منسوخ کریں",
   "closeButtonLabel": "بند کریں",

packages/flutter_localizations/lib/src/l10n/material_zh.arb

@@ -12,6 +12,7 @@
   "pageRowsInfoTitle": "第 $firstRow-$lastRow 行（共 $rowCount 行）",
   "pageRowsInfoTitleApproximate": "第 $firstRow-$lastRow 行（共约 $rowCount 行）",
   "rowsPerPageTitle": "每页行数：",
+  "tabLabel": "第 $tabIndex 行（共 $tabCount 行）",
   "selectedRowCountTitleOther": "已选择 $selectedRowCount 项内容",
   "cancelButtonLabel": "取消",
   "continueButtonLabel": "继续",

packages/flutter_localizations/lib/src/material_localizations.dart

@@ -272,6 +272,16 @@ class GlobalMaterialLocalizations implements MaterialLocalizations {
   @override
   String get rowsPerPageTitle => _translationBundle.rowsPerPageTitle;
 
+  @override
+  String tabLabel({int tabIndex, int tabCount}) {
+    assert(tabIndex >= 1);
+    assert(tabCount >= 1);
+    final String template = _translationBundle.tabLabel;
+    return template
+      .replaceFirst(r'$tabIndex', formatDecimal(tabIndex))
+      .replaceFirst(r'tabCount', formatDecimal(tabCount));
+  }
+
   @override
   String selectedRowCountTitle(int selectedRowCount) {
     // TODO(hmuller): the rules for mapping from an integer value to

packages/flutter_localizations/test/translations_test.dart

@@ -61,19 +61,25 @@ void main() {
       expect(localizations.selectedRowCountTitle(1), isNotNull);
       expect(localizations.selectedRowCountTitle(2), isNotNull);
       expect(localizations.selectedRowCountTitle(100), isNotNull);
-      expect(localizations.selectedRowCountTitle(0).contains(r'$selectedRowCount'), isFalse);
-      expect(localizations.selectedRowCountTitle(1).contains(r'$selectedRowCount'), isFalse);
-      expect(localizations.selectedRowCountTitle(2).contains(r'$selectedRowCount'), isFalse);
-      expect(localizations.selectedRowCountTitle(100).contains(r'$selectedRowCount'), isFalse);
+      expect(localizations.selectedRowCountTitle(0), isNot(contains(r'$selectedRowCount')));
+      expect(localizations.selectedRowCountTitle(1), isNot(contains(r'$selectedRowCount')));
+      expect(localizations.selectedRowCountTitle(2), isNot(contains(r'$selectedRowCount')));
+      expect(localizations.selectedRowCountTitle(100), isNot(contains(r'$selectedRowCount')));
 
       expect(localizations.pageRowsInfoTitle(1, 10, 100, true), isNotNull);
       expect(localizations.pageRowsInfoTitle(1, 10, 100, false), isNotNull);
-      expect(localizations.pageRowsInfoTitle(1, 10, 100, true).contains(r'$firstRow'), isFalse);
-      expect(localizations.pageRowsInfoTitle(1, 10, 100, true).contains(r'$lastRow'), isFalse);
-      expect(localizations.pageRowsInfoTitle(1, 10, 100, true).contains(r'$rowCount'), isFalse);
-      expect(localizations.pageRowsInfoTitle(1, 10, 100, false).contains(r'$firstRow'), isFalse);
-      expect(localizations.pageRowsInfoTitle(1, 10, 100, false).contains(r'$lastRow'), isFalse);
-      expect(localizations.pageRowsInfoTitle(1, 10, 100, false).contains(r'$rowCount'), isFalse);
+      expect(localizations.pageRowsInfoTitle(1, 10, 100, true), isNot(contains(r'$firstRow')));
+      expect(localizations.pageRowsInfoTitle(1, 10, 100, true), isNot(contains(r'$lastRow')));
+      expect(localizations.pageRowsInfoTitle(1, 10, 100, true), isNot(contains(r'$rowCount')));
+      expect(localizations.pageRowsInfoTitle(1, 10, 100, false), isNot(contains(r'$firstRow')));
+      expect(localizations.pageRowsInfoTitle(1, 10, 100, false), isNot(contains(r'$lastRow')));
+      expect(localizations.pageRowsInfoTitle(1, 10, 100, false), isNot(contains(r'$rowCount')));
+
+      expect(localizations.tabLabel(tabIndex: 2, tabCount: 5), isNotNull);
+      expect(localizations.tabLabel(tabIndex: 2, tabCount: 5), isNot(contains('tabIndex')));
+      expect(localizations.tabLabel(tabIndex: 2, tabCount: 5), isNot(contains('tabCount')));
+      expect(() => localizations.tabLabel(tabIndex: 0, tabCount: 5), throwsAssertionError);
+      expect(() => localizations.tabLabel(tabIndex: 2, tabCount: 0), throwsAssertionError);
     });
   }