Support password fields for a11y (#15497)

* Support password fields for a11y

* rename to obscured

* Roll engine to c3ab0c9143029f0267a05b99effbfbd280a4901b

bin/internal/engine.version

-1348ab5b63adc18148f161876a4b1cacd5ec0779
+c3ab0c9143029f0267a05b99effbfbd280a4901b

packages/flutter/lib/src/rendering/custom_paint.dart

@@ -831,6 +831,9 @@ class RenderCustomPaint extends RenderProxyBox {
     if (properties.inMutuallyExclusiveGroup != null) {
       config.isInMutuallyExclusiveGroup = properties.inMutuallyExclusiveGroup;
     }
+    if (properties.obscured != null) {
+      config.isObscured = properties.obscured;
+    }
     if (properties.header != null) {
       config.isHeader = properties.header;
     }

packages/flutter/lib/src/rendering/editable.dart

@@ -132,12 +132,14 @@ class RenderEditable extends RenderBox {
     this.onSelectionChanged,
     this.onCaretChanged,
     this.ignorePointer: false,
+    bool obscureText: false,
   }) : assert(textAlign != null),
        assert(textDirection != null, 'RenderEditable created without a textDirection.'),
        assert(maxLines == null || maxLines > 0),
        assert(textScaleFactor != null),
        assert(offset != null),
        assert(ignorePointer != null),
+       assert(obscureText != null),
        _textPainter = new TextPainter(
          text: text,
          textAlign: textAlign,
@@ -150,7 +152,8 @@ class RenderEditable extends RenderBox {
        _maxLines = maxLines,
        _selectionColor = selectionColor,
        _selection = selection,
-       _offset = offset {
+       _offset = offset,
+       _obscureText = obscureText {
     assert(_showCursor != null);
     assert(!_showCursor.value || cursorColor != null);
     _tap = new TapGestureRecognizer(debugOwner: this)
@@ -160,6 +163,9 @@ class RenderEditable extends RenderBox {
       ..onLongPress = _handleLongPress;
   }
 
+  /// Character used to obscure text if [obscureText] is true.
+  static const String obscuringCharacter = '•';
+
   /// Called when the selection changes.
   SelectionChangedHandler onSelectionChanged;
 
@@ -175,6 +181,16 @@ class RenderEditable extends RenderBox {
   /// The default value of this property is false.
   bool ignorePointer;
 
+  /// Whether to hide the text being edited (e.g., for passwords).
+  bool get obscureText => _obscureText;
+  bool _obscureText;
+  set obscureText(bool value) {
+    if (_obscureText == value)
+      return;
+    _obscureText = value;
+    markNeedsSemanticsUpdate();
+  }
+
   Rect _lastCaretRect;
 
   /// Marks the render object as needing to be laid out again and have its text
@@ -351,7 +367,10 @@ class RenderEditable extends RenderBox {
     super.describeSemanticsConfiguration(config);
 
     config
-      ..value = text.toPlainText()
+      ..value = obscureText
+          ? obscuringCharacter * text.toPlainText().length
+          : text.toPlainText()
+      ..isObscured = obscureText
       ..textDirection = textDirection
       ..isFocused = hasFocus
       ..isTextField = true;

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -3019,6 +3019,7 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
     bool textField,
     bool focused,
     bool inMutuallyExclusiveGroup,
+    bool obscured,
     String label,
     String value,
     String increasedValue,
@@ -3053,6 +3054,7 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
        _textField = textField,
        _focused = focused,
        _inMutuallyExclusiveGroup = inMutuallyExclusiveGroup,
+       _obscured = obscured,
        _label = label,
        _value = value,
        _increasedValue = increasedValue,
@@ -3201,6 +3203,17 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
     markNeedsSemanticsUpdate();
   }
 
+  /// If non-null, sets the [SemanticsNode.isObscured] semantic to the given
+  /// value.
+  bool get obscured => _obscured;
+  bool _obscured;
+  set obscured(bool value) {
+    if (obscured == value)
+      return;
+    _obscured = value;
+    markNeedsSemanticsUpdate();
+  }
+
   /// If non-null, sets the [SemanticsNode.label] semantic to the given value.
   ///
   /// The reading direction is given by [textDirection].
@@ -3638,6 +3651,8 @@ class RenderSemanticsAnnotations extends RenderProxyBox {
       config.isFocused = focused;
     if (inMutuallyExclusiveGroup != null)
       config.isInMutuallyExclusiveGroup = inMutuallyExclusiveGroup;
+    if (obscured != null)
+      config.isObscured = obscured;
     if (label != null)
       config.label = label;
     if (value != null)

packages/flutter/lib/src/semantics/semantics.dart

@@ -319,6 +319,7 @@ class SemanticsProperties extends DiagnosticableTree {
     this.textField,
     this.focused,
     this.inMutuallyExclusiveGroup,
+    this.obscured,
     this.label,
     this.value,
     this.increasedValue,
@@ -398,6 +399,13 @@ class SemanticsProperties extends DiagnosticableTree {
   /// For example, a radio button is in a mutually exclusive group because only
   /// one radio button in that group can be marked as [checked].
   final bool inMutuallyExclusiveGroup;
+  
+  /// If non-null, whether [value] should be obscured.
+  ///
+  /// This option is usually set in combination with [textField] to indicate
+  /// that the text field contains a password (or other sensitive information).
+  /// Doing so instructs screen readers to not read out the [value].
+  final bool obscured;
 
   /// Provides a textual description of the widget.
   ///
@@ -2405,6 +2413,16 @@ class SemanticsConfiguration {
     _setFlag(SemanticsFlag.isTextField, value);
   }
 
+  /// Whether the [value] should be obscured.
+  ///
+  /// This option is usually set in combination with [textField] to indicate
+  /// that the text field contains a password (or other sensitive information).
+  /// Doing so instructs screen readers to not read out the [value].
+  bool get isObscured => _hasFlag(SemanticsFlag.isObscured);
+  set isObscured(bool value) {
+    _setFlag(SemanticsFlag.isObscured, value);
+  }
+
   /// The currently selected text (or the position of the cursor) within [value]
   /// if this node represents a text field.
   TextSelection get textSelection => _textSelection;

packages/flutter/lib/src/widgets/basic.dart

@@ -4892,6 +4892,7 @@ class Semantics extends SingleChildRenderObjectWidget {
     bool textField,
     bool focused,
     bool inMutuallyExclusiveGroup,
+    bool obscured,
     String label,
     String value,
     String increasedValue,
@@ -4929,6 +4930,7 @@ class Semantics extends SingleChildRenderObjectWidget {
       textField: textField,
       focused: focused,
       inMutuallyExclusiveGroup: inMutuallyExclusiveGroup,
+      obscured: obscured,
       label: label,
       value: value,
       increasedValue: increasedValue,
@@ -5007,6 +5009,7 @@ class Semantics extends SingleChildRenderObjectWidget {
       textField: properties.textField,
       focused: properties.focused,
       inMutuallyExclusiveGroup: properties.inMutuallyExclusiveGroup,
+      obscured: properties.obscured,
       label: properties.label,
       value: properties.value,
       increasedValue: properties.increasedValue,

packages/flutter/lib/src/widgets/editable_text.dart

@@ -759,6 +759,7 @@ class _Editable extends LeafRenderObjectWidget {
       onSelectionChanged: onSelectionChanged,
       onCaretChanged: onCaretChanged,
       ignorePointer: rendererIgnoresPointer,
+      obscureText: obscureText,
     );
   }
 
@@ -778,7 +779,8 @@ class _Editable extends LeafRenderObjectWidget {
       ..offset = offset
       ..onSelectionChanged = onSelectionChanged
       ..onCaretChanged = onCaretChanged
-      ..ignorePointer = rendererIgnoresPointer;
+      ..ignorePointer = rendererIgnoresPointer
+      ..obscureText = obscureText;
   }
 
   TextSpan get _styledTextSpan {
@@ -801,7 +803,7 @@ class _Editable extends LeafRenderObjectWidget {
 
     String text = value.text;
     if (obscureText) {
-      text = new String.fromCharCodes(new List<int>.filled(text.length, 0x2022));
+      text = RenderEditable.obscuringCharacter * text.length;
       final int o = obscureShowCharacterAtIndex;
       if (o != null && o >= 0 && o < text.length)
         text = text.replaceRange(o, o + 1, value.text.substring(o, o + 1));

packages/flutter/test/widgets/custom_painter_test.dart

@@ -415,6 +415,7 @@ void _defineTests() {
             focused: true,
             inMutuallyExclusiveGroup: true,
             header: true,
+            obscured: true,
           ),
         ),
       ),

packages/flutter/test/widgets/editable_text_test.dart

@@ -575,6 +575,38 @@ void main() {
     semantics.dispose();
   });
 
+  testWidgets('password fields have correct semantics', (WidgetTester tester) async {
+    final SemanticsTester semantics = new SemanticsTester(tester);
+
+    controller.text = 'super-secret-password!!1';
+
+    await tester.pumpWidget(new MaterialApp(
+      home: new EditableText(
+        obscureText: true,
+        controller: controller,
+        focusNode: focusNode,
+        style: textStyle,
+        cursorColor: cursorColor,
+      ),
+    ));
+
+    final String expectedValue = '•' * controller.text.length;
+
+    expect(semantics, hasSemantics(new TestSemantics(
+      children: <TestSemantics>[
+        new TestSemantics(
+          flags: <SemanticsFlag>[SemanticsFlag.isTextField, SemanticsFlag.isObscured],
+          value: expectedValue,
+          textDirection: TextDirection.ltr,
+          nextNodeId: -1,
+          previousNodeId: -1,
+        ),
+      ],
+    ), ignoreTransform: true, ignoreRect: true, ignoreId: true));
+
+    semantics.dispose();
+  });
+
   group('a11y copy/cut/paste', () {
     Future<Null> _buildApp(MockTextSelectionControls controls, WidgetTester tester) {
       return tester.pumpWidget(new MaterialApp(

packages/flutter/test/widgets/semantics_test.dart

@@ -470,6 +470,7 @@ void main() {
           focused: true,
           inMutuallyExclusiveGroup: true,
           header: true,
+          obscured: true,
         )
     );