add textCapitalization property (#19367)

examples/flutter_gallery/lib/demo/material/text_form_field_demo.dart

@@ -180,6 +180,7 @@ class TextFormFieldDemoState extends State<TextFormFieldDemo> {
               children: <Widget>[
                 const SizedBox(height: 24.0),
                 new TextFormField(
+                  textCapitalization: TextCapitalization.words,
                   decoration: const InputDecoration(
                     border: const UnderlineInputBorder(),
                     filled: true,

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

@@ -103,6 +103,7 @@ class TextField extends StatefulWidget {
     this.decoration = const InputDecoration(),
     TextInputType keyboardType = TextInputType.text,
     this.textInputAction = TextInputAction.done,
+    this.textCapitalization = TextCapitalization.none,
     this.style,
     this.textAlign = TextAlign.start,
     this.autofocus = false,
@@ -160,6 +161,19 @@ class TextField extends StatefulWidget {
   /// Defaults to [TextInputAction.done]. Must not be null.
   final TextInputAction textInputAction;
 
+  /// Configures how the platform keyboard will select an uppercase or 
+  /// lowercase keyboard.
+  ///
+  /// Only supports text keyboards, other keyboard types will ignore this
+  /// configuration. Capitalization is locale-aware.
+  ///
+  /// Defaults to [TextCapitalization.none]. Must not be null.
+  /// 
+  /// See also:
+  /// 
+  ///   * [TextCapitalization], for a description of each capitalization behavior.
+  final TextCapitalization textCapitalization;
+
   /// The style to use for the text being edited.
   ///
   /// This text style is also used as the base style for the [decoration].
@@ -509,6 +523,7 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
         focusNode: focusNode,
         keyboardType: widget.keyboardType,
         textInputAction: widget.textInputAction,
+        textCapitalization: widget.textCapitalization,
         style: style,
         textAlign: widget.textAlign,
         autofocus: widget.autofocus,

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

@@ -55,6 +55,7 @@ class TextFormField extends FormField<String> {
     FocusNode focusNode,
     InputDecoration decoration = const InputDecoration(),
     TextInputType keyboardType = TextInputType.text,
+    TextCapitalization textCapitalization = TextCapitalization.none,
     TextInputAction textInputAction = TextInputAction.done,
     TextStyle style,
     TextAlign textAlign = TextAlign.start,
@@ -101,6 +102,7 @@ class TextFormField extends FormField<String> {
         textInputAction: textInputAction,
         style: style,
         textAlign: textAlign,
+        textCapitalization: textCapitalization,
         autofocus: autofocus,
         obscureText: obscureText,
         autocorrect: autocorrect,

packages/flutter/lib/src/services/text_input.dart

@@ -314,6 +314,34 @@ enum TextInputAction {
   newline,
 }
 
+/// Configures how the platform keyboard will select an uppercase or 
+/// lowercase keyboard.
+///
+/// Only supports text keyboards, other keyboard types will ignore this
+/// configuration. Capitalization is locale-aware.
+enum TextCapitalization {
+  /// Defaults to an uppercase keyboard for the first letter of each word.
+  /// 
+  /// Corresponds to `InputType.TYPE_TEXT_FLAG_CAP_WORDS` on Android, and
+  /// `UITextAutocapitalizationTypeWords` on iOS.
+  words,
+
+  /// Defaults to an uppercase keyboard for the first letter of each sentence.
+  /// 
+  /// Corresponds to `InputType.TYPE_TEXT_FLAG_CAP_SENTENCES` on Android, and
+  /// `UITextAutocapitalizationTypeSentences` on iOS.
+  sentences,
+
+  /// Defaults to an uppercase keyboard for each character.
+  /// 
+  /// Corresponds to `InputType.TYPE_TEXT_FLAG_CAP_CHARACTERS` on Android, and
+  /// `UITextAutocapitalizationTypeAllCharacters` on iOS.
+  characters,
+
+  /// Defaults to a lowercase keyboard.
+  none,
+}
+
 /// Controls the visual appearance of the text input control.
 ///
 /// Many [TextInputAction]s are common between Android and iOS. However, if an
@@ -343,11 +371,13 @@ class TextInputConfiguration {
     this.actionLabel,
     this.inputAction = TextInputAction.done,
     this.keyboardAppearance = Brightness.light,
+    this.textCapitalization = TextCapitalization.none,
   }) : assert(inputType != null),
        assert(obscureText != null),
        assert(autocorrect != null),
        assert(keyboardAppearance != null),
-       assert(inputAction != null);
+       assert(inputAction != null),
+       assert(textCapitalization != null);
 
   /// The type of information for which to optimize the text input control.
   final TextInputType inputType;
@@ -368,6 +398,16 @@ class TextInputConfiguration {
   /// What kind of action to request for the action button on the IME.
   final TextInputAction inputAction;
 
+  /// Specifies how platforms may automatically capitialize text entered by the
+  /// user.
+  /// 
+  /// Defaults to [TextCapitalization.none].
+  /// 
+  /// See also:
+  /// 
+  ///   * [TextCapitalization], for a description of each capitalization behavior.
+  final TextCapitalization textCapitalization;
+  
   /// The appearance of the keyboard.
   /// 
   /// This setting is only honored on iOS devices.
@@ -383,6 +423,7 @@ class TextInputConfiguration {
       'autocorrect': autocorrect,
       'actionLabel': actionLabel,
       'inputAction': inputAction.toString(),
+      'textCapitalization': textCapitalization.toString(),
       'keyboardAppearance': keyboardAppearance.toString(),
     };
   }

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

@@ -202,6 +202,7 @@ class EditableText extends StatefulWidget {
     this.selectionControls,
     TextInputType keyboardType,
     this.textInputAction = TextInputAction.done,
+    this.textCapitalization = TextCapitalization.none,
     this.onChanged,
     this.onEditingComplete,
     this.onSubmitted,
@@ -269,6 +270,19 @@ class EditableText extends StatefulWidget {
   /// Defaults to the ambient [Directionality], if any.
   final TextDirection textDirection;
 
+  /// Configures how the platform keyboard will select an uppercase or 
+  /// lowercase keyboard.
+  ///
+  /// Only supports text keyboards, other keyboard types will ignore this
+  /// configuration. Capitalization is locale-aware.
+  /// 
+  /// Defaults to [TextCapitalization.none]. Must not be null.
+  /// 
+  /// See also:
+  /// 
+  ///   * [TextCapitalization], for a description of each capitalization behavior.
+  final TextCapitalization textCapitalization;
+
   /// Used to select a font when the same Unicode character can
   /// be rendered differently, depending on the locale.
   ///
@@ -569,6 +583,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
               inputAction: widget.keyboardType == TextInputType.multiline
                   ? TextInputAction.newline
                   : widget.textInputAction,
+              textCapitalization: widget.textCapitalization,
           )
       )..setEditingState(localValue);
     }

packages/flutter/test/services/text_input_test.dart

@@ -13,6 +13,7 @@ void main() {
       expect(configuration.obscureText, false);
       expect(configuration.autocorrect, true);
       expect(configuration.actionLabel, null);
+      expect(configuration.textCapitalization, TextCapitalization.none);
       expect(configuration.keyboardAppearance, Brightness.light);
     });