Align TextEditingValue and InputValue (#8922)

This patch prepares us to remove InputValue in favor of TextEditingValue.

packages/flutter/lib/painting.dart

@@ -25,7 +25,6 @@ export 'src/painting/decoration.dart';
 export 'src/painting/edge_insets.dart';
 export 'src/painting/flutter_logo.dart';
 export 'src/painting/fractional_offset.dart';
-export 'src/painting/text_editing.dart';
 export 'src/painting/text_painter.dart';
 export 'src/painting/text_span.dart';
 export 'src/painting/text_style.dart';

packages/flutter/lib/services.dart

@@ -30,5 +30,6 @@ export 'src/services/system_channels.dart';
 export 'src/services/system_chrome.dart';
 export 'src/services/system_navigator.dart';
 export 'src/services/system_sound.dart';
+export 'src/services/text_editing.dart';
 export 'src/services/text_input.dart';
 export 'src/services/url_launcher.dart';

packages/flutter/lib/src/painting/flutter_logo.dart

@@ -12,7 +12,6 @@ import 'basic_types.dart';
 import 'box_fit.dart';
 import 'decoration.dart';
 import 'fractional_offset.dart';
-import 'text_editing.dart';
 import 'text_painter.dart';
 import 'text_span.dart';
 import 'text_style.dart';

packages/flutter/lib/src/painting/text_painter.dart

@@ -4,11 +4,11 @@
 
 import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphConstraints, ParagraphStyle, TextBox;
 
-import 'package:flutter/gestures.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/services.dart';
 
 import 'basic_types.dart';
-import 'text_editing.dart';
 import 'text_span.dart';
 
 final String _kZeroWidthSpace = new String.fromCharCode(0x200B);

packages/flutter/lib/src/painting/text_span.dart

@@ -4,11 +4,11 @@
 
 import 'dart:ui' as ui show ParagraphBuilder;
 
-import 'package:flutter/gestures.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
+import 'package:flutter/services.dart';
 
 import 'basic_types.dart';
-import 'text_editing.dart';
 import 'text_style.dart';
 
 // TODO(abarth): Should this be somewhere more general?

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

@@ -6,6 +6,7 @@ import 'dart:math' as math;
 import 'dart:ui' as ui show TextBox;
 
 import 'package:flutter/gestures.dart';
+import 'package:flutter/services.dart';
 import 'package:meta/meta.dart';
 
 import 'box.dart';

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

@@ -5,6 +5,7 @@
 import 'dart:ui' as ui;
 
 import 'package:flutter/gestures.dart';
+import 'package:flutter/services.dart';
 
 import 'box.dart';
 import 'debug.dart';

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

@@ -3,11 +3,12 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:ui' show TextAffinity;
+import 'dart:ui' show TextAffinity, hashValues;
 
 import 'package:flutter/foundation.dart';
 
 import 'system_channels.dart';
+import 'text_editing.dart';
 import 'message_codec.dart';
 
 export 'dart:ui' show TextAffinity;
@@ -73,72 +74,33 @@ TextAffinity _toTextAffinity(String affinity) {
 }
 
 /// The current text, selection, and composing state for editing a run of text.
-class TextEditingState {
-  /// Creates state for text editing.
+class TextEditingValue {
+  /// Creates information for editing a run of text.
   ///
-  /// The [selectionBase], [selectionExtent], [selectionAffinity],
-  /// [selectionIsDirectional], [selectionIsDirectional], [composingBase], and
-  /// [composingExtent] arguments must not be null.
-  const TextEditingState({
-    this.text,
-    this.selectionBase: -1,
-    this.selectionExtent: -1,
-    this.selectionAffinity: TextAffinity.downstream,
-    this.selectionIsDirectional: false,
-    this.composingBase: -1,
-    this.composingExtent: -1,
+  /// The selection and composing range must be within the text.
+  ///
+  /// The [text], [selection], and [composing] arguments must not be null but
+  /// each have default values.
+  const TextEditingValue({
+    this.text: '',
+    this.selection: const TextSelection.collapsed(offset: -1),
+    this.composing: TextRange.empty
   });
 
-  /// The text that is currently being edited.
-  final String text;
-
-  /// The offset in [text] at which the selection originates.
-  ///
-  /// Might be larger than, smaller than, or equal to [selectionExtent].
-  final int selectionBase;
-
-  /// The offset in [text] at which the selection terminates.
-  ///
-  /// When the user uses the arrow keys to adjust the selection, this is the
-  /// value that changes. Similarly, if the current theme paints a caret on one
-  /// side of the selection, this is the location at which to paint the caret.
-  ///
-  /// Might be larger than, smaller than, or equal to [selectionBase].
-  final int selectionExtent;
-
-  /// If the the text range is collapsed and has more than one visual location
-  /// (e.g., occurs at a line break), which of the two locations to use when
-  /// painting the caret.
-  final TextAffinity selectionAffinity;
-
-  /// Whether this selection has disambiguated its base and extent.
-  ///
-  /// On some platforms, the base and extent are not disambiguated until the
-  /// first time the user adjusts the selection. At that point, either the start
-  /// or the end of the selection becomes the base and the other one becomes the
-  /// extent and is adjusted.
-  final bool selectionIsDirectional;
-
-  /// The offset in [text] at which the composing region originates.
-  ///
-  /// Always smaller than, or equal to, [composingExtent].
-  final int composingBase;
-
-  /// The offset in [text] at which the selection terminates.
-  ///
-  /// Always larger than, or equal to, [composingBase].
-  final int composingExtent;
-
   /// Creates an instance of this class from a JSON object.
-  factory TextEditingState.fromJSON(Map<String, dynamic> encoded) {
-    return new TextEditingState(
+  factory TextEditingValue.fromJSON(Map<String, dynamic> encoded) {
+    return new TextEditingValue(
       text: encoded['text'],
-      selectionBase: encoded['selectionBase'] ?? -1,
-      selectionExtent: encoded['selectionExtent'] ?? -1,
-      selectionIsDirectional: encoded['selectionIsDirectional'] ?? false,
-      selectionAffinity: _toTextAffinity(encoded['selectionAffinity']) ?? TextAffinity.downstream,
-      composingBase: encoded['composingBase'] ?? -1,
-      composingExtent: encoded['composingExtent'] ?? -1,
+      selection: new TextSelection(
+        baseOffset: encoded['selectionBase'] ?? -1,
+        extentOffset: encoded['selectionExtent'] ?? -1,
+        affinity: _toTextAffinity(encoded['selectionAffinity']) ?? TextAffinity.downstream,
+        isDirectional: encoded['selectionIsDirectional'] ?? false,
+      ),
+      composing: new TextRange(
+        start: encoded['composingBase'] ?? -1,
+        end: encoded['composingExtent'] ?? -1,
+      ),
     );
   }
 
@@ -146,14 +108,61 @@ class TextEditingState {
   Map<String, dynamic> toJSON() {
     return <String, dynamic>{
       'text': text,
-      'selectionBase': selectionBase,
-      'selectionExtent': selectionExtent,
-      'selectionAffinity': selectionAffinity.toString(),
-      'selectionIsDirectional': selectionIsDirectional,
-      'composingBase': composingBase,
-      'composingExtent': composingExtent,
+      'selectionBase': selection.baseOffset,
+      'selectionExtent': selection.extentOffset,
+      'selectionAffinity': selection.affinity.toString(),
+      'selectionIsDirectional': selection.isDirectional,
+      'composingBase': composing.start,
+      'composingExtent': composing.end,
     };
   }
+
+  /// The current text being edited.
+  final String text;
+
+  /// The range of text that is currently selected.
+  final TextSelection selection;
+
+  /// The range of text that is still being composed.
+  final TextRange composing;
+
+  /// A value that corresponds to the empty string with no selection and no composing range.
+  static const TextEditingValue empty = const TextEditingValue();
+
+  /// Creates a copy of this value but with the given fields replaced with the new values.
+  TextEditingValue copyWith({
+    String text,
+    TextSelection selection,
+    TextRange composing
+  }) {
+    return new TextEditingValue(
+      text: text ?? this.text,
+      selection: selection ?? this.selection,
+      composing: composing ?? this.composing
+    );
+  }
+
+  @override
+  String toString() => '$runtimeType(text: \u2524$text\u251C, selection: $selection, composing: $composing)';
+
+  @override
+  bool operator ==(dynamic other) {
+    if (identical(this, other))
+      return true;
+    if (other is! TextEditingValue)
+      return false;
+    final TextEditingValue typedOther = other;
+    return typedOther.text == text
+        && typedOther.selection == selection
+        && typedOther.composing == composing;
+  }
+
+  @override
+  int get hashCode => hashValues(
+    text.hashCode,
+    selection.hashCode,
+    composing.hashCode
+  );
 }
 
 /// An interface to receive information from [TextInput].
@@ -167,7 +176,7 @@ abstract class TextInputClient {
   const TextInputClient();
 
   /// Requests that this client update its editing state to the given value.
-  void updateEditingState(TextEditingState state);
+  void updateEditingValue(TextEditingValue value);
 
   /// Requests that this client perform the given action.
   void performAction(TextInputAction action);
@@ -198,11 +207,11 @@ class TextInputConnection {
   }
 
   /// Requests that the text input control change its internal state to match the given state.
-  void setEditingState(TextEditingState state) {
+  void setEditingState(TextEditingValue value) {
     assert(attached);
     SystemChannels.textInput.invokeMethod(
       'TextInput.setEditingState',
-      state.toJSON(),
+      value.toJSON(),
     );
   }
 
@@ -247,7 +256,7 @@ class _TextInputClientHandler {
       return;
     switch (method) {
       case 'TextInputClient.updateEditingState':
-        _currentConnection._client.updateEditingState(new TextEditingState.fromJSON(args[1]));
+        _currentConnection._client.updateEditingValue(new TextEditingValue.fromJSON(args[1]));
         break;
       case 'TextInputClient.performAction':
         _currentConnection._client.performAction(_toTextInputAction(args[1]));

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

@@ -17,37 +17,23 @@ import 'scroll_physics.dart';
 import 'scrollable.dart';
 import 'text_selection.dart';
 
-export 'package:flutter/painting.dart' show TextSelection;
-export 'package:flutter/services.dart' show TextInputType;
+export 'package:flutter/services.dart' show TextSelection, TextInputType;
 
 const Duration _kCursorBlinkHalfPeriod = const Duration(milliseconds: 500);
 
-TextSelection _getTextSelectionFromEditingState(TextEditingState state) {
-  return new TextSelection(
-    baseOffset: state.selectionBase,
-    extentOffset: state.selectionExtent,
-    affinity: state.selectionAffinity,
-    isDirectional: state.selectionIsDirectional,
-  );
-}
-
-InputValue _getInputValueFromEditingState(TextEditingState state) {
+InputValue _getInputValueFromEditingValue(TextEditingValue value) {
   return new InputValue(
-    text: state.text,
-    selection: _getTextSelectionFromEditingState(state),
-    composing: new TextRange(start: state.composingBase, end: state.composingExtent),
+    text: value.text,
+    selection: value.selection,
+    composing: value.composing,
   );
 }
 
-TextEditingState _getTextEditingStateFromInputValue(InputValue value) {
-  return new TextEditingState(
+TextEditingValue _getTextEditingValueFromInputValue(InputValue value) {
+  return new TextEditingValue(
     text: value.text,
-    selectionBase: value.selection.baseOffset,
-    selectionExtent: value.selection.extentOffset,
-    selectionAffinity: value.selection.affinity,
-    selectionIsDirectional: value.selection.isDirectional,
-    composingBase: value.composing.start,
-    composingExtent: value.composing.end,
+    selection: value.selection,
+    composing: value.composing,
   );
 }
 
@@ -243,7 +229,7 @@ class EditableTextState extends State<EditableText> implements TextInputClient {
     if (_currentValue != config.value) {
       _currentValue = config.value;
       if (_isAttachedToKeyboard)
-        _textInputConnection.setEditingState(_getTextEditingStateFromInputValue(_currentValue));
+        _textInputConnection.setEditingState(_getTextEditingValueFromInputValue(_currentValue));
     }
   }
 
@@ -271,7 +257,7 @@ class EditableTextState extends State<EditableText> implements TextInputClient {
   void _attachOrDetachKeyboard(bool focused) {
     if (focused && !_isAttachedToKeyboard && (_requestingFocus || config.autofocus)) {
       _textInputConnection = TextInput.attach(this, new TextInputConfiguration(inputType: config.keyboardType))
-        ..setEditingState(_getTextEditingStateFromInputValue(_currentValue))
+        ..setEditingState(_getTextEditingValueFromInputValue(_currentValue))
         ..show();
     } else if (!focused) {
       if (_isAttachedToKeyboard) {
@@ -308,8 +294,8 @@ class EditableTextState extends State<EditableText> implements TextInputClient {
   }
 
   @override
-  void updateEditingState(TextEditingState state) {
-    _currentValue = _getInputValueFromEditingState(state);
+  void updateEditingValue(TextEditingValue value) {
+    _currentValue = _getInputValueFromEditingValue(value);
     if (config.onChanged != null)
       config.onChanged(_currentValue);
     if (_currentValue.text != config.value.text) {

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

@@ -4,6 +4,7 @@
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter/scheduler.dart';
 
 import 'basic.dart';

packages/flutter/test/rendering/paragraph_test.dart

@@ -5,6 +5,7 @@
 import 'dart:ui' as ui show TextBox;
 
 import 'package:flutter/rendering.dart';
+import 'package:flutter/services.dart';
 import 'package:test/test.dart';
 
 import 'rendering_tester.dart';

packages/flutter/test/widgets/input_test.dart

@@ -155,10 +155,9 @@ void main() {
     await tester.showKeyboard(find.byType(EditableText));
 
     // Try the test again with a nonempty EditableText.
-    tester.testTextInput.updateEditingState(const TextEditingState(
+    tester.testTextInput.updateEditingValue(const TextEditingValue(
       text: 'X',
-      selectionBase: 1,
-      selectionExtent: 1,
+      selection: const TextSelection.collapsed(offset: 1),
     ));
     await checkCursorToggle();
   });
@@ -182,10 +181,9 @@ void main() {
     await tester.showKeyboard(find.byType(EditableText));
 
     const String testValue = 'ABC';
-    tester.testTextInput.updateEditingState(const TextEditingState(
+    tester.testTextInput.updateEditingValue(const TextEditingValue(
       text: testValue,
-      selectionBase: testValue.length,
-      selectionExtent: testValue.length,
+      selection: const TextSelection.collapsed(offset: testValue.length),
     ));
 
     await tester.pump();

packages/flutter_test/lib/src/test_text_input.dart

@@ -38,14 +38,14 @@ class TestTextInput {
     }
   }
 
-  void updateEditingState(TextEditingState state) {
+  void updateEditingValue(TextEditingValue value) {
     expect(_client, isNonZero);
     PlatformMessages.handlePlatformMessage(
       SystemChannels.textInput.name,
       SystemChannels.textInput.codec.encodeMethodCall(
         new MethodCall(
           'TextInputClient.updateEditingState',
-          <dynamic>[_client, state.toJSON()],
+          <dynamic>[_client, value.toJSON()],
         ),
       ),
       (_) {},
@@ -53,10 +53,9 @@ class TestTextInput {
   }
 
   void enterText(String text) {
-    updateEditingState(new TextEditingState(
+    updateEditingValue(new TextEditingValue(
       text: text,
-      composingBase: 0,
-      composingExtent: text.length,
+      composing: new TextRange(start: 0, end: text.length),
     ));
   }
 }