Merge pull request #1496 from abarth/move_caret

Adds the ability to move the caret by tapping

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

@@ -121,6 +121,16 @@ class _InputState extends State<Input> {
     }
   }
 
+  void _requestKeyboard() {
+    if (Focus.at(context)) {
+      assert(_isAttachedToKeyboard);
+      _keyboardHandle.showByRequest();
+    } else {
+      Focus.moveTo(config.key);
+      // we'll get told to rebuild and we'll take care of the keyboard then
+    }
+  }
+
   void _handleTextUpdated() {
     if (_value != _editableString.text) {
       setState(() {
@@ -137,6 +147,15 @@ class _InputState extends State<Input> {
       config.onSubmitted(_value);
   }
 
+  void _handleSelectionChanged(TextSelection selection) {
+    if (_isAttachedToKeyboard) {
+      _keyboardHandle.setSelection(selection.start, selection.end);
+    } else {
+      _editableString.setSelection(selection);
+      _requestKeyboard();
+    }
+  }
+
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterial(context));
     ThemeData themeData = Theme.of(context);
@@ -221,7 +240,8 @@ class _InputState extends State<Input> {
         style: textStyle,
         hideText: config.hideText,
         cursorColor: cursorColor,
-        selectionColor: cursorColor
+        selectionColor: cursorColor,
+        onSelectionChanged: _handleSelectionChanged
       )
     ));
 
@@ -258,15 +278,7 @@ class _InputState extends State<Input> {
 
     return new GestureDetector(
       behavior: HitTestBehavior.opaque,
-      onTap: () {
-        if (Focus.at(context)) {
-          assert(_isAttachedToKeyboard);
-          _keyboardHandle.showByRequest();
-        } else {
-          Focus.moveTo(config.key);
-          // we'll get told to rebuild and we'll take care of the keyboard then
-        }
-      },
+      onTap: _requestKeyboard,
       child: new Padding(
         padding: const EdgeDims.symmetric(horizontal: 16.0),
         child: child

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

@@ -2,38 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-/// Whether a [TextPosition] is visually upstream or downstream of its offset.
-///
-/// For example, when a text position exists at a line break, a single offset has
-/// two visual positions, one prior to the line break (at the end of the first
-/// line) and one after the line break (at the start of the second line). A text
-/// affinity disambiguates between those cases. (Something similar happens with
-/// between runs of bidirectional text.)
-enum TextAffinity {
-  /// The position has affinity for the upstream side of the text position.
-  ///
-  /// For example, if the offset of the text position is a line break, the
-  /// position represents the end of the first line.
-  upstream,
+import 'dart:ui' show TextAffinity, TextPosition;
 
-  /// The position has affinity for the downstream side of the text position.
-  ///
-  /// For example, if the offset of the text position is a line break, the
-  /// position represents the start of the second line.
-  downstream
-}
-
-/// A visual position in a string of text.
-class TextPosition {
-  const TextPosition({ this.offset, this.affinity: TextAffinity.downstream });
-
-  /// The index of the character just prior to the position.
-  final int offset;
-
-  /// If the offset has more than one visual location (e.g., occurs at a line
-  /// break), which of the two locations is represented by this position.
-  final TextAffinity affinity;
-}
+export 'dart:ui' show TextAffinity, TextPosition;
 
 /// A range of characters in a string of text.
 class TextRange {
@@ -97,9 +68,15 @@ class TextSelection extends TextRange {
 
   const TextSelection.collapsed({
     int offset,
-    this.affinity: TextAffinity.downstream,
-    this.isDirectional: false
-  }) : baseOffset = offset, extentOffset = offset, super.collapsed(offset);
+    this.affinity: TextAffinity.downstream
+  }) : baseOffset = offset, extentOffset = offset, isDirectional = false, super.collapsed(offset);
+
+  TextSelection.fromPosition(TextPosition position)
+    : baseOffset = position.offset,
+      extentOffset = position.offset,
+      affinity = position.affinity,
+      isDirectional = false,
+      super.collapsed(position.offset);
 
   /// The offset at which the selection originates.
   ///
@@ -141,4 +118,8 @@ class TextSelection extends TextRange {
   ///
   /// Might be larger than, smaller than, or equal to base.
   TextPosition get extent => new TextPosition(offset: extentOffset, affinity: affinity);
+
+  String toString() {
+    return '$runtimeType(baseOffset: $baseOffset, extentOffset: $extentOffset, affinity: $affinity, isDirectional: $isDirectional)';
+  }
 }

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

@@ -265,4 +265,9 @@ class TextPainter {
     return _paragraph.getBoxesForRange(selection.start, selection.end);
   }
 
+  TextPosition getPositionForOffset(Offset offset) {
+    assert(!_needsLayout);
+    return _paragraph.getPositionForOffset(offset);
+  }
+
 }

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

@@ -4,12 +4,12 @@
 
 import 'dart:ui' as ui;
 
+import 'package:flutter/gestures.dart';
 import 'package:flutter/painting.dart';
 
 import 'box.dart';
 import 'object.dart';
 import 'paragraph.dart';
-import 'proxy_box.dart' show SizeChangedCallback;
 
 const _kCaretGap = 1.0; // pixels
 const _kCaretHeightOffset = 2.0; // pixels
@@ -26,22 +26,28 @@ class RenderEditableLine extends RenderBox {
     Color selectionColor,
     TextSelection selection,
     Offset paintOffset: Offset.zero,
+    this.onSelectionChanged,
     this.onContentSizeChanged
   }) : _textPainter = new TextPainter(text),
        _cursorColor = cursorColor,
        _showCursor = showCursor,
        _selection = selection,
        _paintOffset = paintOffset {
-  assert(!showCursor || cursorColor != null);
-  // TODO(abarth): These min/max values should be the default for TextPainter.
-  _textPainter
-    ..minWidth = 0.0
-    ..maxWidth = double.INFINITY
-    ..minHeight = 0.0
-    ..maxHeight = double.INFINITY;
+    assert(!showCursor || cursorColor != null);
+    // TODO(abarth): These min/max values should be the default for TextPainter.
+    _textPainter
+      ..minWidth = 0.0
+      ..maxWidth = double.INFINITY
+      ..minHeight = 0.0
+      ..maxHeight = double.INFINITY;
+    _tap = new TapGestureRecognizer(router: Gesturer.instance.pointerRouter, gestureArena: Gesturer.instance.gestureArena)
+      ..onTapDown = _handleTapDown
+      ..onTap = _handleTap
+      ..onTapCancel = _handleTapCancel;
   }
 
-  SizeChangedCallback onContentSizeChanged;
+  ValueChanged<Size> onContentSizeChanged;
+  ValueChanged<TextSelection> onSelectionChanged;
 
   /// The text to display
   StyledTextSpan get text => _textPainter.text;
@@ -147,6 +153,31 @@ class RenderEditableLine extends RenderBox {
 
   bool hitTestSelf(Point position) => true;
 
+  TapGestureRecognizer _tap;
+  void handleEvent(PointerEvent event, BoxHitTestEntry entry) {
+    if (event is PointerDownEvent && onSelectionChanged != null)
+      _tap.addPointer(event);
+  }
+
+  Point _lastTapDownPosition;
+  void _handleTapDown(Point globalPosition) {
+    _lastTapDownPosition = globalPosition;
+  }
+
+  void _handleTap() {
+    assert(_lastTapDownPosition != null);
+    final Point global = _lastTapDownPosition;
+    _lastTapDownPosition = null;
+    if (onSelectionChanged != null) {
+      TextPosition position = _textPainter.getPositionForOffset(globalToLocal(global).toOffset());
+      onSelectionChanged(new TextSelection.fromPosition(position));
+    }
+  }
+
+  void _handleTapCancel() {
+    _lastTapDownPosition = null;
+  }
+
   BoxConstraints _constraintsForCurrentLayout; // when null, we don't have a current layout
 
   // TODO(abarth): This logic should live in TextPainter and be shared with RenderParagraph.

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

@@ -1115,9 +1115,6 @@ class RenderFractionalTranslation extends RenderProxyBox {
   }
 }
 
-/// Called when a size changes.
-typedef void SizeChangedCallback(Size newSize);
-
 /// Calls [onSizeChanged] whenever the child's layout size changes
 ///
 /// Because size observer calls its callback during layout, you cannot modify
@@ -1131,7 +1128,7 @@ class RenderSizeObserver extends RenderProxyBox {
   }
 
   /// The callback to call whenever the child's layout size changes
-  SizeChangedCallback onSizeChanged;
+  ValueChanged<Size> onSizeChanged;
 
   void performLayout() {
     Size oldSize = hasSize ? size : null;
@@ -1540,7 +1537,7 @@ class RenderSemanticAnnotations extends RenderProxyBox {
   /// If 'container' is true, this RenderObject will introduce a new
   /// node in the semantics tree. Otherwise, the semantics will be
   /// merged with the semantics of any ancestors.
-  /// 
+  ///
   /// The 'container' flag is implicitly set to true on the immediate
   /// semantics-providing descendants of a node where multiple
   /// children have semantics or have descendants providing semantics.

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

@@ -819,7 +819,7 @@ class SizeObserver extends OneChildRenderObjectWidget {
   }
 
   /// The callback to call whenever the child's layout size changes
-  final SizeChangedCallback onSizeChanged;
+  final ValueChanged<Size> onSizeChanged;
 
   RenderSizeObserver createRenderObject() => new RenderSizeObserver(onSizeChanged: onSizeChanged);
 

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

@@ -158,6 +158,10 @@ class EditableString {
   /// The range of text that is currently selected.
   TextSelection get selection => _client.selection;
 
+  void setSelection(TextSelection selection) {
+    _client.selection = selection;
+  }
+
   /// A keyboard client stub that can be attached to a keyboard service.
   ///
   /// See [Keyboard].
@@ -180,7 +184,8 @@ class RawEditableLine extends Scrollable {
     this.hideText: false,
     this.style,
     this.cursorColor,
-    this.selectionColor
+    this.selectionColor,
+    this.onSelectionChanged
   }) : super(
     key: key,
     initialScrollOffset: 0.0,
@@ -205,6 +210,9 @@ class RawEditableLine extends Scrollable {
   /// The color to use when painting the selection.
   final Color selectionColor;
 
+  /// Called when the user requests a change to the selection.
+  final ValueChanged<TextSelection> onSelectionChanged;
+
   RawEditableTextState createState() => new RawEditableTextState();
 }
 
@@ -290,6 +298,7 @@ class RawEditableTextState extends ScrollableState<RawEditableLine> {
         selectionColor: config.selectionColor,
         hideText: config.hideText,
         onContentSizeChanged: _handleContentSizeChanged,
+        onSelectionChanged: config.onSelectionChanged,
         paintOffset: new Offset(-scrollOffset, 0.0)
       )
     );
@@ -306,6 +315,7 @@ class _EditableLineWidget extends LeafRenderObjectWidget {
     this.selectionColor,
     this.hideText,
     this.onContentSizeChanged,
+    this.onSelectionChanged,
     this.paintOffset
   }) : super(key: key);
 
@@ -315,7 +325,8 @@ class _EditableLineWidget extends LeafRenderObjectWidget {
   final bool showCursor;
   final Color selectionColor;
   final bool hideText;
-  final SizeChangedCallback onContentSizeChanged;
+  final ValueChanged<Size> onContentSizeChanged;
+  final ValueChanged<TextSelection> onSelectionChanged;
   final Offset paintOffset;
 
   RenderEditableLine createRenderObject() {
@@ -326,19 +337,22 @@ class _EditableLineWidget extends LeafRenderObjectWidget {
       selectionColor: selectionColor,
       selection: value.selection,
       onContentSizeChanged: onContentSizeChanged,
+      onSelectionChanged: onSelectionChanged,
       paintOffset: paintOffset
     );
   }
 
   void updateRenderObject(RenderEditableLine renderObject,
                           _EditableLineWidget oldWidget) {
-    renderObject.text = _styledTextSpan;
-    renderObject.cursorColor = cursorColor;
-    renderObject.showCursor = showCursor;
-    renderObject.selectionColor = selectionColor;
-    renderObject.selection = value.selection;
-    renderObject.onContentSizeChanged = onContentSizeChanged;
-    renderObject.paintOffset = paintOffset;
+    renderObject
+      ..text = _styledTextSpan
+      ..cursorColor = cursorColor
+      ..showCursor = showCursor
+      ..selectionColor = selectionColor
+      ..selection = value.selection
+      ..onContentSizeChanged = onContentSizeChanged
+      ..onSelectionChanged = onSelectionChanged
+      ..paintOffset = paintOffset;
   }
 
   StyledTextSpan get _styledTextSpan {