[rename fixit] DismissDirection left -> endToStart, right -> startToEnd

Removes an LTR bias in DismissDirection.

Fixes #2562

dev/manual_tests/card_collection.dart

@@ -135,8 +135,8 @@ class CardCollectionState extends State<CardCollection> {
           buildDrawerColorRadioItem("Teal", Colors.teal, _primaryColor, _selectColor),
           new Divider(),
           buildDrawerDirectionRadioItem("Dismiss horizontally", DismissDirection.horizontal, _dismissDirection, _changeDismissDirection, icon: Icons.code),
-          buildDrawerDirectionRadioItem("Dismiss left", DismissDirection.left, _dismissDirection, _changeDismissDirection, icon: Icons.arrow_back),
-          buildDrawerDirectionRadioItem("Dismiss right", DismissDirection.right, _dismissDirection, _changeDismissDirection, icon: Icons.arrow_forward),
+          buildDrawerDirectionRadioItem("Dismiss left", DismissDirection.endToStart, _dismissDirection, _changeDismissDirection, icon: Icons.arrow_back),
+          buildDrawerDirectionRadioItem("Dismiss right", DismissDirection.startToEnd, _dismissDirection, _changeDismissDirection, icon: Icons.arrow_forward),
           new Divider(),
           buildFontRadioItem("Left-align text", new TextStyle(textAlign: TextAlign.left), _textStyle, _changeTextStyle, icon: Icons.format_align_left, enabled: !_editable),
           buildFontRadioItem("Center-align text", new TextStyle(textAlign: TextAlign.center), _textStyle, _changeTextStyle, icon: Icons.format_align_center, enabled: !_editable),
@@ -338,22 +338,24 @@ class CardCollectionState extends State<CardCollection> {
       case DismissDirection.horizontal:
         backgroundMessage = "Swipe in either direction";
         break;
-      case DismissDirection.left:
+      case DismissDirection.endToStart:
         backgroundMessage = "Swipe left to dismiss";
         break;
-      case DismissDirection.right:
+      case DismissDirection.startToEnd:
         backgroundMessage = "Swipe right to dismiss";
         break;
       default:
         backgroundMessage = "Unsupported dismissDirection";
     }
 
+    // TODO(abarth): This icon is wrong in RTL.
     Widget leftArrowIcon =  new Icon(icon: Icons.arrow_back, size: 36.0);
-    if (_dismissDirection == DismissDirection.right)
+    if (_dismissDirection == DismissDirection.startToEnd)
       leftArrowIcon = new Opacity(opacity: 0.1, child: leftArrowIcon);
 
+      // TODO(abarth): This icon is wrong in RTL.
     Widget rightArrowIcon =  new Icon(icon: Icons.arrow_forward, size: 36.0);
-    if (_dismissDirection == DismissDirection.left)
+    if (_dismissDirection == DismissDirection.endToStart)
       rightArrowIcon = new Opacity(opacity: 0.1, child: rightArrowIcon);
 
     // The background Widget appears behind the Dismissable card when the card

examples/material_gallery/lib/demo/leave_behind_demo.dart

@@ -61,10 +61,10 @@ class LeaveBehindDemoState extends State<LeaveBehindDemo> {
         _dismissDirection = DismissDirection.horizontal;
         break;
       case LeaveBehindDemoAction.leftSwipe:
-        _dismissDirection = DismissDirection.left;
+        _dismissDirection = DismissDirection.endToStart;
         break;
       case LeaveBehindDemoAction.rightSwipe:
-        _dismissDirection = DismissDirection.right;
+        _dismissDirection = DismissDirection.startToEnd;
         break;
     }
   }
@@ -87,7 +87,7 @@ class LeaveBehindDemoState extends State<LeaveBehindDemo> {
         setState(() {
           leaveBehindItems.remove(item);
         });
-        final String action = (direction == DismissDirection.left) ? 'archived' : 'deleted';
+        final String action = (direction == DismissDirection.endToStart) ? 'archived' : 'deleted';
         _scaffoldKey.currentState.showSnackBar(new SnackBar(
           content: new Text('You $action item ${item.index}'),
           action: new SnackBarAction(
@@ -143,12 +143,12 @@ class LeaveBehindDemoState extends State<LeaveBehindDemo> {
               ),
               new CheckedPopupMenuItem<LeaveBehindDemoAction>(
                 value: LeaveBehindDemoAction.leftSwipe,
-                checked: _dismissDirection == DismissDirection.left,
+                checked: _dismissDirection == DismissDirection.endToStart,
                 child: new Text('Only swipe left')
               ),
               new CheckedPopupMenuItem<LeaveBehindDemoAction>(
                 value: LeaveBehindDemoAction.rightSwipe,
-                checked: _dismissDirection == DismissDirection.right,
+                checked: _dismissDirection == DismissDirection.startToEnd,
                 child: new Text('Only swipe right')
               )
             ]

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

@@ -25,11 +25,13 @@ enum DismissDirection {
   /// The [Dismissable] can be dismissed by dragging either left or right.
   horizontal,
 
-  /// The [Dismissable] can be dismissed by dragging left only.
-  left,
+  /// The [Dismissable] can be dismissed by dragging in the reverse of the
+  /// reading direction (e.g., from right to left in left-to-right languages).
+  endToStart,
 
-  /// The [Dismissable] can be dismissed by dragging right only.
-  right,
+  /// The [Dismissable] can be dismissed by dragging in the reading direction
+  /// (e.g., from left to right in left-to-right languages).
+  startToEnd,
 
   /// The [Dismissable] can be dismissed by dragging up only.
   up,
@@ -115,13 +117,13 @@ class _DismissableState extends State<Dismissable> {
 
   bool get _directionIsXAxis {
     return config.direction == DismissDirection.horizontal
-        || config.direction == DismissDirection.left
-        || config.direction == DismissDirection.right;
+        || config.direction == DismissDirection.endToStart
+        || config.direction == DismissDirection.startToEnd;
   }
 
   DismissDirection get _dismissDirection {
     if (_directionIsXAxis)
-      return  _dragExtent > 0 ? DismissDirection.right : DismissDirection.left;
+      return  _dragExtent > 0 ? DismissDirection.startToEnd : DismissDirection.endToStart;
     return _dragExtent > 0 ? DismissDirection.down : DismissDirection.up;
   }
 
@@ -162,13 +164,13 @@ class _DismissableState extends State<Dismissable> {
         break;
 
       case DismissDirection.up:
-      case DismissDirection.left:
+      case DismissDirection.endToStart:
         if (_dragExtent + delta < 0)
           _dragExtent += delta;
         break;
 
       case DismissDirection.down:
-      case DismissDirection.right:
+      case DismissDirection.startToEnd:
         if (_dragExtent + delta > 0)
           _dragExtent += delta;
         break;
@@ -201,7 +203,7 @@ class _DismissableState extends State<Dismissable> {
       switch(config.direction) {
         case DismissDirection.horizontal:
           return vx.abs() > _kMinFlingVelocity;
-        case DismissDirection.left:
+        case DismissDirection.endToStart:
           return -vx > _kMinFlingVelocity;
         default:
           return vx > _kMinFlingVelocity;
@@ -275,7 +277,7 @@ class _DismissableState extends State<Dismissable> {
     Widget background = config.background;
     if (config.secondaryBackground != null) {
       final DismissDirection direction = _dismissDirection;
-      if (direction == DismissDirection.left || direction == DismissDirection.up)
+      if (direction == DismissDirection.endToStart || direction == DismissDirection.up)
         background = config.secondaryBackground;
     }
 

packages/flutter/test/widget/dismissable_test.dart

@@ -58,13 +58,13 @@ void dismissElement(WidgetTester tester, Element itemElement, { DismissDirection
   Point downLocation;
   Point upLocation;
   switch(gestureDirection) {
-    case DismissDirection.left:
+    case DismissDirection.endToStart:
       // getTopRight() returns a point that's just beyond itemWidget's right
       // edge and outside the Dismissable event listener's bounds.
       downLocation = tester.getTopRight(itemElement) + const Offset(-0.1, 0.0);
       upLocation = tester.getTopLeft(itemElement);
       break;
-    case DismissDirection.right:
+    case DismissDirection.startToEnd:
       // we do the same thing here to keep the test symmetric
       downLocation = tester.getTopLeft(itemElement) + const Offset(0.1, 0.0);
       upLocation = tester.getTopRight(itemElement);
@@ -129,15 +129,15 @@ void main() {
       tester.pumpWidget(widgetBuilder());
       expect(dismissedItems, isEmpty);
 
-      dismissItem(tester, 0, gestureDirection: DismissDirection.right);
+      dismissItem(tester, 0, gestureDirection: DismissDirection.startToEnd);
       expect(tester.findText('0'), isNull);
       expect(dismissedItems, equals([0]));
-      expect(reportedDismissDirection, DismissDirection.right);
+      expect(reportedDismissDirection, DismissDirection.startToEnd);
 
-      dismissItem(tester, 1, gestureDirection: DismissDirection.left);
+      dismissItem(tester, 1, gestureDirection: DismissDirection.endToStart);
       expect(tester.findText('1'), isNull);
       expect(dismissedItems, equals([0, 1]));
-      expect(reportedDismissDirection, DismissDirection.left);
+      expect(reportedDismissDirection, DismissDirection.endToStart);
     });
   });
 
@@ -165,38 +165,38 @@ void main() {
   test('drag-left with DismissDirection.left triggers dismiss', () {
     testWidgets((WidgetTester tester) {
       scrollDirection = Axis.vertical;
-      dismissDirection = DismissDirection.left;
+      dismissDirection = DismissDirection.endToStart;
       dismissedItems = <int>[];
 
       tester.pumpWidget(widgetBuilder());
       expect(dismissedItems, isEmpty);
 
-      dismissItem(tester, 0, gestureDirection: DismissDirection.right);
+      dismissItem(tester, 0, gestureDirection: DismissDirection.startToEnd);
       expect(tester.findText('0'), isNotNull);
       expect(dismissedItems, isEmpty);
-      dismissItem(tester, 1, gestureDirection: DismissDirection.right);
+      dismissItem(tester, 1, gestureDirection: DismissDirection.startToEnd);
 
-      dismissItem(tester, 0, gestureDirection: DismissDirection.left);
+      dismissItem(tester, 0, gestureDirection: DismissDirection.endToStart);
       expect(tester.findText('0'), isNull);
       expect(dismissedItems, equals([0]));
-      dismissItem(tester, 1, gestureDirection: DismissDirection.left);
+      dismissItem(tester, 1, gestureDirection: DismissDirection.endToStart);
     });
   });
 
   test('drag-right with DismissDirection.right triggers dismiss', () {
     testWidgets((WidgetTester tester) {
       scrollDirection = Axis.vertical;
-      dismissDirection = DismissDirection.right;
+      dismissDirection = DismissDirection.startToEnd;
       dismissedItems = <int>[];
 
       tester.pumpWidget(widgetBuilder());
       expect(dismissedItems, isEmpty);
 
-      dismissItem(tester, 0, gestureDirection: DismissDirection.left);
+      dismissItem(tester, 0, gestureDirection: DismissDirection.endToStart);
       expect(tester.findText('0'), isNotNull);
       expect(dismissedItems, isEmpty);
 
-      dismissItem(tester, 0, gestureDirection: DismissDirection.right);
+      dismissItem(tester, 0, gestureDirection: DismissDirection.startToEnd);
       expect(tester.findText('0'), isNull);
       expect(dismissedItems, equals([0]));
     });
@@ -292,12 +292,12 @@ void main() {
       ));
       expect(tester.findText('1'), isNotNull);
       expect(tester.findText('2'), isNotNull);
-      dismissElement(tester, tester.findText('2'), gestureDirection: DismissDirection.right);
+      dismissElement(tester, tester.findText('2'), gestureDirection: DismissDirection.startToEnd);
       tester.pump(); // start the slide away
       tester.pump(new Duration(seconds: 1)); // finish the slide away
       expect(tester.findText('1'), isNotNull);
       expect(tester.findText('2'), isNull);
-      dismissElement(tester, tester.findText('1'), gestureDirection: DismissDirection.right);
+      dismissElement(tester, tester.findText('1'), gestureDirection: DismissDirection.startToEnd);
       tester.pump(); // start the slide away
       tester.pump(new Duration(seconds: 1)); // finish the slide away (at which point the child is no longer included in the tree)
       expect(tester.findText('1'), isNull);