Skip to content

F
Front-End
Unverified Commit 0234b18f authored by Greg Spencer's avatar Greg Spencer Committed by GitHub
Browse files
Options

Tweak directional focus traversal (#116230) 

* Use distance instead of coord

* Sort by distance prefer axis

* Switch initial sort back to sort by coordinate.

* revert test change

* Fix tests

* Simplify test case

* Add a test for irregular grids

* Review Changes
parent b02a9c24
Show whitespace changes
Inline Side-by-side
Showing with 252 additions and 112 deletions
packages/flutter/lib/src/widgets/focus_traversal.dart
View file @ 0234b18f
......@@ -82,9 +82,6 @@ enum TraversalDirection {
/// This direction is unaffected by the [Directionality] of the current
/// context.
left,
// TODO(gspencer): Add diagonal traversal directions used by TV remotes and
// game controllers when we support them.
}
/// An object used to specify a focus traversal policy used for configuring a
......@@ -547,6 +544,46 @@ mixin DirectionalFocusTraversalPolicyMixin on FocusTraversalPolicy {
return null;
}
static int _verticalCompare(Offset target, Offset a, Offset b) {
return (a.dy - target.dy).abs().compareTo((b.dy - target.dy).abs());
}
static int _horizontalCompare(Offset target, Offset a, Offset b) {
return (a.dx - target.dx).abs().compareTo((b.dx - target.dx).abs());
}
// Sort the ones that are closest to target vertically first, and if two are
// the same vertical distance, pick the one that is closest horizontally.
static Iterable<FocusNode> _sortByDistancePreferVertical(Offset target, Iterable<FocusNode> nodes) {
final List<FocusNode> sorted = nodes.toList();
mergeSort<FocusNode>(sorted, compare: (FocusNode nodeA, FocusNode nodeB) {
final Offset a = nodeA.rect.center;
final Offset b = nodeB.rect.center;
final int vertical = _verticalCompare(target, a, b);
if (vertical == 0) {
return _horizontalCompare(target, a, b);
}
return vertical;
});
return sorted;
}
// Sort the ones that are closest horizontally first, and if two are the same
// horizontal distance, pick the one that is closest vertically.
static Iterable<FocusNode> _sortByDistancePreferHorizontal(Offset target, Iterable<FocusNode> nodes) {
final List<FocusNode> sorted = nodes.toList();
mergeSort<FocusNode>(sorted, compare: (FocusNode nodeA, FocusNode nodeB) {
final Offset a = nodeA.rect.center;
final Offset b = nodeB.rect.center;
final int horizontal = _horizontalCompare(target, a, b);
if (horizontal == 0) {
return _verticalCompare(target, a, b);
}
return horizontal;
});
return sorted;
}
// Sorts nodes from left to right horizontally, and removes nodes that are
// either to the right of the left side of the target node if we're going
// left, or to the left of the right side of the target node if we're going
......@@ -555,52 +592,54 @@ mixin DirectionalFocusTraversalPolicyMixin on FocusTraversalPolicy {
// This doesn't need to take into account directionality because it is
// typically intending to actually go left or right, not in a reading
// direction.
Iterable<FocusNode>? _sortAndFilterHorizontally(
Iterable<FocusNode> _sortAndFilterHorizontally(
TraversalDirection direction,
Rect target,
FocusNode nearestScope,
Iterable<FocusNode> nodes,
) {
assert(direction == TraversalDirection.left || direction == TraversalDirection.right);
final Iterable<FocusNode> nodes = nearestScope.traversalDescendants;
assert(!nodes.contains(nearestScope));
final List<FocusNode> sorted = nodes.toList();
mergeSort<FocusNode>(sorted, compare: (FocusNode a, FocusNode b) => a.rect.center.dx.compareTo(b.rect.center.dx));
Iterable<FocusNode>? result;
final Iterable<FocusNode> filtered;
switch (direction) {
case TraversalDirection.left:
result = sorted.where((FocusNode node) => node.rect != target && node.rect.center.dx <= target.left);
filtered = nodes.where((FocusNode node) => node.rect != target && node.rect.center.dx <= target.left);
break;
case TraversalDirection.right:
result = sorted.where((FocusNode node) => node.rect != target && node.rect.center.dx >= target.right);
filtered = nodes.where((FocusNode node) => node.rect != target && node.rect.center.dx >= target.right);
break;
case TraversalDirection.up:
case TraversalDirection.down:
break;
throw ArgumentError('Invalid direction $direction');
}
return result;
final List<FocusNode> sorted = filtered.toList();
// Sort all nodes from left to right.
mergeSort<FocusNode>(sorted, compare: (FocusNode a, FocusNode b) => a.rect.center.dx.compareTo(b.rect.center.dx));
return sorted;
}
// Sorts nodes from top to bottom vertically, and removes nodes that are
// either below the top of the target node if we're going up, or above the
// bottom of the target node if we're going down.
Iterable<FocusNode>? _sortAndFilterVertically(
Iterable<FocusNode> _sortAndFilterVertically(
TraversalDirection direction,
Rect target,
Iterable<FocusNode> nodes,
) {
final List<FocusNode> sorted = nodes.toList();
mergeSort<FocusNode>(sorted, compare: (FocusNode a, FocusNode b) => a.rect.center.dy.compareTo(b.rect.center.dy));
assert(direction == TraversalDirection.up || direction == TraversalDirection.down);
final Iterable<FocusNode> filtered;
switch (direction) {
case TraversalDirection.up:
return sorted.where((FocusNode node) => node.rect != target && node.rect.center.dy <= target.top);
filtered = nodes.where((FocusNode node) => node.rect != target && node.rect.center.dy <= target.top);
break;
case TraversalDirection.down:
return sorted.where((FocusNode node) => node.rect != target && node.rect.center.dy >= target.bottom);
filtered = nodes.where((FocusNode node) => node.rect != target && node.rect.center.dy >= target.bottom);
break;
case TraversalDirection.left:
case TraversalDirection.right:
break;
throw ArgumentError('Invalid direction $direction');
}
assert(direction == TraversalDirection.up || direction == TraversalDirection.down);
return null;
final List<FocusNode> sorted = filtered.toList();
mergeSort<FocusNode>(sorted, compare: (FocusNode a, FocusNode b) => a.rect.center.dy.compareTo(b.rect.center.dy));
return sorted;
}
// Updates the policy data to keep the previously visited node so that we can
......@@ -745,71 +784,55 @@ mixin DirectionalFocusTraversalPolicyMixin on FocusTraversalPolicy {
switch (direction) {
case TraversalDirection.down:
case TraversalDirection.up:
Iterable<FocusNode>? eligibleNodes = _sortAndFilterVertically(
direction,
focusedChild.rect,
nearestScope.traversalDescendants,
);
Iterable<FocusNode> eligibleNodes = _sortAndFilterVertically(direction, focusedChild.rect, nearestScope.traversalDescendants);
if (eligibleNodes.isEmpty) {
break;
}
if (focusedScrollable != null && !focusedScrollable.position.atEdge) {
final Iterable<FocusNode> filteredEligibleNodes = eligibleNodes!.where((FocusNode node) => Scrollable.maybeOf(node.context!) == focusedScrollable);
final Iterable<FocusNode> filteredEligibleNodes = eligibleNodes.where((FocusNode node) => Scrollable.maybeOf(node.context!) == focusedScrollable);
if (filteredEligibleNodes.isNotEmpty) {
eligibleNodes = filteredEligibleNodes;
}
}
if (eligibleNodes!.isEmpty) {
break;
}
List<FocusNode> sorted = eligibleNodes.toList();
if (direction == TraversalDirection.up) {
sorted = sorted.reversed.toList();
eligibleNodes = eligibleNodes.toList().reversed;
}
// Find any nodes that intersect the band of the focused child.
final Rect band = Rect.fromLTRB(focusedChild.rect.left, -double.infinity, focusedChild.rect.right, double.infinity);
final Iterable<FocusNode> inBand = sorted.where((FocusNode node) => !node.rect.intersect(band).isEmpty);
final Iterable<FocusNode> inBand = eligibleNodes.where((FocusNode node) => !node.rect.intersect(band).isEmpty);
if (inBand.isNotEmpty) {
// The inBand list is already sorted by horizontal distance, so pick
// the closest one.
found = inBand.first;
found = _sortByDistancePreferVertical(focusedChild.rect.center, inBand).first;
break;
}
// Only out-of-band targets remain, so pick the one that is closest the
// to the center line horizontally.
mergeSort<FocusNode>(sorted, compare: (FocusNode a, FocusNode b) {
return (a.rect.center.dx - focusedChild.rect.center.dx).abs().compareTo((b.rect.center.dx - focusedChild.rect.center.dx).abs());
});
found = sorted.first;
// Only out-of-band targets are eligible, so pick the one that is
// closest the to the center line horizontally.
found = _sortByDistancePreferHorizontal(focusedChild.rect.center, eligibleNodes).first;
break;
case TraversalDirection.right:
case TraversalDirection.left:
Iterable<FocusNode>? eligibleNodes = _sortAndFilterHorizontally(direction, focusedChild.rect, nearestScope);
Iterable<FocusNode> eligibleNodes = _sortAndFilterHorizontally(direction, focusedChild.rect, nearestScope.traversalDescendants);
if (eligibleNodes.isEmpty) {
break;
}
if (focusedScrollable != null && !focusedScrollable.position.atEdge) {
final Iterable<FocusNode> filteredEligibleNodes = eligibleNodes!.where((FocusNode node) => Scrollable.maybeOf(node.context!) == focusedScrollable);
final Iterable<FocusNode> filteredEligibleNodes = eligibleNodes.where((FocusNode node) => Scrollable.maybeOf(node.context!) == focusedScrollable);
if (filteredEligibleNodes.isNotEmpty) {
eligibleNodes = filteredEligibleNodes;
}
}
if (eligibleNodes!.isEmpty) {
break;
}
List<FocusNode> sorted = eligibleNodes.toList();
if (direction == TraversalDirection.left) {
sorted = sorted.reversed.toList();
eligibleNodes = eligibleNodes.toList().reversed;
}
// Find any nodes that intersect the band of the focused child.
final Rect band = Rect.fromLTRB(-double.infinity, focusedChild.rect.top, double.infinity, focusedChild.rect.bottom);
final Iterable<FocusNode> inBand = sorted.where((FocusNode node) => !node.rect.intersect(band).isEmpty);
final Iterable<FocusNode> inBand = eligibleNodes.where((FocusNode node) => !node.rect.intersect(band).isEmpty);
if (inBand.isNotEmpty) {
// The inBand list is already sorted by vertical distance, so pick the
// closest one.
found = inBand.first;
found = _sortByDistancePreferHorizontal(focusedChild.rect.center, inBand).first;
break;
}
// Only out-of-band targets remain, so pick the one that is closest the
// Only out-of-band targets are eligible, so pick the one that is
// to the center line vertically.
mergeSort<FocusNode>(sorted, compare: (FocusNode a, FocusNode b) {
return (a.rect.center.dy - focusedChild.rect.center.dy).abs().compareTo((b.rect.center.dy - focusedChild.rect.center.dy).abs());
});
found = sorted.first;
found = _sortByDistancePreferVertical(focusedChild.rect.center, eligibleNodes).first;
break;
}
if (found != null) {
......@@ -892,8 +915,8 @@ class _ReadingOrderSortData with Diagnosticable {
}
if (common!.isEmpty) {
// If there is no common ancestor, then arbitrarily pick the
// directionality of the first group, which is the equivalent of the "first
// strongly typed" item in a bidi algorithm.
// directionality of the first group, which is the equivalent of the
// "first strongly typed" item in a bidirectional algorithm.
return list.first.directionality;
}
// Find the closest common ancestor. The memberAncestors list contains the
......
packages/flutter/test/widgets/focus_traversal_test.dart
View file @ 0234b18f
......@@ -10,18 +10,6 @@ import 'package:flutter_test/flutter_test.dart';
import 'semantics_tester.dart';
/// Used to test removal of nodes while sorting.
class SkipAllButFirstAndLastPolicy extends FocusTraversalPolicy with DirectionalFocusTraversalPolicyMixin {
@override
Iterable<FocusNode> sortDescendants(Iterable<FocusNode> descendants, FocusNode currentNode) {
return <FocusNode>[
descendants.first,
if (currentNode != descendants.first && currentNode != descendants.last) currentNode,
descendants.last,
];
}
}
void main() {
group(WidgetOrderTraversalPolicy, () {
testWidgets('Find the initial focus if there is none yet.', (WidgetTester tester) async {
......@@ -1343,27 +1331,21 @@ void main() {
});
testWidgets('Directional focus avoids hysteresis.', (WidgetTester tester) async {
final List<GlobalKey> keys = <GlobalKey>[
GlobalKey(debugLabel: 'row 1:1'),
GlobalKey(debugLabel: 'row 2:1'),
GlobalKey(debugLabel: 'row 2:2'),
GlobalKey(debugLabel: 'row 3:1'),
GlobalKey(debugLabel: 'row 3:2'),
GlobalKey(debugLabel: 'row 3:3'),
];
List<bool?> focus = List<bool?>.generate(keys.length, (int _) => null);
List<bool?> focus = List<bool?>.generate(6, (int _) => null);
final List<FocusNode> nodes = List<FocusNode>.generate(6, (int index) => FocusNode(debugLabel: 'Node $index'));
Focus makeFocus(int index) {
return Focus(
debugLabel: keys[index].toString(),
debugLabel: '[$index]',
focusNode: nodes[index],
onFocusChange: (bool isFocused) => focus[index] = isFocused,
child: SizedBox(width: 100, height: 100, key: keys[index]),
child: const SizedBox(width: 100, height: 100),
);
}
/// Layout is:
/// keys[0]
/// keys[1] keys[2]
/// keys[3] keys[4] keys[5]
/// [0]
/// [1] [2]
/// [3] [4] [5]
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
......@@ -1402,80 +1384,203 @@ void main() {
);
void clear() {
focus = List<bool?>.generate(keys.length, (int _) => null);
focus = List<bool?>.generate(focus.length, (int _) => null);
}
final List<FocusNode> nodes = keys.map<FocusNode>((GlobalKey key) => Focus.of(tester.element(find.byKey(key)))).toList();
final FocusNode scope = nodes[0].enclosingScope!;
nodes[4].requestFocus();
void expectState(List<bool?> states) {
for (int index = 0; index < states.length; ++index) {
expect(focus[index], states[index] == null ? isNull : (states[index]! ? isTrue : isFalse));
if (states[index] == null) {
expect(nodes[index].hasFocus, isFalse);
} else {
expect(nodes[index].hasFocus, states[index]);
}
expect(scope.hasFocus, isTrue);
}
}
// Test to make sure that the same path is followed backwards and forwards.
await tester.pump();
expectState(<bool?>[null, null, null, null, true, null]);
expect(focus, orderedEquals(<bool?>[null, null, null, null, true, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isTrue);
await tester.pump();
expectState(<bool?>[null, null, true, null, false, null]);
expect(focus, orderedEquals(<bool?>[null, null, true, null, false, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isTrue);
await tester.pump();
expectState(<bool?>[true, null, false, null, null, null]);
expect(focus, orderedEquals(<bool?>[true, null, false, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isTrue);
await tester.pump();
expectState(<bool?>[false, null, true, null, null, null]);
expect(focus, orderedEquals(<bool?>[false, null, true, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isTrue);
await tester.pump();
expectState(<bool?>[null, null, false, null, true, null]);
expect(focus, orderedEquals(<bool?>[null, null, false, null, true, null]));
clear();
// Make sure that moving in a different axis clears the history.
expect(scope.focusInDirection(TraversalDirection.left), isTrue);
await tester.pump();
expectState(<bool?>[null, null, null, true, false, null]);
expect(focus, orderedEquals(<bool?>[null, null, null, true, false, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isTrue);
await tester.pump();
expectState(<bool?>[null, true, null, false, null, null]);
expect(focus, orderedEquals(<bool?>[null, true, null, false, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isTrue);
await tester.pump();
expectState(<bool?>[true, false, null, null, null, null]);
expect(focus, orderedEquals(<bool?>[true, false, null, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isTrue);
await tester.pump();
expectState(<bool?>[false, true, null, null, null, null]);
expect(focus, orderedEquals(<bool?>[false, true, null, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, false, null, true, null, null]));
clear();
});
testWidgets('Directional prefers the closest node even on irregular grids', (WidgetTester tester) async {
const int cols = 3;
const int rows = 3;
List<bool?> focus = List<bool?>.generate(rows * cols, (int _) => null);
final List<FocusNode> nodes = List<FocusNode>.generate(rows * cols, (int index) => FocusNode(debugLabel: 'Node $index'));
Widget makeFocus(int row, int col) {
final int index = row * rows + col;
return Focus(
focusNode: nodes[index],
onFocusChange: (bool isFocused) => focus[index] = isFocused,
child: Container(
// Make some of the items a different size to test the code that
// checks for the closest node.
width: index == 3 ? 150 : 100,
height: index == 1 ? 150 : 100,
color: Colors.primaries[index],
child: Text('[$row, $col]'),
),
);
}
/// Layout is:
/// [0, 1]
/// [0, 0] [ ] [0, 2]
/// [ 1, 0 ] [1, 1] [1, 2]
/// [2, 0] [2, 1] [2, 2]
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: FocusTraversalGroup(
policy: WidgetOrderTraversalPolicy(),
child: FocusScope(
debugLabel: 'Scope',
child: Column(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
makeFocus(0, 0),
makeFocus(0, 1),
makeFocus(0, 2),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
makeFocus(1, 0),
makeFocus(1, 1),
makeFocus(1, 2),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
makeFocus(2, 0),
makeFocus(2, 1),
makeFocus(2, 2),
],
),
],
),
),
),
),
);
void clear() {
focus = List<bool?>.generate(focus.length, (int _) => null);
}
final FocusNode scope = nodes[0].enclosingScope!;
// Go down the center column and make sure that the focus stays in that
// column, even though the second row is irregular.
nodes[1].requestFocus();
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, true, null, null, null, null, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, false, null, null, true, null, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isTrue);
await tester.pump();
expectState(<bool?>[null, false, null, true, null, null]);
expect(focus, orderedEquals(<bool?>[null, null, null, null, false, null, null, true, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.down), isFalse);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, null, null, null, null, null, null, null, null]));
clear();
// Go back up the right column and make sure that the focus stays in that
// column, even though the second row is irregular.
expect(scope.focusInDirection(TraversalDirection.right), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, null, null, null, null, null, null, false, true]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, null, null, null, null, true, null, null, false]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, null, true, null, null, false, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.up), isFalse);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, null, null, null, null, null, null, null, null]));
clear();
// Go left on the top row and make sure that the focus stays in that
// row, even though the second column is irregular.
expect(scope.focusInDirection(TraversalDirection.left), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, true, false, null, null, null, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.left), isTrue);
await tester.pump();
expect(focus, orderedEquals(<bool?>[true, false, null, null, null, null, null, null, null]));
clear();
expect(scope.focusInDirection(TraversalDirection.left), isFalse);
await tester.pump();
expect(focus, orderedEquals(<bool?>[null, null, null, null, null, null, null, null, null]));
clear();
});
......@@ -2129,7 +2234,7 @@ void main() {
expect(node2.hasPrimaryFocus, isFalse);
});
testWidgets("FocusTraversalGroup with skipTraversal for all descendents set to true doesn't cause an exception.", (WidgetTester tester) async {
testWidgets("FocusTraversalGroup with skipTraversal for all descendants set to true doesn't cause an exception.", (WidgetTester tester) async {
final FocusNode node1 = FocusNode();
final FocusNode node2 = FocusNode();
......@@ -2352,3 +2457,15 @@ class TestRoute extends PageRouteBuilder<void> {
},
);
}
/// Used to test removal of nodes while sorting.
class SkipAllButFirstAndLastPolicy extends FocusTraversalPolicy with DirectionalFocusTraversalPolicyMixin {
@override
Iterable<FocusNode> sortDescendants(Iterable<FocusNode> descendants, FocusNode currentNode) {
return <FocusNode>[
descendants.first,
if (currentNode != descendants.first && currentNode != descendants.last) currentNode,
descendants.last,
];
}
}
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment

HIAST - GitLab