34 lines
1.3 KiB
Dart
34 lines
1.3 KiB
Dart
import 'package:flutter/gestures.dart';
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import 'package:flutter/widgets.dart';
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// `PageView` contains a `Scrollable` which sets up a `HorizontalDragGestureRecognizer`.
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// This recognizer will win in the gesture arena when the drag distance reaches
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// `kTouchSlop` (or platform settings, cf gestures/events.dart `computeHitSlop`).
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// We cannot change that, but we can prevent the scrollable from panning until this threshold is reached
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// and let other recognizers accept the gesture instead.
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class MagnifierScrollerPhysics extends ScrollPhysics {
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final DeviceGestureSettings? gestureSettings;
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// in [0, 1]
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// 0: most reactive but will not let Magnifier recognizers accept gestures
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// 1: less reactive but gives the most leeway to Magnifier recognizers
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final double touchSlopFactor;
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const MagnifierScrollerPhysics({
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required this.gestureSettings,
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this.touchSlopFactor = 1,
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ScrollPhysics? parent,
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}) : super(parent: parent);
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@override
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MagnifierScrollerPhysics applyTo(ScrollPhysics? ancestor) {
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return MagnifierScrollerPhysics(
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gestureSettings: gestureSettings,
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touchSlopFactor: touchSlopFactor,
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parent: buildParent(ancestor),
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);
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}
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@override
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double get dragStartDistanceMotionThreshold => (gestureSettings?.touchSlop ?? kTouchSlop) * touchSlopFactor;
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}
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