josxha
commented
1 year ago Example implementation of the new `InteractiveFlags` class
```dart @immutable class InteractiveFlags { const InteractiveFlags._({ required this.drag, required this.flingAnimation, required this.pinchMove, required this.pinchZoom, required this.doubleTapZoom, required this.doubleTapDragZoom, required this.scrollWheelZoom, required this.rotate, }); const InteractiveFlags.all({ this.drag = true, this.flingAnimation = true, this.pinchMove = true, this.pinchZoom = true, this.doubleTapZoom = true, this.doubleTapDragZoom = true, this.scrollWheelZoom = true, this.rotate = true, }); const InteractiveFlags.none({ this.drag = false, this.flingAnimation = false, this.pinchMove = false, this.pinchZoom = false, this.doubleTapZoom = false, this.doubleTapDragZoom = false, this.scrollWheelZoom = false, this.rotate = false, }); /// Enable panning with a single finger or cursor final bool drag; /// Enable fling animation after panning if velocity is great enough. final bool flingAnimation; /// Enable panning with multiple fingers final bool pinchMove; /// Enable zooming with a multi-finger pinch gesture final bool pinchZoom; /// Enable zooming with a single-finger double tap gesture final bool doubleTapZoom; /// Enable zooming with a single-finger double-tap-drag gesture /// /// The associated [MapEventSource] is [MapEventSource.doubleTapHold]. final bool doubleTapDragZoom; /// Enable zooming with a mouse scroll wheel final bool scrollWheelZoom; /// Enable rotation with two-finger twist gesture /// /// For controlling cursor/keyboard rotation, see /// [InteractionOptions.cursorKeyboardRotationOptions]. final bool rotate; bool hasMultiFinger() => pinchMove || pinchZoom || rotate; /// This constructor gives wither functionality to the model InteractiveFlags withFlag({ bool? pinchZoom, bool? drag, bool? flingAnimation, bool? pinchMove, bool? doubleTapZoom, bool? doubleTapDragZoom, bool? scrollWheelZoom, bool? rotate, }) => InteractiveFlags._( pinchZoom: pinchZoom ?? this.pinchZoom, drag: drag ?? this.drag, flingAnimation: flingAnimation ?? this.flingAnimation, pinchMove: pinchMove ?? this.pinchMove, doubleTapZoom: doubleTapZoom ?? this.doubleTapZoom, doubleTapDragZoom: doubleTapDragZoom ?? this.doubleTapDragZoom, scrollWheelZoom: scrollWheelZoom ?? this.scrollWheelZoom, rotate: rotate ?? this.rotate, ); } ```This would make the following changes:
final int flags;
// turns into
final InteractiveFlags flags;
flags: InteractiveFlags.all - InteractiveFlags.rotate,
// turns into
flags: InteractiveFlags.all(rotate: false),
if (InteractiveFlag.hasDoubleTapZoom(newOptions.flags)) {
// turns into
if (newOptions.flags.doubleTapZoom) {
hobleyd
JaffaKetchup
Motivation
As mentioned by @JaffaKetchup in https://github.com/fleaflet/flutter_map/issues/1529#issue-1718239936, "much of the [gesture handling] code that does this was written in the first few releases, and has not been significantly changed since. [...] Gesture handling at this low-level often differs slightly between platforms, which means that manual testing succeeds on one platform, but a bug occurs on another."
Rewrite Proposals
Use boolean fields in InteractiveFlag and MultiFingerGesture. This simplifies internal usage, is more beginner friendly in our public API and has no performance penalty. I'll write some code examples in the next comment.https://github.com/fleaflet/flutter_map/issues/1732If feasible do the following changes:
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