public override void addAllowedPointer(PointerDownEvent evt)
{
startTrackingPointer(evt.pointer, evt.transform);
_velocityTrackers[evt.pointer] = new VelocityTracker();
if (_state == _DragState.ready)
{
_state = _DragState.possible;
_initialPosition = new OffsetPair(global: evt.position, local: evt.localPosition);
_pendingDragOffset = OffsetPair.zero;
_globalDistanceMoved = 0f;
_lastPendingEventTimestamp = evt.timeStamp;
_lastTransform = evt.transform;
if (onDown != null)
{
invokeCallback <object>("onDown",
() => {
onDown(new DragDownDetails(
globalPosition: _initialPosition.global,
localPosition: _initialPosition.local));
return(null);
});
}
}
else if (_state == _DragState.accepted)
{
resolve(GestureDisposition.accepted);
}
}
public override void acceptGesture(int pointer)
{
if (this._state != _DragState.accepted)
{
this._state = _DragState.accepted;
Offset delta = this._pendingDragOffset;
var timestamp = this._lastPendingEventTimestamp;
this._pendingDragOffset = Offset.zero;
this._lastPendingEventTimestamp = default(TimeSpan);
if (this.onStart != null)
{
this.invokeCallback <object>("onStart", () => {
this.onStart(new DragStartDetails(
sourceTimeStamp: timestamp,
globalPosition: this._initialPosition
));
return(null);
});
}
if (delta != Offset.zero && this.onUpdate != null)
{
this.invokeCallback <object>("onUpdate", () => {
this.onUpdate(new DragUpdateDetails(
sourceTimeStamp: timestamp,
delta: this._getDeltaForDetails(delta),
primaryDelta: this._getPrimaryValueFromOffset(delta),
globalPosition: this._initialPosition
));
return(null);
});
}
}
}
protected override void didStopTrackingLastPointer(int pointer)
{
if (_state == _DragState.possible)
{
resolve(GestureDisposition.rejected);
_state = _DragState.ready;
if (onCancel != null)
{
invokeCallback <object>("onCancel", () => {
onCancel();
return(null);
});
}
return;
}
bool wasAccepted = _state == _DragState.accepted;
_state = _DragState.ready;
if (wasAccepted && onEnd != null)
{
var tracker = _velocityTrackers[pointer];
D.assert(tracker != null);
var estimate = tracker.getVelocityEstimate();
if (estimate != null && _isFlingGesture(estimate))
{
Velocity velocity = new Velocity(pixelsPerSecond: estimate.pixelsPerSecond)
.clampMagnitude(minFlingVelocity ?? Constants.kMinFlingVelocity,
maxFlingVelocity ?? Constants.kMaxFlingVelocity);
invokeCallback <object>("onEnd", () => {
onEnd(new DragEndDetails(
velocity: velocity,
primaryVelocity: _getPrimaryValueFromOffset(velocity.pixelsPerSecond)
));
return(null);
}, debugReport: () =>
$"{estimate}; fling at {velocity}.");
}
else
{
invokeCallback <object>("onEnd", () => {
onEnd(new DragEndDetails(
velocity: Velocity.zero,
primaryVelocity: 0.0f
));
return(null);
}, debugReport: () =>
estimate == null
? "Could not estimate velocity."
: estimate + "; judged to not be a fling."
);
}
}
_velocityTrackers.Clear();
}
protected override void didStopTrackingLastScrollerPointer(int pointer)
{
_state = _DragState.ready;
invokeCallback <object>("onEnd", () => {
onEnd(new DragEndDetails(
velocity: Velocity.zero,
primaryVelocity: 0.0f
));
return(null);
}, debugReport: () => { return("Pointer scroll end"); }
);
}
public override void acceptGesture(int pointer)
{
if (this._state != _DragState.accepted)
{
this._state = _DragState.accepted;
Offset delta = this._pendingDragOffset;
var timestamp = this._lastPendingEventTimestamp;
Offset updateDelta = null;
switch (this.dragStartBehavior)
{
case DragStartBehavior.start:
this._initialPosition = this._initialPosition + delta;
updateDelta = Offset.zero;
break;
case DragStartBehavior.down:
updateDelta = this._getDeltaForDetails(delta);
break;
}
D.assert(updateDelta != null);
this._pendingDragOffset = Offset.zero;
this._lastPendingEventTimestamp = default(TimeSpan);
if (this.onStart != null)
{
this.invokeCallback <object>("onStart", () => {
this.onStart(new DragStartDetails(
sourceTimeStamp: timestamp,
globalPosition: this._initialPosition
));
return(null);
});
}
if (updateDelta != Offset.zero && this.onUpdate != null)
{
this.invokeCallback <object>("onUpdate", () => {
this.onUpdate(new DragUpdateDetails(
sourceTimeStamp: timestamp,
delta: updateDelta,
primaryDelta: this._getPrimaryValueFromOffset(updateDelta),
globalPosition: this._initialPosition + updateDelta
));
return(null);
});
}
}
}
public override void addScrollPointer(PointerScrollEvent evt)
{
this.startTrackingScrollerPointer(evt.pointer);
if (this._state == _DragState.ready)
{
this._state = _DragState.possible;
this._initialPosition = evt.position;
if (this.onStart != null)
{
this.invokeCallback <object>("onStart", () => {
this.onStart(new DragStartDetails(
sourceTimeStamp: evt.timeStamp,
globalPosition: this._initialPosition
));
return(null);
});
}
}
}
public override void addScrollPointer(PointerScrollEvent evt)
{
startTrackingScrollerPointer(evt.pointer);
if (_state == _DragState.ready)
{
_state = _DragState.possible;
_initialPosition = new OffsetPair(global: evt.position, local: evt.localPosition);
if (onStart != null)
{
invokeCallback <object>("onStart", () => {
onStart(new DragStartDetails(
sourceTimeStamp: evt.timeStamp,
globalPosition: _initialPosition.global,
localPosition: _initialPosition.local
));
return(null);
});
}
}
}
public override void addAllowedPointer(PointerDownEvent evt)
{
this.startTrackingPointer(evt.pointer);
this._velocityTrackers[evt.pointer] = new VelocityTracker();
if (this._state == _DragState.ready)
{
this._state = _DragState.possible;
this._initialPosition = evt.position;
this._pendingDragOffset = Offset.zero;
this._lastPendingEventTimestamp = evt.timeStamp;
if (this.onDown != null)
{
this.invokeCallback <object>("onDown",
() => {
this.onDown(new DragDownDetails(globalPosition: this._initialPosition));
return(null);
});
}
}
else if (this._state == _DragState.accepted)
{
this.resolve(GestureDisposition.accepted);
}
}
public override void acceptGesture(int pointer)
{
if (_state != _DragState.accepted)
{
_state = _DragState.accepted;
OffsetPair delta = _pendingDragOffset;
var timestamp = _lastPendingEventTimestamp;
Matrix4 transform = _lastTransform;
Offset localUpdateDelta = null;
switch (dragStartBehavior)
{
case DragStartBehavior.start:
_initialPosition = _initialPosition + delta;
localUpdateDelta = Offset.zero;
break;
case DragStartBehavior.down:
localUpdateDelta = _getDeltaForDetails(delta.local);
break;
}
D.assert(localUpdateDelta != null);
_pendingDragOffset = OffsetPair.zero;
_lastPendingEventTimestamp = default(TimeSpan);
_lastTransform = null;
if (onStart != null)
{
invokeCallback <object>("onStart", () => {
onStart(new DragStartDetails(
sourceTimeStamp: timestamp,
globalPosition: _initialPosition.global,
localPosition: _initialPosition.local
));
return(null);
});
}
if (localUpdateDelta != Offset.zero && onUpdate != null)
{
Matrix4 localToGlobal = transform != null?Matrix4.tryInvert(transform) : null;
Offset correctedLocalPosition = _initialPosition.local + localUpdateDelta;
Offset globalUpdateDelta = PointerEvent.transformDeltaViaPositions(
untransformedEndPosition: correctedLocalPosition,
untransformedDelta: localUpdateDelta,
transform: localToGlobal
);
OffsetPair updateDelta = new OffsetPair(local: localUpdateDelta, global: globalUpdateDelta);
OffsetPair correctedPosition = _initialPosition + updateDelta; // Only adds delta for down behaviour
invokeCallback <object>("onUpdate", () => {
onUpdate(new DragUpdateDetails(
sourceTimeStamp: timestamp,
delta: localUpdateDelta,
primaryDelta: _getPrimaryValueFromOffset(localUpdateDelta),
globalPosition: _initialPosition.global,
localPosition: _initialPosition.local
));
return(null);
});
}
}
}
protected override void handleEvent(PointerEvent evt)
{
D.assert(this._state != _DragState.ready);
if (evt is PointerScrollEvent)
{
Offset delta = evt.delta;
if (this.onUpdate != null)
{
this.invokeCallback <object>("onUpdate", () => {
this.onUpdate(new DragUpdateDetails(
sourceTimeStamp: evt.timeStamp,
delta: this._getDeltaForDetails(delta),
primaryDelta: this._getPrimaryValueFromOffset(delta),
globalPosition: evt.position,
isScroll: true
));
return(null);
});
}
this.invokeCallback <object>("onEnd", () => {
this.onEnd(new DragEndDetails(
velocity: Velocity.zero,
primaryVelocity: 0.0f
));
return(null);
}, debugReport: () => { return("Pointer scroll end"); }
);
this._state = _DragState.ready;
return;
}
if (!evt.synthesized &&
(evt is PointerDownEvent || evt is PointerMoveEvent))
{
var tracker = this._velocityTrackers[evt.pointer];
D.assert(tracker != null);
tracker.addPosition(evt.timeStamp, evt.position);
}
if (evt is PointerMoveEvent)
{
Offset delta = evt.delta;
if (this._state == _DragState.accepted)
{
if (this.onUpdate != null)
{
this.invokeCallback <object>("onUpdate", () => {
this.onUpdate(new DragUpdateDetails(
sourceTimeStamp: evt.timeStamp,
delta: this._getDeltaForDetails(delta),
primaryDelta: this._getPrimaryValueFromOffset(delta),
globalPosition: evt.position
));
return(null);
});
}
}
else
{
this._pendingDragOffset += delta;
this._lastPendingEventTimestamp = evt.timeStamp;
if (this._hasSufficientPendingDragDeltaToAccept)
{
this.resolve(GestureDisposition.accepted);
}
}
}
this.stopTrackingIfPointerNoLongerDown(evt);
}
