@tamagui/react-native-web-lite
Version:
React Native for Web
103 lines (102 loc) • 3.7 kB
JavaScript
const TouchHistoryMath = {
/**
* This code is optimized and not intended to look beautiful. This allows
* computing of touch centroids that have moved after `touchesChangedAfter`
* timeStamp. You can compute the current centroid involving all touches
* moves after `touchesChangedAfter`, or you can compute the previous
* centroid of all touches that were moved after `touchesChangedAfter`.
*
* @param {TouchHistoryMath} touchHistory Standard Responder touch track
* data.
* @param {number} touchesChangedAfter timeStamp after which moved touches
* are considered "actively moving" - not just "active".
* @param {boolean} isXAxis Consider `x` dimension vs. `y` dimension.
* @param {boolean} ofCurrent Compute current centroid for actively moving
* touches vs. previous centroid of now actively moving touches.
* @return {number} value of centroid in specified dimension.
*/
centroidDimension: function(touchHistory, touchesChangedAfter, isXAxis, ofCurrent) {
const touchBank = touchHistory.touchBank;
let total = 0, count = 0;
const oneTouchData = touchHistory.numberActiveTouches === 1 ? touchHistory.touchBank[touchHistory.indexOfSingleActiveTouch] : null;
if (oneTouchData !== null)
oneTouchData.touchActive && oneTouchData.currentTimeStamp > touchesChangedAfter && (total += ofCurrent && isXAxis ? oneTouchData.currentPageX : ofCurrent && !isXAxis ? oneTouchData.currentPageY : !ofCurrent && isXAxis ? oneTouchData.previousPageX : oneTouchData.previousPageY, count = 1);
else
for (let i = 0; i < touchBank.length; i++) {
const touchTrack = touchBank[i];
if (touchTrack != null && touchTrack.touchActive && touchTrack.currentTimeStamp >= touchesChangedAfter) {
let toAdd;
ofCurrent && isXAxis ? toAdd = touchTrack.currentPageX : ofCurrent && !isXAxis ? toAdd = touchTrack.currentPageY : !ofCurrent && isXAxis ? toAdd = touchTrack.previousPageX : toAdd = touchTrack.previousPageY, total += toAdd, count++;
}
}
return count > 0 ? total / count : TouchHistoryMath.noCentroid;
},
currentCentroidXOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
return TouchHistoryMath.centroidDimension(
touchHistory,
touchesChangedAfter,
!0,
// isXAxis
!0
// ofCurrent
);
},
currentCentroidYOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
return TouchHistoryMath.centroidDimension(
touchHistory,
touchesChangedAfter,
!1,
// isXAxis
!0
// ofCurrent
);
},
previousCentroidXOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
return TouchHistoryMath.centroidDimension(
touchHistory,
touchesChangedAfter,
!0,
// isXAxis
!1
// ofCurrent
);
},
previousCentroidYOfTouchesChangedAfter: function(touchHistory, touchesChangedAfter) {
return TouchHistoryMath.centroidDimension(
touchHistory,
touchesChangedAfter,
!1,
// isXAxis
!1
// ofCurrent
);
},
currentCentroidX: function(touchHistory) {
return TouchHistoryMath.centroidDimension(
touchHistory,
0,
// touchesChangedAfter
!0,
// isXAxis
!0
// ofCurrent
);
},
currentCentroidY: function(touchHistory) {
return TouchHistoryMath.centroidDimension(
touchHistory,
0,
// touchesChangedAfter
!1,
// isXAxis
!0
// ofCurrent
);
},
noCentroid: -1
};
var TouchHistoryMath_default = TouchHistoryMath;
export {
TouchHistoryMath_default as default
};
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