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Diffstat (limited to 'src/client/util/InteractionUtils.tsx')
| -rw-r--r-- | src/client/util/InteractionUtils.tsx | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/client/util/InteractionUtils.tsx b/src/client/util/InteractionUtils.tsx new file mode 100644 index 000000000..34c7cfa74 --- /dev/null +++ b/src/client/util/InteractionUtils.tsx @@ -0,0 +1,182 @@ +import React = require("react"); + +export namespace InteractionUtils { + export const MOUSETYPE = "mouse"; + export const TOUCHTYPE = "touch"; + export const PENTYPE = "pen"; + export const ERASERTYPE = "eraser"; + + const POINTER_PEN_BUTTON = -1; + const REACT_POINTER_PEN_BUTTON = 0; + const ERASER_BUTTON = 5; + + export function GetMyTargetTouches(e: TouchEvent | React.TouchEvent, prevPoints: Map<number, React.Touch>, ignorePen: boolean): React.Touch[] { + const myTouches = new Array<React.Touch>(); + for (let i = 0; i < e.targetTouches.length; i++) { + const pt: any = e.targetTouches.item(i); + if (pt && prevPoints.has(pt.identifier)) { + if (ignorePen || (pt.radiusX > 1 && pt.radiusY > 1)) { + myTouches.push(pt); + } + } + } + return myTouches; + } + + // TODO: find a way to reference this function from InkingStroke instead of copy pastign here. copied bc of weird error when on mobile view + export function CreatePolyline(points: { X: number, Y: number }[], left: number, top: number, color: string, width: number) { + const pts = points.reduce((acc: string, pt: { X: number, Y: number }) => acc + `${pt.X - left},${pt.Y - top} `, ""); + return ( + <polyline + points={pts} + style={{ + fill: "none", + stroke: color, + strokeWidth: width + }} + /> + ); + } + + export function IsType(e: PointerEvent | React.PointerEvent, type: string): boolean { + switch (type) { + // pen and eraser are both pointer type 'pen', but pen is button 0 and eraser is button 5. -syip2 + case PENTYPE: + return e.pointerType === PENTYPE && (e.button === -1 || e.button === 0); + case ERASERTYPE: + return e.pointerType === PENTYPE && e.button === (e instanceof PointerEvent ? ERASER_BUTTON : ERASER_BUTTON); + default: + return e.pointerType === type; + } + } + + export function TwoPointEuclidist(pt1: React.Touch, pt2: React.Touch): number { + return Math.sqrt(Math.pow(pt1.clientX - pt2.clientX, 2) + Math.pow(pt1.clientY - pt2.clientY, 2)); + } + + /** + * Returns the centroid of an n-arbitrary long list of points (takes the average the x and y components of each point) + * @param pts - n-arbitrary long list of points + */ + export function CenterPoint(pts: React.Touch[]): { X: number, Y: number } { + const centerX = pts.map(pt => pt.clientX).reduce((a, b) => a + b, 0) / pts.length; + const centerY = pts.map(pt => pt.clientY).reduce((a, b) => a + b, 0) / pts.length; + return { X: centerX, Y: centerY }; + } + + /** + * Returns -1 if pinching out, 0 if not pinching, and 1 if pinching in + * @param pt1 - new point that corresponds to oldPoint1 + * @param pt2 - new point that corresponds to oldPoint2 + * @param oldPoint1 - previous point 1 + * @param oldPoint2 - previous point 2 + */ + export function Pinching(pt1: React.Touch, pt2: React.Touch, oldPoint1: React.Touch, oldPoint2: React.Touch): number { + const threshold = 4; + const oldDist = TwoPointEuclidist(oldPoint1, oldPoint2); + const newDist = TwoPointEuclidist(pt1, pt2); + + /** if they have the same sign, then we are either pinching in or out. + * threshold it by 10 (it has to be pinching by at least threshold to be a valid pinch) + * so that it can still pan without freaking out + */ + if (Math.sign(oldDist) === Math.sign(newDist) && Math.abs(oldDist - newDist) > threshold) { + return Math.sign(oldDist - newDist); + } + return 0; + } + + /** + * Returns -1 if pinning and pinching out, 0 if not pinning, and 1 if pinching in + * @param pt1 - new point that corresponds to oldPoint1 + * @param pt2 - new point that corresponds to oldPoint2 + * @param oldPoint1 - previous point 1 + * @param oldPoint2 - previous point 2 + */ + export function Pinning(pt1: React.Touch, pt2: React.Touch, oldPoint1: React.Touch, oldPoint2: React.Touch): number { + const threshold = 4; + + const pt1Dist = TwoPointEuclidist(oldPoint1, pt1); + const pt2Dist = TwoPointEuclidist(oldPoint2, pt2); + + const pinching = Pinching(pt1, pt2, oldPoint1, oldPoint2); + + if (pinching !== 0) { + if ((pt1Dist < threshold && pt2Dist > threshold) || (pt1Dist > threshold && pt2Dist < threshold)) { + return pinching; + } + } + return 0; + } + + export function IsDragging(oldTouches: Map<number, React.Touch>, newTouches: React.Touch[], leniency: number): boolean { + for (const touch of newTouches) { + if (touch) { + const oldTouch = oldTouches.get(touch.identifier); + if (oldTouch) { + if (TwoPointEuclidist(touch, oldTouch) >= leniency) { + return true; + } + } + } + } + return false; + } + + // These might not be very useful anymore, but I'll leave them here for now -syip2 + { + + + /** + * Returns the type of Touch Interaction from a list of points. + * Also returns any data that is associated with a Touch Interaction + * @param pts - List of points + */ + // export function InterpretPointers(pts: React.Touch[]): { type: Opt<TouchInteraction>, data?: any } { + // const leniency = 200; + // switch (pts.length) { + // case 1: + // return { type: OneFinger }; + // case 2: + // return { type: TwoSeperateFingers }; + // case 3: + // let pt1 = pts[0]; + // let pt2 = pts[1]; + // let pt3 = pts[2]; + // if (pt1 && pt2 && pt3) { + // let dist12 = TwoPointEuclidist(pt1, pt2); + // let dist23 = TwoPointEuclidist(pt2, pt3); + // let dist13 = TwoPointEuclidist(pt1, pt3); + // console.log(`distances: ${dist12}, ${dist23}, ${dist13}`); + // let dist12close = dist12 < leniency; + // let dist23close = dist23 < leniency; + // let dist13close = dist13 < leniency; + // let xor2313 = dist23close ? !dist13close : dist13close; + // let xor = dist12close ? !xor2313 : xor2313; + // // three input xor because javascript doesn't have logical xor's + // if (xor) { + // let points: number[] = []; + // let min = Math.min(dist12, dist23, dist13); + // switch (min) { + // case dist12: + // points = [0, 1, 2]; + // break; + // case dist23: + // points = [1, 2, 0]; + // break; + // case dist13: + // points = [0, 2, 1]; + // break; + // } + // return { type: TwoToOneFingers, data: points }; + // } + // else { + // return { type: ThreeSeperateFingers, data: null }; + // } + // } + // default: + // return { type: undefined }; + // } + // } + } +}
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