g-element
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A collection of elements used by Authentic System Solutions
510 lines (507 loc) • 19.4 kB
JavaScript
// from https://github.com/szimek/signature_pad
class Point {
constructor(x, y, time) {
this.x = x;
this.y = y;
this.time = time || Date.now();
}
distanceTo(start) {
return Math.sqrt(Math.pow(this.x - start.x, 2) + Math.pow(this.y - start.y, 2));
}
equals(other) {
return this.x === other.x && this.y === other.y && this.time === other.time;
}
velocityFrom(start) {
return (this.time !== start.time) ? this.distanceTo(start) / (this.time - start.time) : 0;
}
}
class Bezier {
constructor(startPoint, control2, control1, endPoint, startWidth, endWidth) {
this.startPoint = startPoint;
this.control2 = control2;
this.control1 = control1;
this.endPoint = endPoint;
this.startWidth = startWidth;
this.endWidth = endWidth;
}
length() {
var steps = 10;
var length = 0;
var px;
var py;
for (var i = 0; i <= steps; i += 1) {
var t = i / steps;
var cx = this.point(t, this.startPoint.x, this.control1.x, this.control2.x, this.endPoint.x);
var cy = this.point(t, this.startPoint.y, this.control1.y, this.control2.y, this.endPoint.y);
if (i > 0) {
var xdiff = cx - px;
var ydiff = cy - py;
length += Math.sqrt((xdiff * xdiff) + (ydiff * ydiff));
}
px = cx;
py = cy;
}
return length;
}
point(t, start, c1, c2, end) {
return (start * (1.0 - t) * (1.0 - t) * (1.0 - t))
+ (3.0 * c1 * (1.0 - t) * (1.0 - t) * t)
+ (3.0 * c2 * (1.0 - t) * t * t)
+ (end * t * t * t);
}
static fromPoints(points, widths) {
var c2 = this.calculateControlPoints(points[0], points[1], points[2]).c2;
var c3 = this.calculateControlPoints(points[1], points[2], points[3]).c1;
return new Bezier(points[1], c2, c3, points[2], widths.start, widths.end);
}
static calculateControlPoints(s1, s2, s3) {
var dx1 = s1.x - s2.x;
var dy1 = s1.y - s2.y;
var dx2 = s2.x - s3.x;
var dy2 = s2.y - s3.y;
var m1 = { x: (s1.x + s2.x) / 2.0, y: (s1.y + s2.y) / 2.0 };
var m2 = { x: (s2.x + s3.x) / 2.0, y: (s2.y + s3.y) / 2.0 };
var l1 = Math.sqrt((dx1 * dx1) + (dy1 * dy1));
var l2 = Math.sqrt((dx2 * dx2) + (dy2 * dy2));
var dxm = (m1.x - m2.x);
var dym = (m1.y - m2.y);
var k = l2 / (l1 + l2);
var cm = { x: m2.x + (dxm * k), y: m2.y + (dym * k) };
var tx = s2.x - cm.x;
var ty = s2.y - cm.y;
return {
c1: new Point(m1.x + tx, m1.y + ty),
c2: new Point(m2.x + tx, m2.y + ty)
};
}
}
function throttle(fn, wait) {
if (wait === void 0) { wait = 250; }
var previous = 0;
var timeout = null;
var result;
var storedContext;
var storedArgs;
var later = function () {
previous = Date.now();
timeout = null;
result = fn.apply(storedContext, storedArgs);
if (!timeout) {
storedContext = null;
storedArgs = [];
}
};
return function () {
var args = [];
for (var _i = 0; _i < arguments.length; _i++) {
args[_i] = arguments[_i];
}
var now = Date.now();
var remaining = wait - (now - previous);
storedContext = this;
storedArgs = args;
if (remaining <= 0 || remaining > wait) {
if (timeout) {
clearTimeout(timeout);
timeout = null;
}
previous = now;
result = fn.apply(storedContext, storedArgs);
if (!timeout) {
storedContext = null;
storedArgs = [];
}
}
else if (!timeout) {
timeout = window.setTimeout(later, remaining);
}
return result;
};
}
export default class SignaturePad {
constructor(canvas, options) {
if (options === void 0) {
options = {};
}
var _this = this;
this.canvas = canvas;
this.options = options;
this._handleMouseDown = function (event) {
if (event.which === 1) {
_this._mouseButtonDown = true;
_this._strokeBegin(event);
}
};
this._handleMouseMove = function (event) {
if (_this._mouseButtonDown) {
_this._strokeMoveUpdate(event);
}
};
this._handleMouseUp = function (event) {
if (event.which === 1 && _this._mouseButtonDown) {
_this._mouseButtonDown = false;
_this._strokeEnd(event);
}
};
this._handleTouchStart = function (event) {
event.preventDefault();
if (event.targetTouches.length === 1) {
var touch = event.changedTouches[0];
_this._strokeBegin(touch);
}
};
this._handleTouchMove = function (event) {
event.preventDefault();
var touch = event.targetTouches[0];
_this._strokeMoveUpdate(touch);
};
this._handleTouchEnd = function (event) {
var wasCanvasTouched = event.target === _this.canvas;
if (wasCanvasTouched) {
event.preventDefault();
var touch = event.changedTouches[0];
_this._strokeEnd(touch);
}
};
this.velocityFilterWeight = options.velocityFilterWeight || 0.7;
this.minWidth = options.minWidth || 0.5;
this.maxWidth = options.maxWidth || 2.5;
this.throttle = ('throttle' in options ? options.throttle : 16);
this.minDistance = ('minDistance' in options ? options.minDistance : 5);
if (this.throttle) {
this._strokeMoveUpdate = throttle(SignaturePad.prototype._strokeUpdate, this.throttle);
}
else {
this._strokeMoveUpdate = SignaturePad.prototype._strokeUpdate;
}
this.dotSize = options.dotSize || function () {
return (this.minWidth + this.maxWidth) / 2;
};
this.penColor = options.penColor || 'black';
this.backgroundColor = options.backgroundColor || 'rgba(0,0,0,0)';
this.onBegin = options.onBegin;
this.onEnd = options.onEnd;
this._ctx = canvas.getContext('2d');
this.clear();
this.on();
}
clear() {
var ctx = this._ctx;
var canvas = this.canvas;
ctx.fillStyle = this.backgroundColor;
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.fillRect(0, 0, canvas.width, canvas.height);
this._data = [];
this._reset();
this._isEmpty = true;
}
fromDataURL(dataUrl, options, callback) {
var _this = this;
if (options === void 0) {
options = {};
}
var image = new Image();
var ratio = options.ratio || window.devicePixelRatio || 1;
var width = options.width || (this.canvas.width / ratio);
var height = options.height || (this.canvas.height / ratio);
this._reset();
image.onload = function () {
_this._ctx.drawImage(image, 0, 0, width, height);
if (callback) {
callback();
}
};
image.onerror = function (error) {
if (callback) {
callback(error);
}
};
image.src = dataUrl;
this._isEmpty = false;
}
toDataURL(type, encoderOptions) {
if (type === void 0) {
type = 'image/png';
}
switch (type) {
case 'image/svg+xml':
return this._toSVG();
default:
return this.canvas.toDataURL(type, encoderOptions);
}
}
on() {
this.canvas.style.touchAction = 'none';
this.canvas.style.msTouchAction = 'none';
if (window.PointerEvent) {
this._handlePointerEvents();
}
else {
this._handleMouseEvents();
if ('ontouchstart' in window) {
this._handleTouchEvents();
}
}
}
off() {
this.canvas.style.touchAction = 'auto';
this.canvas.style.msTouchAction = 'auto';
this.canvas.removeEventListener('pointerdown', this._handleMouseDown);
this.canvas.removeEventListener('pointermove', this._handleMouseMove);
document.removeEventListener('pointerup', this._handleMouseUp);
this.canvas.removeEventListener('mousedown', this._handleMouseDown);
this.canvas.removeEventListener('mousemove', this._handleMouseMove);
document.removeEventListener('mouseup', this._handleMouseUp);
this.canvas.removeEventListener('touchstart', this._handleTouchStart);
this.canvas.removeEventListener('touchmove', this._handleTouchMove);
this.canvas.removeEventListener('touchend', this._handleTouchEnd);
}
isEmpty() {
return this._isEmpty;
}
fromData(pointGroups) {
var _this = this;
this.clear();
this._fromData(pointGroups, function (_a) {
var color = _a.color, curve = _a.curve;
return _this._drawCurve({ color: color, curve: curve });
}, function (_a) {
var color = _a.color, point = _a.point;
return _this._drawDot({ color: color, point: point });
});
this._data = pointGroups;
}
toData() {
return this._data;
}
_strokeBegin(event) {
var newPointGroup = {
color: this.penColor,
points: []
};
this._data.push(newPointGroup);
this._reset();
this._strokeUpdate(event);
if (typeof this.onBegin === 'function') {
this.onBegin(event);
}
}
_strokeUpdate(event) {
var x = event.clientX;
var y = event.clientY;
var point = this._createPoint(x, y);
var lastPointGroup = this._data[this._data.length - 1];
var lastPoints = lastPointGroup.points;
var lastPoint = lastPoints.length > 0 && lastPoints[lastPoints.length - 1];
var isLastPointTooClose = lastPoint ? point.distanceTo(lastPoint) <= this.minDistance : false;
var color = lastPointGroup.color;
if (!lastPoint || !(lastPoint && isLastPointTooClose)) {
var curve = this._addPoint(point);
if (!lastPoint) {
this._drawDot({ color: color, point: point });
}
else if (curve) {
this._drawCurve({ color: color, curve: curve });
}
lastPoints.push({
time: point.time,
x: point.x,
y: point.y
});
}
}
_strokeEnd(event) {
this._strokeUpdate(event);
if (typeof this.onEnd === 'function') {
this.onEnd(event);
}
}
_handlePointerEvents() {
this._mouseButtonDown = false;
this.canvas.addEventListener('pointerdown', this._handleMouseDown);
this.canvas.addEventListener('pointermove', this._handleMouseMove);
document.addEventListener('pointerup', this._handleMouseUp);
}
_handleMouseEvents() {
this._mouseButtonDown = false;
this.canvas.addEventListener('mousedown', this._handleMouseDown);
this.canvas.addEventListener('mousemove', this._handleMouseMove);
document.addEventListener('mouseup', this._handleMouseUp);
}
_handleTouchEvents() {
this.canvas.addEventListener('touchstart', this._handleTouchStart);
this.canvas.addEventListener('touchmove', this._handleTouchMove);
this.canvas.addEventListener('touchend', this._handleTouchEnd);
}
_reset() {
this._lastPoints = [];
this._lastVelocity = 0;
this._lastWidth = (this.minWidth + this.maxWidth) / 2;
this._ctx.fillStyle = this.penColor;
}
_createPoint(x, y) {
var rect = this.canvas.getBoundingClientRect();
return new Point(x - rect.left, y - rect.top, new Date().getTime());
}
_addPoint(point) {
var _lastPoints = this._lastPoints;
_lastPoints.push(point);
if (_lastPoints.length > 2) {
if (_lastPoints.length === 3) {
_lastPoints.unshift(_lastPoints[0]);
}
var widths = this._calculateCurveWidths(_lastPoints[1], _lastPoints[2]);
var curve = Bezier.fromPoints(_lastPoints, widths);
_lastPoints.shift();
return curve;
}
return null;
}
_calculateCurveWidths(startPoint, endPoint) {
var velocity = (this.velocityFilterWeight * endPoint.velocityFrom(startPoint))
+ ((1 - this.velocityFilterWeight) * this._lastVelocity);
var newWidth = this._strokeWidth(velocity);
var widths = {
end: newWidth,
start: this._lastWidth
};
this._lastVelocity = velocity;
this._lastWidth = newWidth;
return widths;
}
_strokeWidth(velocity) {
return Math.max(this.maxWidth / (velocity + 1), this.minWidth);
}
_drawCurveSegment(x, y, width) {
var ctx = this._ctx;
ctx.moveTo(x, y);
ctx.arc(x, y, width, 0, 2 * Math.PI, false);
this._isEmpty = false;
}
_drawCurve(_a) {
var color = _a.color, curve = _a.curve;
var ctx = this._ctx;
var widthDelta = curve.endWidth - curve.startWidth;
var drawSteps = Math.floor(curve.length()) * 2;
ctx.beginPath();
ctx.fillStyle = color;
for (var i = 0; i < drawSteps; i += 1) {
var t = i / drawSteps;
var tt = t * t;
var ttt = tt * t;
var u = 1 - t;
var uu = u * u;
var uuu = uu * u;
var x = uuu * curve.startPoint.x;
x += 3 * uu * t * curve.control1.x;
x += 3 * u * tt * curve.control2.x;
x += ttt * curve.endPoint.x;
var y = uuu * curve.startPoint.y;
y += 3 * uu * t * curve.control1.y;
y += 3 * u * tt * curve.control2.y;
y += ttt * curve.endPoint.y;
var width = curve.startWidth + (ttt * widthDelta);
this._drawCurveSegment(x, y, width);
}
ctx.closePath();
ctx.fill();
}
_drawDot(_a) {
var color = _a.color, point = _a.point;
var ctx = this._ctx;
var width = typeof this.dotSize === 'function' ? this.dotSize() : this.dotSize;
ctx.beginPath();
this._drawCurveSegment(point.x, point.y, width);
ctx.closePath();
ctx.fillStyle = color;
ctx.fill();
}
_fromData(pointGroups, drawCurve, drawDot) {
for (var _i = 0, pointGroups_1 = pointGroups; _i < pointGroups_1.length; _i++) {
var group = pointGroups_1[_i];
var color = group.color, points = group.points;
if (points.length > 1) {
for (var j = 0; j < points.length; j += 1) {
var basicPoint = points[j];
var point = new Point(basicPoint.x, basicPoint.y, basicPoint.time);
this.penColor = color;
if (j === 0) {
this._reset();
}
var curve = this._addPoint(point);
if (curve) {
drawCurve({ color: color, curve: curve });
}
}
}
else {
this._reset();
drawDot({
color: color,
point: points[0]
});
}
}
}
_toSVG() {
var _this = this;
var pointGroups = this._data;
var ratio = Math.max(window.devicePixelRatio || 1, 1);
var minX = 0;
var minY = 0;
var maxX = this.canvas.width / ratio;
var maxY = this.canvas.height / ratio;
var svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
svg.setAttribute('width', this.canvas.width.toString());
svg.setAttribute('height', this.canvas.height.toString());
this._fromData(pointGroups, function (_a) {
var color = _a.color, curve = _a.curve;
var path = document.createElement('path');
if (!isNaN(curve.control1.x) &&
!isNaN(curve.control1.y) &&
!isNaN(curve.control2.x) &&
!isNaN(curve.control2.y)) {
var attr = "M " + curve.startPoint.x.toFixed(3) + "," + curve.startPoint.y.toFixed(3) + " "
+ ("C " + curve.control1.x.toFixed(3) + "," + curve.control1.y.toFixed(3) + " ")
+ (curve.control2.x.toFixed(3) + "," + curve.control2.y.toFixed(3) + " ")
+ (curve.endPoint.x.toFixed(3) + "," + curve.endPoint.y.toFixed(3));
path.setAttribute('d', attr);
path.setAttribute('stroke-width', (curve.endWidth * 2.25).toFixed(3));
path.setAttribute('stroke', color);
path.setAttribute('fill', 'none');
path.setAttribute('stroke-linecap', 'round');
svg.appendChild(path);
}
}, function (_a) {
var color = _a.color, point = _a.point;
var circle = document.createElement('circle');
var dotSize = typeof _this.dotSize === 'function' ? _this.dotSize() : _this.dotSize;
circle.setAttribute('r', dotSize.toString());
circle.setAttribute('cx', point.x.toString());
circle.setAttribute('cy', point.y.toString());
circle.setAttribute('fill', color);
svg.appendChild(circle);
});
var prefix = 'data:image/svg+xml;base64,';
var header = '<svg'
+ ' xmlns="http://www.w3.org/2000/svg"'
+ ' xmlns:xlink="http://www.w3.org/1999/xlink"'
+ (" viewBox=\"" + minX + " " + minY + " " + maxX + " " + maxY + "\"")
+ (" width=\"" + maxX + "\"")
+ (" height=\"" + maxY + "\"")
+ '>';
var body = svg.innerHTML;
if (body === undefined) {
var dummy = document.createElement('dummy');
var nodes = svg.childNodes;
dummy.innerHTML = '';
for (var i = 0; i < nodes.length; i += 1) {
dummy.appendChild(nodes[i].cloneNode(true));
}
body = dummy.innerHTML;
}
var footer = '</svg>';
var data = header + body + footer;
return prefix + btoa(data);
}
}