<!DOCTYPE html>
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<html class="no-js">
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<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title></title>
<meta name="description" content="">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" target="_blank" rel="external nofollow"
integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
<style>
* {
margin: 0;
padding: 0;
}
html,
body {
width: 100%;
height: 100%;
text-align: center;
}
canvas {
max-width: 100%;
border: 2px dotted #ccc;
}
</style>
</head>
<body>
<script>
/**
* @github https://github.com/929467350/draw
* @description 手寫簽字版
*/
(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
typeof define === 'function' && define.amd ? define(factory) :
(global = global || self, global.Draw = factory());
}(this, (function () {
'use strict';
var classCallCheck = function (instance, Constructor) {
if (!(instance instanceof Constructor)) {
throw new TypeError("Cannot call a class as a function");
}
};
var createClass = function () {
function defineProperties(target, props) {
for (var i = 0; i < props.length; i++) {
var descriptor = props[i];
descriptor.enumerable = descriptor.enumerable || false;
descriptor.configurable = true;
if ("value" in descriptor) descriptor.writable = true;
Object.defineProperty(target, descriptor.key, descriptor);
}
}
return function (Constructor, protoProps, staticProps) {
if (protoProps) defineProperties(Constructor.prototype, protoProps);
if (staticProps) defineProperties(Constructor, staticProps);
return Constructor;
};
}();
var Draw = function () {
function Draw() {
var params = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
classCallCheck(this, Draw);
this.el = params.el || document.createElement('canvas');
this.state = {
undopath: [],
index: -1,
old: void 0,
isStart: false,
width: params.width || 400,
height: params.height || 400,
lineWidth: params.lineWidth || 1,
isTouch: 'ontouchstart' in window,
strokeStyle: params.strokeStyle || '#333333'
};
var _state = this.state,
width = _state.width,
height = _state.height,
lineWidth = _state.lineWidth;
this.el.width = width * 2;
this.el.height = height * 2;
document.body.appendChild(this.el);
this.ctx = this.el.getContext('2d');
this.ctx.scale(2, 2);
this.ctx.lineWidth = lineWidth;
this.ctx.lineJoin = 'round';
this.ctx.lineCap = 'round';
this.init();
}
createClass(Draw, [{
key: 'onStart',
value: function onStart() {
++this.state.index;
this.state.isStart = true;
}
}, {
key: 'onMove',
value: function onMove(e) {
e.preventDefault();
if (!this.state.isStart) return;
var pos = this.pos(e);
var index = this.state.index;
this.ctx.strokeStyle = this.state.strokeStyle;
if (this.state.old) {
this.ctx.beginPath();
this.ctx.moveTo(this.state.old.x, this.state.old.y);
this.ctx.lineTo(pos.x, pos.y);
this.ctx.stroke();
}
this.state.old = pos;
if (this.state.undopath[index]) {
this.state.undopath[index].push({
x: this.state.old.x,
y: this.state.old.y
});
} else {
this.state.undopath[index] = [{
x: this.state.old.x,
y: this.state.old.y,
strokeStyle: this.ctx.strokeStyle,
lineWidth: this.ctx.lineWidth
}];
}
}
}, {
key: 'onEnd',
value: function onEnd() {
this.state.old = void 0;
this.state.isStart = false;
}
}, {
key: 'pos',
value: function pos(e) {
var x = 0,
y = 0;
if (e.touches) {
x = e.touches[0].pageX;
y = e.touches[0].pageY;
} else {
x = e.offsetX / 2;
y = e.offsetY / 2;
}
return {
x: x,
y: y
};
}
}, {
key: 'ouput',
value: function ouput() {
// 輸出圖檔
return this.el.toDataURL();
}
}, {
key: 'init',
value: function init() {
// 綁定事件
var isTouch = this.state.isTouch;
this.el.addEventListener(isTouch ? 'touchstart' : 'mousedown', this.onStart.bind(this), false);
this.el.addEventListener(isTouch ? 'touchmove' : 'mousemove', this.onMove.bind(this), false);
this.el.addEventListener(isTouch ? 'touchend' : 'mouseup', this.onEnd.bind(this), false);
this.el.addEventListener(isTouch ? 'touchcancel' : 'mouseout', this.onEnd.bind(this), false);
}
}, {
key: 'destroyed',
value: function destroyed() {
if (this.el) {
var isTouch = this.state.isTouch;
this.el.removeEventListener(isTouch ? 'touchstart' : 'mousedown', this.onStart.bind(this));
this.el.removeEventListener(isTouch ? 'touchmove' : 'mousemove', this.onMove.bind(this));
this.el.removeEventListener(isTouch ? 'touchend' : 'mouseup', this.onEnd.bind(this));
this.el.removeEventListener(isTouch ? 'touchcancel' : 'mouseout', this.onEnd.bind(this));
}
}
}, {
key: 'clear',
value: function clear() {
// 清除畫布
this.state.index = -1;
this.state.undopath = [];
this.ctx.clearRect(0, 0, this.el.width, this.el.height);
}
}, {
key: 'undo',
value: function undo() {
// 撤銷
this.state.index >= 0 && --this.state.index;
this.state.undopath.pop();
var undopath = this.state.undopath;
this.ctx.clearRect(0, 0, this.el.width, this.el.height);
if (undopath.length > 0) {
this.ctx.beginPath();
for (var z = 0; z < undopath.length; ++z) {
this.ctx.moveTo(undopath[z][0].x, undopath[z][0].y);
this.ctx.lineWidth = undopath[z][0].lineWidth;
this.ctx.strokeStyle = undopath[z][0].strokeStyle;
for (var i = 0; i < undopath[z].length; ++i) {
this.ctx.lineTo(undopath[z][i].x, undopath[z][i].y);
}
}
this.ctx.stroke();
this.ctx.closePath();
} else {
this.state.undopath = [];
}
}
}]);
return Draw;
}();
return Draw;
})));
</script>
<!--[if lt IE 7]>
<p class="browsehappy">You are using an <strong>outdated</strong> browser. Please <a href="#" target="_blank" rel="external nofollow" >upgrade your browser</a> to improve your experience.</p>
<![endif]-->
<script>
//初始化
var sign = new Draw({
// canvas:document.getElementById('canvas'),
lineWidth: 1, // 線條寬度
width: 400, // canvas 寬
height: 400, //canvas 高
strokeStyle: '#333333' // 線條顔色
});
// function downQrcode(url) {
// let arr = url.split(","),
// mime = arr[0].match(/:(.*?);/)[1],
// bstr = atob(arr[1]),
// n = bstr.length,
// u8arr = new Uint8Array(n);
// while (n--) {
// u8arr[n] = bstr.charCodeAt(n);
// }
// var blob = new Blob([u8arr], { type: mime });
// const a = document.createElement("a");
// const event = new MouseEvent("click");
// a.download = "二維碼";
// a.href = URL.createObjectURL(blob);
// a.target = "_blank";
// a.dispatchEvent(event);
// }
window.onload = function () {
// 點選輸出圖檔
document.querySelector('.ouput').onclick = function () {
var img = new Image();
img.style.width = '200px';
img.src = sign.ouput();
// downQrcode(sign.ouput())
img.onload = function () {
document.body.appendChild(img);
}
document.querySelector('img') && document.querySelector('img').remove();
}
// 點選清除
document.querySelector('.clear').onclick = function () {
sign.clear();
}
// 點選撤銷
document.querySelector('.undo').onclick = function () {
sign.undo();
}
}
</script>
<div class="buttons">
<button type="button" class="btn btn-primary ouput">生成圖檔</button>
<button type="button" class="btn btn-light undo">撤銷</button>
<button type="button" class="btn btn-light clear">清除畫布</button>
</div>
</body>
</html>
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