120 lines
2.2 KiB
JavaScript
120 lines
2.2 KiB
JavaScript
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'use strict';
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/**
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* Expose `Progress`.
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*/
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module.exports = Progress;
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/**
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* Initialize a new `Progress` indicator.
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*/
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function Progress() {
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this.percent = 0;
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this.size(0);
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this.fontSize(11);
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this.font('helvetica, arial, sans-serif');
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}
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/**
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* Set progress size to `size`.
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*
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* @api public
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* @param {number} size
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* @return {Progress} Progress instance.
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*/
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Progress.prototype.size = function(size) {
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this._size = size;
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return this;
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};
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/**
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* Set text to `text`.
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*
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* @api public
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* @param {string} text
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* @return {Progress} Progress instance.
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*/
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Progress.prototype.text = function(text) {
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this._text = text;
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return this;
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};
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/**
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* Set font size to `size`.
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*
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* @api public
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* @param {number} size
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* @return {Progress} Progress instance.
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*/
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Progress.prototype.fontSize = function(size) {
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this._fontSize = size;
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return this;
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};
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/**
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* Set font to `family`.
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*
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* @param {string} family
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* @return {Progress} Progress instance.
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*/
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Progress.prototype.font = function(family) {
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this._font = family;
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return this;
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};
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/**
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* Update percentage to `n`.
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*
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* @param {number} n
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* @return {Progress} Progress instance.
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*/
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Progress.prototype.update = function(n) {
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this.percent = n;
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return this;
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};
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/**
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* Draw on `ctx`.
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*
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* @param {CanvasRenderingContext2d} ctx
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* @return {Progress} Progress instance.
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*/
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Progress.prototype.draw = function(ctx) {
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try {
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var percent = Math.min(this.percent, 100);
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var size = this._size;
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var half = size / 2;
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var x = half;
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var y = half;
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var rad = half - 1;
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var fontSize = this._fontSize;
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ctx.font = fontSize + 'px ' + this._font;
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var angle = Math.PI * 2 * (percent / 100);
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ctx.clearRect(0, 0, size, size);
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// outer circle
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ctx.strokeStyle = '#9f9f9f';
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ctx.beginPath();
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ctx.arc(x, y, rad, 0, angle, false);
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ctx.stroke();
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// inner circle
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ctx.strokeStyle = '#eee';
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ctx.beginPath();
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ctx.arc(x, y, rad - 1, 0, angle, true);
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ctx.stroke();
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// text
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var text = this._text || (percent | 0) + '%';
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var w = ctx.measureText(text).width;
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ctx.fillText(text, x - w / 2 + 1, y + fontSize / 2 - 1);
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} catch (ignore) {
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// don't fail if we can't render progress
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}
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return this;
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};
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