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/*
This file is part of TALER
(C) 2016 INRIA
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
import {
Badge,
} from "../wallet";
/**
* Polyfill for requestAnimationFrame, which
* doesn't work from a background page.
*/
function rAF(cb: (ts: number) => void) {
window.setTimeout(() => {
cb(performance.now());
}, 100 /* 100 ms delay between frames */);
}
/**
* Badge for Chrome that renders a Taler logo with a rotating ring if some
* background activity is happening.
*/
export class ChromeBadge implements Badge {
private canvas: HTMLCanvasElement;
private ctx: CanvasRenderingContext2D;
/**
* True if animation running. The animation
* might still be running even if we're not busy anymore,
* just to transition to the "normal" state in a animated way.
*/
private animationRunning: boolean = false;
/**
* Is the wallet still busy? Note that we do not stop the
* animation immediately when the wallet goes idle, but
* instead slowly close the gap.
*/
private isBusy: boolean = false;
/**
* Current rotation angle, ranges from 0 to rotationAngleMax.
*/
private rotationAngle: number = 0;
/**
* While animating, how wide is the current gap in the circle?
* Ranges from 0 to openMax.
*/
private gapWidth: number = 0;
/**
* Maximum value for our rotationAngle, corresponds to 2 Pi.
*/
static rotationAngleMax = 1000;
/**
* How fast do we rotate? Given in rotation angle (relative to rotationAngleMax) per millisecond.
*/
static rotationSpeed = 0.5;
/**
* How fast to we open? Given in rotation angle (relative to rotationAngleMax) per millisecond.
*/
static openSpeed = 0.15;
/**
* How fast to we close? Given as a multiplication factor per frame update.
*/
static closeSpeed = 0.7;
/**
* How far do we open? Given relative to rotationAngleMax.
*/
static openMax = 100;
constructor(window?: Window) {
// Allow injecting another window for testing
const bg = window || chrome.extension.getBackgroundPage();
if (!bg) {
throw Error("no window available");
}
this.canvas = bg.document.createElement("canvas");
// Note: changing the width here means changing the font
// size in draw() as well!
this.canvas.width = 32;
this.canvas.height = 32;
this.ctx = this.canvas.getContext("2d")!;
this.draw();
}
/**
* Draw the badge based on the current state.
*/
private draw() {
this.ctx.setTransform(1, 0, 0, 1, 0, 0);
this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
this.ctx.translate(this.canvas.width / 2, this.canvas.height / 2);
this.ctx.beginPath();
this.ctx.arc(0, 0, this.canvas.width / 2 - 2, 0, 2 * Math.PI);
this.ctx.fillStyle = "white";
this.ctx.fill();
// move into the center, off by 2 for aligning the "T" with the bottom
// of the circle.
this.ctx.translate(0, 2);
// pick sans-serif font; note: 14px is based on the 32px width above!
this.ctx.font = "bold 24px sans-serif";
// draw the "T" perfectly centered (x and y) to the current position
this.ctx.textAlign = "center";
this.ctx.textBaseline = "middle";
this.ctx.fillStyle = "black";
this.ctx.fillText("T", 0, 0);
// now move really into the center
this.ctx.translate(0, -2);
// start drawing the (possibly open) circle
this.ctx.beginPath();
this.ctx.lineWidth = 2.5;
if (this.animationRunning) {
/* Draw circle around the "T" with an opening of this.gapWidth */
const aMax = ChromeBadge.rotationAngleMax;
const startAngle = this.rotationAngle / aMax * Math.PI * 2;
const stopAngle = ((this.rotationAngle + aMax - this.gapWidth) / aMax) * Math.PI * 2;
this.ctx.arc(0, 0, this.canvas.width / 2 - 2, /* radius */ startAngle, stopAngle, false);
} else {
/* Draw full circle */
this.ctx.arc(0, 0,
this.canvas.width / 2 - 2, /* radius */
0,
Math.PI * 2,
false);
}
this.ctx.stroke();
// go back to the origin
this.ctx.translate(-this.canvas.width / 2, -this.canvas.height / 2);
// Allow running outside the extension for testing
// tslint:disable-next-line:no-string-literal
if (window["chrome"] && window.chrome["browserAction"]) {
try {
const imageData = this.ctx.getImageData(0,
0,
this.canvas.width,
this.canvas.height);
chrome.browserAction.setIcon({imageData});
} catch (e) {
// Might fail if browser has over-eager canvas fingerprinting countermeasures.
// There's nothing we can do then ...
}
}
}
private animate() {
if (this.animationRunning) {
return;
}
this.animationRunning = true;
let start: number|undefined;
const step = (timestamp: number) => {
if (!this.animationRunning) {
return;
}
if (!start) {
start = timestamp;
}
if (!this.isBusy && 0 === this.gapWidth) {
// stop if we're close enough to origin
this.rotationAngle = 0;
} else {
this.rotationAngle = (this.rotationAngle + (timestamp - start) *
ChromeBadge.rotationSpeed) % ChromeBadge.rotationAngleMax;
}
if (this.isBusy) {
if (this.gapWidth < ChromeBadge.openMax) {
this.gapWidth += ChromeBadge.openSpeed * (timestamp - start);
}
if (this.gapWidth > ChromeBadge.openMax) {
this.gapWidth = ChromeBadge.openMax;
}
} else {
if (this.gapWidth > 0) {
this.gapWidth--;
this.gapWidth *= ChromeBadge.closeSpeed;
}
}
if (this.isBusy || this.gapWidth > 0) {
start = timestamp;
rAF(step);
} else {
this.animationRunning = false;
}
this.draw();
};
rAF(step);
}
startBusy() {
if (this.isBusy) {
return;
}
this.isBusy = true;
this.animate();
}
stopBusy() {
this.isBusy = false;
}
}
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