tor-browser

common.sub.js (6332B)

---

function makeCanvas() {
   return new Promise(resolve => {
       var testCanvas = document.createElement("canvas");
       testCanvas.width = 20;
       testCanvas.height = 20;
       var testCtx = testCanvas.getContext("2d");
       testCtx.fillStyle = "rgb(255, 0, 0)";
       testCtx.fillRect(0, 0, 10, 10);
       testCtx.fillStyle = "rgb(0, 255, 0)";
       testCtx.fillRect(10, 0, 10, 10);
       testCtx.fillStyle = "rgb(0, 0, 255)";
       testCtx.fillRect(0, 10, 10, 10);
       testCtx.fillStyle = "rgb(0, 0, 0)";
       testCtx.fillRect(10, 10, 10, 10);
       resolve(testCanvas);
   });
}

function makeOffscreenCanvas() {
   return new Promise(resolve => {
       let canvas = new OffscreenCanvas(20, 20);
       var testCtx = canvas.getContext("2d");
       testCtx.fillStyle = "rgb(255, 0, 0)";
       testCtx.fillRect(0, 0, 10, 10);
       testCtx.fillStyle = "rgb(0, 255, 0)";
       testCtx.fillRect(10, 0, 10, 10);
       testCtx.fillStyle = "rgb(0, 0, 255)";
       testCtx.fillRect(0, 10, 10, 10);
       testCtx.fillStyle = "rgb(0, 0, 0)";
       testCtx.fillRect(10, 10, 10, 10);
       resolve(canvas);
   });
}

function makeMakeVideo(src) {
   return function () {
       return new Promise(function(resolve, reject) {
           var video = document.createElement("video");
           video.oncanplaythrough = function() {
               resolve(video);
           };
           video.onerror = reject;

           // preload=auto is required to ensure a frame is available once
           // canplaythrough is fired. The default of preload=metadata does not
           // gaurantee this.
           video.preload = "auto";
           video.src = getVideoURI(src);

           // Prevent WebKit from garbage collecting event handlers.
           window._video = video;
       });
   }
}

function makeVideo() {
 return makeMakeVideo("/images/pattern")();
}

var imageBitmapDataUrlVideoPromise = self.GLOBAL && self.GLOBAL.isWorker()
   // /common/media.js can't load in a Worker so we don't have getVideoURI
   ? null
   : fetch(getVideoURI("/images/pattern"))
   .then(response => Promise.all([response.headers.get("Content-Type"), response.arrayBuffer()]))
   .then(([type, data]) => {
       return new Promise(function(resolve, reject) {
           var video = document.createElement("video");
           video.oncanplaythrough = function() {
               resolve(video);
           };
           video.onerror = reject;

           var encoded = btoa(String.fromCodePoint(...new Uint8Array(data)));
           var dataUrl = `data:${type};base64,${encoded}`;

           // preload=auto is required to ensure a frame is available once
           // canplaythrough is fired. The default of preload=metadata does not
           // gaurantee this.
           video.preload = "auto";
           video.src = dataUrl;

           // Prevent WebKit from garbage collecting event handlers.
           window._dataVideo = video;
       });
   });

function makeDataUrlVideo() {
   return imageBitmapDataUrlVideoPromise;
}

function makeMakeHTMLImage(src) {
   return function() {
       return new Promise((resolve, reject) => {
           var img = new Image();
           img.onload = function() {
               resolve(img);
           };
           img.onerror = reject;
           img.src = src;
       });
   }
}

function makeMakeSVGImage(src) {
   return function() {
       return new Promise((resolve, reject) => {
           var image = document.createElementNS("http://www.w3.org/2000/svg", "image");
           image.onload = () => resolve(image);
           image.onerror = reject;
           image.setAttribute("externalResourcesRequired", "true");
           image.setAttributeNS("http://www.w3.org/1999/xlink", 'xlink:href', src);
           document.body.appendChild(image);
       });
   }
}

function makeImageData() {
   return new Promise(function(resolve, reject) {
       var width = 20, height = 20;
       var imgData = new ImageData(width, height);
       for (var i = 0; i < width * height * 4; i += 4) {
           imgData.data[i] = 0;
           imgData.data[i + 1] = 0;
           imgData.data[i + 2] = 0;
           imgData.data[i + 3] = 255; //alpha channel: 255
       }
       var halfWidth = width / 2;
       var halfHeight = height / 2;
       // initialize to R, G, B, Black, with each one 10*10 pixels
       for (var i = 0; i < halfHeight; i++)
           for (var j = 0; j < halfWidth; j++)
               imgData.data[i * width * 4 + j * 4] = 255;
       for (var i = 0; i < halfHeight; i++)
           for (var j = halfWidth; j < width; j++)
               imgData.data[i * width * 4 + j * 4 + 1] = 255;
       for (var i = halfHeight; i < height; i++)
           for (var j = 0; j < halfWidth; j++)
               imgData.data[i * width * 4 + j * 4 + 2] = 255;
       resolve(imgData);
   });
}

function makeImageBitmap() {
   return makeCanvas().then(canvas => {
       return createImageBitmap(canvas);
   });
}

function makeBlob(src) {
   return function () {
       return new Promise(function(resolve, reject) {
           var xhr = new XMLHttpRequest();
           xhr.open("GET", src);
           xhr.responseType = 'blob';
           xhr.send();
           xhr.onload = function() {
               resolve(xhr.response);
           };
       });
   }
}

var imageSourceTypes = [
   { name: 'an HTMLCanvasElement', factory: makeCanvas },
   { name: 'an HTMLVideoElement',  factory: makeVideo },
   { name: 'an HTMLVideoElement from a data URL', factory: makeDataUrlVideo },
   { name: 'a bitmap HTMLImageElement', factory: makeMakeHTMLImage("/images/pattern.png") },
   { name: 'a vector HTMLImageElement', factory: makeMakeHTMLImage("/images/pattern.svg") },
   { name: 'a bitmap SVGImageElement', factory: makeMakeSVGImage("/images/pattern.png") },
   { name: 'a vector SVGImageElement', factory: makeMakeSVGImage("/images/pattern.svg") },
   { name: 'an OffscreenCanvas',   factory: makeOffscreenCanvas },
   { name: 'an ImageData',         factory: makeImageData },
   { name: 'an ImageBitmap',       factory: makeImageBitmap },
   { name: 'a Blob',               factory: makeBlob("/images/pattern.png") },
];