gecko-dev/dom/manifest/ManifestIcons.jsm

86 строки
2.5 KiB
JavaScript

"use strict";
const {
utils: Cu,
classes: Cc,
interfaces: Ci
} = Components;
Cu.import("resource://gre/modules/PromiseMessage.jsm");
this.ManifestIcons = {
async browserFetchIcon(aBrowser, manifest, iconSize) {
const msgKey = "DOM:WebManifest:fetchIcon";
const mm = aBrowser.messageManager;
const {data: {success, result}} =
await PromiseMessage.send(mm, msgKey, {manifest, iconSize});
if (!success) {
throw result;
}
return result;
},
async contentFetchIcon(aWindow, manifest, iconSize) {
return await getIcon(aWindow, toIconArray(manifest.icons), iconSize);
}
};
function parseIconSize(size) {
if (size === "any" || size === "") {
// We want icons without size specified to sorted
// as the largest available icons
return Number.MAX_SAFE_INTEGER;
}
// 100x100 will parse as 100
return parseInt(size, 10);
}
// Create an array of icons sorted by their size
function toIconArray(icons) {
const iconBySize = [];
icons.forEach(icon => {
const sizes = ("sizes" in icon) ? icon.sizes : "";
sizes.split(" ").forEach(size => {
iconBySize.push({src: icon.src, size: parseIconSize(size)});
});
});
return iconBySize.sort((a, b) => a.size - b.size);
}
async function getIcon(aWindow, icons, expectedSize) {
if (!icons.length) {
throw new Error("Could not find valid icon");
}
// We start trying the smallest icon that is larger than the requested
// size and go up to the largest icon if they fail, if all those fail
// go back down to the smallest
let index = icons.findIndex(icon => icon.size >= expectedSize);
if (index === -1) {
index = icons.length - 1;
}
return fetchIcon(aWindow, icons[index].src).catch(err => {
// Remove all icons with the failed source, the same source
// may have been used for multiple sizes
icons = icons.filter(x => x.src === icons[index].src);
return getIcon(aWindow, icons, expectedSize);
});
}
function fetchIcon(aWindow, src) {
const manifestURL = new aWindow.URL(src);
const request = new aWindow.Request(manifestURL, {mode: "cors"});
request.overrideContentPolicyType(Ci.nsIContentPolicy.TYPE_WEB_MANIFEST);
return aWindow.fetch(request)
.then(response => response.blob())
.then(blob => new Promise((resolve, reject) => {
var reader = new FileReader();
reader.onloadend = () => resolve(reader.result);
reader.onerror = reject;
reader.readAsDataURL(blob);
}));
}
this.EXPORTED_SYMBOLS = ["ManifestIcons"]; // jshint ignore:line