blob: dfd03ddfba49c91e015a4d59e70ae4cc343c50a6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const { Cc, Ci, Cu } = require("chrome");
const AppShellService = Cc["@mozilla.org/appshell/appShellService;1"].
getService(Ci.nsIAppShellService);
const NS = "http://www.w3.org/1999/xhtml";
const COLOR = "rgb(255,255,255)";
/**
* Creates canvas element with a thumbnail of the passed window.
* @param {Window} window
* @returns {Element}
*/
function getThumbnailCanvasForWindow(window) {
let aspectRatio = 0.5625; // 16:9
let thumbnail = AppShellService.hiddenDOMWindow.document
.createElementNS(NS, "canvas");
thumbnail.mozOpaque = true;
thumbnail.width = Math.ceil(window.screen.availWidth / 5.75);
thumbnail.height = Math.round(thumbnail.width * aspectRatio);
let ctx = thumbnail.getContext("2d");
let snippetWidth = window.innerWidth * .6;
let scale = thumbnail.width / snippetWidth;
ctx.scale(scale, scale);
ctx.drawWindow(window, window.scrollX, window.scrollY, snippetWidth,
snippetWidth * aspectRatio, COLOR);
return thumbnail;
}
exports.getThumbnailCanvasForWindow = getThumbnailCanvasForWindow;
/**
* Creates Base64 encoded data URI of the thumbnail for the passed window.
* @param {Window} window
* @returns {String}
*/
exports.getThumbnailURIForWindow = function getThumbnailURIForWindow(window) {
return getThumbnailCanvasForWindow(window).toDataURL()
};
|
