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author | Rogan Creswick <creswick@galois.com> | 2012-03-30 17:07:02 -0700 |
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committer | Rogan Creswick <creswick@galois.com> | 2012-03-30 17:07:02 -0700 |
commit | f6ab6622aab00fe7c2f4c3dc41f786ebbe0f0d73 (patch) | |
tree | 870111038542cd27153e1396ebdc063573249689 /tools/addon-sdk-1.5/packages/api-utils/lib/utils/thumbnail.js |
initial revision
Diffstat (limited to 'tools/addon-sdk-1.5/packages/api-utils/lib/utils/thumbnail.js')
-rw-r--r-- | tools/addon-sdk-1.5/packages/api-utils/lib/utils/thumbnail.js | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/tools/addon-sdk-1.5/packages/api-utils/lib/utils/thumbnail.js b/tools/addon-sdk-1.5/packages/api-utils/lib/utils/thumbnail.js new file mode 100644 index 0000000..dfd03dd --- /dev/null +++ b/tools/addon-sdk-1.5/packages/api-utils/lib/utils/thumbnail.js @@ -0,0 +1,43 @@ +/* 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() +}; |