browser/components/customizableui/src/ScrollbarSampler.jsm@8bccb770b82d (annotated)
browser/components/customizableui/src/ScrollbarSampler.jsm
Wed, 31 Dec 2014 13:27:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 13:27:57 +0100
- branch
- TOR_BUG_3246
- changeset 6
- 8bccb770b82d
- permissions
- -rw-r--r--
Ignore runtime configuration files generated during quality assurance.
| michael@0 | 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 4 | |
| michael@0 | 5 | "use strict"; |
| michael@0 | 6 | |
| michael@0 | 7 | this.EXPORTED_SYMBOLS = ["ScrollbarSampler"]; |
| michael@0 | 8 | |
| michael@0 | 9 | const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components; |
| michael@0 | 10 | |
| michael@0 | 11 | Cu.import("resource://gre/modules/Services.jsm"); |
| michael@0 | 12 | Cu.import("resource://gre/modules/XPCOMUtils.jsm"); |
| michael@0 | 13 | XPCOMUtils.defineLazyModuleGetter(this, "Promise", |
| michael@0 | 14 | "resource://gre/modules/Promise.jsm"); |
| michael@0 | 15 | |
| michael@0 | 16 | let gSystemScrollbarWidth = null; |
| michael@0 | 17 | |
| michael@0 | 18 | this.ScrollbarSampler = { |
| michael@0 | 19 | getSystemScrollbarWidth: function() { |
| michael@0 | 20 | let deferred = Promise.defer(); |
| michael@0 | 21 | |
| michael@0 | 22 | if (gSystemScrollbarWidth !== null) { |
| michael@0 | 23 | deferred.resolve(gSystemScrollbarWidth); |
| michael@0 | 24 | return deferred.promise; |
| michael@0 | 25 | } |
| michael@0 | 26 | |
| michael@0 | 27 | this._sampleSystemScrollbarWidth().then(function(systemScrollbarWidth) { |
| michael@0 | 28 | gSystemScrollbarWidth = systemScrollbarWidth; |
| michael@0 | 29 | deferred.resolve(gSystemScrollbarWidth); |
| michael@0 | 30 | }); |
| michael@0 | 31 | return deferred.promise; |
| michael@0 | 32 | }, |
| michael@0 | 33 | |
| michael@0 | 34 | resetSystemScrollbarWidth: function() { |
| michael@0 | 35 | gSystemScrollbarWidth = null; |
| michael@0 | 36 | }, |
| michael@0 | 37 | |
| michael@0 | 38 | _sampleSystemScrollbarWidth: function() { |
| michael@0 | 39 | let deferred = Promise.defer(); |
| michael@0 | 40 | let hwin = Services.appShell.hiddenDOMWindow; |
| michael@0 | 41 | let hdoc = hwin.document.documentElement; |
| michael@0 | 42 | let iframe = hwin.document.createElementNS("http://www.w3.org/1999/xhtml", |
| michael@0 | 43 | "html:iframe"); |
| michael@0 | 44 | iframe.setAttribute("srcdoc", '<body style="overflow-y: scroll"></body>'); |
| michael@0 | 45 | hdoc.appendChild(iframe); |
| michael@0 | 46 | |
| michael@0 | 47 | let cwindow = iframe.contentWindow; |
| michael@0 | 48 | let utils = cwindow.QueryInterface(Ci.nsIInterfaceRequestor) |
| michael@0 | 49 | .getInterface(Ci.nsIDOMWindowUtils); |
| michael@0 | 50 | |
| michael@0 | 51 | cwindow.addEventListener("load", function onLoad(aEvent) { |
| michael@0 | 52 | cwindow.removeEventListener("load", onLoad); |
| michael@0 | 53 | let sbWidth = {}; |
| michael@0 | 54 | try { |
| michael@0 | 55 | utils.getScrollbarSize(true, sbWidth, {}); |
| michael@0 | 56 | } catch(e) { |
| michael@0 | 57 | Cu.reportError("Could not sample scrollbar size: " + e + " -- " + |
| michael@0 | 58 | e.stack); |
| michael@0 | 59 | sbWidth.value = 0; |
| michael@0 | 60 | } |
| michael@0 | 61 | // Minimum width of 10 so that we have enough padding: |
| michael@0 | 62 | sbWidth.value = Math.max(sbWidth.value, 10); |
| michael@0 | 63 | deferred.resolve(sbWidth.value); |
| michael@0 | 64 | iframe.remove(); |
| michael@0 | 65 | }); |
| michael@0 | 66 | |
| michael@0 | 67 | return deferred.promise; |
| michael@0 | 68 | } |
| michael@0 | 69 | }; |
| michael@0 | 70 | Object.freeze(this.ScrollbarSampler); |
