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Diffstat (limited to 'browser/modules/WindowsPreviewPerTab.jsm')
| -rw-r--r-- | browser/modules/WindowsPreviewPerTab.jsm | 862 |
1 files changed, 862 insertions, 0 deletions
diff --git a/browser/modules/WindowsPreviewPerTab.jsm b/browser/modules/WindowsPreviewPerTab.jsm new file mode 100644 index 000000000..6586b5d3b --- /dev/null +++ b/browser/modules/WindowsPreviewPerTab.jsm @@ -0,0 +1,862 @@ +/* vim: se cin sw=2 ts=2 et filetype=javascript : + * 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/. */ +/* + * This module implements the front end behavior for AeroPeek. Starting in + * Windows Vista, the taskbar began showing live thumbnail previews of windows + * when the user hovered over the window icon in the taskbar. Starting with + * Windows 7, the taskbar allows an application to expose its tabbed interface + * in the taskbar by showing thumbnail previews rather than the default window + * preview. Additionally, when a user hovers over a thumbnail (tab or window), + * they are shown a live preview of the window (or tab + its containing window). + * + * In Windows 7, a title, icon, close button and optional toolbar are shown for + * each preview. This feature does not make use of the toolbar. For window + * previews, the title is the window title and the icon the window icon. For + * tab previews, the title is the page title and the page's favicon. In both + * cases, the close button "does the right thing." + * + * The primary objects behind this feature are nsITaskbarTabPreview and + * nsITaskbarPreviewController. Each preview has a controller. The controller + * responds to the user's interactions on the taskbar and provides the required + * data to the preview for determining the size of the tab and thumbnail. The + * PreviewController class implements this interface. The preview will request + * the controller to provide a thumbnail or preview when the user interacts with + * the taskbar. To reduce the overhead of drawing the tab area, the controller + * implementation caches the tab's contents in a <canvas> element. If no + * previews or thumbnails have been requested for some time, the controller will + * discard its cached tab contents. + * + * Screen real estate is limited so when there are too many thumbnails to fit + * on the screen, the taskbar stops displaying thumbnails and instead displays + * just the title, icon and close button in a similar fashion to previous + * versions of the taskbar. If there are still too many previews to fit on the + * screen, the taskbar resorts to a scroll up and scroll down button pair to let + * the user scroll through the list of tabs. Since this is undoubtedly + * inconvenient for users with many tabs, the AeroPeek objects turns off all of + * the tab previews. This tells the taskbar to revert to one preview per window. + * If the number of tabs falls below this magic threshold, the preview-per-tab + * behavior returns. There is no reliable way to determine when the scroll + * buttons appear on the taskbar, so a magic pref-controlled number determines + * when this threshold has been crossed. + */ +this.EXPORTED_SYMBOLS = ["AeroPeek"]; + +const Cc = Components.classes; +const Ci = Components.interfaces; +const Cu = Components.utils; + +Cu.import("resource://gre/modules/NetUtil.jsm"); +Cu.import("resource://gre/modules/PlacesUtils.jsm"); +Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm"); +Cu.import("resource://gre/modules/Services.jsm"); +Cu.import("resource://gre/modules/XPCOMUtils.jsm"); + +// Pref to enable/disable preview-per-tab +const TOGGLE_PREF_NAME = "browser.taskbar.previews.enable"; +// Pref to determine the magic auto-disable threshold +const DISABLE_THRESHOLD_PREF_NAME = "browser.taskbar.previews.max"; +// Pref to control the time in seconds that tab contents live in the cache +const CACHE_EXPIRATION_TIME_PREF_NAME = "browser.taskbar.previews.cachetime"; + +const WINTASKBAR_CONTRACTID = "@mozilla.org/windows-taskbar;1"; + +// Various utility properties +XPCOMUtils.defineLazyServiceGetter(this, "imgTools", + "@mozilla.org/image/tools;1", + "imgITools"); +XPCOMUtils.defineLazyModuleGetter(this, "PageThumbs", + "resource://gre/modules/PageThumbs.jsm"); + +// nsIURI -> imgIContainer +function _imageFromURI(uri, privateMode, callback) { + let channel = NetUtil.newChannel({ + uri: uri, + loadUsingSystemPrincipal: true, + contentPolicyType: Ci.nsIContentPolicy.TYPE_INTERNAL_IMAGE + }); + + try { + channel.QueryInterface(Ci.nsIPrivateBrowsingChannel); + channel.setPrivate(privateMode); + } catch (e) { + // Ignore channels which do not support nsIPrivateBrowsingChannel + } + NetUtil.asyncFetch(channel, function(inputStream, resultCode) { + if (!Components.isSuccessCode(resultCode)) + return; + try { + let out_img = { value: null }; + imgTools.decodeImageData(inputStream, channel.contentType, out_img); + callback(out_img.value); + } catch (e) { + // We failed, so use the default favicon (only if this wasn't the default + // favicon). + let defaultURI = PlacesUtils.favicons.defaultFavicon; + if (!defaultURI.equals(uri)) + _imageFromURI(defaultURI, privateMode, callback); + } + }); +} + +// string? -> imgIContainer +function getFaviconAsImage(iconurl, privateMode, callback) { + if (iconurl) { + _imageFromURI(NetUtil.newURI(iconurl), privateMode, callback); + } else { + _imageFromURI(PlacesUtils.favicons.defaultFavicon, privateMode, callback); + } +} + +// Snaps the given rectangle to be pixel-aligned at the given scale +function snapRectAtScale(r, scale) { + let x = Math.floor(r.x * scale); + let y = Math.floor(r.y * scale); + let width = Math.ceil((r.x + r.width) * scale) - x; + let height = Math.ceil((r.y + r.height) * scale) - y; + + r.x = x / scale; + r.y = y / scale; + r.width = width / scale; + r.height = height / scale; +} + +// PreviewController + +/* + * This class manages the behavior of thumbnails and previews. It has the following + * responsibilities: + * 1) responding to requests from Windows taskbar for a thumbnail or window + * preview. + * 2) listens for dom events that result in a thumbnail or window preview needing + * to be refresh, and communicates this to the taskbar. + * 3) Handles querying and returning to the taskbar new thumbnail or window + * preview images through PageThumbs. + * + * @param win + * The TabWindow (see below) that owns the preview that this controls + * @param tab + * The <tab> that this preview is associated with + */ +function PreviewController(win, tab) { + this.win = win; + this.tab = tab; + this.linkedBrowser = tab.linkedBrowser; + this.preview = this.win.createTabPreview(this); + + this.tab.addEventListener("TabAttrModified", this, false); + + XPCOMUtils.defineLazyGetter(this, "canvasPreview", function () { + let canvas = PageThumbs.createCanvas(); + canvas.mozOpaque = true; + return canvas; + }); +} + +PreviewController.prototype = { + QueryInterface: XPCOMUtils.generateQI([Ci.nsITaskbarPreviewController, + Ci.nsIDOMEventListener]), + + destroy: function () { + this.tab.removeEventListener("TabAttrModified", this, false); + + // Break cycles, otherwise we end up leaking the window with everything + // attached to it. + delete this.win; + delete this.preview; + }, + + get wrappedJSObject() { + return this; + }, + + // Resizes the canvasPreview to 0x0, essentially freeing its memory. + resetCanvasPreview: function () { + this.canvasPreview.width = 0; + this.canvasPreview.height = 0; + }, + + /** + * Set the canvas dimensions. + */ + resizeCanvasPreview: function (aRequestedWidth, aRequestedHeight) { + this.canvasPreview.width = aRequestedWidth; + this.canvasPreview.height = aRequestedHeight; + }, + + + get zoom() { + // Note that winutils.fullZoom accounts for "quantization" of the zoom factor + // from nsIContentViewer due to conversion through appUnits. + // We do -not- want screenPixelsPerCSSPixel here, because that would -also- + // incorporate any scaling that is applied due to hi-dpi resolution options. + return this.tab.linkedBrowser.fullZoom; + }, + + get screenPixelsPerCSSPixel() { + let chromeWin = this.tab.ownerGlobal; + let windowUtils = chromeWin.getInterface(Ci.nsIDOMWindowUtils); + return windowUtils.screenPixelsPerCSSPixel; + }, + + get browserDims() { + return this.tab.linkedBrowser.getBoundingClientRect(); + }, + + cacheBrowserDims: function () { + let dims = this.browserDims; + this._cachedWidth = dims.width; + this._cachedHeight = dims.height; + }, + + testCacheBrowserDims: function () { + let dims = this.browserDims; + return this._cachedWidth == dims.width && + this._cachedHeight == dims.height; + }, + + /** + * Capture a new thumbnail image for this preview. Called by the controller + * in response to a request for a new thumbnail image. + */ + updateCanvasPreview: function (aFullScale, aCallback) { + // Update our cached browser dims so that delayed resize + // events don't trigger another invalidation if this tab becomes active. + this.cacheBrowserDims(); + PageThumbs.captureToCanvas(this.linkedBrowser, this.canvasPreview, + aCallback, { fullScale: aFullScale }); + // If we're updating the canvas, then we're in the middle of a peek so + // don't discard the cache of previews. + AeroPeek.resetCacheTimer(); + }, + + updateTitleAndTooltip: function () { + let title = this.win.tabbrowser.getWindowTitleForBrowser(this.linkedBrowser); + this.preview.title = title; + this.preview.tooltip = title; + }, + + // nsITaskbarPreviewController + + // window width and height, not browser + get width() { + return this.win.width; + }, + + // window width and height, not browser + get height() { + return this.win.height; + }, + + get thumbnailAspectRatio() { + let browserDims = this.browserDims; + // Avoid returning 0 + let tabWidth = browserDims.width || 1; + // Avoid divide by 0 + let tabHeight = browserDims.height || 1; + return tabWidth / tabHeight; + }, + + /** + * Responds to taskbar requests for window previews. Returns the results asynchronously + * through updateCanvasPreview. + * + * @param aTaskbarCallback nsITaskbarPreviewCallback results callback + */ + requestPreview: function (aTaskbarCallback) { + // Grab a high res content preview + this.resetCanvasPreview(); + this.updateCanvasPreview(true, (aPreviewCanvas) => { + let winWidth = this.win.width; + let winHeight = this.win.height; + + let composite = PageThumbs.createCanvas(); + + // Use transparency, Aero glass is drawn black without it. + composite.mozOpaque = false; + + let ctx = composite.getContext('2d'); + let scale = this.screenPixelsPerCSSPixel / this.zoom; + + composite.width = winWidth * scale; + composite.height = winHeight * scale; + + ctx.save(); + ctx.scale(scale, scale); + + // Draw chrome. Note we currently do not get scrollbars for remote frames + // in the image above. + ctx.drawWindow(this.win.win, 0, 0, winWidth, winHeight, "rgba(0,0,0,0)"); + + // Draw the content are into the composite canvas at the right location. + ctx.drawImage(aPreviewCanvas, this.browserDims.x, this.browserDims.y, + aPreviewCanvas.width, aPreviewCanvas.height); + ctx.restore(); + + // Deliver the resulting composite canvas to Windows + this.win.tabbrowser.previewTab(this.tab, function () { + aTaskbarCallback.done(composite, false); + }); + }); + }, + + /** + * Responds to taskbar requests for tab thumbnails. Returns the results asynchronously + * through updateCanvasPreview. + * + * Note Windows requests a specific width and height here, if the resulting thumbnail + * does not match these dimensions thumbnail display will fail. + * + * @param aTaskbarCallback nsITaskbarPreviewCallback results callback + * @param aRequestedWidth width of the requested thumbnail + * @param aRequestedHeight height of the requested thumbnail + */ + requestThumbnail: function (aTaskbarCallback, aRequestedWidth, aRequestedHeight) { + this.resizeCanvasPreview(aRequestedWidth, aRequestedHeight); + this.updateCanvasPreview(false, (aThumbnailCanvas) => { + aTaskbarCallback.done(aThumbnailCanvas, false); + }); + }, + + // Event handling + + onClose: function () { + this.win.tabbrowser.removeTab(this.tab); + }, + + onActivate: function () { + this.win.tabbrowser.selectedTab = this.tab; + + // Accept activation - this will restore the browser window + // if it's minimized + return true; + }, + + // nsIDOMEventListener + handleEvent: function (evt) { + switch (evt.type) { + case "TabAttrModified": + this.updateTitleAndTooltip(); + break; + } + } +}; + +XPCOMUtils.defineLazyGetter(PreviewController.prototype, "canvasPreviewFlags", + function () { let canvasInterface = Ci.nsIDOMCanvasRenderingContext2D; + return canvasInterface.DRAWWINDOW_DRAW_VIEW + | canvasInterface.DRAWWINDOW_DRAW_CARET + | canvasInterface.DRAWWINDOW_ASYNC_DECODE_IMAGES + | canvasInterface.DRAWWINDOW_DO_NOT_FLUSH; +}); + +// TabWindow + +/* + * This class monitors a browser window for changes to its tabs + * + * @param win + * The nsIDOMWindow browser window + */ +function TabWindow(win) { + this.win = win; + this.tabbrowser = win.gBrowser; + + this.previews = new Map(); + + for (let i = 0; i < this.tabEvents.length; i++) + this.tabbrowser.tabContainer.addEventListener(this.tabEvents[i], this, false); + + for (let i = 0; i < this.winEvents.length; i++) + this.win.addEventListener(this.winEvents[i], this, false); + + this.tabbrowser.addTabsProgressListener(this); + + AeroPeek.windows.push(this); + let tabs = this.tabbrowser.tabs; + for (let i = 0; i < tabs.length; i++) + this.newTab(tabs[i]); + + this.updateTabOrdering(); + AeroPeek.checkPreviewCount(); +} + +TabWindow.prototype = { + _enabled: false, + _cachedWidth: 0, + _cachedHeight: 0, + tabEvents: ["TabOpen", "TabClose", "TabSelect", "TabMove"], + winEvents: ["resize"], + + destroy: function () { + this._destroying = true; + + let tabs = this.tabbrowser.tabs; + + this.tabbrowser.removeTabsProgressListener(this); + + for (let i = 0; i < this.winEvents.length; i++) + this.win.removeEventListener(this.winEvents[i], this, false); + + for (let i = 0; i < this.tabEvents.length; i++) + this.tabbrowser.tabContainer.removeEventListener(this.tabEvents[i], this, false); + + for (let i = 0; i < tabs.length; i++) + this.removeTab(tabs[i]); + + let idx = AeroPeek.windows.indexOf(this.win.gTaskbarTabGroup); + AeroPeek.windows.splice(idx, 1); + AeroPeek.checkPreviewCount(); + }, + + get width () { + return this.win.innerWidth; + }, + get height () { + return this.win.innerHeight; + }, + + cacheDims: function () { + this._cachedWidth = this.width; + this._cachedHeight = this.height; + }, + + testCacheDims: function () { + return this._cachedWidth == this.width && this._cachedHeight == this.height; + }, + + // Invoked when the given tab is added to this window + newTab: function (tab) { + let controller = new PreviewController(this, tab); + // It's OK to add the preview now while the favicon still loads. + this.previews.set(tab, controller.preview); + AeroPeek.addPreview(controller.preview); + // updateTitleAndTooltip relies on having controller.preview which is lazily resolved. + // Now that we've updated this.previews, it will resolve successfully. + controller.updateTitleAndTooltip(); + }, + + createTabPreview: function (controller) { + let docShell = this.win + .QueryInterface(Ci.nsIInterfaceRequestor) + .getInterface(Ci.nsIWebNavigation) + .QueryInterface(Ci.nsIDocShell); + let preview = AeroPeek.taskbar.createTaskbarTabPreview(docShell, controller); + preview.visible = AeroPeek.enabled; + preview.active = this.tabbrowser.selectedTab == controller.tab; + this.onLinkIconAvailable(controller.tab.linkedBrowser, + controller.tab.getAttribute("image")); + return preview; + }, + + // Invoked when the given tab is closed + removeTab: function (tab) { + let preview = this.previewFromTab(tab); + preview.active = false; + preview.visible = false; + preview.move(null); + preview.controller.wrappedJSObject.destroy(); + + this.previews.delete(tab); + AeroPeek.removePreview(preview); + }, + + get enabled () { + return this._enabled; + }, + + set enabled (enable) { + this._enabled = enable; + // Because making a tab visible requires that the tab it is next to be + // visible, it is far simpler to unset the 'next' tab and recreate them all + // at once. + for (let [, preview] of this.previews) { + preview.move(null); + preview.visible = enable; + } + this.updateTabOrdering(); + }, + + previewFromTab: function (tab) { + return this.previews.get(tab); + }, + + updateTabOrdering: function () { + let previews = this.previews; + let tabs = this.tabbrowser.tabs; + + // Previews are internally stored using a map, so we need to iterate the + // tabbrowser's array of tabs to retrieve previews in the same order. + let inorder = []; + for (let t of tabs) { + if (previews.has(t)) { + inorder.push(previews.get(t)); + } + } + + // Since the internal taskbar array has not yet been updated we must force + // on it the sorting order of our local array. To do so we must walk + // the local array backwards, otherwise we would send move requests in the + // wrong order. See bug 522610 for details. + for (let i = inorder.length - 1; i >= 0; i--) { + inorder[i].move(inorder[i + 1] || null); + } + }, + + // nsIDOMEventListener + handleEvent: function (evt) { + let tab = evt.originalTarget; + switch (evt.type) { + case "TabOpen": + this.newTab(tab); + this.updateTabOrdering(); + break; + case "TabClose": + this.removeTab(tab); + this.updateTabOrdering(); + break; + case "TabSelect": + this.previewFromTab(tab).active = true; + break; + case "TabMove": + this.updateTabOrdering(); + break; + case "resize": + if (!AeroPeek._prefenabled) + return; + this.onResize(); + break; + } + }, + + // Set or reset a timer that will invalidate visible thumbnails soon. + setInvalidationTimer: function () { + if (!this.invalidateTimer) { + this.invalidateTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer); + } + this.invalidateTimer.cancel(); + + // delay 1 second before invalidating + this.invalidateTimer.initWithCallback(() => { + // invalidate every preview. note the internal implementation of + // invalidate ignores thumbnails that aren't visible. + this.previews.forEach(function (aPreview) { + let controller = aPreview.controller.wrappedJSObject; + if (!controller.testCacheBrowserDims()) { + controller.cacheBrowserDims(); + aPreview.invalidate(); + } + }); + }, 1000, Ci.nsITimer.TYPE_ONE_SHOT); + }, + + onResize: function () { + // Specific to a window. + + // Call invalidate on each tab thumbnail so that Windows will request an + // updated image. However don't do this repeatedly across multiple resize + // events triggered during window border drags. + + if (this.testCacheDims()) { + return; + } + + // update the window dims on our TabWindow object. + this.cacheDims(); + + // invalidate soon + this.setInvalidationTimer(); + }, + + invalidateTabPreview: function(aBrowser) { + for (let [tab, preview] of this.previews) { + if (aBrowser == tab.linkedBrowser) { + preview.invalidate(); + break; + } + } + }, + + // Browser progress listener + + onLocationChange: function (aBrowser) { + // I'm not sure we need this, onStateChange does a really good job + // of picking up page changes. + // this.invalidateTabPreview(aBrowser); + }, + + onStateChange: function (aBrowser, aWebProgress, aRequest, aStateFlags, aStatus) { + if (aStateFlags & Ci.nsIWebProgressListener.STATE_STOP && + aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK) { + this.invalidateTabPreview(aBrowser); + } + }, + + directRequestProtocols: new Set([ + "file", "chrome", "resource", "about" + ]), + onLinkIconAvailable: function (aBrowser, aIconURL) { + let requestURL = null; + if (aIconURL) { + let shouldRequestFaviconURL = true; + try { + let urlObject = NetUtil.newURI(aIconURL); + shouldRequestFaviconURL = + !this.directRequestProtocols.has(urlObject.scheme); + } catch (ex) {} + + requestURL = shouldRequestFaviconURL ? + "moz-anno:favicon:" + aIconURL : + aIconURL; + } + let isDefaultFavicon = !requestURL; + getFaviconAsImage( + requestURL, + PrivateBrowsingUtils.isWindowPrivate(this.win), + img => { + let index = this.tabbrowser.browsers.indexOf(aBrowser); + // Only add it if we've found the index and the URI is still the same. + // The tab could have closed, and there's no guarantee the icons + // will have finished fetching 'in order'. + if (index != -1) { + let tab = this.tabbrowser.tabs[index]; + let preview = this.previews.get(tab); + if (tab.getAttribute("image") == aIconURL || + (!preview.icon && isDefaultFavicon)) { + preview.icon = img; + } + } + } + ); + } +} + +// AeroPeek + +/* + * This object acts as global storage and external interface for this feature. + * It maintains the values of the prefs. + */ +this.AeroPeek = { + available: false, + // Does the pref say we're enabled? + __prefenabled: false, + + _enabled: true, + + initialized: false, + + // nsITaskbarTabPreview array + previews: [], + + // TabWindow array + windows: [], + + // nsIWinTaskbar service + taskbar: null, + + // Maximum number of previews + maxpreviews: 20, + + // Length of time in seconds that previews are cached + cacheLifespan: 20, + + initialize: function () { + if (!(WINTASKBAR_CONTRACTID in Cc)) + return; + this.taskbar = Cc[WINTASKBAR_CONTRACTID].getService(Ci.nsIWinTaskbar); + this.available = this.taskbar.available; + if (!this.available) + return; + + this.prefs.addObserver(TOGGLE_PREF_NAME, this, true); + this.enabled = this._prefenabled = this.prefs.getBoolPref(TOGGLE_PREF_NAME); + this.initialized = true; + }, + + destroy: function destroy() { + this._enabled = false; + + if (this.cacheTimer) + this.cacheTimer.cancel(); + }, + + get enabled() { + return this._enabled; + }, + + set enabled(enable) { + if (this._enabled == enable) + return; + + this._enabled = enable; + + this.windows.forEach(function (win) { + win.enabled = enable; + }); + }, + + get _prefenabled() { + return this.__prefenabled; + }, + + set _prefenabled(enable) { + if (enable == this.__prefenabled) { + return; + } + this.__prefenabled = enable; + + if (enable) { + this.enable(); + } else { + this.disable(); + } + }, + + _observersAdded: false, + + enable() { + if (!this._observersAdded) { + this.prefs.addObserver(DISABLE_THRESHOLD_PREF_NAME, this, true); + this.prefs.addObserver(CACHE_EXPIRATION_TIME_PREF_NAME, this, true); + PlacesUtils.history.addObserver(this, true); + this._observersAdded = true; + } + + this.cacheLifespan = this.prefs.getIntPref(CACHE_EXPIRATION_TIME_PREF_NAME); + + this.maxpreviews = this.prefs.getIntPref(DISABLE_THRESHOLD_PREF_NAME); + + // If the user toggled us on/off while the browser was already up + // (rather than this code running on startup because the pref was + // already set to true), we must initialize previews for open windows: + if (this.initialized) { + let browserWindows = Services.wm.getEnumerator("navigator:browser"); + while (browserWindows.hasMoreElements()) { + let win = browserWindows.getNext(); + if (!win.closed) { + this.onOpenWindow(win); + } + } + } + }, + + disable() { + while (this.windows.length) { + // We can't call onCloseWindow here because it'll bail if we're not + // enabled. + let tabWinObject = this.windows[0]; + tabWinObject.destroy(); // This will remove us from the array. + delete tabWinObject.win.gTaskbarTabGroup; // Tidy up the window. + } + }, + + addPreview: function (preview) { + this.previews.push(preview); + this.checkPreviewCount(); + }, + + removePreview: function (preview) { + let idx = this.previews.indexOf(preview); + this.previews.splice(idx, 1); + this.checkPreviewCount(); + }, + + checkPreviewCount: function () { + if (!this._prefenabled) { + return; + } + this.enabled = this.previews.length <= this.maxpreviews; + }, + + onOpenWindow: function (win) { + // This occurs when the taskbar service is not available (xp, vista) + if (!this.available || !this._prefenabled) + return; + + win.gTaskbarTabGroup = new TabWindow(win); + }, + + onCloseWindow: function (win) { + // This occurs when the taskbar service is not available (xp, vista) + if (!this.available || !this._prefenabled) + return; + + win.gTaskbarTabGroup.destroy(); + delete win.gTaskbarTabGroup; + + if (this.windows.length == 0) + this.destroy(); + }, + + resetCacheTimer: function () { + this.cacheTimer.cancel(); + this.cacheTimer.init(this, 1000*this.cacheLifespan, Ci.nsITimer.TYPE_ONE_SHOT); + }, + + // nsIObserver + observe: function (aSubject, aTopic, aData) { + if (aTopic == "nsPref:changed" && aData == TOGGLE_PREF_NAME) { + this._prefenabled = this.prefs.getBoolPref(TOGGLE_PREF_NAME); + } + if (!this._prefenabled) { + return; + } + switch (aTopic) { + case "nsPref:changed": + if (aData == CACHE_EXPIRATION_TIME_PREF_NAME) + break; + + if (aData == DISABLE_THRESHOLD_PREF_NAME) + this.maxpreviews = this.prefs.getIntPref(DISABLE_THRESHOLD_PREF_NAME); + // Might need to enable/disable ourselves + this.checkPreviewCount(); + break; + case "timer-callback": + this.previews.forEach(function (preview) { + let controller = preview.controller.wrappedJSObject; + controller.resetCanvasPreview(); + }); + break; + } + }, + + /* nsINavHistoryObserver implementation */ + onBeginUpdateBatch() {}, + onEndUpdateBatch() {}, + onVisit() {}, + onTitleChanged() {}, + onFrecencyChanged() {}, + onManyFrecenciesChanged() {}, + onDeleteURI() {}, + onClearHistory() {}, + onDeleteVisits() {}, + onPageChanged(uri, changedConst, newValue) { + if (this.enabled && changedConst == Ci.nsINavHistoryObserver.ATTRIBUTE_FAVICON) { + for (let win of this.windows) { + for (let [tab, ] of win.previews) { + if (tab.getAttribute("image") == newValue) { + win.onLinkIconAvailable(tab.linkedBrowser, newValue); + } + } + } + } + }, + + QueryInterface: XPCOMUtils.generateQI([ + Ci.nsISupportsWeakReference, + Ci.nsINavHistoryObserver, + Ci.nsIObserver + ]), +}; + +XPCOMUtils.defineLazyGetter(AeroPeek, "cacheTimer", () => + Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer) +); + +XPCOMUtils.defineLazyServiceGetter(AeroPeek, "prefs", + "@mozilla.org/preferences-service;1", + "nsIPrefBranch"); + +AeroPeek.initialize(); |