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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /browser/modules/WindowsPreviewPerTab.sys.mjs
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'browser/modules/WindowsPreviewPerTab.sys.mjs')
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1 files changed, 891 insertions, 0 deletions
diff --git a/browser/modules/WindowsPreviewPerTab.sys.mjs b/browser/modules/WindowsPreviewPerTab.sys.mjs
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+/* 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.
+ */
+import { NetUtil } from "resource://gre/modules/NetUtil.sys.mjs";
+import { PlacesUtils } from "resource://gre/modules/PlacesUtils.sys.mjs";
+import { PrivateBrowsingUtils } from "resource://gre/modules/PrivateBrowsingUtils.sys.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+// 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";
+
+const lazy = {};
+
+// Various utility properties
+XPCOMUtils.defineLazyServiceGetter(
+ lazy,
+ "imgTools",
+ "@mozilla.org/image/tools;1",
+ "imgITools"
+);
+ChromeUtils.defineESModuleGetters(lazy, {
+ PageThumbs: "resource://gre/modules/PageThumbs.sys.mjs",
+});
+
+// nsIURI -> imgIContainer
+function _imageFromURI(uri, privateMode, callback) {
+ let channel = NetUtil.newChannel({
+ 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;
+ }
+
+ const decodeCallback = {
+ onImageReady(image, status) {
+ if (!image) {
+ // 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);
+ return;
+ }
+ }
+
+ callback(image);
+ },
+ };
+
+ try {
+ let threadManager = Cc["@mozilla.org/thread-manager;1"].getService();
+ lazy.imgTools.decodeImageAsync(
+ inputStream,
+ channel.contentType,
+ decodeCallback,
+ threadManager.currentThread
+ );
+ } 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);
+ }
+}
+
+// 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);
+
+ ChromeUtils.defineLazyGetter(this, "canvasPreview", function () {
+ let canvas = lazy.PageThumbs.createCanvas(this.win.win);
+ canvas.mozOpaque = true;
+ return canvas;
+ });
+}
+
+PreviewController.prototype = {
+ QueryInterface: ChromeUtils.generateQI(["nsITaskbarPreviewController"]),
+
+ destroy() {
+ this.tab.removeEventListener("TabAttrModified", this);
+
+ // 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() {
+ this.canvasPreview.width = 0;
+ this.canvasPreview.height = 0;
+ },
+
+ /**
+ * Set the canvas dimensions.
+ */
+ resizeCanvasPreview(aRequestedWidth, aRequestedHeight) {
+ this.canvasPreview.width = aRequestedWidth;
+ this.canvasPreview.height = aRequestedHeight;
+ },
+
+ get browserDims() {
+ return this.tab.linkedBrowser.getBoundingClientRect();
+ },
+
+ cacheBrowserDims() {
+ let dims = this.browserDims;
+ this._cachedWidth = dims.width;
+ this._cachedHeight = dims.height;
+ },
+
+ testCacheBrowserDims() {
+ 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(aFullScale) {
+ // Update our cached browser dims so that delayed resize
+ // events don't trigger another invalidation if this tab becomes active.
+ this.cacheBrowserDims();
+ AeroPeek.resetCacheTimer();
+ return lazy.PageThumbs.captureToCanvas(
+ this.linkedBrowser,
+ this.canvasPreview,
+ {
+ fullScale: aFullScale,
+ }
+ ).catch(console.error);
+ // If we're updating the canvas, then we're in the middle of a peek so
+ // don't discard the cache of previews.
+ },
+
+ updateTitleAndTooltip() {
+ 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(aTaskbarCallback) {
+ // Grab a high res content preview
+ this.resetCanvasPreview();
+ this.updateCanvasPreview(true).then(aPreviewCanvas => {
+ let winWidth = this.win.width;
+ let winHeight = this.win.height;
+
+ let composite = lazy.PageThumbs.createCanvas(this.win.win);
+
+ // Use transparency, Aero glass is drawn black without it.
+ composite.mozOpaque = false;
+
+ let ctx = composite.getContext("2d");
+ let scale = this.win.win.devicePixelRatio;
+
+ 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(aTaskbarCallback, aRequestedWidth, aRequestedHeight) {
+ this.resizeCanvasPreview(aRequestedWidth, aRequestedHeight);
+ this.updateCanvasPreview(false).then(aThumbnailCanvas => {
+ aTaskbarCallback.done(aThumbnailCanvas, false);
+ });
+ },
+
+ // Event handling
+
+ onClose() {
+ this.win.tabbrowser.removeTab(this.tab);
+ },
+
+ onActivate() {
+ this.win.tabbrowser.selectedTab = this.tab;
+
+ // Accept activation - this will restore the browser window
+ // if it's minimized
+ return true;
+ },
+
+ // EventListener
+ handleEvent(evt) {
+ switch (evt.type) {
+ case "TabAttrModified":
+ this.updateTitleAndTooltip();
+ break;
+ }
+ },
+};
+
+// 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);
+ }
+
+ for (let i = 0; i < this.winEvents.length; i++) {
+ this.win.addEventListener(this.winEvents[i], this);
+ }
+
+ 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() {
+ 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);
+ }
+
+ for (let i = 0; i < this.tabEvents.length; i++) {
+ this.tabbrowser.tabContainer.removeEventListener(this.tabEvents[i], this);
+ }
+
+ 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() {
+ this._cachedWidth = this.width;
+ this._cachedHeight = this.height;
+ },
+
+ testCacheDims() {
+ return this._cachedWidth == this.width && this._cachedHeight == this.height;
+ },
+
+ // Invoked when the given tab is added to this window
+ newTab(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(controller) {
+ let docShell = this.win.docShell;
+ let preview = AeroPeek.taskbar.createTaskbarTabPreview(
+ docShell,
+ controller
+ );
+ preview.visible = AeroPeek.enabled;
+ let { tab } = controller;
+ preview.active = this.tabbrowser.selectedTab == tab;
+ this.updateFavicon(tab, tab.getAttribute("image"));
+ return preview;
+ },
+
+ // Invoked when the given tab is closed
+ removeTab(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(tab) {
+ return this.previews.get(tab);
+ },
+
+ updateTabOrdering() {
+ 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);
+ }
+ },
+
+ // EventListener
+ handleEvent(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() {
+ 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() {
+ // 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(aBrowser) {
+ for (let [tab, preview] of this.previews) {
+ if (aBrowser == tab.linkedBrowser) {
+ preview.invalidate();
+ break;
+ }
+ }
+ },
+
+ // Browser progress listener
+
+ onLocationChange(aBrowser) {
+ // I'm not sure we need this, onStateChange does a really good job
+ // of picking up page changes.
+ // this.invalidateTabPreview(aBrowser);
+ },
+
+ onStateChange(aBrowser, aWebProgress, aRequest, aStateFlags, aStatus) {
+ if (
+ aStateFlags & Ci.nsIWebProgressListener.STATE_STOP &&
+ aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK
+ ) {
+ this.invalidateTabPreview(aBrowser);
+ }
+ },
+
+ onLinkIconAvailable(aBrowser, aIconURL) {
+ let tab = this.win.gBrowser.getTabForBrowser(aBrowser);
+ this.updateFavicon(tab, aIconURL);
+ },
+ updateFavicon(aTab, aIconURL) {
+ let requestURL = null;
+ if (aIconURL) {
+ try {
+ requestURL = PlacesUtils.favicons.getFaviconLinkForIcon(
+ Services.io.newURI(aIconURL)
+ ).spec;
+ } catch (ex) {
+ requestURL = aIconURL;
+ }
+ }
+ let isDefaultFavicon = !requestURL;
+ getFaviconAsImage(
+ requestURL,
+ PrivateBrowsingUtils.isWindowPrivate(this.win),
+ img => {
+ // The tab could have closed, and there's no guarantee the icons
+ // will have finished fetching 'in order'.
+ if (this.win.closed || aTab.closing || !aTab.linkedBrowser) {
+ return;
+ }
+ // Note that bizarrely, we can get to updateFavicon via a sync codepath
+ // where the new preview controller hasn't yet been added to the
+ // window's map of previews. So `preview` would be null here - except
+ // getFaviconAsImage is async so that should never happen, as we add
+ // the controller to the preview collection straight after creating it.
+ // However, if any of this code ever tries to access this
+ // synchronously, that won't work.
+ let preview = this.previews.get(aTab);
+ if (
+ aTab.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.
+ */
+export var 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() {
+ if (!(WINTASKBAR_CONTRACTID in Cc)) {
+ return;
+ }
+ this.taskbar = Cc[WINTASKBAR_CONTRACTID].getService(Ci.nsIWinTaskbar);
+ this.available = this.taskbar.available;
+ if (!this.available) {
+ return;
+ }
+
+ Services.prefs.addObserver(TOGGLE_PREF_NAME, this, true);
+ this.enabled = this._prefenabled =
+ Services.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) {
+ Services.prefs.addObserver(DISABLE_THRESHOLD_PREF_NAME, this, true);
+ Services.prefs.addObserver(CACHE_EXPIRATION_TIME_PREF_NAME, this, true);
+ this._placesListener = this.handlePlacesEvents.bind(this);
+ PlacesUtils.observers.addListener(
+ ["favicon-changed"],
+ this._placesListener
+ );
+ this._observersAdded = true;
+ }
+
+ this.cacheLifespan = Services.prefs.getIntPref(
+ CACHE_EXPIRATION_TIME_PREF_NAME
+ );
+
+ this.maxpreviews = Services.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) {
+ for (let win of Services.wm.getEnumerator("navigator:browser")) {
+ 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.
+ }
+ PlacesUtils.observers.removeListener(
+ ["favicon-changed"],
+ this._placesListener
+ );
+ },
+
+ addPreview(preview) {
+ this.previews.push(preview);
+ this.checkPreviewCount();
+ },
+
+ removePreview(preview) {
+ let idx = this.previews.indexOf(preview);
+ this.previews.splice(idx, 1);
+ this.checkPreviewCount();
+ },
+
+ checkPreviewCount() {
+ if (!this._prefenabled) {
+ return;
+ }
+ this.enabled = this.previews.length <= this.maxpreviews;
+ },
+
+ onOpenWindow(win) {
+ // This occurs when the taskbar service is not available (xp, vista)
+ if (!this.available || !this._prefenabled) {
+ return;
+ }
+
+ win.gTaskbarTabGroup = new TabWindow(win);
+ },
+
+ onCloseWindow(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) {
+ this.destroy();
+ }
+ },
+
+ resetCacheTimer() {
+ this.cacheTimer.cancel();
+ this.cacheTimer.init(
+ this,
+ 1000 * this.cacheLifespan,
+ Ci.nsITimer.TYPE_ONE_SHOT
+ );
+ },
+
+ // nsIObserver
+ observe(aSubject, aTopic, aData) {
+ if (aTopic == "nsPref:changed" && aData == TOGGLE_PREF_NAME) {
+ this._prefenabled = Services.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 = Services.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;
+ }
+ },
+
+ handlePlacesEvents(events) {
+ for (let event of events) {
+ switch (event.type) {
+ case "favicon-changed": {
+ for (let win of this.windows) {
+ for (let [tab] of win.previews) {
+ if (tab.getAttribute("image") == event.faviconUrl) {
+ win.updateFavicon(tab, event.faviconUrl);
+ }
+ }
+ }
+ }
+ }
+ }
+ },
+
+ QueryInterface: ChromeUtils.generateQI([
+ "nsISupportsWeakReference",
+ "nsIObserver",
+ ]),
+};
+
+ChromeUtils.defineLazyGetter(AeroPeek, "cacheTimer", () =>
+ Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer)
+);
+
+AeroPeek.initialize();