/* 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/. */ /** * Controls the "full zoom" setting and its site-specific preferences. */ var FullZoom = { // Identifies the setting in the content prefs database. name: "browser.content.full-zoom", // browser.zoom.siteSpecific preference cache _siteSpecificPref: undefined, // browser.zoom.updateBackgroundTabs preference cache updateBackgroundTabs: undefined, // This maps the browser to monotonically increasing integer // tokens. _browserTokenMap[browser] is increased each time the zoom is // changed in the browser. See _getBrowserToken and _ignorePendingZoomAccesses. _browserTokenMap: new WeakMap(), // Stores initial locations if we receive onLocationChange // events before we're initialized. _initialLocations: new WeakMap(), get siteSpecific() { return this._siteSpecificPref; }, // nsISupports QueryInterface: XPCOMUtils.generateQI([Ci.nsIDOMEventListener, Ci.nsIObserver, Ci.nsIContentPrefObserver, Ci.nsISupportsWeakReference, Ci.nsISupports]), // Initialization & Destruction init: function FullZoom_init() { gBrowser.addEventListener("ZoomChangeUsingMouseWheel", this); // Register ourselves with the service so we know when our pref changes. this._cps2 = Cc["@mozilla.org/content-pref/service;1"]. getService(Ci.nsIContentPrefService2); this._cps2.addObserverForName(this.name, this); this._siteSpecificPref = gPrefService.getBoolPref("browser.zoom.siteSpecific"); this.updateBackgroundTabs = gPrefService.getBoolPref("browser.zoom.updateBackgroundTabs"); // Listen for changes to the browser.zoom branch so we can enable/disable // updating background tabs and per-site saving and restoring of zoom levels. gPrefService.addObserver("browser.zoom.", this, true); // If we received onLocationChange events for any of the current browsers // before we were initialized we want to replay those upon initialization. for (let browser of gBrowser.browsers) { if (this._initialLocations.has(browser)) { this.onLocationChange(...this._initialLocations.get(browser), browser); } } // This should be nulled after initialization. this._initialLocations = null; }, destroy: function FullZoom_destroy() { gPrefService.removeObserver("browser.zoom.", this); this._cps2.removeObserverForName(this.name, this); gBrowser.removeEventListener("ZoomChangeUsingMouseWheel", this); }, // Event Handlers // nsIDOMEventListener handleEvent: function FullZoom_handleEvent(event) { switch (event.type) { case "ZoomChangeUsingMouseWheel": let browser = this._getTargetedBrowser(event); this._ignorePendingZoomAccesses(browser); this._applyZoomToPref(browser); break; } }, // nsIObserver observe: function (aSubject, aTopic, aData) { switch (aTopic) { case "nsPref:changed": switch (aData) { case "browser.zoom.siteSpecific": this._siteSpecificPref = gPrefService.getBoolPref("browser.zoom.siteSpecific"); break; case "browser.zoom.updateBackgroundTabs": this.updateBackgroundTabs = gPrefService.getBoolPref("browser.zoom.updateBackgroundTabs"); break; } break; } }, // nsIContentPrefObserver onContentPrefSet: function FullZoom_onContentPrefSet(aGroup, aName, aValue, aIsPrivate) { this._onContentPrefChanged(aGroup, aValue, aIsPrivate); }, onContentPrefRemoved: function FullZoom_onContentPrefRemoved(aGroup, aName, aIsPrivate) { this._onContentPrefChanged(aGroup, undefined, aIsPrivate); }, /** * Appropriately updates the zoom level after a content preference has * changed. * * @param aGroup The group of the changed preference. * @param aValue The new value of the changed preference. Pass undefined to * indicate the preference's removal. */ _onContentPrefChanged: function FullZoom__onContentPrefChanged(aGroup, aValue, aIsPrivate) { if (this._isNextContentPrefChangeInternal) { // Ignore changes that FullZoom itself makes. This works because the // content pref service calls callbacks before notifying observers, and it // does both in the same turn of the event loop. delete this._isNextContentPrefChangeInternal; return; } let browser = gBrowser.selectedBrowser; if (!browser.currentURI) return; let ctxt = this._loadContextFromBrowser(browser); let domain = this._cps2.extractDomain(browser.currentURI.spec); if (aGroup) { if (aGroup == domain && ctxt.usePrivateBrowsing == aIsPrivate) this._applyPrefToZoom(aValue, browser); return; } this._globalValue = aValue === undefined ? aValue : this._ensureValid(aValue); // If the current page doesn't have a site-specific preference, then its // zoom should be set to the new global preference now that the global // preference has changed. let hasPref = false; let token = this._getBrowserToken(browser); this._cps2.getByDomainAndName(browser.currentURI.spec, this.name, ctxt, { handleResult: function () { hasPref = true; }, handleCompletion: function () { if (!hasPref && token.isCurrent) this._applyPrefToZoom(undefined, browser); }.bind(this) }); }, // location change observer /** * Called when the location of a tab changes. * When that happens, we need to update the current zoom level if appropriate. * * @param aURI * A URI object representing the new location. * @param aIsTabSwitch * Whether this location change has happened because of a tab switch. * @param aBrowser * (optional) browser object displaying the document */ onLocationChange: function FullZoom_onLocationChange(aURI, aIsTabSwitch, aBrowser) { let browser = aBrowser || gBrowser.selectedBrowser; // If we haven't been initialized yet but receive an onLocationChange // notification then let's store and replay it upon initialization. if (this._initialLocations) { this._initialLocations.set(browser, [aURI, aIsTabSwitch]); return; } // Ignore all pending async zoom accesses in the browser. Pending accesses // that started before the location change will be prevented from applying // to the new location. this._ignorePendingZoomAccesses(browser); if (!aURI || (aIsTabSwitch && !this.siteSpecific)) { this._notifyOnLocationChange(browser); return; } // Avoid the cps roundtrip and apply the default/global pref. if (aURI.spec == "about:blank") { this._applyPrefToZoom(undefined, browser, this._notifyOnLocationChange.bind(this, browser)); return; } // Media documents should always start at 1, and are not affected by prefs. if (!aIsTabSwitch && browser.isSyntheticDocument) { ZoomManager.setZoomForBrowser(browser, 1); // _ignorePendingZoomAccesses already called above, so no need here. this._notifyOnLocationChange(browser); return; } // See if the zoom pref is cached. let ctxt = this._loadContextFromBrowser(browser); let pref = this._cps2.getCachedByDomainAndName(aURI.spec, this.name, ctxt); if (pref) { this._applyPrefToZoom(pref.value, browser, this._notifyOnLocationChange.bind(this, browser)); return; } // It's not cached, so we have to asynchronously fetch it. let value = undefined; let token = this._getBrowserToken(browser); this._cps2.getByDomainAndName(aURI.spec, this.name, ctxt, { handleResult: function (resultPref) { value = resultPref.value; }, handleCompletion: function () { if (!token.isCurrent) { this._notifyOnLocationChange(browser); return; } this._applyPrefToZoom(value, browser, this._notifyOnLocationChange.bind(this, browser)); }.bind(this) }); }, // update state of zoom type menu item updateMenu: function FullZoom_updateMenu() { var menuItem = document.getElementById("toggle_zoom"); menuItem.setAttribute("checked", !ZoomManager.useFullZoom); }, // Setting & Pref Manipulation /** * Reduces the zoom level of the page in the current browser. */ reduce: function FullZoom_reduce() { ZoomManager.reduce(); let browser = gBrowser.selectedBrowser; this._ignorePendingZoomAccesses(browser); this._applyZoomToPref(browser); }, /** * Enlarges the zoom level of the page in the current browser. */ enlarge: function FullZoom_enlarge() { ZoomManager.enlarge(); let browser = gBrowser.selectedBrowser; this._ignorePendingZoomAccesses(browser); this._applyZoomToPref(browser); }, /** * Sets the zoom level for the given browser to the given floating * point value, where 1 is the default zoom level. */ setZoom: function (value, browser = gBrowser.selectedBrowser) { ZoomManager.setZoomForBrowser(browser, value); this._ignorePendingZoomAccesses(browser); this._applyZoomToPref(browser); }, /** * Sets the zoom level of the page in the given browser to the global zoom * level. * * @return A promise which resolves when the zoom reset has been applied. */ reset: function FullZoom_reset(browser = gBrowser.selectedBrowser) { let token = this._getBrowserToken(browser); let result = this._getGlobalValue(browser).then(value => { if (token.isCurrent) { ZoomManager.setZoomForBrowser(browser, value === undefined ? 1 : value); this._ignorePendingZoomAccesses(browser); Services.obs.notifyObservers(browser, "browser-fullZoom:zoomReset", ""); } }); this._removePref(browser); return result; }, /** * Set the zoom level for a given browser. * * Per nsPresContext::setFullZoom, we can set the zoom to its current value * without significant impact on performance, as the setting is only applied * if it differs from the current setting. In fact getting the zoom and then * checking ourselves if it differs costs more. * * And perhaps we should always set the zoom even if it was more expensive, * since nsDocumentViewer::SetTextZoom claims that child documents can have * a different text zoom (although it would be unusual), and it implies that * those child text zooms should get updated when the parent zoom gets set, * and perhaps the same is true for full zoom * (although nsDocumentViewer::SetFullZoom doesn't mention it). * * So when we apply new zoom values to the browser, we simply set the zoom. * We don't check first to see if the new value is the same as the current * one. * * @param aValue The zoom level value. * @param aBrowser The zoom is set in this browser. Required. * @param aCallback If given, it's asynchronously called when complete. */ _applyPrefToZoom: function FullZoom__applyPrefToZoom(aValue, aBrowser, aCallback) { if (!this.siteSpecific || gInPrintPreviewMode) { this._executeSoon(aCallback); return; } // The browser is sometimes half-destroyed because this method is called // by content pref service callbacks, which themselves can be called at any // time, even after browsers are closed. if (!aBrowser.parentNode || aBrowser.isSyntheticDocument) { this._executeSoon(aCallback); return; } if (aValue !== undefined) { ZoomManager.setZoomForBrowser(aBrowser, this._ensureValid(aValue)); this._ignorePendingZoomAccesses(aBrowser); this._executeSoon(aCallback); return; } let token = this._getBrowserToken(aBrowser); this._getGlobalValue(aBrowser).then(value => { if (token.isCurrent) { ZoomManager.setZoomForBrowser(aBrowser, value === undefined ? 1 : value); this._ignorePendingZoomAccesses(aBrowser); } this._executeSoon(aCallback); }); }, /** * Saves the zoom level of the page in the given browser to the content * prefs store. * * @param browser The zoom of this browser will be saved. Required. */ _applyZoomToPref: function FullZoom__applyZoomToPref(browser) { Services.obs.notifyObservers(browser, "browser-fullZoom:zoomChange", ""); if (!this.siteSpecific || gInPrintPreviewMode || browser.isSyntheticDocument) return; this._cps2.set(browser.currentURI.spec, this.name, ZoomManager.getZoomForBrowser(browser), this._loadContextFromBrowser(browser), { handleCompletion: function () { this._isNextContentPrefChangeInternal = true; }.bind(this), }); }, /** * Removes from the content prefs store the zoom level of the given browser. * * @param browser The zoom of this browser will be removed. Required. */ _removePref: function FullZoom__removePref(browser) { Services.obs.notifyObservers(browser, "browser-fullZoom:zoomReset", ""); if (browser.isSyntheticDocument) return; let ctxt = this._loadContextFromBrowser(browser); this._cps2.removeByDomainAndName(browser.currentURI.spec, this.name, ctxt, { handleCompletion: function () { this._isNextContentPrefChangeInternal = true; }.bind(this), }); }, // Utilities /** * Returns the zoom change token of the given browser. Asynchronous * operations that access the given browser's zoom should use this method to * capture the token before starting and use token.isCurrent to determine if * it's safe to access the zoom when done. If token.isCurrent is false, then * after the async operation started, either the browser's zoom was changed or * the browser was destroyed, and depending on what the operation is doing, it * may no longer be safe to set and get its zoom. * * @param browser The token of this browser will be returned. * @return An object with an "isCurrent" getter. */ _getBrowserToken: function FullZoom__getBrowserToken(browser) { let map = this._browserTokenMap; if (!map.has(browser)) map.set(browser, 0); return { token: map.get(browser), get isCurrent() { // At this point, the browser may have been destructed and unbound but // its outer ID not removed from the map because outer-window-destroyed // hasn't been received yet. In that case, the browser is unusable, it // has no properties, so return false. Check for this case by getting a // property, say, docShell. return map.get(browser) === this.token && browser.parentNode; }, }; }, /** * Returns the browser that the supplied zoom event is associated with. * @param event The ZoomChangeUsingMouseWheel event. * @return The associated browser element, if one exists, otherwise null. */ _getTargetedBrowser: function FullZoom__getTargetedBrowser(event) { let target = event.originalTarget; // With remote content browsers, the event's target is the browser // we're looking for. const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"; if (target instanceof window.XULElement && target.localName == "browser" && target.namespaceURI == XUL_NS) return target; // With in-process content browsers, the event's target is the content // document. if (target.nodeType == Node.DOCUMENT_NODE) return gBrowser.getBrowserForDocument(target); throw new Error("Unexpected ZoomChangeUsingMouseWheel event source"); }, /** * Increments the zoom change token for the given browser so that pending * async operations know that it may be unsafe to access they zoom when they * finish. * * @param browser Pending accesses in this browser will be ignored. */ _ignorePendingZoomAccesses: function FullZoom__ignorePendingZoomAccesses(browser) { let map = this._browserTokenMap; map.set(browser, (map.get(browser) || 0) + 1); }, _ensureValid: function FullZoom__ensureValid(aValue) { // Note that undefined is a valid value for aValue that indicates a known- // not-to-exist value. if (isNaN(aValue)) return 1; if (aValue < ZoomManager.MIN) return ZoomManager.MIN; if (aValue > ZoomManager.MAX) return ZoomManager.MAX; return aValue; }, /** * Gets the global browser.content.full-zoom content preference. * * @param browser The browser pertaining to the zoom. * @returns Promise<prefValue> * Resolves to the preference value when done. */ _getGlobalValue: function FullZoom__getGlobalValue(browser) { // * !("_globalValue" in this) => global value not yet cached. // * this._globalValue === undefined => global value known not to exist. // * Otherwise, this._globalValue is a number, the global value. return new Promise(resolve => { if ("_globalValue" in this) { resolve(this._globalValue); return; } let value = undefined; this._cps2.getGlobal(this.name, this._loadContextFromBrowser(browser), { handleResult: function (pref) { value = pref.value; }, handleCompletion: (reason) => { this._globalValue = this._ensureValid(value); resolve(this._globalValue); } }); }); }, /** * Gets the load context from the given Browser. * * @param Browser The Browser whose load context will be returned. * @return The nsILoadContext of the given Browser. */ _loadContextFromBrowser: function FullZoom__loadContextFromBrowser(browser) { return browser.loadContext; }, /** * Asynchronously broadcasts "browser-fullZoom:location-change" so that * listeners can be notified when the zoom levels on those pages change. * The notification is always asynchronous so that observers are guaranteed a * consistent behavior. */ _notifyOnLocationChange: function FullZoom__notifyOnLocationChange(browser) { this._executeSoon(function () { Services.obs.notifyObservers(browser, "browser-fullZoom:location-change", ""); }); }, _executeSoon: function FullZoom__executeSoon(callback) { if (!callback) return; Services.tm.mainThread.dispatch(callback, Ci.nsIThread.DISPATCH_NORMAL); }, };