diff options
Diffstat (limited to 'application/palemoon/base/content/browser-fullZoom.js')
| -rw-r--r-- | application/palemoon/base/content/browser-fullZoom.js | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/application/palemoon/base/content/browser-fullZoom.js b/application/palemoon/base/content/browser-fullZoom.js new file mode 100644 index 000000000..0837bf7c2 --- /dev/null +++ b/application/palemoon/base/content/browser-fullZoom.js @@ -0,0 +1,550 @@ +/* +#ifdef 0 + * 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/. +#endif + */ + +// One of the possible values for the mousewheel.* preferences. +// From nsEventStateManager.cpp. +const MOUSE_SCROLL_ZOOM = 3; + +/** + * 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() { + // Listen for scrollwheel events so we can save scrollwheel-based changes. + window.addEventListener("DOMMouseScroll", this, false); + + // 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.clear(); + this._initialLocations = null; + }, + + destroy: function FullZoom_destroy() { + gPrefService.removeObserver("browser.zoom.", this); + this._cps2.removeObserverForName(this.name, this); + window.removeEventListener("DOMMouseScroll", this, false); + }, + + + //**************************************************************************// + // Event Handlers + + // nsIDOMEventListener + + handleEvent: function FullZoom_handleEvent(event) { + switch (event.type) { + case "DOMMouseScroll": + this._handleMouseScrolled(event); + break; + } + }, + + _handleMouseScrolled: function FullZoom__handleMouseScrolled(event) { + // Construct the "mousewheel action" pref key corresponding to this event. + // Based on nsEventStateManager::WheelPrefs::GetBasePrefName(). + var pref = "mousewheel."; + + var pressedModifierCount = event.shiftKey + event.ctrlKey + event.altKey + + event.metaKey + event.getModifierState("OS"); + if (pressedModifierCount != 1) { + pref += "default."; + } else if (event.shiftKey) { + pref += "with_shift."; + } else if (event.ctrlKey) { + pref += "with_control."; + } else if (event.altKey) { + pref += "with_alt."; + } else if (event.metaKey) { + pref += "with_meta."; + } else { + pref += "with_win."; + } + + pref += "action"; + + // Don't do anything if this isn't a "zoom" scroll event. + var isZoomEvent = false; + try { + isZoomEvent = (gPrefService.getIntPref(pref) == MOUSE_SCROLL_ZOOM); + } catch (e) {} + if (!isZoomEvent) + return; + + // XXX Lazily cache all the possible action prefs so we don't have to get + // them anew from the pref service for every scroll event? We'd have to + // make sure to observe them so we can update the cache when they change. + + // We have to call _applyZoomToPref in a timeout because we handle the + // event before the event state manager has a chance to apply the zoom + // during nsEventStateManager::PostHandleEvent. + let browser = gBrowser.selectedBrowser; + let token = this._getBrowserToken(browser); + window.setTimeout(function () { + if (token.isCurrent) + this._applyZoomToPref(browser); + }.bind(this), 0); + }, + + // 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) { + this._onContentPrefChanged(aGroup, aValue); + }, + + onContentPrefRemoved: function FullZoom_onContentPrefRemoved(aGroup, aName) { + this._onContentPrefChanged(aGroup, undefined); + }, + + /** + * 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) { + 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 domain = this._cps2.extractDomain(browser.currentURI.spec); + if (aGroup) { + if (aGroup == domain) + 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 ctxt = this._loadContextFromBrowser(browser); + 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(); + return; + } + + // Avoid the cps roundtrip and apply the default/global pref. + if (aURI.spec == "about:blank") { + this._applyPrefToZoom(undefined, browser, + this._notifyOnLocationChange.bind(this)); + 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(); + 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)); + 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(); + return; + } + this._applyPrefToZoom(value, browser, + this._notifyOnLocationChange.bind(this)); + }.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 of the page in the current browser to the global zoom + * level. + */ + reset: function FullZoom_reset() { + let browser = gBrowser.selectedBrowser; + let token = this._getBrowserToken(browser); + this._getGlobalValue(browser, function (value) { + if (token.isCurrent) { + ZoomManager.setZoomForBrowser(browser, value === undefined ? 1 : value); + this._ignorePendingZoomAccesses(browser); + } + }); + this._removePref(browser); + }, + + /** + * 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, function (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) { + 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) { + 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; + }, + }; + }, + + /** + * 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. + * + * WARNING: callback may be called synchronously or asynchronously. The + * reason is that it's usually desirable to avoid turns of the event loop + * where possible, since they can lead to visible, jarring jumps in zoom + * level. It's not always possible to avoid them, though. As a convenience, + * then, this method takes a callback and returns nothing. + * + * @param browser The content browser pertaining to the zoom. + * @param callback Synchronously or asynchronously called when done. It's + * bound to this object (FullZoom) and called as: + * callback(prefValue) + */ + _getGlobalValue: function FullZoom__getGlobalValue(browser, callback) { + // * !("_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. + if ("_globalValue" in this) { + callback.call(this, this._globalValue, true); + return; + } + let value = undefined; + this._cps2.getGlobal(this.name, this._loadContextFromBrowser(browser), { + handleResult: function (pref) value = pref.value, + handleCompletion: function (reason) { + this._globalValue = this._ensureValid(value); + callback.call(this, this._globalValue); + }.bind(this) + }); + }, + + /** + * Gets the load context from the given content 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 a "browser-fullZoom:locationChange" notification + * so that tests can select tabs, load pages, etc. and 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() { + this._executeSoon(function () { + Services.obs.notifyObservers(null, "browser-fullZoom:locationChange", ""); + }); + }, + + _executeSoon: function FullZoom__executeSoon(callback) { + if (!callback) + return; + Services.tm.mainThread.dispatch(callback, Ci.nsIThread.DISPATCH_NORMAL); + }, +}; |