gecko/browser/base/content/browser-fullZoom.js

536 lines
18 KiB
JavaScript

/*
#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,
// Incremented each time the zoom is changed so that operations that change
// the zoom asynchronously don't clobber more recent zoom changes. See
// _getState below.
_zoomChangeToken: 0,
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() {
// Bug 691614 - zooming support for electrolysis
if (gMultiProcessBrowser)
return;
// 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);
},
destroy: function FullZoom_destroy() {
// Bug 691614 - zooming support for electrolysis
if (gMultiProcessBrowser)
return;
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 state = this._getState();
window.setTimeout(function () {
if (this._isStateCurrent(state))
this._applyZoomToPref();
}.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;
}
if (!gBrowser.currentURI)
return;
let domain = this._cps2.extractDomain(gBrowser.currentURI.spec);
if (aGroup) {
if (aGroup == domain)
this._applyPrefToZoom(aValue);
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 state = this._getState();
let hasPref = false;
let ctxt = this._loadContextFromWindow(gBrowser.contentWindow);
this._cps2.getByDomainAndName(gBrowser.currentURI.spec, this.name, ctxt, {
handleResult: function () hasPref = true,
handleCompletion: function () {
if (!hasPref && this._isStateCurrent(state))
this._applyPrefToZoom(undefined, { state: state });
}.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) {
// Bug 691614 - zooming support for electrolysis
if (gMultiProcessBrowser)
return;
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: aBrowser,
onDone: this._notifyOnLocationChange.bind(this),
});
return;
}
let browser = aBrowser || gBrowser.selectedBrowser;
// Media documents should always start at 1, and are not affected by prefs.
if (!aIsTabSwitch && browser.contentDocument.mozSyntheticDocument) {
ZoomManager.setZoomForBrowser(browser, 1);
this._zoomChangeToken++;
this._notifyOnLocationChange();
return;
}
// See if the zoom pref is cached.
let ctxt = this._loadContextFromWindow(browser.contentWindow);
let pref = this._cps2.getCachedByDomainAndName(aURI.spec, this.name, ctxt);
if (pref) {
this._applyPrefToZoom(pref.value, {
browser: browser,
onDone: this._notifyOnLocationChange.bind(this),
});
return;
}
// It's not cached, so have to asynchronously fetch it.
let state = this._getState(browser);
let value = undefined;
this._cps2.getByDomainAndName(aURI.spec, this.name, ctxt, {
handleResult: function (resultPref) value = resultPref.value,
handleCompletion: function () {
if (this._isStateCurrent(state)) {
this._applyPrefToZoom(value, {
browser: browser,
state: state,
onDone: 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();
this._zoomChangeToken++;
this._applyZoomToPref();
},
/**
* Enlarges the zoom level of the page in the current browser.
*/
enlarge: function FullZoom_enlarge() {
ZoomManager.enlarge();
this._zoomChangeToken++;
this._applyZoomToPref();
},
/**
* Sets the zoom level of the page in the current browser to the global zoom
* level.
*/
reset: function FullZoom_reset() {
let state = this._getState();
this._getGlobalValue(gBrowser.contentWindow, function (value) {
if (this._isStateCurrent(state)) {
if (value === undefined)
ZoomManager.reset();
else
ZoomManager.zoom = value;
this._zoomChangeToken++;
}
});
this._removePref();
},
/**
* Set the zoom level for the current tab.
*
* 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 aOptions An object with the following optional propeties:
* @prop browser The browser containing the page whose zoom level is to be
* set. If falsey, the currently selected browser is used.
* @prop state This method may need to update the zoom asynchronously.
* If the caller is itself asynchronous, then it should have
* access to a FullZoom state (see _getState); pass that
* state here. If not given, the state is automatically
* captured.
* @prop onDone If given, it's asynchronously called when complete.
*/
_applyPrefToZoom: function FullZoom__applyPrefToZoom(aValue, aOptions={}) {
if (!this.siteSpecific || gInPrintPreviewMode) {
this._executeSoon(aOptions.onDone);
return;
}
var browser = aOptions.browser || (gBrowser && gBrowser.selectedBrowser);
if (browser.contentDocument.mozSyntheticDocument) {
this._executeSoon(aOptions.onDone);
return;
}
if (aValue !== undefined) {
ZoomManager.setZoomForBrowser(browser, this._ensureValid(aValue));
this._zoomChangeToken++;
this._executeSoon(aOptions.onDone);
return;
}
let state = aOptions.state || this._getState(browser);
this._getGlobalValue(browser.contentWindow, function (value) {
if (this._isStateCurrent(state)) {
ZoomManager.setZoomForBrowser(browser, value === undefined ? 1 : value);
this._zoomChangeToken++;
}
this._executeSoon(aOptions.onDone);
});
},
/**
* Saves the zoom level of the page in the current browser to the content
* prefs store.
*/
_applyZoomToPref: function FullZoom__applyZoomToPref() {
if (!this.siteSpecific ||
gInPrintPreviewMode ||
content.document.mozSyntheticDocument)
return;
this._cps2.set(gBrowser.currentURI.spec, this.name, ZoomManager.zoom,
this._loadContextFromWindow(gBrowser.contentWindow), {
handleCompletion: function () {
this._isNextContentPrefChangeInternal = true;
}.bind(this),
});
},
/**
* Removes from the content prefs store the zoom level of the current browser.
*/
_removePref: function FullZoom__removePref() {
if (content.document.mozSyntheticDocument)
return;
let ctxt = this._loadContextFromWindow(gBrowser.contentWindow);
this._cps2.removeByDomainAndName(gBrowser.currentURI.spec, this.name, ctxt, {
handleCompletion: function () {
this._isNextContentPrefChangeInternal = true;
}.bind(this),
});
},
//**************************************************************************//
// Utilities
/**
* Returns the current FullZoom "state". Asynchronous operations that change
* the zoom should use this method to capture the state before starting and
* use _isStateCurrent to determine if it's still current when done. If the
* captured state is no longer current, then the zoom should not be changed.
* Doing so would either change the zoom of the wrong tab or clobber an
* earlier zoom change that occurred after the operation started.
*
* @param browser The browser associated with the state. If not given, the
* currently selected browser is used.
*/
_getState: function FullZoom__getState(browser) {
browser = browser || gBrowser.selectedBrowser;
return {
// Due to async content pref service callbacks, this method can get called
// after the window has closed, so gBrowser.selectedBrowser may be null.
uri: browser ? browser.currentURI : null,
token: this._zoomChangeToken,
};
},
/**
* Returns true if the given state is current.
*/
_isStateCurrent: function FullZoom__isStateCurrent(state) {
// If either state has no URI, then the given state can't be current.
// currState.uri will be null when this method is called after the window
// has closed, which can happen due to async content pref service callbacks.
let currState = this._getState();
return currState.token === state.token &&
currState.uri && state.uri &&
this._cps2.extractDomain(currState.uri.spec) ==
this._cps2.extractDomain(state.uri.spec);
},
_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 window The content window pertaining to the zoom.
* @param callback Synchronously or asynchronously called when done. It's
* bound to this object (FullZoom) and passed the preference
* value.
*/
_getGlobalValue: function FullZoom__getGlobalValue(window, 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);
return;
}
let value = undefined;
this._cps2.getGlobal(this.name, this._loadContextFromWindow(window), {
handleResult: function (pref) value = pref.value,
handleCompletion: function () {
this._globalValue = this._ensureValid(value);
callback.call(this, this._globalValue);
}.bind(this)
});
},
/**
* Gets the load context from the given window.
*
* @param window The window whose load context will be returned.
* @return The nsILoadContext of the given window.
*/
_loadContextFromWindow: function FullZoom__loadContextFromWindow(window) {
return window.
QueryInterface(Ci.nsIInterfaceRequestor).
getInterface(Ci.nsIWebNavigation).
QueryInterface(Ci.nsILoadContext);
},
/**
* 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);
},
};