gecko/browser/modules/NewTabUtils.jsm

575 lines
14 KiB
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/. */
"use strict";
let EXPORTED_SYMBOLS = ["NewTabUtils"];
const Ci = Components.interfaces;
const Cc = Components.classes;
const Cu = Components.utils;
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
"resource://gre/modules/PlacesUtils.jsm");
// The preference that tells whether this feature is enabled.
const PREF_NEWTAB_ENABLED = "browser.newtabpage.enabled";
// The maximum number of results we want to retrieve from history.
const HISTORY_RESULTS_LIMIT = 100;
// The gather telemetry topic.
const TOPIC_GATHER_TELEMETRY = "gather-telemetry";
/**
* Singleton that provides storage functionality.
*/
let Storage = {
/**
* The dom storage instance used to persist data belonging to the New Tab Page.
*/
get domStorage() {
let uri = Services.io.newURI("about:newtab", null, null);
let principal = Services.scriptSecurityManager.getCodebasePrincipal(uri);
let sm = Services.domStorageManager;
let storage = sm.getLocalStorageForPrincipal(principal, "");
// Cache this value, overwrite the getter.
let descriptor = {value: storage, enumerable: true};
Object.defineProperty(this, "domStorage", descriptor);
return storage;
},
/**
* Gets the value for a given key from the storage.
* @param aKey The storage key (a string).
* @param aDefault A default value if the key doesn't exist.
* @return The value for the given key.
*/
get: function Storage_get(aKey, aDefault) {
let value;
try {
value = JSON.parse(this.domStorage.getItem(aKey));
} catch (e) {}
return value || aDefault;
},
/**
* Sets the storage value for a given key.
* @param aKey The storage key (a string).
* @param aValue The value to set.
*/
set: function Storage_set(aKey, aValue) {
this.domStorage.setItem(aKey, JSON.stringify(aValue));
},
/**
* Clears the storage and removes all values.
*/
clear: function Storage_clear() {
this.domStorage.clear();
},
QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
Ci.nsISupportsWeakReference])
};
/**
* Singleton that serves as a registry for all open 'New Tab Page's.
*/
let AllPages = {
/**
* The array containing all active pages.
*/
_pages: [],
/**
* Cached value that tells whether the New Tab Page feature is enabled.
*/
_enabled: null,
/**
* Adds a page to the internal list of pages.
* @param aPage The page to register.
*/
register: function AllPages_register(aPage) {
this._pages.push(aPage);
this._addObserver();
},
/**
* Removes a page from the internal list of pages.
* @param aPage The page to unregister.
*/
unregister: function AllPages_unregister(aPage) {
let index = this._pages.indexOf(aPage);
if (index > -1)
this._pages.splice(index, 1);
},
/**
* Returns whether the 'New Tab Page' is enabled.
*/
get enabled() {
if (this._enabled === null)
this._enabled = Services.prefs.getBoolPref(PREF_NEWTAB_ENABLED);
return this._enabled;
},
/**
* Enables or disables the 'New Tab Page' feature.
*/
set enabled(aEnabled) {
if (this.enabled != aEnabled)
Services.prefs.setBoolPref(PREF_NEWTAB_ENABLED, !!aEnabled);
},
/**
* Returns the number of registered New Tab Pages (i.e. the number of open
* about:newtab instances).
*/
get length() {
return this._pages.length;
},
/**
* Updates all currently active pages but the given one.
* @param aExceptPage The page to exclude from updating.
*/
update: function AllPages_update(aExceptPage) {
this._pages.forEach(function (aPage) {
if (aExceptPage != aPage)
aPage.update();
});
},
/**
* Implements the nsIObserver interface to get notified when the preference
* value changes.
*/
observe: function AllPages_observe() {
// Clear the cached value.
this._enabled = null;
let args = Array.slice(arguments);
this._pages.forEach(function (aPage) {
aPage.observe.apply(aPage, args);
}, this);
},
/**
* Adds a preference observer and turns itself into a no-op after the first
* invokation.
*/
_addObserver: function AllPages_addObserver() {
Services.prefs.addObserver(PREF_NEWTAB_ENABLED, this, true);
this._addObserver = function () {};
},
QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
Ci.nsISupportsWeakReference])
};
/**
* Singleton that keeps track of all pinned links and their positions in the
* grid.
*/
let PinnedLinks = {
/**
* The cached list of pinned links.
*/
_links: null,
/**
* The array of pinned links.
*/
get links() {
if (!this._links)
this._links = Storage.get("pinnedLinks", []);
return this._links;
},
/**
* Pins a link at the given position.
* @param aLink The link to pin.
* @param aIndex The grid index to pin the cell at.
*/
pin: function PinnedLinks_pin(aLink, aIndex) {
// Clear the link's old position, if any.
this.unpin(aLink);
this.links[aIndex] = aLink;
this.save();
},
/**
* Unpins a given link.
* @param aLink The link to unpin.
*/
unpin: function PinnedLinks_unpin(aLink) {
let index = this._indexOfLink(aLink);
if (index != -1) {
this.links[index] = null;
this.save();
}
},
/**
* Saves the current list of pinned links.
*/
save: function PinnedLinks_save() {
Storage.set("pinnedLinks", this.links);
},
/**
* Checks whether a given link is pinned.
* @params aLink The link to check.
* @return whether The link is pinned.
*/
isPinned: function PinnedLinks_isPinned(aLink) {
return this._indexOfLink(aLink) != -1;
},
/**
* Resets the links cache.
*/
resetCache: function PinnedLinks_resetCache() {
this._links = null;
},
/**
* Finds the index of a given link in the list of pinned links.
* @param aLink The link to find an index for.
* @return The link's index.
*/
_indexOfLink: function PinnedLinks_indexOfLink(aLink) {
for (let i = 0; i < this.links.length; i++) {
let link = this.links[i];
if (link && link.url == aLink.url)
return i;
}
// The given link is unpinned.
return -1;
}
};
/**
* Singleton that keeps track of all blocked links in the grid.
*/
let BlockedLinks = {
/**
* The cached list of blocked links.
*/
_links: null,
/**
* The list of blocked links.
*/
get links() {
if (!this._links)
this._links = Storage.get("blockedLinks", {});
return this._links;
},
/**
* Blocks a given link.
* @param aLink The link to block.
*/
block: function BlockedLinks_block(aLink) {
this.links[aLink.url] = 1;
this.save();
// Make sure we unpin blocked links.
PinnedLinks.unpin(aLink);
},
/**
* Unblocks a given link.
* @param aLink The link to unblock.
*/
unblock: function BlockedLinks_unblock(aLink) {
if (this.isBlocked(aLink)) {
delete this.links[aLink.url];
this.save();
}
},
/**
* Saves the current list of blocked links.
*/
save: function BlockedLinks_save() {
Storage.set("blockedLinks", this.links);
},
/**
* Returns whether a given link is blocked.
* @param aLink The link to check.
*/
isBlocked: function BlockedLinks_isBlocked(aLink) {
return (aLink.url in this.links);
},
/**
* Checks whether the list of blocked links is empty.
* @return Whether the list is empty.
*/
isEmpty: function BlockedLinks_isEmpty() {
return Object.keys(this.links).length == 0;
},
/**
* Resets the links cache.
*/
resetCache: function BlockedLinks_resetCache() {
this._links = null;
}
};
/**
* Singleton that serves as the default link provider for the grid. It queries
* the history to retrieve the most frequently visited sites.
*/
let PlacesProvider = {
/**
* Gets the current set of links delivered by this provider.
* @param aCallback The function that the array of links is passed to.
*/
getLinks: function PlacesProvider_getLinks(aCallback) {
let options = PlacesUtils.history.getNewQueryOptions();
options.maxResults = HISTORY_RESULTS_LIMIT;
// Sort by frecency, descending.
options.sortingMode = Ci.nsINavHistoryQueryOptions.SORT_BY_FRECENCY_DESCENDING
let links = [];
let callback = {
handleResult: function (aResultSet) {
let row;
while (row = aResultSet.getNextRow()) {
let url = row.getResultByIndex(1);
let title = row.getResultByIndex(2);
links.push({url: url, title: title});
}
},
handleError: function (aError) {
// Should we somehow handle this error?
aCallback([]);
},
handleCompletion: function (aReason) {
aCallback(links);
}
};
// Execute the query.
let query = PlacesUtils.history.getNewQuery();
let db = PlacesUtils.history.QueryInterface(Ci.nsPIPlacesDatabase);
db.asyncExecuteLegacyQueries([query], 1, options, callback);
}
};
/**
* Singleton that provides access to all links contained in the grid (including
* the ones that don't fit on the grid). A link is a plain object with title
* and url properties.
*
* Example:
*
* {url: "http://www.mozilla.org/", title: "Mozilla"}
*/
let Links = {
/**
* The links cache.
*/
_links: null,
/**
* The default provider for links.
*/
_provider: PlacesProvider,
/**
* List of callbacks waiting for the cache to be populated.
*/
_populateCallbacks: [],
/**
* Populates the cache with fresh links from the current provider.
* @param aCallback The callback to call when finished (optional).
* @param aForce When true, populates the cache even when it's already filled.
*/
populateCache: function Links_populateCache(aCallback, aForce) {
let callbacks = this._populateCallbacks;
// Enqueue the current callback.
callbacks.push(aCallback);
// There was a callback waiting already, thus the cache has not yet been
// populated.
if (callbacks.length > 1)
return;
function executeCallbacks() {
while (callbacks.length) {
let callback = callbacks.shift();
if (callback) {
try {
callback();
} catch (e) {
// We want to proceed even if a callback fails.
}
}
}
}
if (this._links && !aForce) {
executeCallbacks();
} else {
this._provider.getLinks(function (aLinks) {
this._links = aLinks;
executeCallbacks();
}.bind(this));
this._addObserver();
}
},
/**
* Gets the current set of links contained in the grid.
* @return The links in the grid.
*/
getLinks: function Links_getLinks() {
let pinnedLinks = Array.slice(PinnedLinks.links);
// Filter blocked and pinned links.
let links = this._links.filter(function (link) {
return !BlockedLinks.isBlocked(link) && !PinnedLinks.isPinned(link);
});
// Try to fill the gaps between pinned links.
for (let i = 0; i < pinnedLinks.length && links.length; i++)
if (!pinnedLinks[i])
pinnedLinks[i] = links.shift();
// Append the remaining links if any.
if (links.length)
pinnedLinks = pinnedLinks.concat(links);
return pinnedLinks;
},
/**
* Resets the links cache.
*/
resetCache: function Links_resetCache() {
this._links = null;
},
/**
* Implements the nsIObserver interface to get notified about browser history
* sanitization.
*/
observe: function Links_observe(aSubject, aTopic, aData) {
// Make sure to update open about:newtab instances. If there are no opened
// pages we can just wait for the next new tab to populate the cache again.
if (AllPages.length && AllPages.enabled)
this.populateCache(function () { AllPages.update() }, true);
else
this._links = null;
},
/**
* Adds a sanitization observer and turns itself into a no-op after the first
* invokation.
*/
_addObserver: function Links_addObserver() {
Services.obs.addObserver(this, "browser:purge-session-history", true);
this._addObserver = function () {};
},
QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
Ci.nsISupportsWeakReference])
};
/**
* Singleton used to collect telemetry data.
*
*/
let Telemetry = {
/**
* Initializes object.
*/
init: function Telemetry_init() {
Services.obs.addObserver(this, TOPIC_GATHER_TELEMETRY, false);
},
/**
* Collects data.
*/
_collect: function Telemetry_collect() {
let probes = [
{ histogram: "NEWTAB_PAGE_ENABLED",
value: AllPages.enabled },
{ histogram: "NEWTAB_PAGE_PINNED_SITES_COUNT",
value: PinnedLinks.links.length },
{ histogram: "NEWTAB_PAGE_BLOCKED_SITES_COUNT",
value: Object.keys(BlockedLinks.links).length }
];
probes.forEach(function Telemetry_collect_forEach(aProbe) {
Services.telemetry.getHistogramById(aProbe.histogram)
.add(aProbe.value);
});
},
/**
* Listens for gather telemetry topic.
*/
observe: function Telemetry_observe(aSubject, aTopic, aData) {
this._collect();
}
};
Telemetry.init();
/**
* Singleton that provides the public API of this JSM.
*/
let NewTabUtils = {
/**
* Restores all sites that have been removed from the grid.
*/
restore: function NewTabUtils_restore() {
Storage.clear();
Links.resetCache();
PinnedLinks.resetCache();
BlockedLinks.resetCache();
Links.populateCache(function () {
AllPages.update();
}, true);
},
allPages: AllPages,
links: Links,
pinnedLinks: PinnedLinks,
blockedLinks: BlockedLinks
};