The Tor Browser: mobile/android/base/Tabs.java@6474c204b198 (annotated)

mobile/android/base/Tabs.java@6474c204b198 (annotated)

mobile/android/base/Tabs.java

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
  * 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/. */
 package org.mozilla.gecko;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.json.JSONObject;
 import org.mozilla.gecko.db.BrowserDB;
 import org.mozilla.gecko.favicons.Favicons;
 import org.mozilla.gecko.fxa.FirefoxAccounts;
 import org.mozilla.gecko.mozglue.JNITarget;
 import org.mozilla.gecko.mozglue.RobocopTarget;
 import org.mozilla.gecko.sync.setup.SyncAccounts;
 import org.mozilla.gecko.util.GeckoEventListener;
 import org.mozilla.gecko.util.ThreadUtils;
 import android.accounts.Account;
 import android.accounts.AccountManager;
 import android.accounts.OnAccountsUpdateListener;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.database.ContentObserver;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.net.Uri;
 import android.os.Handler;
 import android.util.Log;
 public class Tabs implements GeckoEventListener {
     private static final String LOGTAG = "GeckoTabs";
     // mOrder and mTabs are always of the same cardinality, and contain the same values.
     private final CopyOnWriteArrayList<Tab> mOrder = new CopyOnWriteArrayList<Tab>();
     // All writes to mSelectedTab must be synchronized on the Tabs instance.
     // In general, it's preferred to always use selectTab()).
     private volatile Tab mSelectedTab;
     // All accesses to mTabs must be synchronized on the Tabs instance.
     private final HashMap<Integer, Tab> mTabs = new HashMap<Integer, Tab>();
     private AccountManager mAccountManager;
     private OnAccountsUpdateListener mAccountListener = null;
     public static final int LOADURL_NONE         = 0;
     public static final int LOADURL_NEW_TAB      = 1 << 0;
     public static final int LOADURL_USER_ENTERED = 1 << 1;
     public static final int LOADURL_PRIVATE      = 1 << 2;
     public static final int LOADURL_PINNED       = 1 << 3;
     public static final int LOADURL_DELAY_LOAD   = 1 << 4;
     public static final int LOADURL_DESKTOP      = 1 << 5;
     public static final int LOADURL_BACKGROUND   = 1 << 6;
     public static final int LOADURL_EXTERNAL     = 1 << 7;
     private static final long PERSIST_TABS_AFTER_MILLISECONDS = 1000 * 5;
     private static AtomicInteger sTabId = new AtomicInteger(0);
     private volatile boolean mInitialTabsAdded;
     private Context mAppContext;
     private ContentObserver mContentObserver;
     private final Runnable mPersistTabsRunnable = new Runnable() {
         @Override
         public void run() {
             try {
                 final Context context = getAppContext();
                 boolean syncIsSetup = SyncAccounts.syncAccountsExist(context) ||
                                       FirefoxAccounts.firefoxAccountsExist(context);
                 if (syncIsSetup) {
                     TabsAccessor.persistLocalTabs(getContentResolver(), getTabsInOrder());
                 }
             } catch (SecurityException se) {} // will fail without android.permission.GET_ACCOUNTS
         }
     };
     private Tabs() {
         registerEventListener("Session:RestoreEnd");
         registerEventListener("SessionHistory:New");
         registerEventListener("SessionHistory:Back");
         registerEventListener("SessionHistory:Forward");
         registerEventListener("SessionHistory:Goto");
         registerEventListener("SessionHistory:Purge");
         registerEventListener("Tab:Added");
         registerEventListener("Tab:Close");
         registerEventListener("Tab:Select");
         registerEventListener("Content:LocationChange");
         registerEventListener("Content:SecurityChange");
         registerEventListener("Content:ReaderEnabled");
         registerEventListener("Content:StateChange");
         registerEventListener("Content:LoadError");
         registerEventListener("Content:PageShow");
         registerEventListener("DOMContentLoaded");
         registerEventListener("DOMTitleChanged");
         registerEventListener("Link:Favicon");
         registerEventListener("Link:Feed");
         registerEventListener("Link:OpenSearch");
         registerEventListener("DesktopMode:Changed");
         registerEventListener("Tab:ViewportMetadata");
         registerEventListener("Tab:StreamStart");
         registerEventListener("Tab:StreamStop");
     }
     public synchronized void attachToContext(Context context) {
         final Context appContext = context.getApplicationContext();
         if (mAppContext == appContext) {
             return;
         }
         if (mAppContext != null) {
             // This should never happen.
             Log.w(LOGTAG, "The application context has changed!");
         }
         mAppContext = appContext;
         mAccountManager = AccountManager.get(appContext);
         mAccountListener = new OnAccountsUpdateListener() {
             @Override
             public void onAccountsUpdated(Account[] accounts) {
                 persistAllTabs();
             }
         };
         // The listener will run on the background thread (see 2nd argument).
         mAccountManager.addOnAccountsUpdatedListener(mAccountListener, ThreadUtils.getBackgroundHandler(), false);
         if (mContentObserver != null) {
             BrowserDB.registerBookmarkObserver(getContentResolver(), mContentObserver);
         }
     }
     /**
      * Gets the tab count corresponding to the private state of the selected
      * tab.
      *
      * If the selected tab is a non-private tab, this will return the number of
      * non-private tabs; likewise, if this is a private tab, this will return
      * the number of private tabs.
      *
      * @return the number of tabs in the current private state
      */
     public synchronized int getDisplayCount() {
         // Once mSelectedTab is non-null, it cannot be null for the remainder
         // of the object's lifetime.
         boolean getPrivate = mSelectedTab != null && mSelectedTab.isPrivate();
         int count = 0;
         for (Tab tab : mOrder) {
             if (tab.isPrivate() == getPrivate) {
                 count++;
             }
         }
         return count;
     }
     public int isOpen(String url) {
         for (Tab tab : mOrder) {
             if (tab.getURL().equals(url)) {
                 return tab.getId();
             }
         }
         return -1;
     }
     // Must be synchronized to avoid racing on mContentObserver.
     private void lazyRegisterBookmarkObserver() {
         if (mContentObserver == null) {
             mContentObserver = new ContentObserver(null) {
                 @Override
                 public void onChange(boolean selfChange) {
                     for (Tab tab : mOrder) {
                         tab.updateBookmark();
                     }
                 }
             };
             BrowserDB.registerBookmarkObserver(getContentResolver(), mContentObserver);
         }
     }
     private Tab addTab(int id, String url, boolean external, int parentId, String title, boolean isPrivate) {
         final Tab tab = isPrivate ? new PrivateTab(mAppContext, id, url, external, parentId, title) :
                                     new Tab(mAppContext, id, url, external, parentId, title);
         synchronized (this) {
             lazyRegisterBookmarkObserver();
             mTabs.put(id, tab);
             mOrder.add(tab);
         }
         // Suppress the ADDED event to prevent animation of tabs created via session restore.
         if (mInitialTabsAdded) {
             notifyListeners(tab, TabEvents.ADDED);
         }
         return tab;
     }
     public synchronized void removeTab(int id) {
         if (mTabs.containsKey(id)) {
             Tab tab = getTab(id);
             mOrder.remove(tab);
             mTabs.remove(id);
         }
     }
     public synchronized Tab selectTab(int id) {
         if (!mTabs.containsKey(id))
             return null;
         final Tab oldTab = getSelectedTab();
         final Tab tab = mTabs.get(id);
         // This avoids a NPE below, but callers need to be careful to
         // handle this case.
         if (tab == null || oldTab == tab) {
             return null;
         }
         mSelectedTab = tab;
         notifyListeners(tab, TabEvents.SELECTED);
         if (oldTab != null) {
             notifyListeners(oldTab, TabEvents.UNSELECTED);
         }
         // Pass a message to Gecko to update tab state in BrowserApp.
         GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Tab:Selected", String.valueOf(tab.getId())));
         return tab;
     }
     private int getIndexOf(Tab tab) {
         return mOrder.lastIndexOf(tab);
     }
     private Tab getNextTabFrom(Tab tab, boolean getPrivate) {
         int numTabs = mOrder.size();
         int index = getIndexOf(tab);
         for (int i = index + 1; i < numTabs; i++) {
             Tab next = mOrder.get(i);
             if (next.isPrivate() == getPrivate) {
                 return next;
             }
         }
         return null;
     }
     private Tab getPreviousTabFrom(Tab tab, boolean getPrivate) {
         int index = getIndexOf(tab);
         for (int i = index - 1; i >= 0; i--) {
             Tab prev = mOrder.get(i);
             if (prev.isPrivate() == getPrivate) {
                 return prev;
             }
         }
         return null;
     }
     /**
      * Gets the selected tab.
      *
      * The selected tab can be null if we're doing a session restore after a
      * crash and Gecko isn't ready yet.
      *
      * @return the selected tab, or null if no tabs exist
      */
     public Tab getSelectedTab() {
         return mSelectedTab;
     }
     public boolean isSelectedTab(Tab tab) {
         return tab != null && tab == mSelectedTab;
     }
     public boolean isSelectedTabId(int tabId) {
         final Tab selected = mSelectedTab;
         return selected != null && selected.getId() == tabId;
     }
     @RobocopTarget
     public synchronized Tab getTab(int id) {
         if (id == -1)
             return null;
         if (mTabs.size() == 0)
             return null;
         if (!mTabs.containsKey(id))
            return null;
         return mTabs.get(id);
     }
     /** Close tab and then select the default next tab */
     @RobocopTarget
     public synchronized void closeTab(Tab tab) {
         closeTab(tab, getNextTab(tab));
     }
     /** Close tab and then select nextTab */
     public synchronized void closeTab(final Tab tab, Tab nextTab) {
         if (tab == null)
             return;
         int tabId = tab.getId();
         removeTab(tabId);
         if (nextTab == null) {
             nextTab = loadUrl(AboutPages.HOME, LOADURL_NEW_TAB);
         }
         selectTab(nextTab.getId());
         tab.onDestroy();
         // Pass a message to Gecko to update tab state in BrowserApp
         GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Tab:Closed", String.valueOf(tabId)));
     }
     /** Return the tab that will be selected by default after this one is closed */
     public Tab getNextTab(Tab tab) {
         Tab selectedTab = getSelectedTab();
         if (selectedTab != tab)
             return selectedTab;
         boolean getPrivate = tab.isPrivate();
         Tab nextTab = getNextTabFrom(tab, getPrivate);
         if (nextTab == null)
             nextTab = getPreviousTabFrom(tab, getPrivate);
         if (nextTab == null && getPrivate) {
             // If there are no private tabs remaining, get the last normal tab
             Tab lastTab = mOrder.get(mOrder.size() - 1);
             if (!lastTab.isPrivate()) {
                 nextTab = lastTab;
             } else {
                 nextTab = getPreviousTabFrom(lastTab, false);
             }
         }
         Tab parent = getTab(tab.getParentId());
         if (parent != null) {
             // If the next tab is a sibling, switch to it. Otherwise go back to the parent.
             if (nextTab != null && nextTab.getParentId() == tab.getParentId())
                 return nextTab;
             else
                 return parent;
         }
         return nextTab;
     }
     public Iterable<Tab> getTabsInOrder() {
         return mOrder;
     }
     /**
      * @return the current GeckoApp instance, or throws if
      *         we aren't correctly initialized.
      */
     private synchronized Context getAppContext() {
         if (mAppContext == null) {
             throw new IllegalStateException("Tabs not initialized with a GeckoApp instance.");
         }
         return mAppContext;
     }
     public ContentResolver getContentResolver() {
         return getAppContext().getContentResolver();
     }
     // Make Tabs a singleton class.
     private static class TabsInstanceHolder {
         private static final Tabs INSTANCE = new Tabs();
     }
     @RobocopTarget
     public static Tabs getInstance() {
        return Tabs.TabsInstanceHolder.INSTANCE;
     }
     // GeckoEventListener implementation
     @Override
     public void handleMessage(String event, JSONObject message) {
         Log.d(LOGTAG, "handleMessage: " + event);
         try {
             if (event.equals("Session:RestoreEnd")) {
                 notifyListeners(null, TabEvents.RESTORED);
                 return;
             }
             // All other events handled below should contain a tabID property
             int id = message.getInt("tabID");
             Tab tab = getTab(id);
             // "Tab:Added" is a special case because tab will be null if the tab was just added
             if (event.equals("Tab:Added")) {
                 String url = message.isNull("uri") ? null : message.getString("uri");
                 if (message.getBoolean("stub")) {
                     if (tab == null) {
                         // Tab was already closed; abort
                         return;
                     }
                 } else {
                     tab = addTab(id, url, message.getBoolean("external"),
                                           message.getInt("parentId"),
                                           message.getString("title"),
                                           message.getBoolean("isPrivate"));
                     // If we added the tab as a stub, we should have already
                     // selected it, so ignore this flag for stubbed tabs.
                     if (message.getBoolean("selected"))
                         selectTab(id);
                 }
                 if (message.getBoolean("delayLoad"))
                     tab.setState(Tab.STATE_DELAYED);
                 if (message.getBoolean("desktopMode"))
                     tab.setDesktopMode(true);
                 return;
             }
             // Tab was already closed; abort
             if (tab == null)
                 return;
             if (event.startsWith("SessionHistory:")) {
                 event = event.substring("SessionHistory:".length());
                 tab.handleSessionHistoryMessage(event, message);
             } else if (event.equals("Tab:Close")) {
                 closeTab(tab);
             } else if (event.equals("Tab:Select")) {
                 selectTab(tab.getId());
             } else if (event.equals("Content:LocationChange")) {
                 tab.handleLocationChange(message);
             } else if (event.equals("Content:SecurityChange")) {
                 tab.updateIdentityData(message.getJSONObject("identity"));
                 notifyListeners(tab, TabEvents.SECURITY_CHANGE);
             } else if (event.equals("Content:ReaderEnabled")) {
                 tab.setReaderEnabled(true);
                 notifyListeners(tab, TabEvents.READER_ENABLED);
             } else if (event.equals("Content:StateChange")) {
                 int state = message.getInt("state");
                 if ((state & GeckoAppShell.WPL_STATE_IS_NETWORK) != 0) {
                     if ((state & GeckoAppShell.WPL_STATE_START) != 0) {
                         boolean restoring = message.getBoolean("restoring");
                         tab.handleDocumentStart(restoring, message.getString("uri"));
                         notifyListeners(tab, Tabs.TabEvents.START);
                     } else if ((state & GeckoAppShell.WPL_STATE_STOP) != 0) {
                         tab.handleDocumentStop(message.getBoolean("success"));
                         notifyListeners(tab, Tabs.TabEvents.STOP);
                     }
                 }
             } else if (event.equals("Content:LoadError")) {
                 tab.handleContentLoaded();
                 notifyListeners(tab, Tabs.TabEvents.LOAD_ERROR);
             } else if (event.equals("Content:PageShow")) {
                 notifyListeners(tab, TabEvents.PAGE_SHOW);
             } else if (event.equals("DOMContentLoaded")) {
                 tab.handleContentLoaded();
                 String backgroundColor = message.getString("bgColor");
                 if (backgroundColor != null) {
                     tab.setBackgroundColor(backgroundColor);
                 } else {
                     // Default to white if no color is given
                     tab.setBackgroundColor(Color.WHITE);
                 }
                 tab.setErrorType(message.optString("errorType"));
                 notifyListeners(tab, Tabs.TabEvents.LOADED);
             } else if (event.equals("DOMTitleChanged")) {
                 tab.updateTitle(message.getString("title"));
             } else if (event.equals("Link:Favicon")) {
                 tab.updateFaviconURL(message.getString("href"), message.getInt("size"));
                 notifyListeners(tab, TabEvents.LINK_FAVICON);
             } else if (event.equals("Link:Feed")) {
                 tab.setHasFeeds(true);
                 notifyListeners(tab, TabEvents.LINK_FEED);
             } else if (event.equals("Link:OpenSearch")) {
                 boolean visible = message.getBoolean("visible");
                 tab.setHasOpenSearch(visible);
             } else if (event.equals("DesktopMode:Changed")) {
                 tab.setDesktopMode(message.getBoolean("desktopMode"));
                 notifyListeners(tab, TabEvents.DESKTOP_MODE_CHANGE);
             } else if (event.equals("Tab:ViewportMetadata")) {
                 tab.setZoomConstraints(new ZoomConstraints(message));
                 tab.setIsRTL(message.getBoolean("isRTL"));
                 notifyListeners(tab, TabEvents.VIEWPORT_CHANGE);
             } else if (event.equals("Tab:StreamStart")) {
                 tab.setRecording(true);
                 notifyListeners(tab, TabEvents.RECORDING_CHANGE);
             } else if (event.equals("Tab:StreamStop")) {
                 tab.setRecording(false);
                 notifyListeners(tab, TabEvents.RECORDING_CHANGE);
             }
         } catch (Exception e) {
             Log.w(LOGTAG, "handleMessage threw for " + event, e);
         }
     }
     /**
      * Set the favicon for any tabs loaded with this page URL.
      */
     public void updateFaviconForURL(String pageURL, Bitmap favicon) {
         // The tab might be pointing to another URL by the time the
         // favicon is finally loaded, in which case we won't find the tab.
         // See also: Bug 920331.
         for (Tab tab : mOrder) {
             String tabURL = tab.getURL();
             if (pageURL.equals(tabURL)) {
                 tab.setFaviconLoadId(Favicons.NOT_LOADING);
                 if (tab.updateFavicon(favicon)) {
                     notifyListeners(tab, TabEvents.FAVICON);
                 }
             }
         }
     }
     public void refreshThumbnails() {
         final ThumbnailHelper helper = ThumbnailHelper.getInstance();
         ThreadUtils.postToBackgroundThread(new Runnable() {
             @Override
             public void run() {
                 for (final Tab tab : mOrder) {
                     helper.getAndProcessThumbnailFor(tab);
                 }
             }
         });
     }
     public interface OnTabsChangedListener {
         public void onTabChanged(Tab tab, TabEvents msg, Object data);
     }
     private static final List<OnTabsChangedListener> TABS_CHANGED_LISTENERS = new CopyOnWriteArrayList<OnTabsChangedListener>();
     public static void registerOnTabsChangedListener(OnTabsChangedListener listener) {
         TABS_CHANGED_LISTENERS.add(listener);
     }
     public static void unregisterOnTabsChangedListener(OnTabsChangedListener listener) {
         TABS_CHANGED_LISTENERS.remove(listener);
     }
     public enum TabEvents {
         CLOSED,
         START,
         LOADED,
         LOAD_ERROR,
         STOP,
         FAVICON,
         THUMBNAIL,
         TITLE,
         SELECTED,
         UNSELECTED,
         ADDED,
         RESTORED,
         LOCATION_CHANGE,
         MENU_UPDATED,
         PAGE_SHOW,
         LINK_FAVICON,
         LINK_FEED,
         SECURITY_CHANGE,
         READER_ENABLED,
         DESKTOP_MODE_CHANGE,
         VIEWPORT_CHANGE,
         RECORDING_CHANGE
     }
     public void notifyListeners(Tab tab, TabEvents msg) {
         notifyListeners(tab, msg, "");
     }
     public void notifyListeners(final Tab tab, final TabEvents msg, final Object data) {
         if (tab == null &&
             msg != TabEvents.RESTORED) {
             throw new IllegalArgumentException("onTabChanged:" + msg + " must specify a tab.");
         }
         ThreadUtils.postToUiThread(new Runnable() {
             @Override
             public void run() {
                 onTabChanged(tab, msg, data);
                 if (TABS_CHANGED_LISTENERS.isEmpty()) {
                     return;
                 }
                 Iterator<OnTabsChangedListener> items = TABS_CHANGED_LISTENERS.iterator();
                 while (items.hasNext()) {
                     items.next().onTabChanged(tab, msg, data);
                 }
             }
         });
     }
     private void onTabChanged(Tab tab, Tabs.TabEvents msg, Object data) {
         switch (msg) {
             case LOCATION_CHANGE:
                 queuePersistAllTabs();
                 break;
             case RESTORED:
                 mInitialTabsAdded = true;
                 break;
             // When one tab is deselected, another one is always selected, so only
             // queue a single persist operation. When tabs are added/closed, they
             // are also selected/unselected, so it would be redundant to also listen
             // for ADDED/CLOSED events.
             case SELECTED:
                 queuePersistAllTabs();
             case UNSELECTED:
                 tab.onChange();
                 break;
             default:
                 break;
         }
     }
     // This method persists the current ordered list of tabs in our tabs content provider.
     public void persistAllTabs() {
         ThreadUtils.postToBackgroundThread(mPersistTabsRunnable);
     }
     /**
      * Queues a request to persist tabs after PERSIST_TABS_AFTER_MILLISECONDS
      * milliseconds have elapsed. If any existing requests are already queued then
      * those requests are removed.
      */
     private void queuePersistAllTabs() {
         Handler backgroundHandler = ThreadUtils.getBackgroundHandler();
         backgroundHandler.removeCallbacks(mPersistTabsRunnable);
         backgroundHandler.postDelayed(mPersistTabsRunnable, PERSIST_TABS_AFTER_MILLISECONDS);
     }
     private void registerEventListener(String event) {
         GeckoAppShell.getEventDispatcher().registerEventListener(event, this);
     }
     /**
      * Looks for an open tab with the given URL.
      * @param url       the URL of the tab we're looking for
      *
      * @return first Tab with the given URL, or null if there is no such tab.
      */
     public Tab getFirstTabForUrl(String url) {
         return getFirstTabForUrlHelper(url, null);
     }
     /**
      * Looks for an open tab with the given URL and private state.
      * @param url       the URL of the tab we're looking for
      * @param isPrivate if true, only look for tabs that are private. if false,
      *                  only look for tabs that are non-private.
      *
      * @return first Tab with the given URL, or null if there is no such tab.
      */
     public Tab getFirstTabForUrl(String url, boolean isPrivate) {
         return getFirstTabForUrlHelper(url, isPrivate);
     }
     private Tab getFirstTabForUrlHelper(String url, Boolean isPrivate) {
         if (url == null) {
             return null;
         }
         for (Tab tab : mOrder) {
             if (isPrivate != null && isPrivate != tab.isPrivate()) {
                 continue;
             }
             String tabUrl = tab.getURL();
             if (AboutPages.isAboutReader(tabUrl)) {
                 tabUrl = ReaderModeUtils.getUrlFromAboutReader(tabUrl);
             }
             if (url.equals(tabUrl)) {
                 return tab;
             }
         }
         return null;
     }
     /**
      * Loads a tab with the given URL in the currently selected tab.
      *
      * @param url URL of page to load, or search term used if searchEngine is given
      */
     @RobocopTarget
     public Tab loadUrl(String url) {
         return loadUrl(url, LOADURL_NONE);
     }
     /**
      * Loads a tab with the given URL.
      *
      * @param url   URL of page to load, or search term used if searchEngine is given
      * @param flags flags used to load tab
      *
      * @return      the Tab if a new one was created; null otherwise
      */
     public Tab loadUrl(String url, int flags) {
         return loadUrl(url, null, -1, flags);
     }
     /**
      * Loads a tab with the given URL.
      *
      * @param url          URL of page to load, or search term used if searchEngine is given
      * @param searchEngine if given, the search engine with this name is used
      *                     to search for the url string; if null, the URL is loaded directly
      * @param parentId     ID of this tab's parent, or -1 if it has no parent
      * @param flags        flags used to load tab
      *
      * @return             the Tab if a new one was created; null otherwise
      */
     public Tab loadUrl(String url, String searchEngine, int parentId, int flags) {
         JSONObject args = new JSONObject();
         Tab added = null;
         boolean delayLoad = (flags & LOADURL_DELAY_LOAD) != 0;
         // delayLoad implies background tab
         boolean background = delayLoad || (flags & LOADURL_BACKGROUND) != 0;
         try {
             boolean isPrivate = (flags & LOADURL_PRIVATE) != 0;
             boolean userEntered = (flags & LOADURL_USER_ENTERED) != 0;
             boolean desktopMode = (flags & LOADURL_DESKTOP) != 0;
             boolean external = (flags & LOADURL_EXTERNAL) != 0;
             args.put("url", url);
             args.put("engine", searchEngine);
             args.put("parentId", parentId);
             args.put("userEntered", userEntered);
             args.put("newTab", (flags & LOADURL_NEW_TAB) != 0);
             args.put("isPrivate", isPrivate);
             args.put("pinned", (flags & LOADURL_PINNED) != 0);
             args.put("delayLoad", delayLoad);
             args.put("desktopMode", desktopMode);
             args.put("selected", !background);
             if ((flags & LOADURL_NEW_TAB) != 0) {
                 int tabId = getNextTabId();
                 args.put("tabID", tabId);
                 // The URL is updated for the tab once Gecko responds with the
                 // Tab:Added message. We can preliminarily set the tab's URL as
                 // long as it's a valid URI.
                 String tabUrl = (url != null && Uri.parse(url).getScheme() != null) ? url : null;
                 added = addTab(tabId, tabUrl, external, parentId, url, isPrivate);
                 added.setDesktopMode(desktopMode);
             }
         } catch (Exception e) {
             Log.w(LOGTAG, "Error building JSON arguments for loadUrl.", e);
         }
         GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Tab:Load", args.toString()));
         if (added == null) {
             return null;
         }
         if (!delayLoad && !background) {
             selectTab(added.getId());
         }
         // TODO: surely we could just fetch *any* cached icon?
         if (AboutPages.isDefaultIconPage(url)) {
             Log.d(LOGTAG, "Setting about: tab favicon inline.");
             added.updateFavicon(getAboutPageFavicon(url));
         }
         return added;
     }
     /**
      * These favicons are only used for the URL bar, so
      * we fetch with that size.
      *
      * This method completes on the calling thread.
      */
     private Bitmap getAboutPageFavicon(final String url) {
         int faviconSize = Math.round(mAppContext.getResources().getDimension(R.dimen.browser_toolbar_favicon_size));
         return Favicons.getSizedFaviconForPageFromCache(url, faviconSize);
     }
     /**
      * Open the url as a new tab, and mark the selected tab as its "parent".
      *
      * If the url is already open in a tab, the existing tab is selected.
      * Use this for tabs opened by the browser chrome, so users can press the
      * "Back" button to return to the previous tab.
      *
      * @param url URL of page to load
      */
     public void loadUrlInTab(String url) {
         Iterable<Tab> tabs = getTabsInOrder();
         for (Tab tab : tabs) {
             if (url.equals(tab.getURL())) {
                 selectTab(tab.getId());
                 return;
             }
         }
         // getSelectedTab() can return null if no tab has been created yet
         // (i.e., we're restoring a session after a crash). In these cases,
         // don't mark any tabs as a parent.
         int parentId = -1;
         Tab selectedTab = getSelectedTab();
         if (selectedTab != null) {
             parentId = selectedTab.getId();
         }
         loadUrl(url, null, parentId, LOADURL_NEW_TAB);
     }
     /**
      * Gets the next tab ID.
      */
     @JNITarget
     public static int getNextTabId() {
         return sTabId.getAndIncrement();
     }
 }

The Tor Browser / annotate

mobile/android/base/Tabs.java@6474c204b198 (annotated)

mobile/android/base/Tabs.java