/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; 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 org.mozilla.gecko.db.BrowserContract.Combined;
import org.mozilla.gecko.db.BrowserDB;
import org.mozilla.gecko.gfx.BitmapUtils;
import org.mozilla.gecko.gfx.GeckoLayerClient;
import org.mozilla.gecko.gfx.ImmutableViewportMetrics;
import org.mozilla.gecko.gfx.LayerView;
import org.mozilla.gecko.gfx.PanZoomController;
import org.mozilla.gecko.util.FloatUtils;
import org.mozilla.gecko.util.GamepadUtils;
import org.mozilla.gecko.util.HardwareUtils;
import org.mozilla.gecko.util.ThreadUtils;
import org.mozilla.gecko.util.UiAsyncTask;
import org.mozilla.gecko.widget.AboutHome;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.PointF;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.NfcEvent;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.InputDevice;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.SubMenu;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Interpolator;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.Toast;

import java.io.InputStream;
import java.net.URL;
import java.util.EnumSet;
import java.util.Vector;

abstract public class BrowserApp extends GeckoApp
                                 implements TabsPanel.TabsLayoutChangeListener,
                                            PropertyAnimator.PropertyAnimationListener,
                                            View.OnKeyListener,
                                            GeckoLayerClient.OnMetricsChangedListener,
                                            AboutHome.UriLoadListener,
                                            AboutHome.LoadCompleteListener {
    private static final String LOGTAG = "GeckoBrowserApp";

    private static final String PREF_CHROME_DYNAMICTOOLBAR = "browser.chrome.dynamictoolbar";

    private static final int TABS_ANIMATION_DURATION = 450;

    private static final int READER_ADD_SUCCESS = 0;
    private static final int READER_ADD_FAILED = 1;
    private static final int READER_ADD_DUPLICATE = 2;

    public static BrowserToolbar mBrowserToolbar;
    private AboutHome mAboutHome;
    protected Telemetry.Timer mAboutHomeStartupTimer = null;

    private static final int ADDON_MENU_OFFSET = 1000;
    private class MenuItemInfo {
        public int id;
        public String label;
        public String icon;
        public boolean checkable;
        public boolean checked;
        public boolean enabled;
        public boolean visible;
        public int parent;
    }

    private Vector<MenuItemInfo> mAddonMenuItemsCache;

    private PropertyAnimator mMainLayoutAnimator;

    private static final Interpolator sTabsInterpolator = new Interpolator() {
        @Override
        public float getInterpolation(float t) {
            t -= 1.0f;
            return t * t * t * t * t + 1.0f;
        }
    };

    private FindInPageBar mFindInPageBar;

    private boolean mAccessibilityEnabled = false;

    // We'll ask for feedback after the user launches the app this many times.
    private static final int FEEDBACK_LAUNCH_COUNT = 15;

    // Stored value of the toolbar height, so we know when it's changed.
    private int mToolbarHeight = 0;

    private Integer mPrefObserverId;

    // Tag for the AboutHome fragment. The fragment is automatically attached
    // after restoring from a saved state, so we use this tag to identify it.
    private static final String ABOUTHOME_TAG = "abouthome";

    @Override
    public void onTabChanged(Tab tab, Tabs.TabEvents msg, Object data) {
        switch(msg) {
            case LOCATION_CHANGE:
                if (Tabs.getInstance().isSelectedTab(tab)) {
                    maybeCancelFaviconLoad(tab);
                }
                // fall through
            case SELECTED:
                if (Tabs.getInstance().isSelectedTab(tab)) {
                    if ("about:home".equals(tab.getURL())) {
                        showAboutHome();

                        if (isDynamicToolbarEnabled()) {
                            // Show the toolbar.
                            mLayerView.getLayerMarginsAnimator().showMargins(false);
                        }
                    } else {
                        hideAboutHome();
                    }

                    // Dismiss any SiteIdentity Popup
                    SiteIdentityPopup.getInstance().dismiss();

                    final TabsPanel.Panel panel = tab.isPrivate()
                                                ? TabsPanel.Panel.PRIVATE_TABS
                                                : TabsPanel.Panel.NORMAL_TABS;
                    // Delay calling showTabs so that it does not modify the mTabsChangedListeners
                    // array while we are still iterating through the array.
                    ThreadUtils.postToUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (areTabsShown() && mTabsPanel.getCurrentPanel() != panel)
                                showTabs(panel);
                        }
                    });
                }
                break;
            case START:
                if (Tabs.getInstance().isSelectedTab(tab)) {
                    invalidateOptionsMenu();

                    if (isDynamicToolbarEnabled()) {
                        // Show the toolbar.
                        mLayerView.getLayerMarginsAnimator().showMargins(false);
                    }
                }
                break;
            case LOAD_ERROR:
            case STOP:
            case MENU_UPDATED:
                if (Tabs.getInstance().isSelectedTab(tab)) {
                    invalidateOptionsMenu();
                }
                break;
            case PAGE_SHOW:
                loadFavicon(tab);
                break;
            case LINK_FAVICON:
                // If tab is not loading and the favicon is updated, we
                // want to load the image straight away. If tab is still
                // loading, we only load the favicon once the page's content
                // is fully loaded.
                if (tab.getState() != Tab.STATE_LOADING) {
                    loadFavicon(tab);
                }
                break;
        }
        super.onTabChanged(tab, msg, data);
    }

    @Override
    void handleClearHistory() {
        super.handleClearHistory();
        updateAboutHomeTopSites();
    }

    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        // Global onKey handler. This is called if the focused UI doesn't
        // handle the key event, and before Gecko swallows the events.
        if (event.getAction() != KeyEvent.ACTION_DOWN) {
            return false;
        }

        // Gamepad support only exists in API-level >= 9
        if (Build.VERSION.SDK_INT >= 9 &&
            (event.getSource() & InputDevice.SOURCE_GAMEPAD) == InputDevice.SOURCE_GAMEPAD) {
            switch (keyCode) {
                case KeyEvent.KEYCODE_BUTTON_Y:
                    // Toggle/focus the address bar on gamepad-y button.
                    if (mBrowserToolbar.isVisible()) {
                        if (isDynamicToolbarEnabled() && !mAboutHome.getUserVisibleHint()) {
                            if (mLayerView != null) {
                                mLayerView.getLayerMarginsAnimator().hideMargins(false);
                                mLayerView.requestFocus();
                            }
                        } else {
                            // Just focus the address bar when about:home is visible
                            // or when the dynamic toolbar isn't enabled.
                            mBrowserToolbar.requestFocusFromTouch();
                        }
                    } else {
                        if (mLayerView != null) {
                            mLayerView.getLayerMarginsAnimator().showMargins(false);
                        }
                        mBrowserToolbar.requestFocusFromTouch();
                    }
                    return true;
                case KeyEvent.KEYCODE_BUTTON_L1:
                    // Go back on L1
                    Tabs.getInstance().getSelectedTab().doBack();
                    return true;
                case KeyEvent.KEYCODE_BUTTON_R1:
                    // Go forward on R1
                    Tabs.getInstance().getSelectedTab().doForward();
                    return true;
            }
        }

        // Check if this was a shortcut. Meta keys exists only on 11+.
        final Tab tab = Tabs.getInstance().getSelectedTab();
        if (Build.VERSION.SDK_INT >= 11 && tab != null && event.isCtrlPressed()) {
            switch (keyCode) {
                case KeyEvent.KEYCODE_LEFT_BRACKET:
                    tab.doBack();
                    return true;

                case KeyEvent.KEYCODE_RIGHT_BRACKET:
                    tab.doForward();
                    return true;

                case KeyEvent.KEYCODE_R:
                    tab.doReload();
                    return true;

                case KeyEvent.KEYCODE_PERIOD:
                    tab.doStop();
                    return true;

                case KeyEvent.KEYCODE_T:
                    addTab();
                    return true;

                case KeyEvent.KEYCODE_W:
                    Tabs.getInstance().closeTab(tab);
                    return true;

                case KeyEvent.KEYCODE_F:
                    mFindInPageBar.show();
                return true;
            }
        }

        return false;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (onKey(null, keyCode, event)) {
            return true;
        }

        return super.onKeyDown(keyCode, event);
    }

    void handleReaderAdded(int result, final String title, final String url) {
        if (result != READER_ADD_SUCCESS) {
            if (result == READER_ADD_FAILED) {
                showToast(R.string.reading_list_failed, Toast.LENGTH_SHORT);
            } else if (result == READER_ADD_DUPLICATE) {
                showToast(R.string.reading_list_duplicate, Toast.LENGTH_SHORT);
            }

            return;
        }

        ThreadUtils.postToBackgroundThread(new Runnable() {
            @Override
            public void run() {
                BrowserDB.addReadingListItem(getContentResolver(), title, url);
                showToast(R.string.reading_list_added, Toast.LENGTH_SHORT);
            }
        });
    }

    void handleReaderRemoved(final String url) {
        ThreadUtils.postToBackgroundThread(new Runnable() {
            @Override
            public void run() {
                BrowserDB.removeReadingListItemWithURL(getContentResolver(), url);
                showToast(R.string.reading_list_removed, Toast.LENGTH_SHORT);
            }
        });
    }

    @Override
    void onStatePurged() {
        ThreadUtils.postToUiThread(new Runnable() {
            @Override
            public void run() {
                if (mAboutHome != null)
                    mAboutHome.setLastTabsVisibility(false);
            }
        });

        super.onStatePurged();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        mAboutHomeStartupTimer = new Telemetry.Timer("FENNEC_STARTUP_TIME_ABOUTHOME");

        super.onCreate(savedInstanceState);

        LinearLayout actionBar = (LinearLayout) getActionBarLayout();
        mMainLayout.addView(actionBar, 2);

        ((GeckoApp.MainLayout) mMainLayout).setTouchEventInterceptor(new HideTabsTouchListener());
        ((GeckoApp.MainLayout) mMainLayout).setMotionEventInterceptor(new MotionEventInterceptor() {
            @Override
            public boolean onInterceptMotionEvent(View view, MotionEvent event) {
                // If we get a gamepad panning MotionEvent while the focus is not on the layerview,
                // put the focus on the layerview and carry on
                if (mLayerView != null && !mLayerView.hasFocus() && GamepadUtils.isPanningControl(event)) {
                    if (mAboutHome.getUserVisibleHint()) {
                        mLayerView.requestFocus();
                    } else {
                        mAboutHome.requestFocus();
                    }
                }
                return false;
            }
        });

        // Find the Fragment if it was already added from a restored instance state.
        mAboutHome = (AboutHome) getSupportFragmentManager().findFragmentByTag(ABOUTHOME_TAG);

        if (mAboutHome == null) {
            // AboutHome will be dynamically attached and detached as
            // about:home is shown. Adding/removing the fragment is not synchronous,
            // so we can't use Fragment#isVisible() to determine whether the
            // about:home is shown. Instead, we use Fragment#getUserVisibleHint()
            // with the hint we set ourselves.
            mAboutHome = AboutHome.newInstance();
            mAboutHome.setUserVisibleHint(false);
        }

        mBrowserToolbar = new BrowserToolbar(this);
        mBrowserToolbar.from(actionBar);

        // Intercept key events for gamepad shortcuts
        actionBar.setOnKeyListener(this);

        if (mTabsPanel != null) {
            mTabsPanel.setTabsLayoutChangeListener(this);
            updateSideBarState();
        }

        mFindInPageBar = (FindInPageBar) findViewById(R.id.find_in_page);

        registerEventListener("CharEncoding:Data");
        registerEventListener("CharEncoding:State");
        registerEventListener("Feedback:LastUrl");
        registerEventListener("Feedback:OpenPlayStore");
        registerEventListener("Feedback:MaybeLater");
        registerEventListener("Telemetry:Gather");

        Distribution.init(this, getPackageResourcePath());
        JavaAddonManager.getInstance().init(getApplicationContext());

        if (AppConstants.MOZ_ANDROID_BEAM && Build.VERSION.SDK_INT >= 14) {
            NfcAdapter nfc = NfcAdapter.getDefaultAdapter(this);
            if (nfc != null) {
                nfc.setNdefPushMessageCallback(new NfcAdapter.CreateNdefMessageCallback() {
                    @Override
                    public NdefMessage createNdefMessage(NfcEvent event) {
                        Tab tab = Tabs.getInstance().getSelectedTab();
                        if (tab == null || tab.isPrivate()) {
                            return null;
                        }
                        return new NdefMessage(new NdefRecord[] { NdefRecord.createUri(tab.getURL()) });
                    }
                }, this);
            }
        }

        // Listen to the dynamic toolbar pref
        mPrefObserverId = PrefsHelper.getPref(PREF_CHROME_DYNAMICTOOLBAR, new PrefsHelper.PrefHandlerBase() {
            @Override
            public void prefValue(String pref, boolean value) {
                if (value == mDynamicToolbarEnabled) {
                    return;
                }
                mDynamicToolbarEnabled = value;

                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        // If accessibility is enabled, the dynamic toolbar is
                        // forced to be off.
                        if (!mAccessibilityEnabled) {
                            setDynamicToolbarEnabled(mDynamicToolbarEnabled);
                        }
                    }
                });
            }

            @Override
            public boolean isObserver() {
                // We want to be notified of changes to be able to switch mode
                // without restarting.
                return true;
            }
        });
    }

    private void setDynamicToolbarEnabled(boolean enabled) {
        if (enabled) {
            if (mLayerView != null) {
                mLayerView.getLayerClient().setOnMetricsChangedListener(this);
            }
            setToolbarMargin(0);
        } else {
            // Immediately show the toolbar when disabling the dynamic
            // toolbar.
            if (mLayerView != null) {
                mLayerView.getLayerClient().setOnMetricsChangedListener(null);
            }
            mAboutHome.setPadding(0, 0, 0, 0);
            if (mBrowserToolbar != null) {
                mBrowserToolbar.getLayout().scrollTo(0, 0);
            }
        }

        refreshToolbarHeight();
    }

    private boolean isDynamicToolbarEnabled() {
        return mDynamicToolbarEnabled && !mAccessibilityEnabled;
    }

    @Override
    public void setAccessibilityEnabled(boolean enabled) {
        if (mAccessibilityEnabled == enabled) {
            return;
        }

        // Disable the dynamic toolbar when accessibility features are enabled,
        // and re-read the preference when they're disabled.
        mAccessibilityEnabled = enabled;
        if (mDynamicToolbarEnabled) {
            setDynamicToolbarEnabled(!enabled);
        }
    }

    @Override
    public void onDestroy() {
        if (mPrefObserverId != null) {
            PrefsHelper.removeObserver(mPrefObserverId);
            mPrefObserverId = null;
        }
        if (mBrowserToolbar != null)
            mBrowserToolbar.onDestroy();

        unregisterEventListener("CharEncoding:Data");
        unregisterEventListener("CharEncoding:State");
        unregisterEventListener("Feedback:LastUrl");
        unregisterEventListener("Feedback:OpenPlayStore");
        unregisterEventListener("Feedback:MaybeLater");
        unregisterEventListener("Telemetry:Gather");

        if (AppConstants.MOZ_ANDROID_BEAM && Build.VERSION.SDK_INT >= 14) {
            NfcAdapter nfc = NfcAdapter.getDefaultAdapter(this);
            if (nfc != null) {
                // null this out even though the docs say it's not needed,
                // because the source code looks like it will only do this
                // automatically on API 14+
                nfc.setNdefPushMessageCallback(null, this);
            }
        }

        super.onDestroy();
    }

    @Override
    protected void finishProfileMigration() {
        // Update about:home with the new information.
        updateAboutHomeTopSites();

        super.finishProfileMigration();
    }

    @Override
    protected void initializeChrome(String uri, boolean isExternalURL) {
        super.initializeChrome(uri, isExternalURL);

        mBrowserToolbar.updateBackButton(false);
        mBrowserToolbar.updateForwardButton(false);

        mDoorHangerPopup.setAnchor(mBrowserToolbar.mFavicon);

        if (isExternalURL || mRestoreMode != RESTORE_NONE) {
            mAboutHomeStartupTimer.cancel();
        }

        if (!mIsRestoringActivity) {
            if (!isExternalURL) {
                // show about:home if we aren't restoring previous session
                if (mRestoreMode == RESTORE_NONE) {
                    Tab tab = Tabs.getInstance().loadUrl("about:home", Tabs.LOADURL_NEW_TAB);
                }
            } else {
                int flags = Tabs.LOADURL_NEW_TAB | Tabs.LOADURL_USER_ENTERED;
                Tabs.getInstance().loadUrl(uri, flags);
            }
        }

        // Listen to margin changes to position the toolbar correctly
        if (isDynamicToolbarEnabled()) {
            refreshToolbarHeight();
            mLayerView.getLayerMarginsAnimator().showMargins(true);
            mLayerView.getLayerClient().setOnMetricsChangedListener(this);
        }

        // Intercept key events for gamepad shortcuts
        mLayerView.setOnKeyListener(this);
    }

    private void setSidebarMargin(int margin) {
        ((RelativeLayout.LayoutParams) mGeckoLayout.getLayoutParams()).leftMargin = margin;
        mGeckoLayout.requestLayout();
    }

    private void setToolbarMargin(int margin) {
        ((RelativeLayout.LayoutParams) mGeckoLayout.getLayoutParams()).topMargin = margin;
        mGeckoLayout.requestLayout();
    }

    @Override
    public void onMetricsChanged(ImmutableViewportMetrics aMetrics) {
        if (mAboutHome.getUserVisibleHint() || mBrowserToolbar == null) {
            return;
        }

        final View toolbarLayout = mBrowserToolbar.getLayout();
        final int marginTop = Math.round(aMetrics.marginTop);
        ThreadUtils.postToUiThread(new Runnable() {
            public void run() {
                toolbarLayout.scrollTo(0, toolbarLayout.getHeight() - marginTop);
            }
        });
    }

    @Override
    public void onPanZoomStopped() {
        if (!isDynamicToolbarEnabled() || mAboutHome.getUserVisibleHint()) {
            return;
        }

        ImmutableViewportMetrics metrics = mLayerView.getViewportMetrics();
        if (metrics.marginTop >= mToolbarHeight / 2) {
            mLayerView.getLayerMarginsAnimator().showMargins(false);
        } else {
            mLayerView.getLayerMarginsAnimator().hideMargins(false);
        }
    }

    public void refreshToolbarHeight() {
        int height = 0;
        if (mBrowserToolbar != null) {
            height = mBrowserToolbar.getLayout().getHeight();
        }

        if (!isDynamicToolbarEnabled() || mAboutHome.getUserVisibleHint()) {
            // Use aVisibleHeight here so that when the dynamic toolbar is
            // enabled, the padding will animate with the toolbar becoming
            // visible.
            if (isDynamicToolbarEnabled()) {
                // When the dynamic toolbar is enabled, set the padding on the
                // about:home widget directly - this is to avoid resizing the
                // LayerView, which can cause visible artifacts.
                mAboutHome.setPadding(0, height, 0, 0);
            } else {
                setToolbarMargin(height);
                height = 0;
            }
        } else {
            setToolbarMargin(0);
        }

        if (mLayerView != null && height != mToolbarHeight) {
            mToolbarHeight = height;
            mLayerView.getLayerMarginsAnimator().setMaxMargins(0, height, 0, 0);
            mLayerView.getLayerMarginsAnimator().showMargins(true);
        }
    }

    @Override
    void toggleChrome(final boolean aShow) {
        ThreadUtils.postToUiThread(new Runnable() {
            @Override
            public void run() {
                if (aShow) {
                    mBrowserToolbar.show();
                } else {
                    mBrowserToolbar.hide();
                    if (hasTabsSideBar()) {
                        hideTabs();
                    }
                }
            }
        });

        super.toggleChrome(aShow);
    }

    @Override
    void focusChrome() {
        ThreadUtils.postToUiThread(new Runnable() {
            @Override
            public void run() {
                mBrowserToolbar.show();
                mBrowserToolbar.requestFocusFromTouch();
            }
        });
    }

    @Override
    public void refreshChrome() {
        invalidateOptionsMenu();
        updateSideBarState();
        mTabsPanel.refresh();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        String url = null;

        // Don't update the url in the toolbar if the activity was cancelled.
        if (resultCode == Activity.RESULT_OK && data != null) {
            // Don't update the url if the activity was launched to pick a site.
            String targetKey = data.getStringExtra(AwesomeBar.TARGET_KEY);
            if (!AwesomeBar.Target.PICK_SITE.toString().equals(targetKey)) {
                // Update the toolbar with the url that was just entered.
                url = data.getStringExtra(AwesomeBar.URL_KEY);
            }
        }

        // We always need to call fromAwesomeBarSearch to perform the toolbar animation.
        mBrowserToolbar.fromAwesomeBarSearch(url);
    }

    public View getActionBarLayout() {
        int actionBarRes;

        if (!HardwareUtils.hasMenuButton() || HardwareUtils.isTablet())
           actionBarRes = R.layout.browser_toolbar_menu;
        else
           actionBarRes = R.layout.browser_toolbar;

        LinearLayout actionBar = (LinearLayout) LayoutInflater.from(this).inflate(actionBarRes, null);
        actionBar.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,
                                                                (int) getResources().getDimension(R.dimen.browser_toolbar_height)));
        return actionBar;
    }

    @Override
    public boolean hasTabsSideBar() {
        return (mTabsPanel != null && mTabsPanel.isSideBar());
    }

    private void updateSideBarState() {
        if (mMainLayoutAnimator != null)
            mMainLayoutAnimator.stop();

        boolean isSideBar = (HardwareUtils.isTablet() && mOrientation == Configuration.ORIENTATION_LANDSCAPE);

        ViewGroup.LayoutParams lp = mTabsPanel.getLayoutParams();
        if (isSideBar) {
            lp.width = getResources().getDimensionPixelSize(R.dimen.tabs_sidebar_width);
        } else {
            lp.width = ViewGroup.LayoutParams.FILL_PARENT;
        }
        mTabsPanel.requestLayout();

        final boolean changed = (mTabsPanel.isSideBar() != isSideBar);
        final boolean needsRelayout = (changed && mTabsPanel.isShown());

        if (needsRelayout) {
            final int width;
            final int scrollY;

            if (isSideBar) {
                width = lp.width;
                mMainLayout.scrollTo(0, 0);
            } else {
                width = 0;
            }

            mBrowserToolbar.adjustForTabsLayout(width);
            setSidebarMargin(width);
        }

        if (changed) {
            // Cancel state of previous sidebar state
            mBrowserToolbar.updateTabs(false);

            mTabsPanel.setIsSideBar(isSideBar);
            mBrowserToolbar.setIsSideBar(isSideBar);

            // Update with new sidebar state
            mBrowserToolbar.updateTabs(mTabsPanel.isShown());
        }
    }

    @Override
    public void handleMessage(String event, JSONObject message) {
        try {
            if (event.equals("Menu:Add")) {
                MenuItemInfo info = new MenuItemInfo();
                info.label = message.getString("name");
                info.id = message.getInt("id") + ADDON_MENU_OFFSET;
                info.checkable = false;
                info.checked = false;
                info.enabled = true;
                info.visible = true;
                String iconRes = null;
                try { // icon is optional
                    iconRes = message.getString("icon");
                } catch (Exception ex) { }
                info.icon = iconRes;
                try {
                    info.checkable = message.getBoolean("checkable");
                } catch (Exception ex) { }
                try { // parent is optional
                    info.parent = message.getInt("parent") + ADDON_MENU_OFFSET;
                } catch (Exception ex) { }
                final MenuItemInfo menuItemInfo = info;
                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        addAddonMenuItem(menuItemInfo);
                    }
                });
            } else if (event.equals("Menu:Remove")) {
                final int id = message.getInt("id") + ADDON_MENU_OFFSET;
                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        removeAddonMenuItem(id);
                    }
                });
            } else if (event.equals("Menu:Update")) {
                final int id = message.getInt("id") + ADDON_MENU_OFFSET;
                final JSONObject options = message.getJSONObject("options");
                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        updateAddonMenuItem(id, options);
                    }
                });
            } else if (event.equals("CharEncoding:Data")) {
                final JSONArray charsets = message.getJSONArray("charsets");
                int selected = message.getInt("selected");

                final int len = charsets.length();
                final String[] titleArray = new String[len];
                for (int i = 0; i < len; i++) {
                    JSONObject charset = charsets.getJSONObject(i);
                    titleArray[i] = charset.getString("title");
                }

                final AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
                dialogBuilder.setSingleChoiceItems(titleArray, selected, new AlertDialog.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        try {
                            JSONObject charset = charsets.getJSONObject(which);
                            GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("CharEncoding:Set", charset.getString("code")));
                            dialog.dismiss();
                        } catch (JSONException e) {
                            Log.e(LOGTAG, "error parsing json", e);
                        }
                    }
                });
                dialogBuilder.setNegativeButton(R.string.button_cancel, new AlertDialog.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        dialogBuilder.show();
                    }
                });
            } else if (event.equals("CharEncoding:State")) {
                final boolean visible = message.getString("visible").equals("true");
                GeckoPreferences.setCharEncodingState(visible);
                final Menu menu = mMenu;
                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if (menu != null)
                            menu.findItem(R.id.char_encoding).setVisible(visible);
                    }
                });
            } else if (event.equals("Feedback:OpenPlayStore")) {
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setData(Uri.parse("market://details?id=" + getPackageName()));
                startActivity(intent);
            } else if (event.equals("Feedback:MaybeLater")) {
                resetFeedbackLaunchCount();
            } else if (event.equals("Feedback:LastUrl")) {
                getLastUrl();
            } else if (event.equals("Gecko:Ready")) {
                // Handle this message in GeckoApp, but also enable the Settings
                // menuitem, which is specific to BrowserApp.
                super.handleMessage(event, message);
                final Menu menu = mMenu;
                ThreadUtils.postToUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if (menu != null)
                            menu.findItem(R.id.settings).setEnabled(true);
                    }
                });
            } else if (event.equals("Telemetry:Gather")) {
                Telemetry.HistogramAdd("PLACES_PAGES_COUNT", BrowserDB.getCount(getContentResolver(), "history"));
                Telemetry.HistogramAdd("PLACES_BOOKMARKS_COUNT", BrowserDB.getCount(getContentResolver(), "bookmarks"));
                Telemetry.HistogramAdd("FENNEC_FAVICONS_COUNT", BrowserDB.getCount(getContentResolver(), "favicons"));
                Telemetry.HistogramAdd("FENNEC_THUMBNAILS_COUNT", BrowserDB.getCount(getContentResolver(), "thumbnails"));
            } else if (event.equals("Reader:Added")) {
                final int result = message.getInt("result");
                final String title = message.getString("title");
                final String url = message.getString("url");
                handleReaderAdded(result, title, url);
            } else if (event.equals("Reader:Removed")) {
                final String url = message.getString("url");
                handleReaderRemoved(url);
            } else if (event.equals("Reader:Share")) {
                final String title = message.getString("title");
                final String url = message.getString("url");
                GeckoAppShell.openUriExternal(url, "text/plain", "", "",
                                              Intent.ACTION_SEND, title);
            } else {
                super.handleMessage(event, message);
            }
        } catch (Exception e) {
            Log.e(LOGTAG, "Exception handling message \"" + event + "\":", e);
        }
    }

    @Override
    public void addTab() {
        showAwesomebar(AwesomeBar.Target.NEW_TAB);
    }

    @Override
    public void addPrivateTab() {
        Tabs.getInstance().loadUrl("about:privatebrowsing", Tabs.LOADURL_NEW_TAB | Tabs.LOADURL_PRIVATE);
    }

    @Override
    public void showNormalTabs() {
        showTabs(TabsPanel.Panel.NORMAL_TABS);
    }

    @Override
    public void showPrivateTabs() {
        showTabs(TabsPanel.Panel.PRIVATE_TABS);
    }

    @Override
    public void showRemoteTabs() {
        showTabs(TabsPanel.Panel.REMOTE_TABS);
    }

    private void showTabs(TabsPanel.Panel panel) {
        if (Tabs.getInstance().getDisplayCount() == 0)
            return;

        mTabsPanel.show(panel);
    }

    @Override
    public void hideTabs() {
        mTabsPanel.hide();
    }

    @Override
    public boolean autoHideTabs() {
        if (!hasTabsSideBar() && areTabsShown()) {
            hideTabs();
            return true;
        }
        return false;
    }

    @Override
    public boolean areTabsShown() {
        return mTabsPanel.isShown();
    }

    @Override
    public void onTabsLayoutChange(int width, int height) {
        int animationLength = TABS_ANIMATION_DURATION;

        if (mMainLayoutAnimator != null) {
            animationLength = Math.max(1, animationLength - (int)mMainLayoutAnimator.getRemainingTime());
            mMainLayoutAnimator.stop(false);
        }

        if (mTabsPanel.isShown())
            mTabsPanel.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);

        mMainLayoutAnimator = new PropertyAnimator(animationLength, sTabsInterpolator);
        mMainLayoutAnimator.setPropertyAnimationListener(this);

        boolean usingTextureView = mLayerView.shouldUseTextureView();
        mMainLayoutAnimator.setUseHardwareLayer(usingTextureView);

        if (hasTabsSideBar()) {
            mBrowserToolbar.prepareTabsAnimation(mMainLayoutAnimator, width);

            // Set the gecko layout for sliding.
            if (!mTabsPanel.isShown()) {
                mGeckoLayout.scrollTo(mTabsPanel.getWidth() * -1, 0);
                setSidebarMargin(0);
            }

            mMainLayoutAnimator.attach(mGeckoLayout,
                                       PropertyAnimator.Property.SCROLL_X,
                                       -width);
        } else {
            mMainLayoutAnimator.attach(mMainLayout,
                                       PropertyAnimator.Property.SCROLL_Y,
                                       -height);
        }

        // If the tabs layout is animating onto the screen, pin the dynamic
        // toolbar.
        if (mLayerView != null && isDynamicToolbarEnabled()) {
            if (width > 0 && height > 0) {
                mLayerView.getLayerMarginsAnimator().showMargins(false);
                mLayerView.getLayerMarginsAnimator().setMarginsPinned(true);
            } else {
                mLayerView.getLayerMarginsAnimator().setMarginsPinned(false);
            }
        }

        mMainLayoutAnimator.start();
    }

    @Override
    public void onPropertyAnimationStart() {
        mBrowserToolbar.updateTabs(true);

        // Although the tabs panel is not animating per se, it will be re-drawn several
        // times while the main/gecko layout slides to left/top. Adding a hardware layer
        // here considerably improves the frame rate of the animation.
        if (Build.VERSION.SDK_INT >= 11)
            mTabsPanel.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        else
            mTabsPanel.setDrawingCacheEnabled(true);
    }

    @Override
    public void onPropertyAnimationEnd() {
        // Destroy the hardware layer used during the animation
        if (Build.VERSION.SDK_INT >= 11)
            mTabsPanel.setLayerType(View.LAYER_TYPE_NONE, null);
        else
            mTabsPanel.setDrawingCacheEnabled(false);

        if (mTabsPanel.isShown()) {
            if (hasTabsSideBar()) {
                setSidebarMargin(mTabsPanel.getWidth());
                mGeckoLayout.scrollTo(0, 0);
            }

            mGeckoLayout.requestLayout();
        } else {
            mTabsPanel.setVisibility(View.INVISIBLE);
            mBrowserToolbar.updateTabs(false);
            mBrowserToolbar.finishTabsAnimation();
            mTabsPanel.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
        }

        mBrowserToolbar.refreshBackground();

        if (hasTabsSideBar())
            mBrowserToolbar.adjustTabsAnimation(true);

        mMainLayoutAnimator = null;
    }

    /* Favicon methods */
    private void loadFavicon(final Tab tab) {
        maybeCancelFaviconLoad(tab);

        long id = Favicons.getInstance().loadFavicon(tab.getURL(), tab.getFaviconURL(), !tab.isPrivate(),
                        new Favicons.OnFaviconLoadedListener() {

            @Override
            public void onFaviconLoaded(String pageUrl, Bitmap favicon) {
                // Leave favicon UI untouched if we failed to load the image
                // for some reason.
                if (favicon == null)
                    return;

                // The tab might be pointing to another URL by the time the
                // favicon is finally loaded, in which case we simply ignore it.
                if (!tab.getURL().equals(pageUrl))
                    return;

                tab.updateFavicon(favicon);
                tab.setFaviconLoadId(Favicons.NOT_LOADING);

                Tabs.getInstance().notifyListeners(tab, Tabs.TabEvents.FAVICON);
            }
        });

        tab.setFaviconLoadId(id);
    }

    private void maybeCancelFaviconLoad(Tab tab) {
        long faviconLoadId = tab.getFaviconLoadId();

        if (faviconLoadId == Favicons.NOT_LOADING)
            return;

        // Cancel pending favicon load task
        Favicons.getInstance().cancelFaviconLoad(faviconLoadId);

        // Reset favicon load state
        tab.setFaviconLoadId(Favicons.NOT_LOADING);
    }


    /* About:home UI */
    void updateAboutHomeTopSites() {
        mAboutHome.update(EnumSet.of(AboutHome.UpdateFlags.TOP_SITES));
    }

    private void showAboutHome() {
        if (mAboutHome.getUserVisibleHint()) {
            return;
        }

        // Refresh toolbar height to possibly restore the toolbar padding
        refreshToolbarHeight();

        // Show the toolbar before hiding about:home so the
        // onMetricsChanged callback still works.
        if (isDynamicToolbarEnabled() && mLayerView != null) {
            mLayerView.getLayerMarginsAnimator().showMargins(true);
        }

        // We use commitAllowingStateLoss() instead of commit() here to avoid an
        // IllegalStateException. showAboutHome() and hideAboutHome() are
        // executed inside of tab's onChange() callback. Since that callback can
        // be triggered asynchronously from Gecko, it's possible that this
        // method can be called while Fennec is in the background. If that
        // happens, using commit() would throw an IllegalStateException since
        // it can't be used between the Activity's onSaveInstanceState() and
        // onResume().
        getSupportFragmentManager().beginTransaction()
                .add(R.id.gecko_layout, mAboutHome, ABOUTHOME_TAG).commitAllowingStateLoss();
        mAboutHome.setUserVisibleHint(true);

        mBrowserToolbar.setNextFocusDownId(R.id.abouthome_content);
    }

    private void hideAboutHome() {
        if (!mAboutHome.getUserVisibleHint()) {
            return;
        }

        getSupportFragmentManager().beginTransaction()
                .remove(mAboutHome).commitAllowingStateLoss();
        mAboutHome.setUserVisibleHint(false);

        mBrowserToolbar.setShadowVisibility(true);
        mBrowserToolbar.setNextFocusDownId(R.id.layer_view);

        // Refresh toolbar height to possibly restore the toolbar padding
        refreshToolbarHeight();
    }

    private class HideTabsTouchListener implements TouchEventInterceptor {
        private boolean mIsHidingTabs = false;

        @Override
        public boolean onInterceptTouchEvent(View view, MotionEvent event) {
            // We need to account for scroll state for the touched view otherwise
            // tapping on an "empty" part of the view will still be considered a
            // valid touch event.
            if (view.getScrollX() != 0 || view.getScrollY() != 0) {
                Rect rect = new Rect();
                view.getHitRect(rect);
                rect.offset(-view.getScrollX(), -view.getScrollY());

                int[] viewCoords = new int[2];
                view.getLocationOnScreen(viewCoords);

                int x = (int) event.getRawX() - viewCoords[0];
                int y = (int) event.getRawY() - viewCoords[1];

                if (!rect.contains(x, y))
                    return false;
            }

            // If the tab tray is showing, hide the tab tray and don't send the event to content.
            if (event.getActionMasked() == MotionEvent.ACTION_DOWN && autoHideTabs()) {
                mIsHidingTabs = true;
                return true;
            }
            return false;
        }

        @Override
        public boolean onTouch(View view, MotionEvent event) {
            if (mIsHidingTabs) {
                // Keep consuming events until the gesture finishes.
                int action = event.getActionMasked();
                if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
                    mIsHidingTabs = false;
                }
                return true;
            }
            return false;
        }
    }

    private void addAddonMenuItem(final MenuItemInfo info) {
        if (mMenu == null) {
            if (mAddonMenuItemsCache == null)
                mAddonMenuItemsCache = new Vector<MenuItemInfo>();

            mAddonMenuItemsCache.add(info);
            return;
        }

        Menu menu;
        if (info.parent == 0) {
            menu = mMenu;
        } else {
            MenuItem parent = mMenu.findItem(info.parent);
            if (parent == null)
                return;

            if (!parent.hasSubMenu()) {
                mMenu.removeItem(parent.getItemId());
                menu = mMenu.addSubMenu(Menu.NONE, parent.getItemId(), Menu.NONE, parent.getTitle());
                if (parent.getIcon() != null)
                    ((SubMenu) menu).getItem().setIcon(parent.getIcon());
            } else {
                menu = parent.getSubMenu();
            }
        }

        final MenuItem item = menu.add(Menu.NONE, info.id, Menu.NONE, info.label);
        item.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem item) {
                Log.i(LOGTAG, "menu item clicked");
                GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Menu:Clicked", Integer.toString(info.id - ADDON_MENU_OFFSET)));
                return true;
            }
        });

        if (info.icon != null) {
            if (info.icon.startsWith("data")) {
                BitmapDrawable drawable = new BitmapDrawable(BitmapUtils.getBitmapFromDataURI(info.icon));
                item.setIcon(drawable);
            }
            else if (info.icon.startsWith("jar:") || info.icon.startsWith("file://")) {
                ThreadUtils.postToBackgroundThread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            URL url = new URL(info.icon);
                            InputStream is = (InputStream) url.getContent();
                            try {
                                Drawable drawable = Drawable.createFromStream(is, "src");
                                item.setIcon(drawable);
                            } finally {
                                is.close();
                            }
                        } catch (Exception e) {
                            Log.w(LOGTAG, "Unable to set icon", e);
                        }
                    }
                });
            } else {
                item.setIcon(R.drawable.ic_menu_addons_filler);
            }
        } else {
            item.setIcon(R.drawable.ic_menu_addons_filler);
        }

        item.setCheckable(info.checkable);
        item.setChecked(info.checked);
        item.setEnabled(info.enabled);
        item.setVisible(info.visible);
    }

    private void removeAddonMenuItem(int id) {
        // Remove add-on menu item from cache, if available.
        if (mAddonMenuItemsCache != null && !mAddonMenuItemsCache.isEmpty()) {
            for (MenuItemInfo item : mAddonMenuItemsCache) {
                 if (item.id == id) {
                     mAddonMenuItemsCache.remove(item);
                     break;
                 }
            }
        }

        if (mMenu == null)
            return;

        MenuItem menuItem = mMenu.findItem(id);
        if (menuItem != null)
            mMenu.removeItem(id);
    }

    private void updateAddonMenuItem(int id, JSONObject options) {
        // Set attribute for the menu item in cache, if available
        if (mAddonMenuItemsCache != null && !mAddonMenuItemsCache.isEmpty()) {
            for (MenuItemInfo item : mAddonMenuItemsCache) {
                 if (item.id == id) {
                     try {
                        item.checkable = options.getBoolean("checkable");
                     } catch (JSONException e) {}

                     try {
                        item.checked = options.getBoolean("checked");
                     } catch (JSONException e) {}

                     try {
                        item.enabled = options.getBoolean("enabled");
                     } catch (JSONException e) {}

                     try {
                        item.visible = options.getBoolean("visible");
                     } catch (JSONException e) {}
                     break;
                 }
            }
        }

        if (mMenu == null)
            return;

        MenuItem menuItem = mMenu.findItem(id);
        if (menuItem != null) {
            try {
               menuItem.setCheckable(options.getBoolean("checkable"));
            } catch (JSONException e) {}

            try {
               menuItem.setChecked(options.getBoolean("checked"));
            } catch (JSONException e) {}

            try {
               menuItem.setEnabled(options.getBoolean("enabled"));
            } catch (JSONException e) {}

            try {
               menuItem.setVisible(options.getBoolean("visible"));
            } catch (JSONException e) {}
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);

        // Inform the menu about the action-items bar. 
        if (menu instanceof GeckoMenu && HardwareUtils.isTablet())
            ((GeckoMenu) menu).setActionItemBarPresenter(mBrowserToolbar);

        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.browser_app_menu, mMenu);

        // Add add-on menu items if any.
        if (mAddonMenuItemsCache != null && !mAddonMenuItemsCache.isEmpty()) {
            for (MenuItemInfo item : mAddonMenuItemsCache) {
                 addAddonMenuItem(item);
            }

            mAddonMenuItemsCache.clear();
        }

        return true;
    }

    @Override
    public void openOptionsMenu() {
        if (!hasTabsSideBar() && areTabsShown())
            return;

        // Scroll custom menu to the top
        if (mMenuPanel != null)
            mMenuPanel.scrollTo(0, 0);

        if (!mBrowserToolbar.openOptionsMenu())
            super.openOptionsMenu();

        if (isDynamicToolbarEnabled() && mLayerView != null)
            mLayerView.getLayerMarginsAnimator().showMargins(false);
    }

    @Override
    public void closeOptionsMenu() {
        if (!mBrowserToolbar.closeOptionsMenu())
            super.closeOptionsMenu();
    }

    @Override
    public void setFullScreen(final boolean fullscreen) {
        super.setFullScreen(fullscreen);
        ThreadUtils.postToUiThread(new Runnable() {
            @Override
            public void run() {
                if (fullscreen)
                    mBrowserToolbar.hide();
                else
                    mBrowserToolbar.show();
            }
        });
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu aMenu) {
        if (aMenu == null)
            return false;

        if (!GeckoThread.checkLaunchState(GeckoThread.LaunchState.GeckoRunning))
            aMenu.findItem(R.id.settings).setEnabled(false);

        Tab tab = Tabs.getInstance().getSelectedTab();
        MenuItem bookmark = aMenu.findItem(R.id.bookmark);
        MenuItem forward = aMenu.findItem(R.id.forward);
        MenuItem share = aMenu.findItem(R.id.share);
        MenuItem saveAsPDF = aMenu.findItem(R.id.save_as_pdf);
        MenuItem charEncoding = aMenu.findItem(R.id.char_encoding);
        MenuItem findInPage = aMenu.findItem(R.id.find_in_page);
        MenuItem desktopMode = aMenu.findItem(R.id.desktop_mode);

        // Only show the "Quit" menu item on pre-ICS or television devices.
        // In ICS+, it's easy to kill an app through the task switcher.
        aMenu.findItem(R.id.quit).setVisible(Build.VERSION.SDK_INT < 14 || HardwareUtils.isTelevision());

        if (tab == null || tab.getURL() == null) {
            bookmark.setEnabled(false);
            forward.setEnabled(false);
            share.setEnabled(false);
            saveAsPDF.setEnabled(false);
            findInPage.setEnabled(false);
            return true;
        }

        bookmark.setEnabled(!tab.getURL().startsWith("about:reader"));
        bookmark.setCheckable(true);
        bookmark.setChecked(tab.isBookmark());
        bookmark.setIcon(tab.isBookmark() ? R.drawable.ic_menu_bookmark_remove : R.drawable.ic_menu_bookmark_add);

        forward.setEnabled(tab.canDoForward());
        desktopMode.setChecked(tab.getDesktopMode());
        desktopMode.setIcon(tab.getDesktopMode() ? R.drawable.ic_menu_desktop_mode_on : R.drawable.ic_menu_desktop_mode_off);

        String url = tab.getURL();
        if (ReaderModeUtils.isAboutReader(url)) {
            String urlFromReader = ReaderModeUtils.getUrlFromAboutReader(url);
            if (urlFromReader != null)
                url = urlFromReader;
        }

        // Disable share menuitem for about:, chrome:, file:, and resource: URIs
        String scheme = Uri.parse(url).getScheme();
        share.setEnabled(!(scheme.equals("about") || scheme.equals("chrome") ||
                           scheme.equals("file") || scheme.equals("resource")));

        // Disable save as PDF for about:home and xul pages
        saveAsPDF.setEnabled(!(tab.getURL().equals("about:home") ||
                               tab.getContentType().equals("application/vnd.mozilla.xul+xml")));

        // Disable find in page for about:home, since it won't work on Java content
        findInPage.setEnabled(!tab.getURL().equals("about:home"));

        charEncoding.setVisible(GeckoPreferences.getCharEncodingState());

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        Tab tab = null;
        Intent intent = null;
        switch (item.getItemId()) {
            case R.id.bookmark:
                tab = Tabs.getInstance().getSelectedTab();
                if (tab != null) {
                    if (item.isChecked()) {
                        tab.removeBookmark();
                        Toast.makeText(this, R.string.bookmark_removed, Toast.LENGTH_SHORT).show();
                        item.setIcon(R.drawable.ic_menu_bookmark_add);
                    } else {
                        tab.addBookmark();
                        Toast.makeText(this, R.string.bookmark_added, Toast.LENGTH_SHORT).show();
                        item.setIcon(R.drawable.ic_menu_bookmark_remove);
                    }
                }
                return true;
            case R.id.share:
                shareCurrentUrl();
                return true;
            case R.id.reload:
                tab = Tabs.getInstance().getSelectedTab();
                if (tab != null)
                    tab.doReload();
                return true;
            case R.id.forward:
                tab = Tabs.getInstance().getSelectedTab();
                if (tab != null)
                    tab.doForward();
                return true;
            case R.id.save_as_pdf:
                GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("SaveAs:PDF", null));
                return true;
            case R.id.settings:
                intent = new Intent(this, GeckoPreferences.class);
                startActivity(intent);
                return true;
            case R.id.addons:
                Tabs.getInstance().loadUrlInTab("about:addons");
                return true;
            case R.id.downloads:
                Tabs.getInstance().loadUrlInTab("about:downloads");
                return true;
            case R.id.apps:
                Tabs.getInstance().loadUrlInTab("about:apps");
                return true;
            case R.id.char_encoding:
                GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("CharEncoding:Get", null));
                return true;
            case R.id.find_in_page:
                mFindInPageBar.show();
                return true;
            case R.id.desktop_mode:
                Tab selectedTab = Tabs.getInstance().getSelectedTab();
                if (selectedTab == null)
                    return true;
                JSONObject args = new JSONObject();
                try {
                    args.put("desktopMode", !item.isChecked());
                    args.put("tabId", selectedTab.getId());
                } catch (JSONException e) {
                    Log.e(LOGTAG, "error building json arguments");
                }
                GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("DesktopMode:Change", args.toString()));
                return true;
            case R.id.new_tab:
                addTab();
                return true;
            case R.id.new_private_tab:
                addPrivateTab();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    /**
     * This will detect if the key pressed is back. If so, will show the history.
     */
    @Override
    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            Tab tab = Tabs.getInstance().getSelectedTab();
            if (tab != null) {
                return tab.showAllHistory();
            }
        }
        return super.onKeyLongPress(keyCode, event);
    }

    /*
     * If the app has been launched a certain number of times, and we haven't asked for feedback before,
     * open a new tab with about:feedback when launching the app from the icon shortcut.
     */ 
    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);

        String action = intent.getAction();

        if (AppConstants.MOZ_ANDROID_BEAM && Build.VERSION.SDK_INT >= 10 && NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
            String uri = intent.getDataString();
            GeckoAppShell.sendEventToGecko(GeckoEvent.createURILoadEvent(uri));
        }

        if (!Intent.ACTION_MAIN.equals(action) || !mInitialized) {
            return;
        }

        (new UiAsyncTask<Void, Void, Boolean>(ThreadUtils.getBackgroundHandler()) {
            @Override
            public synchronized Boolean doInBackground(Void... params) {
                // Check to see how many times the app has been launched.
                SharedPreferences settings = getPreferences(Activity.MODE_PRIVATE);
                String keyName = getPackageName() + ".feedback_launch_count";
                int launchCount = settings.getInt(keyName, 0);
                if (launchCount >= FEEDBACK_LAUNCH_COUNT)
                    return false;

                // Increment the launch count and store the new value.
                launchCount++;
                settings.edit().putInt(keyName, launchCount).commit();

                // If we've reached our magic number, show the feedback page.
                return launchCount == FEEDBACK_LAUNCH_COUNT;
            }

            @Override
            public void onPostExecute(Boolean shouldShowFeedbackPage) {
                if (shouldShowFeedbackPage)
                    Tabs.getInstance().loadUrlInTab("about:feedback");
            }
        }).execute();
    }

    @Override
    protected NotificationClient makeNotificationClient() {
        // The service is local to Fennec, so we can use it to keep
        // Fennec alive during downloads.
        return new ServiceNotificationClient(getApplicationContext());
    }

    private void resetFeedbackLaunchCount() {
        ThreadUtils.postToBackgroundThread(new Runnable() {
            @Override
            public synchronized void run() {
                SharedPreferences settings = getPreferences(Activity.MODE_PRIVATE);
                settings.edit().putInt(getPackageName() + ".feedback_launch_count", 0).commit();
            }
        });
    }

    private void getLastUrl() {
        (new UiAsyncTask<Void, Void, String>(ThreadUtils.getBackgroundHandler()) {
            @Override
            public synchronized String doInBackground(Void... params) {
                // Get the most recent URL stored in browser history.
                String url = "";
                Cursor c = BrowserDB.getRecentHistory(getContentResolver(), 1);
                if (c.moveToFirst()) {
                    url = c.getString(c.getColumnIndexOrThrow(Combined.URL));
                }
                c.close();
                return url;
            }

            @Override
            public void onPostExecute(String url) {
                // Don't bother sending a message if there is no URL.
                if (url.length() > 0)
                    GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Feedback:LastUrl", url));
            }
        }).execute();
    }

    @Override
    public void onAboutHomeUriLoad(String url) {
        mBrowserToolbar.setProgressVisibility(true);
        Tabs.getInstance().loadUrl(url);
    }

    @Override
    public void onAboutHomeLoadComplete() {
        mAboutHomeStartupTimer.stop();
    }

    @Override
    public int getLayout() { return R.layout.gecko_app; }

    @Override
    protected String getDefaultProfileName() {
        String profile = GeckoProfile.findDefaultProfile(this);
        return (profile != null ? profile : "default");
    }
}