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 /* -*- 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.gfx.InputConnectionHandler;

 import org.mozilla.gecko.gfx.LayerView;

 import org.mozilla.gecko.util.GeckoEventListener;

 import org.mozilla.gecko.util.ThreadUtils;

 import org.mozilla.gecko.util.ThreadUtils.AssertBehavior;

 import org.json.JSONObject;

 import android.os.Build;

 import android.os.Handler;

 import android.os.Looper;

 import android.text.Editable;

 import android.text.InputFilter;

 import android.text.Selection;

 import android.text.Spannable;

 import android.text.SpannableString;

 import android.text.SpannableStringBuilder;

 import android.text.Spanned;

 import android.text.TextPaint;

 import android.text.TextUtils;

 import android.text.style.CharacterStyle;

 import android.util.Log;

 import android.view.KeyCharacterMap;

 import android.view.KeyEvent;

 import java.lang.reflect.Field;

 import java.lang.reflect.InvocationHandler;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import java.lang.reflect.Proxy;

 import java.util.concurrent.ConcurrentLinkedQueue;

 import java.util.concurrent.Semaphore;

 // interface for the IC thread

 interface GeckoEditableClient {

     void sendEvent(GeckoEvent event);

     Editable getEditable();

     void setUpdateGecko(boolean update);

     void setSuppressKeyUp(boolean suppress);

     Handler getInputConnectionHandler();

     boolean setInputConnectionHandler(Handler handler);

 }

 /* interface for the Editable to listen to the Gecko thread

    and also for the IC thread to listen to the Editable */

 interface GeckoEditableListener {

     // IME notification type for notifyIME(), corresponding to NotificationToIME enum in Gecko

     final int NOTIFY_IME_OPEN_VKB = -2;

     final int NOTIFY_IME_REPLY_EVENT = -1;

     final int NOTIFY_IME_OF_FOCUS = 1;

     final int NOTIFY_IME_OF_BLUR = 2;

     final int NOTIFY_IME_TO_COMMIT_COMPOSITION = 7;

     final int NOTIFY_IME_TO_CANCEL_COMPOSITION = 8;

     // IME enabled state for notifyIMEContext()

     final int IME_STATE_DISABLED = 0;

     final int IME_STATE_ENABLED = 1;

     final int IME_STATE_PASSWORD = 2;

     final int IME_STATE_PLUGIN = 3;

     void notifyIME(int type);

     void notifyIMEContext(int state, String typeHint,

                           String modeHint, String actionHint);

     void onSelectionChange(int start, int end);

     void onTextChange(String text, int start, int oldEnd, int newEnd);

 }

 /*

    GeckoEditable implements only some functions of Editable

    The field mText contains the actual underlying

    SpannableStringBuilder/Editable that contains our text.

 */

 final class GeckoEditable

         implements InvocationHandler, Editable,

                    GeckoEditableClient, GeckoEditableListener, GeckoEventListener {

     private static final boolean DEBUG = false;

     private static final String LOGTAG = "GeckoEditable";

     // Filters to implement Editable's filtering functionality

     private InputFilter[] mFilters;

     private final SpannableStringBuilder mText;

     private final SpannableStringBuilder mChangedText;

     private final Editable mProxy;

     private final ActionQueue mActionQueue;

     // mIcRunHandler is the Handler that currently runs Gecko-to-IC Runnables

     // mIcPostHandler is the Handler to post Gecko-to-IC Runnables to

     // The two can be different when switching from one handler to another

     private Handler mIcRunHandler;

     private Handler mIcPostHandler;

     private GeckoEditableListener mListener;

     private int mSavedSelectionStart;

     private volatile int mGeckoUpdateSeqno;

     private int mIcUpdateSeqno;

     private int mLastIcUpdateSeqno;

     private boolean mUpdateGecko;

     private boolean mFocused; // Used by IC thread

     private boolean mGeckoFocused; // Used by Gecko thread

     private volatile boolean mSuppressCompositions;

     private volatile boolean mSuppressKeyUp;

     /* An action that alters the Editable

        Each action corresponds to a Gecko event. While the Gecko event is being sent to the Gecko

        thread, the action stays on top of mActions queue. After the Gecko event is processed and

        replied, the action is removed from the queue

     */

     private static final class Action {

         // For input events (keypress, etc.); use with IME_SYNCHRONIZE

         static final int TYPE_EVENT = 0;

         // For Editable.replace() call; use with IME_REPLACE_TEXT

         static final int TYPE_REPLACE_TEXT = 1;

         /* For Editable.setSpan(Selection...) call; use with IME_SYNCHRONIZE

            Note that we don't use this with IME_SET_SELECTION because we don't want to update the

            Gecko selection at the point of this action. The Gecko selection is updated only after

            IC has updated its selection (during IME_SYNCHRONIZE reply) */

         static final int TYPE_SET_SELECTION = 2;

         // For Editable.setSpan() call; use with IME_SYNCHRONIZE

         static final int TYPE_SET_SPAN = 3;

         // For Editable.removeSpan() call; use with IME_SYNCHRONIZE

         static final int TYPE_REMOVE_SPAN = 4;

         // For focus events (in notifyIME); use with IME_ACKNOWLEDGE_FOCUS

         static final int TYPE_ACKNOWLEDGE_FOCUS = 5;

         // For switching handler; use with IME_SYNCHRONIZE

         static final int TYPE_SET_HANDLER = 6;

         final int mType;

         int mStart;

         int mEnd;

         CharSequence mSequence;

         Object mSpanObject;

         int mSpanFlags;

         boolean mShouldUpdate;

         Handler mHandler;

         Action(int type) {

             mType = type;

         }

         static Action newReplaceText(CharSequence text, int start, int end) {

             if (start < 0 || start > end) {

                 throw new IllegalArgumentException(

                     "invalid replace text offsets: " + start + " to " + end);

             }

             final Action action = new Action(TYPE_REPLACE_TEXT);

             action.mSequence = text;

             action.mStart = start;

             action.mEnd = end;

             return action;

         }

         static Action newSetSelection(int start, int end) {

             // start == -1 when the start offset should remain the same

             // end == -1 when the end offset should remain the same

             if (start < -1 || end < -1) {

                 throw new IllegalArgumentException(

                     "invalid selection offsets: " + start + " to " + end);

             }

             final Action action = new Action(TYPE_SET_SELECTION);

             action.mStart = start;

             action.mEnd = end;

             return action;

         }

         static Action newSetSpan(Object object, int start, int end, int flags) {

             if (start < 0 || start > end) {

                 throw new IllegalArgumentException(

                     "invalid span offsets: " + start + " to " + end);

             }

             final Action action = new Action(TYPE_SET_SPAN);

             action.mSpanObject = object;

             action.mStart = start;

             action.mEnd = end;

             action.mSpanFlags = flags;

             return action;

         }

         static Action newSetHandler(Handler handler) {

             final Action action = new Action(TYPE_SET_HANDLER);

             action.mHandler = handler;

             return action;

         }

     }

     /* Queue of editing actions sent to Gecko thread that

        the Gecko thread has not responded to yet */

     private final class ActionQueue {

         private final ConcurrentLinkedQueue<Action> mActions;

         private final Semaphore mActionsActive;

         private KeyCharacterMap mKeyMap;

         ActionQueue() {

             mActions = new ConcurrentLinkedQueue<Action>();

             mActionsActive = new Semaphore(1);

         }

         void offer(Action action) {

             if (DEBUG) {

                 assertOnIcThread();

                 Log.d(LOGTAG, "offer: Action(" +

                               getConstantName(Action.class, "TYPE_", action.mType) + ")");

             }

             /* Events don't need update because they generate text/selection

                notifications which will do the updating for us */

             if (action.mType != Action.TYPE_EVENT &&

                 action.mType != Action.TYPE_ACKNOWLEDGE_FOCUS &&

                 action.mType != Action.TYPE_SET_HANDLER) {

                 action.mShouldUpdate = mUpdateGecko;

             }

             if (mActions.isEmpty()) {

                 mActionsActive.acquireUninterruptibly();

                 mActions.offer(action);

             } else synchronized(this) {

                 // tryAcquire here in case Gecko thread has just released it

                 mActionsActive.tryAcquire();

                 mActions.offer(action);

             }

             switch (action.mType) {

             case Action.TYPE_EVENT:

             case Action.TYPE_SET_SELECTION:

             case Action.TYPE_SET_SPAN:

             case Action.TYPE_REMOVE_SPAN:

             case Action.TYPE_SET_HANDLER:

                 GeckoAppShell.sendEventToGecko(GeckoEvent.createIMEEvent(

                         GeckoEvent.ImeAction.IME_SYNCHRONIZE));

                 break;

             case Action.TYPE_REPLACE_TEXT:

                 // try key events first

                 sendCharKeyEvents(action);

                 GeckoAppShell.sendEventToGecko(GeckoEvent.createIMEReplaceEvent(

                         action.mStart, action.mEnd, action.mSequence.toString()));

                 break;

             case Action.TYPE_ACKNOWLEDGE_FOCUS:

                 GeckoAppShell.sendEventToGecko(GeckoEvent.createIMEEvent(

                         GeckoEvent.ImeAction.IME_ACKNOWLEDGE_FOCUS));

                 break;

             }

             ++mIcUpdateSeqno;

         }

         private KeyEvent [] synthesizeKeyEvents(CharSequence cs) {

             try {

                 if (mKeyMap == null) {

                     mKeyMap = KeyCharacterMap.load(

                         Build.VERSION.SDK_INT < 11 ? KeyCharacterMap.ALPHA :

                                                      KeyCharacterMap.VIRTUAL_KEYBOARD);

                 }

             } catch (Exception e) {

                 // KeyCharacterMap.UnavailableExcepton is not found on Gingerbread;

                 // besides, it seems like HC and ICS will throw something other than

                 // KeyCharacterMap.UnavailableExcepton; so use a generic Exception here

                 return null;

             }

             KeyEvent [] keyEvents = mKeyMap.getEvents(cs.toString().toCharArray());

             if (keyEvents == null || keyEvents.length == 0) {

                 return null;

             }

             return keyEvents;

         }

         private void sendCharKeyEvents(Action action) {

             if (action.mSequence.length() == 0 ||

                 (action.mSequence instanceof Spannable &&

                 ((Spannable)action.mSequence).nextSpanTransition(

                     -1, Integer.MAX_VALUE, null) < Integer.MAX_VALUE)) {

                 // Spans are not preserved when we use key events,

                 // so we need the sequence to not have any spans

                 return;

             }

             KeyEvent [] keyEvents = synthesizeKeyEvents(action.mSequence);

             if (keyEvents == null) {

                 return;

             }

             for (KeyEvent event : keyEvents) {

                 if (KeyEvent.isModifierKey(event.getKeyCode())) {

                     continue;

                 }

                 if (event.getAction() == KeyEvent.ACTION_UP && mSuppressKeyUp) {

                     continue;

                 }

                 if (DEBUG) {

                     Log.d(LOGTAG, "sending: " + event);

                 }

                 GeckoAppShell.sendEventToGecko(GeckoEvent.createIMEKeyEvent(event));

             }

         }

         void poll() {

             if (DEBUG) {

                 ThreadUtils.assertOnGeckoThread();

             }

             if (mActions.isEmpty()) {

                 throw new IllegalStateException("empty actions queue");

             }

             mActions.poll();

             // Don't bother locking if queue is not empty yet

             if (mActions.isEmpty()) {

                 synchronized(this) {

                     if (mActions.isEmpty()) {

                         mActionsActive.release();

                     }

                 }

             }

         }

         Action peek() {

             if (DEBUG) {

                 ThreadUtils.assertOnGeckoThread();

             }

             if (mActions.isEmpty()) {

                 throw new IllegalStateException("empty actions queue");

             }

             return mActions.peek();

         }

         void syncWithGecko() {

             if (DEBUG) {

                 assertOnIcThread();

             }

             if (mFocused && !mActions.isEmpty()) {

                 if (DEBUG) {

                     Log.d(LOGTAG, "syncWithGecko blocking on thread " +

                                   Thread.currentThread().getName());

                 }

                 mActionsActive.acquireUninterruptibly();

                 mActionsActive.release();

             } else if (DEBUG && !mFocused) {

                 Log.d(LOGTAG, "skipped syncWithGecko (no focus)");

             }

         }

         boolean isEmpty() {

             return mActions.isEmpty();

         }

     }

     GeckoEditable() {

         mActionQueue = new ActionQueue();

         mSavedSelectionStart = -1;

         mUpdateGecko = true;

         mText = new SpannableStringBuilder();

         mChangedText = new SpannableStringBuilder();

         final Class<?>[] PROXY_INTERFACES = { Editable.class };

         mProxy = (Editable)Proxy.newProxyInstance(

                 Editable.class.getClassLoader(),

                 PROXY_INTERFACES, this);

         LayerView v = GeckoAppShell.getLayerView();

         mListener = GeckoInputConnection.create(v, this);

         mIcRunHandler = mIcPostHandler = ThreadUtils.getUiHandler();

     }

     private boolean onIcThread() {

         return mIcRunHandler.getLooper() == Looper.myLooper();

     }

     private void assertOnIcThread() {

         ThreadUtils.assertOnThread(mIcRunHandler.getLooper().getThread(), AssertBehavior.THROW);

     }

     private void geckoPostToIc(Runnable runnable) {

         mIcPostHandler.post(runnable);

     }

     private void geckoUpdateGecko(final boolean force) {

         /* We do not increment the seqno here, but only check it, because geckoUpdateGecko is a

            request for update. If we incremented the seqno here, geckoUpdateGecko would have

            prevented other updates from occurring */

         final int seqnoWhenPosted = mGeckoUpdateSeqno;

         geckoPostToIc(new Runnable() {

             @Override

             public void run() {

                 mActionQueue.syncWithGecko();

                 if (seqnoWhenPosted == mGeckoUpdateSeqno) {

                     icUpdateGecko(force);

                 }

             }

         });

     }

     private Object getField(Object obj, String field, Object def) {

         try {

             return obj.getClass().getField(field).get(obj);

         } catch (Exception e) {

             return def;

         }

     }

     private void icUpdateGecko(boolean force) {

         // Skip if receiving a repeated request, or

         // if suppressing compositions during text selection.

         if ((!force && mIcUpdateSeqno == mLastIcUpdateSeqno) ||

             mSuppressCompositions) {

             if (DEBUG) {

                 Log.d(LOGTAG, "icUpdateGecko() skipped");

             }

             return;

         }

         mLastIcUpdateSeqno = mIcUpdateSeqno;

         mActionQueue.syncWithGecko();

         if (DEBUG) {

             Log.d(LOGTAG, "icUpdateGecko()");

         }

         final int selStart = mText.getSpanStart(Selection.SELECTION_START);

         final int selEnd = mText.getSpanEnd(Selection.SELECTION_END);

         int composingStart = mText.length();

         int composingEnd = 0;

         Object[] spans = mText.getSpans(0, composingStart, Object.class);

         for (Object span : spans) {

             if ((mText.getSpanFlags(span) & Spanned.SPAN_COMPOSING) != 0) {

                 composingStart = Math.min(composingStart, mText.getSpanStart(span));

                 composingEnd = Math.max(composingEnd, mText.getSpanEnd(span));

             }

         }

         if (DEBUG) {

             Log.d(LOGTAG, " range = " + composingStart + "-" + composingEnd);

             Log.d(LOGTAG, " selection = " + selStart + "-" + selEnd);

         }

         if (composingStart >= composingEnd) {

             if (selStart >= 0 && selEnd >= 0) {

                 GeckoAppShell.sendEventToGecko(

                         GeckoEvent.createIMESelectEvent(selStart, selEnd));

             } else {

                 GeckoAppShell.sendEventToGecko(GeckoEvent.createIMEEvent(

                         GeckoEvent.ImeAction.IME_REMOVE_COMPOSITION));

             }

             return;

         }

         if (selEnd >= composingStart && selEnd <= composingEnd) {

             GeckoAppShell.sendEventToGecko(GeckoEvent.createIMERangeEvent(

                     selEnd - composingStart, selEnd - composingStart,

                     GeckoEvent.IME_RANGE_CARETPOSITION, 0, 0, false, 0, 0, 0));

         }

         int rangeStart = composingStart;

         TextPaint tp = new TextPaint();

         TextPaint emptyTp = new TextPaint();

         // set initial foreground color to 0, because we check for tp.getColor() == 0

         // below to decide whether to pass a foreground color to Gecko

         emptyTp.setColor(0);

         do {

             int rangeType, rangeStyles = 0, rangeLineStyle = GeckoEvent.IME_RANGE_LINE_NONE;

             boolean rangeBoldLine = false;

             int rangeForeColor = 0, rangeBackColor = 0, rangeLineColor = 0;

             int rangeEnd = mText.nextSpanTransition(rangeStart, composingEnd, Object.class);

             if (selStart > rangeStart && selStart < rangeEnd) {

                 rangeEnd = selStart;

             } else if (selEnd > rangeStart && selEnd < rangeEnd) {

                 rangeEnd = selEnd;

             }

             CharacterStyle[] styleSpans =

                     mText.getSpans(rangeStart, rangeEnd, CharacterStyle.class);

             if (DEBUG) {

                 Log.d(LOGTAG, " found " + styleSpans.length + " spans @ " +

                               rangeStart + "-" + rangeEnd);

             }

             if (styleSpans.length == 0) {

                 rangeType = (selStart == rangeStart && selEnd == rangeEnd)

                             ? GeckoEvent.IME_RANGE_SELECTEDRAWTEXT

                             : GeckoEvent.IME_RANGE_RAWINPUT;

             } else {

                 rangeType = (selStart == rangeStart && selEnd == rangeEnd)

                             ? GeckoEvent.IME_RANGE_SELECTEDCONVERTEDTEXT

                             : GeckoEvent.IME_RANGE_CONVERTEDTEXT;

                 tp.set(emptyTp);

                 for (CharacterStyle span : styleSpans) {

                     span.updateDrawState(tp);

                 }

                 int tpUnderlineColor = 0;

                 float tpUnderlineThickness = 0.0f;

                 // These TextPaint fields only exist on Android ICS+ and are not in the SDK

                 if (Build.VERSION.SDK_INT >= 14) {

                     tpUnderlineColor = (Integer)getField(tp, "underlineColor", 0);

                     tpUnderlineThickness = (Float)getField(tp, "underlineThickness", 0.0f);

                 }

                 if (tpUnderlineColor != 0) {

                     rangeStyles |= GeckoEvent.IME_RANGE_UNDERLINE | GeckoEvent.IME_RANGE_LINECOLOR;

                     rangeLineColor = tpUnderlineColor;

                     // Approximately translate underline thickness to what Gecko understands

                     if (tpUnderlineThickness <= 0.5f) {

                         rangeLineStyle = GeckoEvent.IME_RANGE_LINE_DOTTED;

                     } else {

                         rangeLineStyle = GeckoEvent.IME_RANGE_LINE_SOLID;

                         if (tpUnderlineThickness >= 2.0f) {

                             rangeBoldLine = true;

                         }

                     }

                 } else if (tp.isUnderlineText()) {

                     rangeStyles |= GeckoEvent.IME_RANGE_UNDERLINE;

                     rangeLineStyle = GeckoEvent.IME_RANGE_LINE_SOLID;

                 }

                 if (tp.getColor() != 0) {

                     rangeStyles |= GeckoEvent.IME_RANGE_FORECOLOR;

                     rangeForeColor = tp.getColor();

                 }

                 if (tp.bgColor != 0) {

                     rangeStyles |= GeckoEvent.IME_RANGE_BACKCOLOR;

                     rangeBackColor = tp.bgColor;

                 }

             }

             GeckoAppShell.sendEventToGecko(GeckoEvent.createIMERangeEvent(

                     rangeStart - composingStart, rangeEnd - composingStart,

                     rangeType, rangeStyles, rangeLineStyle, rangeBoldLine,

                     rangeForeColor, rangeBackColor, rangeLineColor));

             rangeStart = rangeEnd;

             if (DEBUG) {

                 Log.d(LOGTAG, " added " + rangeType +

                               " : " + Integer.toHexString(rangeStyles) +

                               " : " + Integer.toHexString(rangeForeColor) +

                               " : " + Integer.toHexString(rangeBackColor));

             }

         } while (rangeStart < composingEnd);

         GeckoAppShell.sendEventToGecko(GeckoEvent.createIMECompositionEvent(

                 composingStart, composingEnd));

     }

     // GeckoEditableClient interface

     @Override

     public void sendEvent(final GeckoEvent event) {

         if (DEBUG) {

             assertOnIcThread();

             Log.d(LOGTAG, "sendEvent(" + event + ")");

         }

         /*

            We are actually sending two events to Gecko here,

            1. Event from the event parameter (key event, etc.)

            2. Sync event from the mActionQueue.offer call

            The first event is a normal GeckoEvent that does not reply back to us,

            the second sync event will have a reply, during which we see that there is a pending

            event-type action, and update the selection/composition/etc. accordingly.

         */

         GeckoAppShell.sendEventToGecko(event);

         mActionQueue.offer(new Action(Action.TYPE_EVENT));

     }

     @Override

     public Editable getEditable() {

         if (!onIcThread()) {

             // Android may be holding an old InputConnection; ignore

             if (DEBUG) {

                 Log.i(LOGTAG, "getEditable() called on non-IC thread");

             }

             return null;

         }

         return mProxy;

     }

     @Override

     public void setUpdateGecko(boolean update) {

         if (!onIcThread()) {

             // Android may be holding an old InputConnection; ignore

             if (DEBUG) {

                 Log.i(LOGTAG, "setUpdateGecko() called on non-IC thread");

             }

             return;

         }

         if (update) {

             icUpdateGecko(false);

         }

         mUpdateGecko = update;

     }

     @Override

     public void setSuppressKeyUp(boolean suppress) {

         if (DEBUG) {

             // only used by key event handler

             ThreadUtils.assertOnUiThread();

         }

         // Suppress key up event generated as a result of

         // translating characters to key events

         mSuppressKeyUp = suppress;

     }

     @Override

     public Handler getInputConnectionHandler() {

         // Can be called from either UI thread or IC thread;

         // care must be taken to avoid race conditions

         return mIcRunHandler;

     }

     @Override

     public boolean setInputConnectionHandler(Handler handler) {

         if (handler == mIcPostHandler) {

             return true;

         }

         if (!mFocused) {

             return false;

         }

         if (DEBUG) {

             assertOnIcThread();

         }

         // There are three threads at this point: Gecko thread, old IC thread, and new IC

         // thread, and we want to safely switch from old IC thread to new IC thread.

         // We first send a TYPE_SET_HANDLER action to the Gecko thread; this ensures that

         // the Gecko thread is stopped at a known point. At the same time, the old IC

         // thread blocks on the action; this ensures that the old IC thread is stopped at

         // a known point. Finally, inside the Gecko thread, we post a Runnable to the old

         // IC thread; this Runnable switches from old IC thread to new IC thread. We

         // switch IC thread on the old IC thread to ensure any pending Runnables on the

         // old IC thread are processed before we switch over. Inside the Gecko thread, we

         // also post a Runnable to the new IC thread; this Runnable blocks until the

         // switch is complete; this ensures that the new IC thread won't accept

         // InputConnection calls until after the switch.

         mActionQueue.offer(Action.newSetHandler(handler));

         mActionQueue.syncWithGecko();

         return true;

     }

     private void geckoSetIcHandler(final Handler newHandler) {

         geckoPostToIc(new Runnable() { // posting to old IC thread

             @Override

             public void run() {

                 synchronized (newHandler) {

                     mIcRunHandler = newHandler;

                     newHandler.notify();

                 }

             }

         });

         // At this point, all future Runnables should be posted to the new IC thread, but

         // we don't switch mIcRunHandler yet because there may be pending Runnables on the

         // old IC thread still waiting to run.

         mIcPostHandler = newHandler;

         geckoPostToIc(new Runnable() { // posting to new IC thread

             @Override

             public void run() {

                 synchronized (newHandler) {

                     while (mIcRunHandler != newHandler) {

                         try {

                             newHandler.wait();

                         } catch (InterruptedException e) {

                         }

                     }

                 }

             }

         });

     }

     // GeckoEditableListener interface

     private void geckoActionReply() {

         if (DEBUG) {

             // GeckoEditableListener methods should all be called from the Gecko thread

             ThreadUtils.assertOnGeckoThread();

         }

         final Action action = mActionQueue.peek();

         if (DEBUG) {

             Log.d(LOGTAG, "reply: Action(" +

                           getConstantName(Action.class, "TYPE_", action.mType) + ")");

         }

         switch (action.mType) {

         case Action.TYPE_SET_SELECTION:

             final int len = mText.length();

             final int curStart = Selection.getSelectionStart(mText);

             final int curEnd = Selection.getSelectionEnd(mText);

             // start == -1 when the start offset should remain the same

             // end == -1 when the end offset should remain the same

             final int selStart = Math.min(action.mStart < 0 ? curStart : action.mStart, len);

             final int selEnd = Math.min(action.mEnd < 0 ? curEnd : action.mEnd, len);

             if (selStart < action.mStart || selEnd < action.mEnd) {

                 Log.w(LOGTAG, "IME sync error: selection out of bounds");

             }

             Selection.setSelection(mText, selStart, selEnd);

             geckoPostToIc(new Runnable() {

                 @Override

                 public void run() {

                     mActionQueue.syncWithGecko();

                     final int start = Selection.getSelectionStart(mText);

                     final int end = Selection.getSelectionEnd(mText);

                     if (selStart == start && selEnd == end) {

                         // There has not been another new selection in the mean time that

                         // made this notification out-of-date

                         mListener.onSelectionChange(start, end);

                     }

                 }

             });

             break;

         case Action.TYPE_SET_SPAN:

             mText.setSpan(action.mSpanObject, action.mStart, action.mEnd, action.mSpanFlags);

             break;

         case Action.TYPE_SET_HANDLER:

             geckoSetIcHandler(action.mHandler);

             break;

         }

         if (action.mShouldUpdate) {

             geckoUpdateGecko(false);

         }

     }

     @Override

     public void notifyIME(final int type) {

         if (DEBUG) {

             // GeckoEditableListener methods should all be called from the Gecko thread

             ThreadUtils.assertOnGeckoThread();

             // NOTIFY_IME_REPLY_EVENT is logged separately, inside geckoActionReply()

             if (type != NOTIFY_IME_REPLY_EVENT) {

                 Log.d(LOGTAG, "notifyIME(" +

                               getConstantName(GeckoEditableListener.class, "NOTIFY_IME_", type) +

                               ")");

             }

         }

         if (type == NOTIFY_IME_REPLY_EVENT) {

             try {

                 if (mFocused) {

                     // When mFocused is false, the reply is for a stale action,

                     // and we should not do anything

                     geckoActionReply();

                 } else if (DEBUG) {

                     Log.d(LOGTAG, "discarding stale reply");

                 }

             } finally {

                 // Ensure action is always removed from queue

                 // even if stale action results in exception in geckoActionReply

                 mActionQueue.poll();

             }

             return;

         }

         geckoPostToIc(new Runnable() {

             @Override

             public void run() {

                 if (type == NOTIFY_IME_OF_BLUR) {

                     mFocused = false;

                 } else if (type == NOTIFY_IME_OF_FOCUS) {

                     mFocused = true;

                     // Unmask events on the Gecko side

                     mActionQueue.offer(new Action(Action.TYPE_ACKNOWLEDGE_FOCUS));

                 }

                 // Make sure there are no other things going on. If we sent

                 // GeckoEvent.IME_ACKNOWLEDGE_FOCUS, this line also makes us

                 // wait for Gecko to update us on the newly focused content

                 mActionQueue.syncWithGecko();

                 mListener.notifyIME(type);

             }

         });

         // Register/unregister Gecko-side text selection listeners

         // and update the mGeckoFocused flag.

         if (type == NOTIFY_IME_OF_BLUR && mGeckoFocused) {

             // Check for focus here because Gecko may send us a blur before a focus in some

             // cases, and we don't want to unregister an event that was not registered.

             mGeckoFocused = false;

             mSuppressCompositions = false;

             GeckoAppShell.getEventDispatcher().

                 unregisterEventListener("TextSelection:DraggingHandle", this);

         } else if (type == NOTIFY_IME_OF_FOCUS) {

             mGeckoFocused = true;

             mSuppressCompositions = false;

             GeckoAppShell.getEventDispatcher().

                 registerEventListener("TextSelection:DraggingHandle", this);

         }

     }

     @Override

     public void notifyIMEContext(final int state, final String typeHint,

                           final String modeHint, final String actionHint) {

         // Because we want to be able to bind GeckoEditable to the newest LayerView instance,

         // this can be called from the Java IC thread in addition to the Gecko thread.

         if (DEBUG) {

             Log.d(LOGTAG, "notifyIMEContext(" +

                           getConstantName(GeckoEditableListener.class, "IME_STATE_", state) +

                           ", \"" + typeHint + "\", \"" + modeHint + "\", \"" + actionHint + "\")");

         }

         geckoPostToIc(new Runnable() {

             @Override

             public void run() {

                 // Make sure there are no other things going on

                 mActionQueue.syncWithGecko();

                 // Set InputConnectionHandler in notifyIMEContext because

                 // GeckoInputConnection.notifyIMEContext calls restartInput() which will invoke

                 // InputConnectionHandler.onCreateInputConnection

                 LayerView v = GeckoAppShell.getLayerView();

                 if (v != null) {

                     mListener = GeckoInputConnection.create(v, GeckoEditable.this);

                     v.setInputConnectionHandler((InputConnectionHandler)mListener);

                     mListener.notifyIMEContext(state, typeHint, modeHint, actionHint);

                 }

             }

         });

     }

     @Override

     public void onSelectionChange(final int start, final int end) {

         if (DEBUG) {

             // GeckoEditableListener methods should all be called from the Gecko thread

             ThreadUtils.assertOnGeckoThread();

             Log.d(LOGTAG, "onSelectionChange(" + start + ", " + end + ")");

         }

         if (start < 0 || start > mText.length() || end < 0 || end > mText.length()) {

             throw new IllegalArgumentException("invalid selection notification range: " +

                 start + " to " + end + ", length: " + mText.length());

         }

         final int seqnoWhenPosted = ++mGeckoUpdateSeqno;

         /* An event (keypress, etc.) has potentially changed the selection,

            synchronize the selection here. There is not a race with the IC thread

            because the IC thread should be blocked on the event action */

         if (!mActionQueue.isEmpty() &&

             mActionQueue.peek().mType == Action.TYPE_EVENT) {

             Selection.setSelection(mText, start, end);

             return;

         }

         geckoPostToIc(new Runnable() {

             @Override

             public void run() {

                 mActionQueue.syncWithGecko();

                 /* check to see there has not been another action that potentially changed the

                    selection. If so, we can skip this update because we know there is another

                    update right after this one that will replace the effect of this update */

                 if (mGeckoUpdateSeqno == seqnoWhenPosted) {

                     /* In this case, Gecko's selection has changed and it's notifying us to change

                        Java's selection. In the normal case, whenever Java's selection changes,

                        we go back and set Gecko's selection as well. However, in this case,

                        since Gecko's selection is already up-to-date, we skip this step. */

                     boolean oldUpdateGecko = mUpdateGecko;

                     mUpdateGecko = false;

                     Selection.setSelection(mProxy, start, end);

                     mUpdateGecko = oldUpdateGecko;

                 }

             }

         });

     }

     private void geckoReplaceText(int start, int oldEnd, CharSequence newText) {

         // Don't use replace() because Gingerbread has a bug where if the replaced text

         // has the same spans as the original text, the spans will end up being deleted

         mText.delete(start, oldEnd);

         mText.insert(start, newText);

     }

     @Override

     public void onTextChange(final String text, final int start,

                       final int unboundedOldEnd, final int unboundedNewEnd) {

         if (DEBUG) {

             // GeckoEditableListener methods should all be called from the Gecko thread

             ThreadUtils.assertOnGeckoThread();

             StringBuilder sb = new StringBuilder("onTextChange(");

             debugAppend(sb, text);

             sb.append(", ").append(start).append(", ")

                 .append(unboundedOldEnd).append(", ")

                 .append(unboundedNewEnd).append(")");

             Log.d(LOGTAG, sb.toString());

         }

         if (start < 0 || start > unboundedOldEnd) {

             throw new IllegalArgumentException("invalid text notification range: " +

                 start + " to " + unboundedOldEnd);

         }

         /* For the "end" parameters, Gecko can pass in a large

            number to denote "end of the text". Fix that here */

         final int oldEnd = unboundedOldEnd > mText.length() ? mText.length() : unboundedOldEnd;

         // new end should always match text

         if (start != 0 && unboundedNewEnd != (start + text.length())) {

             throw new IllegalArgumentException("newEnd does not match text: " +

                 unboundedNewEnd + " vs " + (start + text.length()));

         }

         final int newEnd = start + text.length();

         /* Text changes affect the selection as well, and we may not receive another selection

            update as a result of selection notification masking on the Gecko side; therefore,

            in order to prevent previous stale selection notifications from occurring, we need

            to increment the seqno here as well */

         ++mGeckoUpdateSeqno;

         mChangedText.clearSpans();

         mChangedText.replace(0, mChangedText.length(), text);

         // Preserve as many spans as possible

         TextUtils.copySpansFrom(mText, start, Math.min(oldEnd, newEnd),

                                 Object.class, mChangedText, 0);

         if (!mActionQueue.isEmpty()) {

             final Action action = mActionQueue.peek();

             if (action.mType == Action.TYPE_REPLACE_TEXT &&

                     start <= action.mStart &&

                     action.mStart + action.mSequence.length() <= newEnd) {

                 // actionNewEnd is the new end of the original replacement action

                 final int actionNewEnd = action.mStart + action.mSequence.length();

                 int selStart = Selection.getSelectionStart(mText);

                 int selEnd = Selection.getSelectionEnd(mText);

                 // Replace old spans with new spans

                 mChangedText.replace(action.mStart - start, actionNewEnd - start,

                                      action.mSequence);

                 geckoReplaceText(start, oldEnd, mChangedText);

                 // delete/insert above might have moved our selection to somewhere else

                 // this happens when the Gecko text change covers a larger range than

                 // the original replacement action. Fix selection here

                 if (selStart >= start && selStart <= oldEnd) {

                     selStart = selStart < action.mStart ? selStart :

                                selStart < action.mEnd   ? actionNewEnd :

                                                           selStart + actionNewEnd - action.mEnd;

                     mText.setSpan(Selection.SELECTION_START, selStart, selStart,

                                   Spanned.SPAN_POINT_POINT);

                 }

                 if (selEnd >= start && selEnd <= oldEnd) {

                     selEnd = selEnd < action.mStart ? selEnd :

                              selEnd < action.mEnd   ? actionNewEnd :

                                                       selEnd + actionNewEnd - action.mEnd;

                     mText.setSpan(Selection.SELECTION_END, selEnd, selEnd,

                                   Spanned.SPAN_POINT_POINT);

                 }

             } else {

                 geckoReplaceText(start, oldEnd, mChangedText);

             }

         } else {

             geckoReplaceText(start, oldEnd, mChangedText);

         }

         geckoPostToIc(new Runnable() {

             @Override

             public void run() {

                 mListener.onTextChange(text, start, oldEnd, newEnd);

             }

         });

     }

     // InvocationHandler interface

     static String getConstantName(Class<?> cls, String prefix, Object value) {

         for (Field fld : cls.getDeclaredFields()) {

             try {

                 if (fld.getName().startsWith(prefix) &&

                     fld.get(null).equals(value)) {

                     return fld.getName();

                 }

             } catch (IllegalAccessException e) {

             }

         }

         return String.valueOf(value);

     }

     static StringBuilder debugAppend(StringBuilder sb, Object obj) {

         if (obj == null) {

             sb.append("null");

         } else if (obj instanceof GeckoEditable) {

             sb.append("GeckoEditable");

         } else if (Proxy.isProxyClass(obj.getClass())) {

             debugAppend(sb, Proxy.getInvocationHandler(obj));

         } else if (obj instanceof CharSequence) {

             sb.append("\"").append(obj.toString().replace('\n', '\u21b2')).append("\"");

         } else if (obj.getClass().isArray()) {

             sb.append(obj.getClass().getComponentType().getSimpleName()).append("[")

               .append(java.lang.reflect.Array.getLength(obj)).append("]");

         } else {

             sb.append(obj.toString());

         }

         return sb;

     }

     @Override

     public Object invoke(Object proxy, Method method, Object[] args)

                          throws Throwable {

         Object target;

         final Class<?> methodInterface = method.getDeclaringClass();

         if (DEBUG) {

             // Editable methods should all be called from the IC thread

             assertOnIcThread();

         }

         if (methodInterface == Editable.class ||

                 methodInterface == Appendable.class ||

                 methodInterface == Spannable.class) {

             // Method alters the Editable; route calls to our implementation

             target = this;

         } else {

             // Method queries the Editable; must sync with Gecko first

             // then call on the inner Editable itself

             mActionQueue.syncWithGecko();

             target = mText;

         }

         Object ret;

         try {

             ret = method.invoke(target, args);

         } catch (InvocationTargetException e) {

             // Bug 817386

             // Most likely Gecko has changed the text while GeckoInputConnection is

             // trying to access the text. If we pass through the exception here, Fennec

             // will crash due to a lack of exception handler. Log the exception and

             // return an empty value instead.

             if (!(e.getCause() instanceof IndexOutOfBoundsException)) {

                 // Only handle IndexOutOfBoundsException for now,

                 // as other exceptions might signal other bugs

                 throw e;

             }

             Log.w(LOGTAG, "Exception in GeckoEditable." + method.getName(), e.getCause());

             Class<?> retClass = method.getReturnType();

             if (retClass == Character.TYPE) {

                 ret = '\0';

             } else if (retClass == Integer.TYPE) {

                 ret = 0;

             } else if (retClass == String.class) {

                 ret = "";

             } else {

                 ret = null;

             }

         }

         if (DEBUG) {

             StringBuilder log = new StringBuilder(method.getName());

             log.append("(");

             for (Object arg : args) {

                 debugAppend(log, arg).append(", ");

             }

             if (args.length > 0) {

                 log.setLength(log.length() - 2);

             }

             if (method.getReturnType().equals(Void.TYPE)) {

                 log.append(")");

             } else {

                 debugAppend(log.append(") = "), ret);

             }

             Log.d(LOGTAG, log.toString());

         }

         return ret;

     }

     // Spannable interface

     @Override

     public void removeSpan(Object what) {

         if (what == Selection.SELECTION_START ||

                 what == Selection.SELECTION_END) {

             Log.w(LOGTAG, "selection removed with removeSpan()");

         }

         if (mText.getSpanStart(what) >= 0) { // only remove if it's there

             // Okay to remove immediately

             mText.removeSpan(what);

             mActionQueue.offer(new Action(Action.TYPE_REMOVE_SPAN));

         }

     }

     @Override

     public void setSpan(Object what, int start, int end, int flags) {

         if (what == Selection.SELECTION_START) {

             if ((flags & Spanned.SPAN_INTERMEDIATE) != 0) {

                 // We will get the end offset next, just save the start for now

                 mSavedSelectionStart = start;

             } else {

                 mActionQueue.offer(Action.newSetSelection(start, -1));

             }

         } else if (what == Selection.SELECTION_END) {

             mActionQueue.offer(Action.newSetSelection(mSavedSelectionStart, end));

             mSavedSelectionStart = -1;

         } else {

             mActionQueue.offer(Action.newSetSpan(what, start, end, flags));

         }

     }

     // Appendable interface

     @Override

     public Editable append(CharSequence text) {

         return replace(mProxy.length(), mProxy.length(), text, 0, text.length());

     }

     @Override

     public Editable append(CharSequence text, int start, int end) {

         return replace(mProxy.length(), mProxy.length(), text, start, end);

     }

     @Override

     public Editable append(char text) {

         return replace(mProxy.length(), mProxy.length(), String.valueOf(text), 0, 1);

     }

     // Editable interface

     @Override

     public InputFilter[] getFilters() {

         return mFilters;

     }

     @Override

     public void setFilters(InputFilter[] filters) {

         mFilters = filters;

     }

     @Override

     public void clearSpans() {

         /* XXX this clears the selection spans too,

            but there is no way to clear the corresponding selection in Gecko */

         Log.w(LOGTAG, "selection cleared with clearSpans()");

         mText.clearSpans();

     }

     @Override

     public Editable replace(int st, int en,

             CharSequence source, int start, int end) {

         CharSequence text = source;

         if (start < 0 || start > end || end > text.length()) {

             throw new IllegalArgumentException("invalid replace offsets: " +

                 start + " to " + end + ", length: " + text.length());

         }

         if (start != 0 || end != text.length()) {

             text = text.subSequence(start, end);

         }

         if (mFilters != null) {

             // Filter text before sending the request to Gecko

             for (int i = 0; i < mFilters.length; ++i) {

                 final CharSequence cs = mFilters[i].filter(

                         text, 0, text.length(), mProxy, st, en);

                 if (cs != null) {

                     text = cs;

                 }

             }

         }

         if (text == source) {

             // Always create a copy

             text = new SpannableString(source);

         }

         mActionQueue.offer(Action.newReplaceText(text,

                 Math.min(st, en), Math.max(st, en)));

         return mProxy;

     }

     @Override

     public void clear() {

         replace(0, mProxy.length(), "", 0, 0);

     }

     @Override

     public Editable delete(int st, int en) {

         return replace(st, en, "", 0, 0);

     }

     @Override

     public Editable insert(int where, CharSequence text,

                                 int start, int end) {

         return replace(where, where, text, start, end);

     }

     @Override

     public Editable insert(int where, CharSequence text) {

         return replace(where, where, text, 0, text.length());

     }

     @Override

     public Editable replace(int st, int en, CharSequence text) {

         return replace(st, en, text, 0, text.length());

     }

     /* GetChars interface */

     @Override

     public void getChars(int start, int end, char[] dest, int destoff) {

         /* overridden Editable interface methods in GeckoEditable must not be called directly

            outside of GeckoEditable. Instead, the call must go through mProxy, which ensures

            that Java is properly synchronized with Gecko */

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     /* Spanned interface */

     @Override

     public int getSpanEnd(Object tag) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     public int getSpanFlags(Object tag) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     public int getSpanStart(Object tag) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     public <T> T[] getSpans(int start, int end, Class<T> type) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     @SuppressWarnings("rawtypes") // nextSpanTransition uses raw Class in its Android declaration

     public int nextSpanTransition(int start, int limit, Class type) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     /* CharSequence interface */

     @Override

     public char charAt(int index) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     public int length() {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     public CharSequence subSequence(int start, int end) {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     @Override

     public String toString() {

         throw new UnsupportedOperationException("method must be called through mProxy");

     }

     // GeckoEventListener implementation

     @Override

     public void handleMessage(String event, JSONObject message) {

         if (!"TextSelection:DraggingHandle".equals(event)) {

             return;

         }

         mSuppressCompositions = message.optBoolean("dragging", false);

     }

 }