Rename LatinKeyboardBaseView class to KeyboardBaseView

Change-Id: I496ecbfa7d398583d01f821398f49f75d17311d8

1 files changed, 1480 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/BaseKeyboardView.java b/java/src/com/android/inputmethod/latin/BaseKeyboardView.java
new file mode 100644
index 000000000..4ba6fbddc
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/BaseKeyboardView.java
@@ -0,0 +1,1480 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.inputmethod.latin;
+
+import com.android.inputmethod.latin.BaseKeyboard.Key;
+
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.content.res.Resources;
+import android.content.res.TypedArray;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Paint.Align;
+import android.graphics.PorterDuff;
+import android.graphics.Rect;
+import android.graphics.Region.Op;
+import android.graphics.Typeface;
+import android.graphics.drawable.Drawable;
+import android.os.Handler;
+import android.os.Message;
+import android.os.SystemClock;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.util.TypedValue;
+import android.view.GestureDetector;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewGroup.LayoutParams;
+import android.view.WindowManager;
+import android.widget.PopupWindow;
+import android.widget.TextView;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.WeakHashMap;
+
+/**
+ * A view that renders a virtual {@link LatinKeyboard}. It handles rendering of keys and
+ * detecting key presses and touch movements.
+ *
+ * TODO: References to LatinKeyboard in this class should be replaced with ones to its base class.
+ *
+ * @attr ref R.styleable#BaseKeyboardView_keyBackground
+ * @attr ref R.styleable#BaseKeyboardView_keyPreviewLayout
+ * @attr ref R.styleable#BaseKeyboardView_keyPreviewOffset
+ * @attr ref R.styleable#BaseKeyboardView_labelTextSize
+ * @attr ref R.styleable#BaseKeyboardView_keyTextSize
+ * @attr ref R.styleable#BaseKeyboardView_keyTextColor
+ * @attr ref R.styleable#BaseKeyboardView_verticalCorrection
+ * @attr ref R.styleable#BaseKeyboardView_popupLayout
+ */
+public class BaseKeyboardView extends View implements PointerTracker.UIProxy {
+    private static final String TAG = "BaseKeyboardView";
+    private static final boolean DEBUG = false;
+
+    public static final int NOT_A_TOUCH_COORDINATE = -1;
+
+    public interface OnKeyboardActionListener {
+
+        /**
+         * Called when the user presses a key. This is sent before the
+         * {@link #onKey} is called. For keys that repeat, this is only
+         * called once.
+         *
+         * @param primaryCode
+         *            the unicode of the key being pressed. If the touch is
+         *            not on a valid key, the value will be zero.
+         */
+        void onPress(int primaryCode);
+
+        /**
+         * Called when the user releases a key. This is sent after the
+         * {@link #onKey} is called. For keys that repeat, this is only
+         * called once.
+         *
+         * @param primaryCode
+         *            the code of the key that was released
+         */
+        void onRelease(int primaryCode);
+
+        /**
+         * Send a key press to the listener.
+         *
+         * @param primaryCode
+         *            this is the key that was pressed
+         * @param keyCodes
+         *            the codes for all the possible alternative keys with
+         *            the primary code being the first. If the primary key
+         *            code is a single character such as an alphabet or
+         *            number or symbol, the alternatives will include other
+         *            characters that may be on the same key or adjacent
+         *            keys. These codes are useful to correct for
+         *            accidental presses of a key adjacent to the intended
+         *            key.
+         * @param x
+         *            x-coordinate pixel of touched event. If onKey is not called by onTouchEvent,
+         *            the value should be NOT_A_TOUCH_COORDINATE.
+         * @param y
+         *            y-coordinate pixel of touched event. If onKey is not called by onTouchEvent,
+         *            the value should be NOT_A_TOUCH_COORDINATE.
+         */
+        void onKey(int primaryCode, int[] keyCodes, int x, int y);
+
+        /**
+         * Sends a sequence of characters to the listener.
+         *
+         * @param text
+         *            the sequence of characters to be displayed.
+         */
+        void onText(CharSequence text);
+
+        /**
+         * Called when user released a finger outside any key.
+         */
+        void onCancel();
+
+        /**
+         * Called when the user quickly moves the finger from right to
+         * left.
+         */
+        void swipeLeft();
+
+        /**
+         * Called when the user quickly moves the finger from left to
+         * right.
+         */
+        void swipeRight();
+
+        /**
+         * Called when the user quickly moves the finger from up to down.
+         */
+        void swipeDown();
+
+        /**
+         * Called when the user quickly moves the finger from down to up.
+         */
+        void swipeUp();
+    }
+
+    // Timing constants
+    private final int mKeyRepeatInterval;
+
+    // Miscellaneous constants
+    /* package */ static final int NOT_A_KEY = -1;
+    private static final int[] LONG_PRESSABLE_STATE_SET = { android.R.attr.state_long_pressable };
+    private static final int HINT_ICON_VERTICAL_ADJUSTMENT_PIXEL = -1;
+
+    // XML attribute
+    private int mKeyTextSize;
+    private int mKeyTextColor;
+    private Typeface mKeyTextStyle = Typeface.DEFAULT;
+    private int mLabelTextSize;
+    private int mSymbolColorScheme = 0;
+    private int mShadowColor;
+    private float mShadowRadius;
+    private Drawable mKeyBackground;
+    private float mBackgroundDimAmount;
+    private float mKeyHysteresisDistance;
+    private float mVerticalCorrection;
+    private int mPreviewOffset;
+    private int mPreviewHeight;
+    private int mPopupLayout;
+
+    // Main keyboard
+    private BaseKeyboard mKeyboard;
+    private Key[] mKeys;
+    // TODO this attribute should be gotten from Keyboard.
+    private int mKeyboardVerticalGap;
+
+    // Key preview popup
+    private boolean mInForeground;
+    private TextView mPreviewText;
+    private PopupWindow mPreviewPopup;
+    private int mPreviewTextSizeLarge;
+    private int[] mOffsetInWindow;
+    private int mOldPreviewKeyIndex = NOT_A_KEY;
+    private boolean mShowPreview = true;
+    private boolean mShowTouchPoints = true;
+    private int mPopupPreviewOffsetX;
+    private int mPopupPreviewOffsetY;
+    private int mWindowY;
+    private int mPopupPreviewDisplayedY;
+    private final int mDelayBeforePreview;
+    private final int mDelayAfterPreview;
+
+    // Popup mini keyboard
+    private PopupWindow mMiniKeyboardPopup;
+    private BaseKeyboardView mMiniKeyboard;
+    private View mMiniKeyboardParent;
+    private final WeakHashMap<Key, View> mMiniKeyboardCache = new WeakHashMap<Key, View>();
+    private int mMiniKeyboardOriginX;
+    private int mMiniKeyboardOriginY;
+    private long mMiniKeyboardPopupTime;
+    private int[] mWindowOffset;
+    private final float mMiniKeyboardSlideAllowance;
+    private int mMiniKeyboardTrackerId;
+
+    /** Listener for {@link OnKeyboardActionListener}. */
+    private OnKeyboardActionListener mKeyboardActionListener;
+
+    private final ArrayList<PointerTracker> mPointerTrackers = new ArrayList<PointerTracker>();
+
+    // TODO: Let the PointerTracker class manage this pointer queue
+    private final PointerQueue mPointerQueue = new PointerQueue();
+
+    private final boolean mHasDistinctMultitouch;
+    private int mOldPointerCount = 1;
+
+    protected KeyDetector mKeyDetector = new ProximityKeyDetector();
+
+    // Swipe gesture detector
+    private GestureDetector mGestureDetector;
+    private final SwipeTracker mSwipeTracker = new SwipeTracker();
+    private final int mSwipeThreshold;
+    private final boolean mDisambiguateSwipe;
+
+    // Drawing
+    /** Whether the keyboard bitmap needs to be redrawn before it's blitted. **/
+    private boolean mDrawPending;
+    /** The dirty region in the keyboard bitmap */
+    private final Rect mDirtyRect = new Rect();
+    /** The keyboard bitmap for faster updates */
+    private Bitmap mBuffer;
+    /** Notes if the keyboard just changed, so that we could possibly reallocate the mBuffer. */
+    private boolean mKeyboardChanged;
+    private Key mInvalidatedKey;
+    /** The canvas for the above mutable keyboard bitmap */
+    private Canvas mCanvas;
+    private final Paint mPaint;
+    private final Rect mPadding;
+    private final Rect mClipRegion = new Rect(0, 0, 0, 0);
+    // This map caches key label text height in pixel as value and key label text size as map key.
+    private final HashMap<Integer, Integer> mTextHeightCache = new HashMap<Integer, Integer>();
+    // Distance from horizontal center of the key, proportional to key label text height.
+    private final float KEY_LABEL_VERTICAL_ADJUSTMENT_FACTOR = 0.55f;
+    private final String KEY_LABEL_HEIGHT_REFERENCE_CHAR = "H";
+
+    private final UIHandler mHandler = new UIHandler();
+
+    class UIHandler extends Handler {
+        private static final int MSG_POPUP_PREVIEW = 1;
+        private static final int MSG_DISMISS_PREVIEW = 2;
+        private static final int MSG_REPEAT_KEY = 3;
+        private static final int MSG_LONGPRESS_KEY = 4;
+        private static final int MSG_LONGPRESS_SHIFT_KEY = 5;
+
+        private boolean mInKeyRepeat;
+
+        @Override
+        public void handleMessage(Message msg) {
+            switch (msg.what) {
+                case MSG_POPUP_PREVIEW:
+                    showKey(msg.arg1, (PointerTracker)msg.obj);
+                    break;
+                case MSG_DISMISS_PREVIEW:
+                    mPreviewPopup.dismiss();
+                    break;
+                case MSG_REPEAT_KEY: {
+                    final PointerTracker tracker = (PointerTracker)msg.obj;
+                    tracker.repeatKey(msg.arg1);
+                    startKeyRepeatTimer(mKeyRepeatInterval, msg.arg1, tracker);
+                    break;
+                }
+                case MSG_LONGPRESS_KEY: {
+                    final PointerTracker tracker = (PointerTracker)msg.obj;
+                    openPopupIfRequired(msg.arg1, tracker);
+                    break;
+                }
+                case MSG_LONGPRESS_SHIFT_KEY: {
+                    final PointerTracker tracker = (PointerTracker)msg.obj;
+                    onLongPressShiftKey(tracker);
+                    break;
+                }
+            }
+        }
+
+        public void popupPreview(long delay, int keyIndex, PointerTracker tracker) {
+            removeMessages(MSG_POPUP_PREVIEW);
+            if (mPreviewPopup.isShowing() && mPreviewText.getVisibility() == VISIBLE) {
+                // Show right away, if it's already visible and finger is moving around
+                showKey(keyIndex, tracker);
+            } else {
+                sendMessageDelayed(obtainMessage(MSG_POPUP_PREVIEW, keyIndex, 0, tracker),
+                        delay);
+            }
+        }
+
+        public void cancelPopupPreview() {
+            removeMessages(MSG_POPUP_PREVIEW);
+        }
+
+        public void dismissPreview(long delay) {
+            if (mPreviewPopup.isShowing()) {
+                sendMessageDelayed(obtainMessage(MSG_DISMISS_PREVIEW), delay);
+            }
+        }
+
+        public void cancelDismissPreview() {
+            removeMessages(MSG_DISMISS_PREVIEW);
+        }
+
+        public void startKeyRepeatTimer(long delay, int keyIndex, PointerTracker tracker) {
+            mInKeyRepeat = true;
+            sendMessageDelayed(obtainMessage(MSG_REPEAT_KEY, keyIndex, 0, tracker), delay);
+        }
+
+        public void cancelKeyRepeatTimer() {
+            mInKeyRepeat = false;
+            removeMessages(MSG_REPEAT_KEY);
+        }
+
+        public boolean isInKeyRepeat() {
+            return mInKeyRepeat;
+        }
+
+        public void startLongPressTimer(long delay, int keyIndex, PointerTracker tracker) {
+            removeMessages(MSG_LONGPRESS_KEY);
+            sendMessageDelayed(obtainMessage(MSG_LONGPRESS_KEY, keyIndex, 0, tracker), delay);
+        }
+
+        public void cancelLongPressTimer() {
+            removeMessages(MSG_LONGPRESS_KEY);
+        }
+
+        public void startLongPressShiftTimer(long delay, int keyIndex, PointerTracker tracker) {
+            removeMessages(MSG_LONGPRESS_SHIFT_KEY);
+            sendMessageDelayed(
+                    obtainMessage(MSG_LONGPRESS_SHIFT_KEY, keyIndex, 0, tracker), delay);
+        }
+
+        public void cancelLongPressShiftTimer() {
+            removeMessages(MSG_LONGPRESS_SHIFT_KEY);
+        }
+
+        public void cancelKeyTimers() {
+            cancelKeyRepeatTimer();
+            cancelLongPressTimer();
+            cancelLongPressShiftTimer();
+        }
+
+        public void cancelAllMessages() {
+            cancelKeyTimers();
+            cancelPopupPreview();
+            cancelDismissPreview();
+        }
+    };
+
+    static class PointerQueue {
+        private LinkedList<PointerTracker> mQueue = new LinkedList<PointerTracker>();
+
+        public void add(PointerTracker tracker) {
+            mQueue.add(tracker);
+        }
+
+        public int lastIndexOf(PointerTracker tracker) {
+            LinkedList<PointerTracker> queue = mQueue;
+            for (int index = queue.size() - 1; index >= 0; index--) {
+                PointerTracker t = queue.get(index);
+                if (t == tracker)
+                    return index;
+            }
+            return -1;
+        }
+
+        public void releaseAllPointersOlderThan(PointerTracker tracker, long eventTime) {
+            LinkedList<PointerTracker> queue = mQueue;
+            int oldestPos = 0;
+            for (PointerTracker t = queue.get(oldestPos); t != tracker; t = queue.get(oldestPos)) {
+                if (t.isModifier()) {
+                    oldestPos++;
+                } else {
+                    t.onUpEvent(t.getLastX(), t.getLastY(), eventTime);
+                    t.setAlreadyProcessed();
+                    queue.remove(oldestPos);
+                }
+            }
+        }
+
+        public void releaseAllPointersExcept(PointerTracker tracker, long eventTime) {
+            for (PointerTracker t : mQueue) {
+                if (t == tracker)
+                    continue;
+                t.onUpEvent(t.getLastX(), t.getLastY(), eventTime);
+                t.setAlreadyProcessed();
+            }
+            mQueue.clear();
+            if (tracker != null)
+                mQueue.add(tracker);
+        }
+
+        public void remove(PointerTracker tracker) {
+            mQueue.remove(tracker);
+        }
+    }
+
+    public BaseKeyboardView(Context context, AttributeSet attrs) {
+        this(context, attrs, R.attr.keyboardViewStyle);
+    }
+
+    public BaseKeyboardView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+
+        TypedArray a = context.obtainStyledAttributes(
+                attrs, R.styleable.BaseKeyboardView, defStyle, R.style.BaseKeyboardView);
+        LayoutInflater inflate =
+                (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+        int previewLayout = 0;
+        int keyTextSize = 0;
+
+        int n = a.getIndexCount();
+
+        for (int i = 0; i < n; i++) {
+            int attr = a.getIndex(i);
+
+            switch (attr) {
+            case R.styleable.BaseKeyboardView_keyBackground:
+                mKeyBackground = a.getDrawable(attr);
+                break;
+            case R.styleable.BaseKeyboardView_keyHysteresisDistance:
+                mKeyHysteresisDistance = a.getDimensionPixelOffset(attr, 0);
+                break;
+            case R.styleable.BaseKeyboardView_verticalCorrection:
+                mVerticalCorrection = a.getDimensionPixelOffset(attr, 0);
+                break;
+            case R.styleable.BaseKeyboardView_keyPreviewLayout:
+                previewLayout = a.getResourceId(attr, 0);
+                break;
+            case R.styleable.BaseKeyboardView_keyPreviewOffset:
+                mPreviewOffset = a.getDimensionPixelOffset(attr, 0);
+                break;
+            case R.styleable.BaseKeyboardView_keyPreviewHeight:
+                mPreviewHeight = a.getDimensionPixelSize(attr, 80);
+                break;
+            case R.styleable.BaseKeyboardView_keyTextSize:
+                mKeyTextSize = a.getDimensionPixelSize(attr, 18);
+                break;
+            case R.styleable.BaseKeyboardView_keyTextColor:
+                mKeyTextColor = a.getColor(attr, 0xFF000000);
+                break;
+            case R.styleable.BaseKeyboardView_labelTextSize:
+                mLabelTextSize = a.getDimensionPixelSize(attr, 14);
+                break;
+            case R.styleable.BaseKeyboardView_popupLayout:
+                mPopupLayout = a.getResourceId(attr, 0);
+                break;
+            case R.styleable.BaseKeyboardView_shadowColor:
+                mShadowColor = a.getColor(attr, 0);
+                break;
+            case R.styleable.BaseKeyboardView_shadowRadius:
+                mShadowRadius = a.getFloat(attr, 0f);
+                break;
+            // TODO: Use Theme (android.R.styleable.Theme_backgroundDimAmount)
+            case R.styleable.BaseKeyboardView_backgroundDimAmount:
+                mBackgroundDimAmount = a.getFloat(attr, 0.5f);
+                break;
+            //case android.R.styleable.
+            case R.styleable.BaseKeyboardView_keyTextStyle:
+                int textStyle = a.getInt(attr, 0);
+                switch (textStyle) {
+                    case 0:
+                        mKeyTextStyle = Typeface.DEFAULT;
+                        break;
+                    case 1:
+                        mKeyTextStyle = Typeface.DEFAULT_BOLD;
+                        break;
+                    default:
+                        mKeyTextStyle = Typeface.defaultFromStyle(textStyle);
+                        break;
+                }
+                break;
+            case R.styleable.BaseKeyboardView_symbolColorScheme:
+                mSymbolColorScheme = a.getInt(attr, 0);
+                break;
+            }
+        }
+
+        final Resources res = getResources();
+
+        mPreviewPopup = new PopupWindow(context);
+        if (previewLayout != 0) {
+            mPreviewText = (TextView) inflate.inflate(previewLayout, null);
+            mPreviewTextSizeLarge = (int) res.getDimension(R.dimen.key_preview_text_size_large);
+            mPreviewPopup.setContentView(mPreviewText);
+            mPreviewPopup.setBackgroundDrawable(null);
+        } else {
+            mShowPreview = false;
+        }
+        mPreviewPopup.setTouchable(false);
+        mPreviewPopup.setAnimationStyle(R.style.KeyPreviewAnimation);
+        mDelayBeforePreview = res.getInteger(R.integer.config_delay_before_preview);
+        mDelayAfterPreview = res.getInteger(R.integer.config_delay_after_preview);
+
+        mMiniKeyboardParent = this;
+        mMiniKeyboardPopup = new PopupWindow(context);
+        mMiniKeyboardPopup.setBackgroundDrawable(null);
+        mMiniKeyboardPopup.setAnimationStyle(R.style.MiniKeyboardAnimation);
+
+        mPaint = new Paint();
+        mPaint.setAntiAlias(true);
+        mPaint.setTextSize(keyTextSize);
+        mPaint.setTextAlign(Align.CENTER);
+        mPaint.setAlpha(255);
+
+        mPadding = new Rect(0, 0, 0, 0);
+        mKeyBackground.getPadding(mPadding);
+
+        mSwipeThreshold = (int) (500 * res.getDisplayMetrics().density);
+        // TODO: Refer frameworks/base/core/res/res/values/config.xml
+        mDisambiguateSwipe = res.getBoolean(R.bool.config_swipeDisambiguation);
+        mMiniKeyboardSlideAllowance = res.getDimension(R.dimen.mini_keyboard_slide_allowance);
+
+        GestureDetector.SimpleOnGestureListener listener =
+                new GestureDetector.SimpleOnGestureListener() {
+            @Override
+            public boolean onFling(MotionEvent me1, MotionEvent me2, float velocityX,
+                    float velocityY) {
+                final float absX = Math.abs(velocityX);
+                final float absY = Math.abs(velocityY);
+                float deltaX = me2.getX() - me1.getX();
+                float deltaY = me2.getY() - me1.getY();
+                int travelX = getWidth() / 2; // Half the keyboard width
+                int travelY = getHeight() / 2; // Half the keyboard height
+                mSwipeTracker.computeCurrentVelocity(1000);
+                final float endingVelocityX = mSwipeTracker.getXVelocity();
+                final float endingVelocityY = mSwipeTracker.getYVelocity();
+                if (velocityX > mSwipeThreshold && absY < absX && deltaX > travelX) {
+                    if (mDisambiguateSwipe && endingVelocityX >= velocityX / 4) {
+                        swipeRight();
+                        return true;
+                    }
+                } else if (velocityX < -mSwipeThreshold && absY < absX && deltaX < -travelX) {
+                    if (mDisambiguateSwipe && endingVelocityX <= velocityX / 4) {
+                        swipeLeft();
+                        return true;
+                    }
+                } else if (velocityY < -mSwipeThreshold && absX < absY && deltaY < -travelY) {
+                    if (mDisambiguateSwipe && endingVelocityY <= velocityY / 4) {
+                        swipeUp();
+                        return true;
+                    }
+                } else if (velocityY > mSwipeThreshold && absX < absY / 2 && deltaY > travelY) {
+                    if (mDisambiguateSwipe && endingVelocityY >= velocityY / 4) {
+                        swipeDown();
+                        return true;
+                    }
+                }
+                return false;
+            }
+        };
+
+        final boolean ignoreMultitouch = true;
+        mGestureDetector = new GestureDetector(getContext(), listener, null, ignoreMultitouch);
+        mGestureDetector.setIsLongpressEnabled(false);
+
+        mHasDistinctMultitouch = context.getPackageManager()
+                .hasSystemFeature(PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH_DISTINCT);
+        mKeyRepeatInterval = res.getInteger(R.integer.config_key_repeat_interval);
+    }
+
+    public void setOnKeyboardActionListener(OnKeyboardActionListener listener) {
+        mKeyboardActionListener = listener;
+        for (PointerTracker tracker : mPointerTrackers) {
+            tracker.setOnKeyboardActionListener(listener);
+        }
+    }
+
+    /**
+     * Returns the {@link OnKeyboardActionListener} object.
+     * @return the listener attached to this keyboard
+     */
+    protected OnKeyboardActionListener getOnKeyboardActionListener() {
+        return mKeyboardActionListener;
+    }
+
+    /**
+     * Attaches a keyboard to this view. The keyboard can be switched at any time and the
+     * view will re-layout itself to accommodate the keyboard.
+     * @see BaseKeyboard
+     * @see #getKeyboard()
+     * @param keyboard the keyboard to display in this view
+     */
+    protected void setKeyboard(BaseKeyboard keyboard) {
+        if (mKeyboard != null) {
+            dismissKeyPreview();
+        }
+        // Remove any pending messages, except dismissing preview
+        mHandler.cancelKeyTimers();
+        mHandler.cancelPopupPreview();
+        mKeyboard = keyboard;
+        LatinImeLogger.onSetKeyboard(keyboard);
+        mKeys = mKeyDetector.setKeyboard(keyboard, -getPaddingLeft(),
+                -getPaddingTop() + mVerticalCorrection);
+        mKeyboardVerticalGap = (int)getResources().getDimension(R.dimen.key_bottom_gap);
+        for (PointerTracker tracker : mPointerTrackers) {
+            tracker.setKeyboard(keyboard, mKeys, mKeyHysteresisDistance);
+        }
+        requestLayout();
+        // Hint to reallocate the buffer if the size changed
+        mKeyboardChanged = true;
+        invalidateAllKeys();
+        computeProximityThreshold(keyboard);
+        mMiniKeyboardCache.clear();
+    }
+
+    /**
+     * Returns the current keyboard being displayed by this view.
+     * @return the currently attached keyboard
+     * @see #setKeyboard(BaseKeyboard)
+     */
+    protected BaseKeyboard getKeyboard() {
+        return mKeyboard;
+    }
+
+    /**
+     * Return whether the device has distinct multi-touch panel.
+     * @return true if the device has distinct multi-touch panel.
+     */
+    public boolean hasDistinctMultitouch() {
+        return mHasDistinctMultitouch;
+    }
+
+    /**
+     * Enables or disables the key feedback popup. This is a popup that shows a magnified
+     * version of the depressed key. By default the preview is enabled.
+     * @param previewEnabled whether or not to enable the key feedback popup
+     * @see #isPreviewEnabled()
+     */
+    public void setPreviewEnabled(boolean previewEnabled) {
+        mShowPreview = previewEnabled;
+    }
+
+    /**
+     * Returns the enabled state of the key feedback popup.
+     * @return whether or not the key feedback popup is enabled
+     * @see #setPreviewEnabled(boolean)
+     */
+    public boolean isPreviewEnabled() {
+        return mShowPreview;
+    }
+
+    public int getSymbolColorScheme() {
+        return mSymbolColorScheme;
+    }
+
+    public void setPopupParent(View v) {
+        mMiniKeyboardParent = v;
+    }
+
+    public void setPopupOffset(int x, int y) {
+        mPopupPreviewOffsetX = x;
+        mPopupPreviewOffsetY = y;
+        mPreviewPopup.dismiss();
+    }
+
+    /**
+     * When enabled, calls to {@link OnKeyboardActionListener#onKey} will include key
+     * codes for adjacent keys.  When disabled, only the primary key code will be
+     * reported.
+     * @param enabled whether or not the proximity correction is enabled
+     */
+    public void setProximityCorrectionEnabled(boolean enabled) {
+        mKeyDetector.setProximityCorrectionEnabled(enabled);
+    }
+
+    /**
+     * Returns true if proximity correction is enabled.
+     */
+    public boolean isProximityCorrectionEnabled() {
+        return mKeyDetector.isProximityCorrectionEnabled();
+    }
+
+    protected CharSequence adjustCase(CharSequence label) {
+        if (mKeyboard.isShifted() && label != null && label.length() < 3
+                && Character.isLowerCase(label.charAt(0))) {
+            label = label.toString().toUpperCase();
+        }
+        return label;
+    }
+
+    @Override
+    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        // Round up a little
+        if (mKeyboard == null) {
+            setMeasuredDimension(
+                    getPaddingLeft() + getPaddingRight(), getPaddingTop() + getPaddingBottom());
+        } else {
+            int width = mKeyboard.getMinWidth() + getPaddingLeft() + getPaddingRight();
+            if (MeasureSpec.getSize(widthMeasureSpec) < width + 10) {
+                width = MeasureSpec.getSize(widthMeasureSpec);
+            }
+            setMeasuredDimension(
+                    width, mKeyboard.getHeight() + getPaddingTop() + getPaddingBottom());
+        }
+    }
+
+    /**
+     * Compute the average distance between adjacent keys (horizontally and vertically)
+     * and square it to get the proximity threshold. We use a square here and in computing
+     * the touch distance from a key's center to avoid taking a square root.
+     * @param keyboard
+     */
+    private void computeProximityThreshold(BaseKeyboard keyboard) {
+        if (keyboard == null) return;
+        final Key[] keys = mKeys;
+        if (keys == null) return;
+        int length = keys.length;
+        int dimensionSum = 0;
+        for (int i = 0; i < length; i++) {
+            Key key = keys[i];
+            dimensionSum += Math.min(key.width, key.height + mKeyboardVerticalGap) + key.gap;
+        }
+        if (dimensionSum < 0 || length == 0) return;
+        mKeyDetector.setProximityThreshold((int) (dimensionSum * 1.4f / length));
+    }
+
+    @Override
+    public void onSizeChanged(int w, int h, int oldw, int oldh) {
+        super.onSizeChanged(w, h, oldw, oldh);
+        // Release the buffer, if any and it will be reallocated on the next draw
+        mBuffer = null;
+    }
+
+    @Override
+    public void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+        if (mDrawPending || mBuffer == null || mKeyboardChanged) {
+            onBufferDraw();
+        }
+        canvas.drawBitmap(mBuffer, 0, 0, null);
+    }
+
+    private void onBufferDraw() {
+        if (mBuffer == null || mKeyboardChanged) {
+            if (mBuffer == null || mKeyboardChanged &&
+                    (mBuffer.getWidth() != getWidth() || mBuffer.getHeight() != getHeight())) {
+                // Make sure our bitmap is at least 1x1
+                final int width = Math.max(1, getWidth());
+                final int height = Math.max(1, getHeight());
+                mBuffer = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+                mCanvas = new Canvas(mBuffer);
+            }
+            invalidateAllKeys();
+            mKeyboardChanged = false;
+        }
+        final Canvas canvas = mCanvas;
+        canvas.clipRect(mDirtyRect, Op.REPLACE);
+
+        if (mKeyboard == null) return;
+
+        final Paint paint = mPaint;
+        final Drawable keyBackground = mKeyBackground;
+        final Rect clipRegion = mClipRegion;
+        final Rect padding = mPadding;
+        final int kbdPaddingLeft = getPaddingLeft();
+        final int kbdPaddingTop = getPaddingTop();
+        final Key[] keys = mKeys;
+        final Key invalidKey = mInvalidatedKey;
+
+        paint.setColor(mKeyTextColor);
+        boolean drawSingleKey = false;
+        if (invalidKey != null && canvas.getClipBounds(clipRegion)) {
+            // TODO we should use Rect.inset and Rect.contains here.
+            // Is clipRegion completely contained within the invalidated key?
+            if (invalidKey.x + kbdPaddingLeft - 1 <= clipRegion.left &&
+                    invalidKey.y + kbdPaddingTop - 1 <= clipRegion.top &&
+                    invalidKey.x + invalidKey.width + kbdPaddingLeft + 1 >= clipRegion.right &&
+                    invalidKey.y + invalidKey.height + kbdPaddingTop + 1 >= clipRegion.bottom) {
+                drawSingleKey = true;
+            }
+        }
+        canvas.drawColor(0x00000000, PorterDuff.Mode.CLEAR);
+        final int keyCount = keys.length;
+        for (int i = 0; i < keyCount; i++) {
+            final Key key = keys[i];
+            if (drawSingleKey && invalidKey != key) {
+                continue;
+            }
+            int[] drawableState = key.getCurrentDrawableState();
+            keyBackground.setState(drawableState);
+
+            // Switch the character to uppercase if shift is pressed
+            String label = key.label == null? null : adjustCase(key.label).toString();
+
+            final Rect bounds = keyBackground.getBounds();
+            if (key.width != bounds.right || key.height != bounds.bottom) {
+                keyBackground.setBounds(0, 0, key.width, key.height);
+            }
+            canvas.translate(key.x + kbdPaddingLeft, key.y + kbdPaddingTop);
+            keyBackground.draw(canvas);
+
+            boolean drawHintIcon = true;
+            if (label != null) {
+                // If keyboard is multi-touch capable and in temporary upper case state and key has
+                // tempoarary shift label, label should be hint character and hint icon should not
+                // be drawn.
+                if (mHasDistinctMultitouch
+                        && mKeyboard instanceof LatinKeyboard
+                        && ((LatinKeyboard)mKeyboard).isTemporaryUpperCase()
+                        && key.temporaryShiftLabel != null) {
+                    label = key.temporaryShiftLabel.toString();
+                    drawHintIcon = false;
+                }
+
+                // For characters, use large font. For labels like "Done", use small font.
+                final int labelSize;
+                if (label.length() > 1 && key.codes.length < 2) {
+                    labelSize = mLabelTextSize;
+                    paint.setTypeface(Typeface.DEFAULT_BOLD);
+                } else {
+                    labelSize = mKeyTextSize;
+                    paint.setTypeface(mKeyTextStyle);
+                }
+                paint.setTextSize(labelSize);
+
+                Integer labelHeightValue = mTextHeightCache.get(labelSize);
+                final int labelHeight;
+                if (labelHeightValue != null) {
+                    labelHeight = labelHeightValue;
+                } else {
+                    Rect textBounds = new Rect();
+                    paint.getTextBounds(KEY_LABEL_HEIGHT_REFERENCE_CHAR, 0, 1, textBounds);
+                    labelHeight = textBounds.height();
+                    mTextHeightCache.put(labelSize, labelHeight);
+                }
+
+                // Draw a drop shadow for the text
+                paint.setShadowLayer(mShadowRadius, 0, 0, mShadowColor);
+                final int centerX = (key.width + padding.left - padding.right) / 2;
+                final int centerY = (key.height + padding.top - padding.bottom) / 2;
+                final float baseline = centerY
+                        + labelHeight * KEY_LABEL_VERTICAL_ADJUSTMENT_FACTOR;
+                canvas.drawText(label, centerX, baseline, paint);
+                // Turn off drop shadow
+                paint.setShadowLayer(0, 0, 0, 0);
+            }
+            if (key.label == null && key.icon != null) {
+                int drawableWidth = key.icon.getIntrinsicWidth();
+                int drawableHeight = key.icon.getIntrinsicHeight();
+                int drawableX = (key.width + padding.left - padding.right - drawableWidth) / 2;
+                int drawableY = (key.height + padding.top - padding.bottom - drawableHeight) / 2;
+                drawIcon(canvas, key.icon, drawableX, drawableY, drawableWidth, drawableHeight);
+            }
+            if (key.hintIcon != null && drawHintIcon) {
+                int drawableWidth = key.width;
+                int drawableHeight = key.height;
+                int drawableX = 0;
+                int drawableY = HINT_ICON_VERTICAL_ADJUSTMENT_PIXEL;
+                drawIcon(canvas, key.hintIcon, drawableX, drawableY, drawableWidth, drawableHeight);
+            }
+            canvas.translate(-key.x - kbdPaddingLeft, -key.y - kbdPaddingTop);
+        }
+        mInvalidatedKey = null;
+        // Overlay a dark rectangle to dim the keyboard
+        if (mMiniKeyboard != null) {
+            paint.setColor((int) (mBackgroundDimAmount * 0xFF) << 24);
+            canvas.drawRect(0, 0, getWidth(), getHeight(), paint);
+        }
+
+        if (DEBUG) {
+            if (mShowTouchPoints) {
+                for (PointerTracker tracker : mPointerTrackers) {
+                    int startX = tracker.getStartX();
+                    int startY = tracker.getStartY();
+                    int lastX = tracker.getLastX();
+                    int lastY = tracker.getLastY();
+                    paint.setAlpha(128);
+                    paint.setColor(0xFFFF0000);
+                    canvas.drawCircle(startX, startY, 3, paint);
+                    canvas.drawLine(startX, startY, lastX, lastY, paint);
+                    paint.setColor(0xFF0000FF);
+                    canvas.drawCircle(lastX, lastY, 3, paint);
+                    paint.setColor(0xFF00FF00);
+                    canvas.drawCircle((startX + lastX) / 2, (startY + lastY) / 2, 2, paint);
+                }
+            }
+        }
+
+        mDrawPending = false;
+        mDirtyRect.setEmpty();
+    }
+
+    private void drawIcon(Canvas canvas, Drawable icon, int x, int y, int width, int height) {
+        canvas.translate(x, y);
+        icon.setBounds(0, 0, width, height);
+        icon.draw(canvas);
+        canvas.translate(-x, -y);
+    }
+
+    public void setForeground(boolean foreground) {
+        mInForeground = foreground;
+    }
+
+    // TODO: clean up this method.
+    private void dismissKeyPreview() {
+        for (PointerTracker tracker : mPointerTrackers)
+            tracker.releaseKey();
+        showPreview(NOT_A_KEY, null);
+    }
+
+    public void showPreview(int keyIndex, PointerTracker tracker) {
+        int oldKeyIndex = mOldPreviewKeyIndex;
+        mOldPreviewKeyIndex = keyIndex;
+        final boolean isLanguageSwitchEnabled = (mKeyboard instanceof LatinKeyboard)
+                && ((LatinKeyboard)mKeyboard).isLanguageSwitchEnabled();
+        // We should re-draw popup preview when 1) we need to hide the preview, 2) we will show
+        // the space key preview and 3) pointer moves off the space key to other letter key, we
+        // should hide the preview of the previous key.
+        final boolean hidePreviewOrShowSpaceKeyPreview = (tracker == null)
+                || tracker.isSpaceKey(keyIndex) || tracker.isSpaceKey(oldKeyIndex);
+        // If key changed and preview is on or the key is space (language switch is enabled)
+        if (oldKeyIndex != keyIndex
+                && (mShowPreview
+                        || (hidePreviewOrShowSpaceKeyPreview && isLanguageSwitchEnabled))) {
+            if (keyIndex == NOT_A_KEY) {
+                mHandler.cancelPopupPreview();
+                mHandler.dismissPreview(mDelayAfterPreview);
+            } else if (tracker != null) {
+                mHandler.popupPreview(mDelayBeforePreview, keyIndex, tracker);
+            }
+        }
+    }
+
+    // TODO Must fix popup preview on xlarge layout
+    private void showKey(final int keyIndex, PointerTracker tracker) {
+        Key key = tracker.getKey(keyIndex);
+        // If keyIndex is invalid or IME is already closed, we must not show key preview.
+        // Trying to show preview PopupWindow while root window is closed causes
+        // WindowManager.BadTokenException.
+        if (key == null || !mInForeground)
+            return;
+        // What we show as preview should match what we show on key top in onBufferDraw(). 
+        if (key.label != null) {
+            // TODO Should take care of temporaryShiftLabel here.
+            mPreviewText.setCompoundDrawables(null, null, null, null);
+            mPreviewText.setText(adjustCase(tracker.getPreviewText(key)));
+            if (key.label.length() > 1 && key.codes.length < 2) {
+                mPreviewText.setTextSize(TypedValue.COMPLEX_UNIT_PX, mKeyTextSize);
+                mPreviewText.setTypeface(Typeface.DEFAULT_BOLD);
+            } else {
+                mPreviewText.setTextSize(TypedValue.COMPLEX_UNIT_PX, mPreviewTextSizeLarge);
+                mPreviewText.setTypeface(mKeyTextStyle);
+            }
+        } else {
+            mPreviewText.setCompoundDrawables(null, null, null,
+                    key.iconPreview != null ? key.iconPreview : key.icon);
+            mPreviewText.setText(null);
+        }
+        mPreviewText.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
+                MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
+        int popupWidth = Math.max(mPreviewText.getMeasuredWidth(), key.width
+                + mPreviewText.getPaddingLeft() + mPreviewText.getPaddingRight());
+        final int popupHeight = mPreviewHeight;
+        LayoutParams lp = mPreviewText.getLayoutParams();
+        if (lp != null) {
+            lp.width = popupWidth;
+            lp.height = popupHeight;
+        }
+
+        int popupPreviewX = key.x - (popupWidth - key.width) / 2;
+        int popupPreviewY = key.y - popupHeight + mPreviewOffset;
+
+        mHandler.cancelDismissPreview();
+        if (mOffsetInWindow == null) {
+            mOffsetInWindow = new int[2];
+            getLocationInWindow(mOffsetInWindow);
+            mOffsetInWindow[0] += mPopupPreviewOffsetX; // Offset may be zero
+            mOffsetInWindow[1] += mPopupPreviewOffsetY; // Offset may be zero
+            int[] windowLocation = new int[2];
+            getLocationOnScreen(windowLocation);
+            mWindowY = windowLocation[1];
+        }
+        // Set the preview background state
+        mPreviewText.getBackground().setState(
+                key.popupResId != 0 ? LONG_PRESSABLE_STATE_SET : EMPTY_STATE_SET);
+        popupPreviewX += mOffsetInWindow[0];
+        popupPreviewY += mOffsetInWindow[1];
+
+        // If the popup cannot be shown above the key, put it on the side
+        if (popupPreviewY + mWindowY < 0) {
+            // If the key you're pressing is on the left side of the keyboard, show the popup on
+            // the right, offset by enough to see at least one key to the left/right.
+            if (key.x + key.width <= getWidth() / 2) {
+                popupPreviewX += (int) (key.width * 2.5);
+            } else {
+                popupPreviewX -= (int) (key.width * 2.5);
+            }
+            popupPreviewY += popupHeight;
+        }
+
+        try {
+            if (mPreviewPopup.isShowing()) {
+                mPreviewPopup.update(popupPreviewX, popupPreviewY, popupWidth, popupHeight);
+            } else {
+                mPreviewPopup.setWidth(popupWidth);
+                mPreviewPopup.setHeight(popupHeight);
+                mPreviewPopup.showAtLocation(mMiniKeyboardParent, Gravity.NO_GRAVITY,
+                        popupPreviewX, popupPreviewY);
+            }
+        } catch (WindowManager.BadTokenException e) {
+            // Swallow the exception which will be happened when IME is already closed.
+            Log.w(TAG, "LatinIME is already closed when tried showing key preview.");
+        }
+        // Record popup preview position to display mini-keyboard later at the same positon
+        mPopupPreviewDisplayedY = popupPreviewY;
+        mPreviewText.setVisibility(VISIBLE);
+    }
+
+    /**
+     * Requests a redraw of the entire keyboard. Calling {@link #invalidate} is not sufficient
+     * because the keyboard renders the keys to an off-screen buffer and an invalidate() only
+     * draws the cached buffer.
+     * @see #invalidateKey(Key)
+     */
+    public void invalidateAllKeys() {
+        mDirtyRect.union(0, 0, getWidth(), getHeight());
+        mDrawPending = true;
+        invalidate();
+    }
+
+    /**
+     * Invalidates a key so that it will be redrawn on the next repaint. Use this method if only
+     * one key is changing it's content. Any changes that affect the position or size of the key
+     * may not be honored.
+     * @param key key in the attached {@link BaseKeyboard}.
+     * @see #invalidateAllKeys
+     */
+    public void invalidateKey(Key key) {
+        if (key == null)
+            return;
+        mInvalidatedKey = key;
+        // TODO we should clean up this and record key's region to use in onBufferDraw.
+        mDirtyRect.union(key.x + getPaddingLeft(), key.y + getPaddingTop(),
+                key.x + key.width + getPaddingLeft(), key.y + key.height + getPaddingTop());
+        onBufferDraw();
+        invalidate(key.x + getPaddingLeft(), key.y + getPaddingTop(),
+                key.x + key.width + getPaddingLeft(), key.y + key.height + getPaddingTop());
+    }
+
+    private boolean openPopupIfRequired(int keyIndex, PointerTracker tracker) {
+        // Check if we have a popup layout specified first.
+        if (mPopupLayout == 0) {
+            return false;
+        }
+
+        Key popupKey = tracker.getKey(keyIndex);
+        if (popupKey == null)
+            return false;
+        boolean result = onLongPress(popupKey);
+        if (result) {
+            dismissKeyPreview();
+            mMiniKeyboardTrackerId = tracker.mPointerId;
+            // Mark this tracker "already processed" and remove it from the pointer queue
+            tracker.setAlreadyProcessed();
+            mPointerQueue.remove(tracker);
+        }
+        return result;
+    }
+
+    private void onLongPressShiftKey(PointerTracker tracker) {
+        tracker.setAlreadyProcessed();
+        mPointerQueue.remove(tracker);
+        mKeyboardActionListener.onKey(LatinKeyboardView.KEYCODE_CAPSLOCK, null, 0, 0);
+    }
+
+    private View inflateMiniKeyboardContainer(Key popupKey) {
+        int popupKeyboardId = popupKey.popupResId;
+        LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(
+                Context.LAYOUT_INFLATER_SERVICE);
+        View container = inflater.inflate(mPopupLayout, null);
+        if (container == null)
+            throw new NullPointerException();
+
+        BaseKeyboardView miniKeyboard =
+                (BaseKeyboardView)container.findViewById(R.id.BaseKeyboardView);
+        miniKeyboard.setOnKeyboardActionListener(new OnKeyboardActionListener() {
+            public void onKey(int primaryCode, int[] keyCodes, int x, int y) {
+                mKeyboardActionListener.onKey(primaryCode, keyCodes, x, y);
+                dismissPopupKeyboard();
+            }
+
+            public void onText(CharSequence text) {
+                mKeyboardActionListener.onText(text);
+                dismissPopupKeyboard();
+            }
+
+            public void onCancel() {
+                dismissPopupKeyboard();
+            }
+
+            public void swipeLeft() {
+            }
+            public void swipeRight() {
+            }
+            public void swipeUp() {
+            }
+            public void swipeDown() {
+            }
+            public void onPress(int primaryCode) {
+                mKeyboardActionListener.onPress(primaryCode);
+            }
+            public void onRelease(int primaryCode) {
+                mKeyboardActionListener.onRelease(primaryCode);
+            }
+        });
+        // Override default ProximityKeyDetector.
+        miniKeyboard.mKeyDetector = new MiniKeyboardKeyDetector(mMiniKeyboardSlideAllowance);
+        // Remove gesture detector on mini-keyboard
+        miniKeyboard.mGestureDetector = null;
+
+        BaseKeyboard keyboard;
+        if (popupKey.popupCharacters != null) {
+            keyboard = new BaseKeyboard(getContext(), popupKeyboardId, popupKey.popupCharacters,
+                    -1, getPaddingLeft() + getPaddingRight());
+        } else {
+            keyboard = new BaseKeyboard(getContext(), popupKeyboardId);
+        }
+        miniKeyboard.setKeyboard(keyboard);
+        miniKeyboard.setPopupParent(this);
+
+        container.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
+                MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
+
+        return container;
+    }
+
+    private static boolean isOneRowKeys(List<Key> keys) {
+        if (keys.size() == 0) return false;
+        final int edgeFlags = keys.get(0).edgeFlags;
+        // HACK: The first key of mini keyboard which was inflated from xml and has multiple rows,
+        // does not have both top and bottom edge flags on at the same time.  On the other hand,
+        // the first key of mini keyboard that was created with popupCharacters must have both top
+        // and bottom edge flags on.
+        // When you want to use one row mini-keyboard from xml file, make sure that the row has
+        // both top and bottom edge flags set.
+        return (edgeFlags & BaseKeyboard.EDGE_TOP) != 0
+                && (edgeFlags & BaseKeyboard.EDGE_BOTTOM) != 0;
+    }
+
+    /**
+     * Called when a key is long pressed. By default this will open any popup keyboard associated
+     * with this key through the attributes popupLayout and popupCharacters.
+     * @param popupKey the key that was long pressed
+     * @return true if the long press is handled, false otherwise. Subclasses should call the
+     * method on the base class if the subclass doesn't wish to handle the call.
+     */
+    protected boolean onLongPress(Key popupKey) {
+        // TODO if popupKey.popupCharacters has only one letter, send it as key without opening
+        // mini keyboard.
+
+        if (popupKey.popupResId == 0)
+            return false;
+
+        View container = mMiniKeyboardCache.get(popupKey);
+        if (container == null) {
+            container = inflateMiniKeyboardContainer(popupKey);
+            mMiniKeyboardCache.put(popupKey, container);
+        }
+        mMiniKeyboard = (BaseKeyboardView)container.findViewById(R.id.BaseKeyboardView);
+        if (mWindowOffset == null) {
+            mWindowOffset = new int[2];
+            getLocationInWindow(mWindowOffset);
+        }
+
+        // Get width of a key in the mini popup keyboard = "miniKeyWidth".
+        // On the other hand, "popupKey.width" is width of the pressed key on the main keyboard.
+        // We adjust the position of mini popup keyboard with the edge key in it:
+        //  a) When we have the leftmost key in popup keyboard directly above the pressed key
+        //     Right edges of both keys should be aligned for consistent default selection
+        //  b) When we have the rightmost key in popup keyboard directly above the pressed key
+        //     Left edges of both keys should be aligned for consistent default selection
+        final List<Key> miniKeys = mMiniKeyboard.getKeyboard().getKeys();
+        final int miniKeyWidth = miniKeys.size() > 0 ? miniKeys.get(0).width : 0;
+
+        // HACK: Have the leftmost number in the popup characters right above the key
+        boolean isNumberAtLeftmost =
+                hasMultiplePopupChars(popupKey) && isNumberAtLeftmostPopupChar(popupKey);
+        int popupX = popupKey.x + mWindowOffset[0];
+        popupX += getPaddingLeft();
+        if (isNumberAtLeftmost) {
+            popupX += popupKey.width - miniKeyWidth;  // adjustment for a) described above
+            popupX -= container.getPaddingLeft();
+        } else {
+            popupX += miniKeyWidth;  // adjustment for b) described above
+            popupX -= container.getMeasuredWidth();
+            popupX += container.getPaddingRight();
+        }
+        int popupY = popupKey.y + mWindowOffset[1];
+        popupY += getPaddingTop();
+        popupY -= container.getMeasuredHeight();
+        popupY += container.getPaddingBottom();
+        final int x = popupX;
+        final int y = mShowPreview && isOneRowKeys(miniKeys) ? mPopupPreviewDisplayedY : popupY;
+
+        int adjustedX = x;
+        if (x < 0) {
+            adjustedX = 0;
+        } else if (x > (getMeasuredWidth() - container.getMeasuredWidth())) {
+            adjustedX = getMeasuredWidth() - container.getMeasuredWidth();
+        }
+        mMiniKeyboardOriginX = adjustedX + container.getPaddingLeft() - mWindowOffset[0];
+        mMiniKeyboardOriginY = y + container.getPaddingTop() - mWindowOffset[1];
+        mMiniKeyboard.setPopupOffset(adjustedX, y);
+        // TODO: change the below line to use getLatinKeyboard() instead of getKeyboard()
+        BaseKeyboard baseMiniKeyboard = mMiniKeyboard.getKeyboard();
+        if (baseMiniKeyboard != null && baseMiniKeyboard.setShifted(mKeyboard == null
+                ? false : mKeyboard.isShifted())) {
+            mMiniKeyboard.invalidateAllKeys();
+        }
+        // Mini keyboard needs no pop-up key preview displayed.
+        mMiniKeyboard.setPreviewEnabled(false);
+        mMiniKeyboardPopup.setContentView(container);
+        mMiniKeyboardPopup.setWidth(container.getMeasuredWidth());
+        mMiniKeyboardPopup.setHeight(container.getMeasuredHeight());
+        mMiniKeyboardPopup.showAtLocation(this, Gravity.NO_GRAVITY, x, y);
+
+        // Inject down event on the key to mini keyboard.
+        long eventTime = SystemClock.uptimeMillis();
+        mMiniKeyboardPopupTime = eventTime;
+        MotionEvent downEvent = generateMiniKeyboardMotionEvent(MotionEvent.ACTION_DOWN, popupKey.x
+                + popupKey.width / 2, popupKey.y + popupKey.height / 2, eventTime);
+        mMiniKeyboard.onTouchEvent(downEvent);
+        downEvent.recycle();
+
+        invalidateAllKeys();
+        return true;
+    }
+
+    private static boolean hasMultiplePopupChars(Key key) {
+        if (key.popupCharacters != null && key.popupCharacters.length() > 1) {
+            return true;
+        }
+        return false;
+    }
+
+    private static boolean isNumberAtLeftmostPopupChar(Key key) {
+        if (key.popupCharacters != null && key.popupCharacters.length() > 0
+                && isAsciiDigit(key.popupCharacters.charAt(0))) {
+            return true;
+        }
+        return false;
+    }
+
+    private static boolean isAsciiDigit(char c) {
+        return (c < 0x80) && Character.isDigit(c);
+    }
+
+    private MotionEvent generateMiniKeyboardMotionEvent(int action, int x, int y, long eventTime) {
+        return MotionEvent.obtain(mMiniKeyboardPopupTime, eventTime, action,
+                    x - mMiniKeyboardOriginX, y - mMiniKeyboardOriginY, 0);
+    }
+
+    private PointerTracker getPointerTracker(final int id) {
+        final ArrayList<PointerTracker> pointers = mPointerTrackers;
+        final Key[] keys = mKeys;
+        final OnKeyboardActionListener listener = mKeyboardActionListener;
+
+        // Create pointer trackers until we can get 'id+1'-th tracker, if needed.
+        for (int i = pointers.size(); i <= id; i++) {
+            final PointerTracker tracker =
+                new PointerTracker(i, mHandler, mKeyDetector, this, getResources());
+            if (keys != null)
+                tracker.setKeyboard(mKeyboard, keys, mKeyHysteresisDistance);
+            if (listener != null)
+                tracker.setOnKeyboardActionListener(listener);
+            pointers.add(tracker);
+        }
+
+        return pointers.get(id);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent me) {
+        final int pointerCount = me.getPointerCount();
+        final int action = me.getActionMasked();
+
+        // TODO: cleanup this code into a multi-touch to single-touch event converter class?
+        // If the device does not have distinct multi-touch support panel, ignore all multi-touch
+        // events except a transition from/to single-touch.
+        if (!mHasDistinctMultitouch && pointerCount > 1 && mOldPointerCount > 1) {
+            return true;
+        }
+
+        // Track the last few movements to look for spurious swipes.
+        mSwipeTracker.addMovement(me);
+
+        // Gesture detector must be enabled only when mini-keyboard is not on the screen.
+        if (mMiniKeyboard == null
+                && mGestureDetector != null && mGestureDetector.onTouchEvent(me)) {
+            dismissKeyPreview();
+            mHandler.cancelKeyTimers();
+            return true;
+        }
+
+        final long eventTime = me.getEventTime();
+        final int index = me.getActionIndex();
+        final int id = me.getPointerId(index);
+        final int x = (int)me.getX(index);
+        final int y = (int)me.getY(index);
+
+        // Needs to be called after the gesture detector gets a turn, as it may have
+        // displayed the mini keyboard
+        if (mMiniKeyboard != null) {
+            final int miniKeyboardPointerIndex = me.findPointerIndex(mMiniKeyboardTrackerId);
+            if (miniKeyboardPointerIndex >= 0 && miniKeyboardPointerIndex < pointerCount) {
+                final int miniKeyboardX = (int)me.getX(miniKeyboardPointerIndex);
+                final int miniKeyboardY = (int)me.getY(miniKeyboardPointerIndex);
+                MotionEvent translated = generateMiniKeyboardMotionEvent(action,
+                        miniKeyboardX, miniKeyboardY, eventTime);
+                mMiniKeyboard.onTouchEvent(translated);
+                translated.recycle();
+            }
+            return true;
+        }
+
+        if (mHandler.isInKeyRepeat()) {
+            // It will keep being in the key repeating mode while the key is being pressed.
+            if (action == MotionEvent.ACTION_MOVE) {
+                return true;
+            }
+            final PointerTracker tracker = getPointerTracker(id);
+            // Key repeating timer will be canceled if 2 or more keys are in action, and current
+            // event (UP or DOWN) is non-modifier key.
+            if (pointerCount > 1 && !tracker.isModifier()) {
+                mHandler.cancelKeyRepeatTimer();
+            }
+            // Up event will pass through.
+        }
+
+        // TODO: cleanup this code into a multi-touch to single-touch event converter class?
+        // Translate mutli-touch event to single-touch events on the device that has no distinct
+        // multi-touch panel.
+        if (!mHasDistinctMultitouch) {
+            // Use only main (id=0) pointer tracker.
+            PointerTracker tracker = getPointerTracker(0);
+            int oldPointerCount = mOldPointerCount;
+            if (pointerCount == 1 && oldPointerCount == 2) {
+                // Multi-touch to single touch transition.
+                // Send a down event for the latest pointer.
+                tracker.onDownEvent(x, y, eventTime);
+            } else if (pointerCount == 2 && oldPointerCount == 1) {
+                // Single-touch to multi-touch transition.
+                // Send an up event for the last pointer.
+                tracker.onUpEvent(tracker.getLastX(), tracker.getLastY(), eventTime);
+            } else if (pointerCount == 1 && oldPointerCount == 1) {
+                tracker.onTouchEvent(action, x, y, eventTime);
+            } else {
+                Log.w(TAG, "Unknown touch panel behavior: pointer count is " + pointerCount
+                        + " (old " + oldPointerCount + ")");
+            }
+            mOldPointerCount = pointerCount;
+            return true;
+        }
+
+        if (action == MotionEvent.ACTION_MOVE) {
+            for (int i = 0; i < pointerCount; i++) {
+                PointerTracker tracker = getPointerTracker(me.getPointerId(i));
+                tracker.onMoveEvent((int)me.getX(i), (int)me.getY(i), eventTime);
+            }
+        } else {
+            PointerTracker tracker = getPointerTracker(id);
+            switch (action) {
+            case MotionEvent.ACTION_DOWN:
+            case MotionEvent.ACTION_POINTER_DOWN:
+                onDownEvent(tracker, x, y, eventTime);
+                break;
+            case MotionEvent.ACTION_UP:
+            case MotionEvent.ACTION_POINTER_UP:
+                onUpEvent(tracker, x, y, eventTime);
+                break;
+            case MotionEvent.ACTION_CANCEL:
+                onCancelEvent(tracker, x, y, eventTime);
+                break;
+            }
+        }
+
+        return true;
+    }
+
+    private void onDownEvent(PointerTracker tracker, int x, int y, long eventTime) {
+        if (tracker.isOnModifierKey(x, y)) {
+            // Before processing a down event of modifier key, all pointers already being tracked
+            // should be released.
+            mPointerQueue.releaseAllPointersExcept(null, eventTime);
+        }
+        tracker.onDownEvent(x, y, eventTime);
+        mPointerQueue.add(tracker);
+    }
+
+    private void onUpEvent(PointerTracker tracker, int x, int y, long eventTime) {
+        if (tracker.isModifier()) {
+            // Before processing an up event of modifier key, all pointers already being tracked
+            // should be released.
+            mPointerQueue.releaseAllPointersExcept(tracker, eventTime);
+        } else {
+            int index = mPointerQueue.lastIndexOf(tracker);
+            if (index >= 0) {
+                mPointerQueue.releaseAllPointersOlderThan(tracker, eventTime);
+            } else {
+                Log.w(TAG, "onUpEvent: corresponding down event not found for pointer "
+                        + tracker.mPointerId);
+            }
+        }
+        tracker.onUpEvent(x, y, eventTime);
+        mPointerQueue.remove(tracker);
+    }
+
+    private void onCancelEvent(PointerTracker tracker, int x, int y, long eventTime) {
+        tracker.onCancelEvent(x, y, eventTime);
+        mPointerQueue.remove(tracker);
+    }
+
+    protected void swipeRight() {
+        mKeyboardActionListener.swipeRight();
+    }
+
+    protected void swipeLeft() {
+        mKeyboardActionListener.swipeLeft();
+    }
+
+    protected void swipeUp() {
+        mKeyboardActionListener.swipeUp();
+    }
+
+    protected void swipeDown() {
+        mKeyboardActionListener.swipeDown();
+    }
+
+    public void closing() {
+        mPreviewPopup.dismiss();
+        mHandler.cancelAllMessages();
+
+        dismissPopupKeyboard();
+        mBuffer = null;
+        mCanvas = null;
+        mMiniKeyboardCache.clear();
+    }
+
+    @Override
+    public void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        closing();
+    }
+
+    private void dismissPopupKeyboard() {
+        if (mMiniKeyboardPopup.isShowing()) {
+            mMiniKeyboardPopup.dismiss();
+            mMiniKeyboard = null;
+            mMiniKeyboardOriginX = 0;
+            mMiniKeyboardOriginY = 0;
+            invalidateAllKeys();
+        }
+    }
+
+    public boolean handleBack() {
+        if (mMiniKeyboardPopup.isShowing()) {
+            dismissPopupKeyboard();
+            return true;
+        }
+        return false;
+    }
+}