xref: /frameworks/opt/chips/src/com/android/ex/chips/RecipientEditTextView.java

/*
 * Copyright (C) 2011 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.ex.chips;

import android.app.Dialog;
import android.content.ClipData;
import android.content.ClipDescription;
import android.content.ClipboardManager;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnDismissListener;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Message;
import android.os.Parcelable;
import android.text.Editable;
import android.text.InputType;
import android.text.Layout;
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.TextWatcher;
import android.text.method.QwertyKeyListener;
import android.text.style.ImageSpan;
import android.text.util.Rfc822Token;
import android.text.util.Rfc822Tokenizer;
import android.util.AttributeSet;
import android.util.Log;
import android.view.ActionMode;
import android.view.ActionMode.Callback;
import android.view.DragEvent;
import android.view.GestureDetector;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewParent;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListPopupWindow;
import android.widget.ListView;
import android.widget.MultiAutoCompleteTextView;
import android.widget.PopupWindow;
import android.widget.ScrollView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

/**
 * RecipientEditTextView is an auto complete text view for use with applications
 * that use the new Chips UI for addressing a message to recipients.
 */
public class RecipientEditTextView extends MultiAutoCompleteTextView implements
        OnItemClickListener, Callback, RecipientAlternatesAdapter.OnCheckedItemChangedListener,
        GestureDetector.OnGestureListener, OnDismissListener, OnClickListener,
        PopupWindow.OnDismissListener {

    private static final char COMMIT_CHAR_COMMA = ',';

    private static final char COMMIT_CHAR_SEMICOLON = ';';

    private static final char COMMIT_CHAR_SPACE = ' ';

    private static final String TAG = "RecipientEditTextView";

    private static int DISMISS = "dismiss".hashCode();

    private static final long DISMISS_DELAY = 300;

    // TODO: get correct number/ algorithm from with UX.
    private static final int CHIP_LIMIT = 2;

    private static int sSelectedTextColor = -1;

    // Resources for displaying chips.
    private Drawable mChipBackground = null;

    private Drawable mChipDelete = null;

    private Drawable mInvalidChipBackground;

    private Drawable mChipBackgroundPressed;

    private float mChipHeight;

    private float mChipFontSize;

    private int mChipPadding;

    private Tokenizer mTokenizer;

    private Validator mValidator;

    private RecipientChip mSelectedChip;

    private int mAlternatesLayout;

    private Bitmap mDefaultContactPhoto;

    private ImageSpan mMoreChip;

    private TextView mMoreItem;

    private final ArrayList<String> mPendingChips = new ArrayList<String>();

    private Handler mHandler;

    private int mPendingChipsCount = 0;

    private ListPopupWindow mAlternatesPopup;

    private ListPopupWindow mAddressPopup;

    private ArrayList<RecipientChip> mTemporaryRecipients;

    private ArrayList<RecipientChip> mRemovedSpans;

    private boolean mShouldShrink = true;

    // Chip copy fields.
    private GestureDetector mGestureDetector;

    private Dialog mCopyDialog;

    private int mCopyViewRes;

    private String mCopyAddress;

    /**
     * Used with {@link #mAlternatesPopup}. Handles clicks to alternate addresses for a
     * selected chip.
     */
    private OnItemClickListener mAlternatesListener;

    private int mCheckedItem;

    private TextWatcher mTextWatcher;

    // Obtain the enclosing scroll view, if it exists, so that the view can be
    // scrolled to show the last line of chips content.
    private ScrollView mScrollView;

    private boolean mTriedGettingScrollView;

    private boolean mDragEnabled = false;

    private final Runnable mAddTextWatcher = new Runnable() {
        @Override
        public void run() {
            if (mTextWatcher == null) {
                mTextWatcher = new RecipientTextWatcher();
                addTextChangedListener(mTextWatcher);
            }
        }
    };

    private IndividualReplacementTask mIndividualReplacements;

    private Runnable mHandlePendingChips = new Runnable() {

        @Override
        public void run() {
            handlePendingChips();
        }

    };

    private Runnable mDelayedShrink = new Runnable() {

        @Override
        public void run() {
            shrink();
        }

    };

    public RecipientEditTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        if (sSelectedTextColor == -1) {
            sSelectedTextColor = context.getResources().getColor(android.R.color.white);
        }
        mAlternatesPopup = new ListPopupWindow(context);
        mAlternatesPopup.setOnDismissListener(this);
        mAddressPopup = new ListPopupWindow(context);
        mAddressPopup.setOnDismissListener(this);
        mCopyDialog = new Dialog(context);
        mAlternatesListener = new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView,View view, int position,
                    long rowId) {
                mAlternatesPopup.setOnItemClickListener(null);
                setEnabled(true);
                replaceChip(mSelectedChip, ((RecipientAlternatesAdapter) adapterView.getAdapter())
                        .getRecipientEntry(position));
                Message delayed = Message.obtain(mHandler, DISMISS);
                delayed.obj = mAlternatesPopup;
                mHandler.sendMessageDelayed(delayed, DISMISS_DELAY);
                clearComposingText();
            }
        };
        setInputType(getInputType() | InputType.TYPE_TEXT_FLAG_NO_SUGGESTIONS);
        setOnItemClickListener(this);
        setCustomSelectionActionModeCallback(this);
        mHandler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                if (msg.what == DISMISS) {
                    ((ListPopupWindow) msg.obj).dismiss();
                    return;
                }
                super.handleMessage(msg);
            }
        };
        mTextWatcher = new RecipientTextWatcher();
        addTextChangedListener(mTextWatcher);
        mGestureDetector = new GestureDetector(context, this);
    }

    /*package*/ RecipientChip getLastChip() {
        RecipientChip last = null;
        RecipientChip[] chips = getSortedRecipients();
        if (chips != null && chips.length > 0) {
            last = chips[chips.length - 1];
        }
        return last;
    }

    @Override
    public void onSelectionChanged(int start, int end) {
        // When selection changes, see if it is inside the chips area.
        // If so, move the cursor back after the chips again.
        RecipientChip last = getLastChip();
        if (last != null) {
            // Grab the last chip and set the cursor to after it.
            setSelection(Math.min(getSpannable().getSpanEnd(last) + 1, getText().length()));
        }
        super.onSelectionChanged(start, end);
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        if (!TextUtils.isEmpty(getText())) {
            super.onRestoreInstanceState(null);
        } else {
            super.onRestoreInstanceState(state);
        }
    }

    @Override
    public Parcelable onSaveInstanceState() {
        // If the user changes orientation while they are editing, just roll back the selection.
        clearSelectedChip();
        return super.onSaveInstanceState();
    }

    /**
     * Convenience method: Append the specified text slice to the TextView's
     * display buffer, upgrading it to BufferType.EDITABLE if it was
     * not already editable. Commas are excluded as they are added automatically
     * by the view.
     */
    @Override
    public void append(CharSequence text, int start, int end) {
        // We don't care about watching text changes while appending.
        if (mTextWatcher != null) {
            removeTextChangedListener(mTextWatcher);
        }
        super.append(text, start, end);
        if (!TextUtils.isEmpty(text) && TextUtils.getTrimmedLength(text) > 0) {
            final String displayString = (String) text;
            int seperatorPos = displayString.indexOf(COMMIT_CHAR_COMMA);
            if (seperatorPos != 0 && !TextUtils.isEmpty(displayString)
                    && TextUtils.getTrimmedLength(displayString) > 0) {
                mPendingChipsCount++;
                mPendingChips.add((String)text);
            }
        }
        // Put a message on the queue to make sure we ALWAYS handle pending chips.
        if (mPendingChipsCount > 0) {
            postHandlePendingChips();
        }
        mHandler.post(mAddTextWatcher);
    }

    @Override
    public void onFocusChanged(boolean hasFocus, int direction, Rect previous) {
        super.onFocusChanged(hasFocus, direction, previous);
        if (!hasFocus) {
            shrink();
        } else {
            expand();
            scrollLineIntoView(getLineCount());
        }
    }

    @Override
    public void performValidation() {
        // Do nothing. Chips handles its own validation.
    }

    private void shrink() {
        if (mSelectedChip != null
                && mSelectedChip.getEntry().getContactId() != RecipientEntry.INVALID_CONTACT) {
            clearSelectedChip();
        } else {
            if (getWidth() <= 0) {
                // We don't have the width yet which means the view hasn't been drawn yet
                // and there is no reason to attempt to commit chips yet.
                // This focus lost must be the result of an orientation change
                // or an initial rendering.
                // Re-post the shrink for later.
                mHandler.removeCallbacks(mDelayedShrink);
                mHandler.post(mDelayedShrink);
                return;
            }
            // Reset any pending chips as they would have been handled
            // when the field lost focus.
            if (mPendingChipsCount > 0) {
                postHandlePendingChips();
            } else {
                Editable editable = getText();
                int end = getSelectionEnd();
                int start = mTokenizer.findTokenStart(editable, end);
                RecipientChip[] chips = getSpannable().getSpans(start, end, RecipientChip.class);
                if ((chips == null || chips.length == 0)) {
                    Editable text = getText();
                    int whatEnd = mTokenizer.findTokenEnd(text, start);
                    // This token was already tokenized, so skip past the ending token.
                    if (whatEnd < text.length() && text.charAt(whatEnd) == ',') {
                        whatEnd++;
                    }
                    // In the middle of chip; treat this as an edit
                    // and commit the whole token.
                    int selEnd = getSelectionEnd();
                    if (whatEnd != selEnd && whatEnd != editable.toString().trim().length()) {
                        handleEdit(start, whatEnd);
                    } else {
                        commitChip(start, end, editable);
                    }
                }
            }
            mHandler.post(mAddTextWatcher);
        }
        createMoreChip();
    }

    private void expand() {
        removeMoreChip();
        setCursorVisible(true);
        Editable text = getText();
        setSelection(text != null && text.length() > 0 ? text.length() : 0);
        // If there are any temporary chips, try replacing them now that the user
        // has expanded the field.
        if (mTemporaryRecipients != null && mTemporaryRecipients.size() > 0) {
            new RecipientReplacementTask().execute();
            mTemporaryRecipients = null;
        }
    }

    private CharSequence ellipsizeText(CharSequence text, TextPaint paint, float maxWidth) {
        paint.setTextSize(mChipFontSize);
        if (maxWidth <= 0 && Log.isLoggable(TAG, Log.DEBUG)) {
            Log.d(TAG, "Max width is negative: " + maxWidth);
        }
        return TextUtils.ellipsize(text, paint, maxWidth,
                TextUtils.TruncateAt.END);
    }

    private Bitmap createSelectedChip(RecipientEntry contact, TextPaint paint, Layout layout) {
        // Ellipsize the text so that it takes AT MOST the entire width of the
        // autocomplete text entry area. Make sure to leave space for padding
        // on the sides.
        int height = (int) mChipHeight;
        int deleteWidth = height;
        float[] widths = new float[1];
        paint.getTextWidths(" ", widths);
        CharSequence ellipsizedText = ellipsizeText(createChipDisplayText(contact), paint,
                calculateAvailableWidth(true) - deleteWidth - widths[0]);

        // Make sure there is a minimum chip width so the user can ALWAYS
        // tap a chip without difficulty.
        int width = Math.max(deleteWidth * 2, (int) Math.floor(paint.measureText(ellipsizedText, 0,
                ellipsizedText.length()))
                + (mChipPadding * 2) + deleteWidth);

        // Create the background of the chip.
        Bitmap tmpBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(tmpBitmap);
        if (mChipBackgroundPressed != null) {
            mChipBackgroundPressed.setBounds(0, 0, width, height);
            mChipBackgroundPressed.draw(canvas);
            paint.setColor(sSelectedTextColor);
            // Vertically center the text in the chip.
            canvas.drawText(ellipsizedText, 0, ellipsizedText.length(), mChipPadding,
                    getTextYOffset((String) ellipsizedText, paint, height), paint);
            // Make the delete a square.
            Rect backgroundPadding = new Rect();
            mChipBackgroundPressed.getPadding(backgroundPadding);
            mChipDelete.setBounds(width - deleteWidth + backgroundPadding.left,
                    0 + backgroundPadding.top,
                    width - backgroundPadding.right,
                    height - backgroundPadding.bottom);
            mChipDelete.draw(canvas);
        } else {
            Log.w(TAG, "Unable to draw a background for the chips as it was never set");
        }
        return tmpBitmap;
    }


    private Bitmap createUnselectedChip(RecipientEntry contact, TextPaint paint, Layout layout) {
        // Ellipsize the text so that it takes AT MOST the entire width of the
        // autocomplete text entry area. Make sure to leave space for padding
        // on the sides.
        int height = (int) mChipHeight;
        int iconWidth = height;
        float[] widths = new float[1];
        paint.getTextWidths(" ", widths);
        CharSequence ellipsizedText = ellipsizeText(createChipDisplayText(contact), paint,
                calculateAvailableWidth(false) - iconWidth - widths[0]);
        // Make sure there is a minimum chip width so the user can ALWAYS
        // tap a chip without difficulty.
        int width = Math.max(iconWidth * 2, (int) Math.floor(paint.measureText(ellipsizedText, 0,
                ellipsizedText.length()))
                + (mChipPadding * 2) + iconWidth);

        // Create the background of the chip.
        Bitmap tmpBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(tmpBitmap);
        Drawable background = getChipBackground(contact);
        if (background != null) {
            background.setBounds(0, 0, width, height);
            background.draw(canvas);

            // Don't draw photos for recipients that have been typed in.
            if (contact.getContactId() != RecipientEntry.INVALID_CONTACT) {
                byte[] photoBytes = contact.getPhotoBytes();
                // There may not be a photo yet if anything but the first contact address
                // was selected.
                if (photoBytes == null && contact.getPhotoThumbnailUri() != null) {
                    // TODO: cache this in the recipient entry?
                    ((BaseRecipientAdapter) getAdapter()).fetchPhoto(contact, contact
                            .getPhotoThumbnailUri());
                    photoBytes = contact.getPhotoBytes();
                }

                Bitmap photo;
                if (photoBytes != null) {
                    photo = BitmapFactory.decodeByteArray(photoBytes, 0, photoBytes.length);
                } else {
                    // TODO: can the scaled down default photo be cached?
                    photo = mDefaultContactPhoto;
                }
                // Draw the photo on the left side.
                if (photo != null) {
                    RectF src = new RectF(0, 0, photo.getWidth(), photo.getHeight());
                    Rect backgroundPadding = new Rect();
                    mChipBackground.getPadding(backgroundPadding);
                    RectF dst = new RectF(width - iconWidth + backgroundPadding.left,
                            0 + backgroundPadding.top,
                            width - backgroundPadding.right,
                            height - backgroundPadding.bottom);
                    Matrix matrix = new Matrix();
                    matrix.setRectToRect(src, dst, Matrix.ScaleToFit.FILL);
                    canvas.drawBitmap(photo, matrix, paint);
                }
            } else {
                // Don't leave any space for the icon. It isn't being drawn.
                iconWidth = 0;
            }
            paint.setColor(getContext().getResources().getColor(android.R.color.black));
            // Vertically center the text in the chip.
            canvas.drawText(ellipsizedText, 0, ellipsizedText.length(), mChipPadding,
                    getTextYOffset((String)ellipsizedText, paint, height), paint);
        } else {
            Log.w(TAG, "Unable to draw a background for the chips as it was never set");
        }
        return tmpBitmap;
    }

    /**
     * Get the background drawable for a RecipientChip.
     */
    // Visible for testing.
    /*package*/ Drawable getChipBackground(RecipientEntry contact) {
        return (mValidator != null && mValidator.isValid(contact.getDestination())) ?
                mChipBackground : mInvalidChipBackground;
    }

    private float getTextYOffset(String text, TextPaint paint, int height) {
        Rect bounds = new Rect();
        paint.getTextBounds(text, 0, text.length(), bounds);
        int textHeight = bounds.bottom - bounds.top  - (int)paint.descent();
        return height - ((height - textHeight) / 2);
    }

    private RecipientChip constructChipSpan(RecipientEntry contact, int offset, boolean pressed)
            throws NullPointerException {
        if (mChipBackground == null) {
            throw new NullPointerException(
                    "Unable to render any chips as setChipDimensions was not called.");
        }
        Layout layout = getLayout();

        TextPaint paint = getPaint();
        float defaultSize = paint.getTextSize();
        int defaultColor = paint.getColor();

        Bitmap tmpBitmap;
        if (pressed) {
            tmpBitmap = createSelectedChip(contact, paint, layout);

        } else {
            tmpBitmap = createUnselectedChip(contact, paint, layout);
        }

        // Pass the full text, un-ellipsized, to the chip.
        Drawable result = new BitmapDrawable(getResources(), tmpBitmap);
        result.setBounds(0, 0, tmpBitmap.getWidth(), tmpBitmap.getHeight());
        RecipientChip recipientChip = new RecipientChip(result, contact, offset);
        // Return text to the original size.
        paint.setTextSize(defaultSize);
        paint.setColor(defaultColor);
        return recipientChip;
    }

    /**
     * Calculate the bottom of the line the chip will be located on using:
     * 1) which line the chip appears on
     * 2) the height of a chip
     * 3) padding built into the edit text view
     */
    private int calculateOffsetFromBottom(int line) {
        // Line offsets start at zero.
        int actualLine = getLineCount() - (line + 1);
        return -((actualLine * ((int) mChipHeight) + getPaddingBottom()) + getPaddingTop())
                + getDropDownVerticalOffset();
    }

    /**
     * Get the max amount of space a chip can take up. The formula takes into
     * account the width of the EditTextView, any view padding, and padding
     * that will be added to the chip.
     */
    private float calculateAvailableWidth(boolean pressed) {
        return getWidth() - getPaddingLeft() - getPaddingRight() - (mChipPadding * 2);
    }

    /**
     * Set all chip dimensions and resources. This has to be done from the
     * application as this is a static library.
     * @param chipBackground
     * @param chipBackgroundPressed
     * @param invalidChip
     * @param chipDelete
     * @param defaultContact
     * @param moreResource
     * @param alternatesLayout
     * @param chipHeight
     * @param padding Padding around the text in a chip
     * @param chipFontSize
     * @param copyViewRes
     */
    public void setChipDimensions(Drawable chipBackground, Drawable chipBackgroundPressed,
            Drawable invalidChip, Drawable chipDelete, Bitmap defaultContact, int moreResource,
            int alternatesLayout, float chipHeight, float padding,
            float chipFontSize, int copyViewRes) {
        mChipBackground = chipBackground;
        mChipBackgroundPressed = chipBackgroundPressed;
        mChipDelete = chipDelete;
        mChipPadding = (int) padding;
        mAlternatesLayout = alternatesLayout;
        mDefaultContactPhoto = defaultContact;
        mMoreItem = (TextView) LayoutInflater.from(getContext()).inflate(moreResource, null);
        mChipHeight = chipHeight;
        mChipFontSize = chipFontSize;
        mInvalidChipBackground = invalidChip;
        mCopyViewRes = copyViewRes;
    }

    // Visible for testing.
    /* package */ void setMoreItem(TextView moreItem) {
        mMoreItem = moreItem;
    }


    // Visible for testing.
    /* package */ void setChipBackground(Drawable chipBackground) {
        mChipBackground = chipBackground;
    }

    // Visible for testing.
    /* package */ void setChipHeight(int height) {
        mChipHeight = height;
    }

    /**
     * Set whether to shrink the recipients field such that at most
     * one line of recipients chips are shown when the field loses
     * focus. By default, the number of displayed recipients will be
     * limited and a "more" chip will be shown when focus is lost.
     * @param shrink
     */
    public void setOnFocusListShrinkRecipients(boolean shrink) {
        mShouldShrink = shrink;
    }

    @Override
    public void onSizeChanged(int width, int height, int oldw, int oldh) {
        super.onSizeChanged(width, height, oldw, oldh);
        if (width != 0 && height != 0) {
            if (mPendingChipsCount > 0) {
                postHandlePendingChips();
            } else {
                checkChipWidths();
            }
        }
        // Try to find the scroll view parent, if it exists.
        if (mScrollView == null && !mTriedGettingScrollView) {
            ViewParent parent = getParent();
            while (parent != null && !(parent instanceof ScrollView)) {
                parent = parent.getParent();
            }
            if (parent != null) {
                mScrollView = (ScrollView) parent;
            }
            mTriedGettingScrollView = true;
        }
    }

    private void postHandlePendingChips() {
        mHandler.removeCallbacks(mHandlePendingChips);
        mHandler.post(mHandlePendingChips);
    }

    private void checkChipWidths() {
        // Check the widths of the associated chips.
        RecipientChip[] chips = getSortedRecipients();
        if (chips != null) {
            Rect bounds;
            for (RecipientChip chip : chips) {
                bounds = chip.getDrawable().getBounds();
                if (getWidth() > 0 && bounds.right - bounds.left > getWidth()) {
                    // Need to redraw that chip.
                    replaceChip(chip, chip.getEntry());
                }
            }
        }
    }

    private void handlePendingChips() {
        if (getWidth() <= 0) {
            // The widget has not been sized yet.
            // This will be called as a result of onSizeChanged
            // at a later point.
            return;
        }

        if (mPendingChipsCount <= 0) {
            return;
        }

        synchronized (mPendingChips) {
            Editable editable = getText();
            // Tokenize!
            for (int i = 0; i < mPendingChips.size(); i++) {
                String current = mPendingChips.get(i);
                int tokenStart = editable.toString().indexOf(current);
                int tokenEnd = tokenStart + current.length();
                if (tokenStart >= 0) {
                    // When we have a valid token, include it with the token
                    // to the left.
                    if (tokenEnd < editable.length() - 2
                            && editable.charAt(tokenEnd) == COMMIT_CHAR_COMMA) {
                        tokenEnd++;
                    }
                    createReplacementChip(tokenStart, tokenEnd, editable);
                }
                mPendingChipsCount--;
            }
            sanitizeEnd();
            if (mTemporaryRecipients != null && mTemporaryRecipients.size() > 0
                    && mTemporaryRecipients.size() <= RecipientAlternatesAdapter.MAX_LOOKUPS) {
                if (hasFocus() || mTemporaryRecipients.size() < CHIP_LIMIT) {
                    new RecipientReplacementTask().execute();
                    mTemporaryRecipients = null;
                } else {
                    // Create the "more" chip
                    mIndividualReplacements = new IndividualReplacementTask();
                    mIndividualReplacements.execute(new ArrayList<RecipientChip>(
                            mTemporaryRecipients.subList(0, CHIP_LIMIT)));

                    createMoreChip();
                }
            } else {
                // There are too many recipients to look up, so just fall back
                // to showing addresses for all of them.
                mTemporaryRecipients = null;
                createMoreChip();
            }
            mPendingChipsCount = 0;
            mPendingChips.clear();
        }
    }

    /**
     * Remove any characters after the last valid chip.
     */
    // Visible for testing.
    /*package*/ void sanitizeEnd() {
        // Find the last chip; eliminate any commit characters after it.
        RecipientChip[] chips = getSortedRecipients();
        if (chips != null && chips.length > 0) {
            int end;
            ImageSpan lastSpan;
            mMoreChip = getMoreChip();
            if (mMoreChip != null) {
                lastSpan = mMoreChip;
            } else {
                lastSpan = getLastChip();
            }
            end = getSpannable().getSpanEnd(lastSpan);
            Editable editable = getText();
            int length = editable.length();
            if (length > end) {
                // See what characters occur after that and eliminate them.
                if (Log.isLoggable(TAG, Log.DEBUG)) {
                    Log.d(TAG, "There were extra characters after the last tokenizable entry."
                            + editable);
                }
                editable.delete(end + 1, length);
            }
        }
    }

    /**
     * Create a chip that represents just the email address of a recipient. At some later
     * point, this chip will be attached to a real contact entry, if one exists.
     */
    private void createReplacementChip(int tokenStart, int tokenEnd, Editable editable) {
        if (alreadyHasChip(tokenStart, tokenEnd)) {
            // There is already a chip present at this location.
            // Don't recreate it.
            return;
        }
        String token = editable.toString().substring(tokenStart, tokenEnd);
        int commitCharIndex = token.trim().lastIndexOf(COMMIT_CHAR_COMMA);
        if (commitCharIndex == token.length() - 1) {
            token = token.substring(0, token.length() - 1);
        }
        RecipientEntry entry = createTokenizedEntry(token);
        if (entry != null) {
            String destText = createAddressText(entry);
            // Always leave a blank space at the end of a chip.
            int textLength = destText.length() - 1;
            SpannableString chipText = new SpannableString(destText);
            int end = getSelectionEnd();
            int start = mTokenizer.findTokenStart(getText(), end);
            RecipientChip chip = null;
            try {
                chip = constructChipSpan(entry, start, false);
                chipText.setSpan(chip, 0, textLength, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            } catch (NullPointerException e) {
                Log.e(TAG, e.getMessage(), e);
            }
            editable.replace(tokenStart, tokenEnd, chipText);
            // Add this chip to the list of entries "to replace"
            if (chip != null) {
                if (mTemporaryRecipients == null) {
                    mTemporaryRecipients = new ArrayList<RecipientChip>();
                }
                chip.setOriginalText(chipText.toString());
                mTemporaryRecipients.add(chip);
            }
        }
    }

    private RecipientEntry createTokenizedEntry(String token) {
        if (TextUtils.isEmpty(token)) {
            return null;
        }
        Rfc822Token[] tokens = Rfc822Tokenizer.tokenize(token);
        String display = null;
        if (isValid(token) && tokens != null && tokens.length > 0) {
            // If we can get a name from tokenizing, then generate an entry from
            // this.
            display = tokens[0].getName();
            if (!TextUtils.isEmpty(display)) {
                return RecipientEntry.constructGeneratedEntry(display, token);
            } else {
                display = tokens[0].getAddress();
                if (!TextUtils.isEmpty(display)) {
                    return RecipientEntry.constructFakeEntry(display);
                }
            }
        }
        // Unable to validate the token or to create a valid token from it.
        // Just create a chip the user can edit.
        String validatedToken = null;
        if (mValidator != null && !mValidator.isValid(token)) {
            // Try fixing up the entry using the validator.
            validatedToken = mValidator.fixText(token).toString();
            if (!TextUtils.isEmpty(validatedToken)) {
                if (validatedToken.contains(token)) {
                    // protect against the case of a validator with a null domain,
                    // which doesn't add a domain to the token
                    Rfc822Token[] tokenized = Rfc822Tokenizer.tokenize(validatedToken);
                    if (tokenized.length > 0) {
                        validatedToken = tokenized[0].getAddress();
                    }
                } else {
                    // We ran into a case where the token was invalid and removed
                    // by the validator. In this case, just use the original token
                    // and let the user sort out the error chip.
                    validatedToken = null;
                }
            }
        }
        // Otherwise, fallback to just creating an editable email address chip.
        return RecipientEntry
                .constructFakeEntry(!TextUtils.isEmpty(validatedToken) ? validatedToken : token);
    }

    private boolean isValid(String text) {
        return mValidator == null ? true : mValidator.isValid(text);
    }

    private String tokenizeAddress(String destination) {
        Rfc822Token[] tokens = Rfc822Tokenizer.tokenize(destination);
        if (tokens != null && tokens.length > 0) {
            return tokens[0].getAddress();
        }
        return destination;
    }

    @Override
    public void setTokenizer(Tokenizer tokenizer) {
        mTokenizer = tokenizer;
        super.setTokenizer(mTokenizer);
    }

    @Override
    public void setValidator(Validator validator) {
        mValidator = validator;
        super.setValidator(validator);
    }

    /**
     * We cannot use the default mechanism for replaceText. Instead,
     * we override onItemClickListener so we can get all the associated
     * contact information including display text, address, and id.
     */
    @Override
    protected void replaceText(CharSequence text) {
        return;
    }

    /**
     * Dismiss any selected chips when the back key is pressed.
     */
    @Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            clearSelectedChip();
        }
        return super.onKeyPreIme(keyCode, event);
    }

    /**
     * Monitor key presses in this view to see if the user types
     * any commit keys, which consist of ENTER, TAB, or DPAD_CENTER.
     * If the user has entered text that has contact matches and types
     * a commit key, create a chip from the topmost matching contact.
     * If the user has entered text that has no contact matches and types
     * a commit key, then create a chip from the text they have entered.
     */
    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_ENTER:
            case KeyEvent.KEYCODE_DPAD_CENTER:
                if (event.hasNoModifiers()) {
                    if (commitDefault()) {
                        return true;
                    }
                    if (mSelectedChip != null) {
                        clearSelectedChip();
                        return true;
                    } else if (focusNext()) {
                        return true;
                    }
                }
                break;
            case KeyEvent.KEYCODE_TAB:
                if (event.hasNoModifiers()) {
                    if (mSelectedChip != null) {
                        clearSelectedChip();
                    } else {
                        commitDefault();
                    }
                    if (focusNext()) {
                        return true;
                    }
                }
        }
        return super.onKeyUp(keyCode, event);
    }

    private boolean focusNext() {
        View next = focusSearch(View.FOCUS_DOWN);
        if (next != null) {
            next.requestFocus();
            return true;
        }
        return false;
    }

    /**
     * Create a chip from the default selection. If the popup is showing, the
     * default is the first item in the popup suggestions list. Otherwise, it is
     * whatever the user had typed in. End represents where the the tokenizer
     * should search for a token to turn into a chip.
     * @return If a chip was created from a real contact.
     */
    private boolean commitDefault() {
        Editable editable = getText();
        int end = getSelectionEnd();
        int start = mTokenizer.findTokenStart(editable, end);

        if (shouldCreateChip(start, end)) {
            int whatEnd = mTokenizer.findTokenEnd(getText(), start);
            // In the middle of chip; treat this as an edit
            // and commit the whole token.
            if (whatEnd != getSelectionEnd()) {
                handleEdit(start, whatEnd);
                return true;
            }
            return commitChip(start, end , editable);
        }
        return false;
    }

    private void commitByCharacter() {
        Editable editable = getText();
        int end = getSelectionEnd();
        int start = mTokenizer.findTokenStart(editable, end);
        if (shouldCreateChip(start, end)) {
            commitChip(start, end, editable);
        }
        setSelection(getText().length());
    }

    private boolean commitChip(int start, int end, Editable editable) {
        ListAdapter adapter = getAdapter();
        if (adapter != null && adapter.getCount() > 0 && enoughToFilter()
                && end == getSelectionEnd()) {
            // choose the first entry.
            submitItemAtPosition(0);
            dismissDropDown();
            return true;
        } else {
            int tokenEnd = mTokenizer.findTokenEnd(editable, start);
            if (editable.length() > tokenEnd + 1) {
                char charAt = editable.charAt(tokenEnd + 1);
                if (charAt == COMMIT_CHAR_COMMA || charAt == COMMIT_CHAR_SEMICOLON) {
                    tokenEnd++;
                }
            }
            String text = editable.toString().substring(start, tokenEnd).trim();
            clearComposingText();
            if (text != null && text.length() > 0 && !text.equals(" ")) {
                RecipientEntry entry = createTokenizedEntry(text);
                if (entry != null) {
                    QwertyKeyListener.markAsReplaced(editable, start, end, "");
                    CharSequence chipText = createChip(entry, false);
                    if (chipText != null && start > -1 && end > -1) {
                        editable.replace(start, end, chipText);
                    }
                }
                // Only dismiss the dropdown if it is related to the text we
                // just committed.
                // For paste, it may not be as there are possibly multiple
                // tokens being added.
                if (end == getSelectionEnd()) {
                    dismissDropDown();
                }
                sanitizeBetween();
                return true;
            }
        }
        return false;
    }

    // Visible for testing.
    /* package */ void sanitizeBetween() {
        // Find the last chip.
        RecipientChip[] recips = getSortedRecipients();
        if (recips != null && recips.length > 0) {
            RecipientChip last = recips[recips.length - 1];
            RecipientChip beforeLast = null;
            if (recips.length > 1) {
                beforeLast = recips[recips.length - 2];
            }
            int startLooking = 0;
            int end = getSpannable().getSpanStart(last);
            if (beforeLast != null) {
                startLooking = getSpannable().getSpanEnd(beforeLast);
                Editable text = getText();
                if (startLooking == -1 || startLooking > text.length() - 1) {
                    // There is nothing after this chip.
                    return;
                }
                if (text.charAt(startLooking) == ' ') {
                    startLooking++;
                }
            }
            if (startLooking >= 0 && end >= 0 && startLooking != end) {
                getText().delete(startLooking, end);
            }
        }
    }

    private boolean shouldCreateChip(int start, int end) {
        return hasFocus() && enoughToFilter() && !alreadyHasChip(start, end);
    }

    private boolean alreadyHasChip(int start, int end) {
        RecipientChip[] chips = getSpannable().getSpans(start, end, RecipientChip.class);
        if ((chips == null || chips.length == 0)) {
            return false;
        }
        return true;
    }

    private void handleEdit(int start, int end) {
        if (start == -1 || end == -1) {
            // This chip no longer exists in the field.
            dismissDropDown();
            return;
        }
        // This is in the middle of a chip, so select out the whole chip
        // and commit it.
        Editable editable = getText();
        setSelection(end);
        String text = getText().toString().substring(start, end);
        if (!TextUtils.isEmpty(text)) {
            RecipientEntry entry = RecipientEntry.constructFakeEntry(text);
            QwertyKeyListener.markAsReplaced(editable, start, end, "");
            CharSequence chipText = createChip(entry, false);
            if (chipText != null) {
                editable.replace(start, getSelectionEnd(), chipText);
            }
        }
        dismissDropDown();
    }

    /**
     * If there is a selected chip, delegate the key events
     * to the selected chip.
     */
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (mSelectedChip != null && keyCode == KeyEvent.KEYCODE_DEL) {
            if (mAlternatesPopup != null && mAlternatesPopup.isShowing()) {
                mAlternatesPopup.dismiss();
            }
            removeChip(mSelectedChip);
        }

        if (keyCode == KeyEvent.KEYCODE_ENTER && event.hasNoModifiers()) {
            return true;
        }

        return super.onKeyDown(keyCode, event);
    }

    // Visible for testing.
    /* package */ Spannable getSpannable() {
        return getText();
    }

    private int getChipStart(RecipientChip chip) {
        return getSpannable().getSpanStart(chip);
    }

    private int getChipEnd(RecipientChip chip) {
        return getSpannable().getSpanEnd(chip);
    }

    /**
     * Instead of filtering on the entire contents of the edit box,
     * this subclass method filters on the range from
     * {@link Tokenizer#findTokenStart} to {@link #getSelectionEnd}
     * if the length of that range meets or exceeds {@link #getThreshold}
     * and makes sure that the range is not already a Chip.
     */
    @Override
    protected void performFiltering(CharSequence text, int keyCode) {
        if (enoughToFilter() && !isCompletedToken(text)) {
            int end = getSelectionEnd();
            int start = mTokenizer.findTokenStart(text, end);
            // If this is a RecipientChip, don't filter
            // on its contents.
            Spannable span = getSpannable();
            RecipientChip[] chips = span.getSpans(start, end, RecipientChip.class);
            if (chips != null && chips.length > 0) {
                return;
            }
        }
        super.performFiltering(text, keyCode);
    }

    // Visible for testing.
    /*package*/ boolean isCompletedToken(CharSequence text) {
        if (TextUtils.isEmpty(text)) {
            return false;
        }
        // Check to see if this is a completed token before filtering.
        int end = text.length();
        int start = mTokenizer.findTokenStart(text, end);
        String token = text.toString().substring(start, end).trim();
        if (!TextUtils.isEmpty(token)) {
            char atEnd = token.charAt(token.length() - 1);
            return atEnd == COMMIT_CHAR_COMMA || atEnd == COMMIT_CHAR_SEMICOLON;
        }
        return false;
    }

    private void clearSelectedChip() {
        if (mSelectedChip != null) {
            unselectChip(mSelectedChip);
            mSelectedChip = null;
        }
        setCursorVisible(true);
    }

    /**
     * Monitor touch events in the RecipientEditTextView.
     * If the view does not have focus, any tap on the view
     * will just focus the view. If the view has focus, determine
     * if the touch target is a recipient chip. If it is and the chip
     * is not selected, select it and clear any other selected chips.
     * If it isn't, then select that chip.
     */
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (!isFocused()) {
            // Ignore any chip taps until this view is focused.
            return super.onTouchEvent(event);
        }
        boolean handled = super.onTouchEvent(event);
        int action = event.getAction();
        boolean chipWasSelected = false;
        if (mSelectedChip == null) {
            mGestureDetector.onTouchEvent(event);
        }
        if (mCopyAddress == null && action == MotionEvent.ACTION_UP) {
            float x = event.getX();
            float y = event.getY();
            int offset = putOffsetInRange(getOffsetForPosition(x, y));
            RecipientChip currentChip = findChip(offset);
            if (currentChip != null) {
                if (action == MotionEvent.ACTION_UP) {
                    if (mSelectedChip != null && mSelectedChip != currentChip) {
                        clearSelectedChip();
                        mSelectedChip = selectChip(currentChip);
                    } else if (mSelectedChip == null) {
                        setSelection(getText().length());
                        commitDefault();
                        mSelectedChip = selectChip(currentChip);
                    } else {
                        onClick(mSelectedChip, offset, x, y);
                    }
                }
                chipWasSelected = true;
                handled = true;
            } else if (mSelectedChip != null
                    && mSelectedChip.getContactId() == RecipientEntry.INVALID_CONTACT) {
                chipWasSelected = true;
            }
        }
        if (action == MotionEvent.ACTION_UP && !chipWasSelected) {
            clearSelectedChip();
        }
        return handled;
    }

    private void scrollLineIntoView(int line) {
        if (mScrollView != null) {
            mScrollView.scrollBy(0, calculateOffsetFromBottom(line));
        }
    }

    private void showAlternates(RecipientChip currentChip, ListPopupWindow alternatesPopup,
            int width, Context context) {
        int line = getLayout().getLineForOffset(getChipStart(currentChip));
        int bottom = calculateOffsetFromBottom(line);
        // Align the alternates popup with the left side of the View,
        // regardless of the position of the chip tapped.
        alternatesPopup.setWidth(width);
        setEnabled(false);
        alternatesPopup.setAnchorView(this);
        alternatesPopup.setVerticalOffset(bottom);
        alternatesPopup.setAdapter(createAlternatesAdapter(currentChip));
        alternatesPopup.setOnItemClickListener(mAlternatesListener);
        // Clear the checked item.
        mCheckedItem = -1;
        alternatesPopup.show();
        ListView listView = alternatesPopup.getListView();
        listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
        // Checked item would be -1 if the adapter has not
        // loaded the view that should be checked yet. The
        // variable will be set correctly when onCheckedItemChanged
        // is called in a separate thread.
        if (mCheckedItem != -1) {
            listView.setItemChecked(mCheckedItem, true);
            mCheckedItem = -1;
        }
    }

    // Dismiss listener for alterns and single address popup.
    @Override
    public void onDismiss() {
        setEnabled(true);
    }

    private ListAdapter createAlternatesAdapter(RecipientChip chip) {
        return new RecipientAlternatesAdapter(getContext(), chip.getContactId(), chip.getDataId(),
                mAlternatesLayout, this);
    }

    private ListAdapter createSingleAddressAdapter(RecipientChip currentChip) {
        return new SingleRecipientArrayAdapter(getContext(), mAlternatesLayout, currentChip
                .getEntry());
    }

    @Override
    public void onCheckedItemChanged(int position) {
        ListView listView = mAlternatesPopup.getListView();
        if (listView != null && listView.getCheckedItemCount() == 0) {
            listView.setItemChecked(position, true);
        }
        mCheckedItem = position;
    }

    // TODO: This algorithm will need a lot of tweaking after more people have used
    // the chips ui. This attempts to be "forgiving" to fat finger touches by favoring
    // what comes before the finger.
    private int putOffsetInRange(int o) {
        int offset = o;
        Editable text = getText();
        int length = text.length();
        // Remove whitespace from end to find "real end"
        int realLength = length;
        for (int i = length - 1; i >= 0; i--) {
            if (text.charAt(i) == ' ') {
                realLength--;
            } else {
                break;
            }
        }

        // If the offset is beyond or at the end of the text,
        // leave it alone.
        if (offset >= realLength) {
            return offset;
        }
        Editable editable = getText();
        while (offset >= 0 && findText(editable, offset) == -1 && findChip(offset) == null) {
            // Keep walking backward!
            offset--;
        }
        return offset;
    }

    private int findText(Editable text, int offset) {
        if (text.charAt(offset) != ' ') {
            return offset;
        }
        return -1;
    }

    private RecipientChip findChip(int offset) {
        RecipientChip[] chips = getSpannable().getSpans(0, getText().length(), RecipientChip.class);
        // Find the chip that contains this offset.
        for (int i = 0; i < chips.length; i++) {
            RecipientChip chip = chips[i];
            int start = getChipStart(chip);
            int end = getChipEnd(chip);
            if (offset >= start && offset <= end) {
                return chip;
            }
        }
        return null;
    }

    // Visible for testing.
    // Use this method to generate text to add to the list of addresses.
    /*package*/ String createAddressText(RecipientEntry entry) {
        String display = entry.getDisplayName();
        String address = entry.getDestination();
        if (TextUtils.isEmpty(display) || TextUtils.equals(display, address)) {
            display = null;
        }
        if (address != null) {
            // Tokenize out the address in case the address already
            // contained the username as well.
            Rfc822Token[] tokenized = Rfc822Tokenizer.tokenize(address);
            if (tokenized != null && tokenized.length > 0) {
                address = tokenized[0].getAddress();
            }
        }
        Rfc822Token token = new Rfc822Token(display, address, null);
        String trimmedDisplayText = token.toString().trim();
        int index = trimmedDisplayText.indexOf(",");
        return index < trimmedDisplayText.length() - 1 ? (String) mTokenizer
                .terminateToken(trimmedDisplayText) : trimmedDisplayText;
    }

    // Visible for testing.
    // Use this method to generate text to display in a chip.
    /*package*/ String createChipDisplayText(RecipientEntry entry) {
        String display = entry.getDisplayName();
        String address = entry.getDestination();
        if (TextUtils.isEmpty(display) || TextUtils.equals(display, address)) {
            display = null;
        }
        if (address != null) {
            // Tokenize out the address in case the address already
            // contained the username as well.
            Rfc822Token[] tokenized = Rfc822Tokenizer.tokenize(address);
            if (tokenized != null && tokenized.length > 0) {
                address = tokenized[0].getAddress();
            }
        }
        if (!TextUtils.isEmpty(display)) {
            return display;
        } else if (!TextUtils.isEmpty(address)){
            return address;
        } else {
            return new Rfc822Token(display, address, null).toString();
        }
    }

    private CharSequence createChip(RecipientEntry entry, boolean pressed) {
        String displayText = createAddressText(entry);
        if (TextUtils.isEmpty(displayText)) {
            return null;
        }
        // Always leave a blank space at the end of a chip.
        int textLength = displayText.length()-1;
        SpannableString chipText = new SpannableString(displayText);
        int end = getSelectionEnd();
        int start = mTokenizer.findTokenStart(getText(), end);
        try {
            RecipientChip chip = constructChipSpan(entry, start, pressed);
            chipText.setSpan(chip, 0, textLength,
                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            chip.setOriginalText(chipText.toString());
        } catch (NullPointerException e) {
            Log.e(TAG, e.getMessage(), e);
            return null;
        }

        return chipText;
    }

    /**
     * When an item in the suggestions list has been clicked, create a chip from the
     * contact information of the selected item.
     */
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        submitItemAtPosition(position);
    }

    private void submitItemAtPosition(int position) {
        RecipientEntry entry = createValidatedEntry(
                (RecipientEntry)getAdapter().getItem(position));
        if (entry == null) {
            return;
        }
        clearComposingText();

        int end = getSelectionEnd();
        int start = mTokenizer.findTokenStart(getText(), end);

        Editable editable = getText();
        QwertyKeyListener.markAsReplaced(editable, start, end, "");
        CharSequence chip = createChip(entry, false);
        if (chip != null) {
            editable.replace(start, end, chip);
        }
        sanitizeBetween();
    }

    private RecipientEntry createValidatedEntry(RecipientEntry item) {
        if (item == null) {
            return null;
        }
        final RecipientEntry entry;
        // If the display name and the address are the same, or if this is a
        // valid contact, but the destination is invalid, then make this a fake
        // recipient that is editable.
        String destination = item.getDestination();
        if (RecipientEntry.isCreatedRecipient(item.getContactId())
                && (TextUtils.isEmpty(item.getDisplayName())
                        || TextUtils.equals(item.getDisplayName(), destination)
                        || (mValidator != null && !mValidator.isValid(destination)))) {
            entry = RecipientEntry.constructFakeEntry(destination);
        } else {
            entry = item;
        }
        return entry;
    }

    /** Returns a collection of contact Id for each chip inside this View. */
    /* package */ Collection<Long> getContactIds() {
        final Set<Long> result = new HashSet<Long>();
        RecipientChip[] chips = getSortedRecipients();
        if (chips != null) {
            for (RecipientChip chip : chips) {
                result.add(chip.getContactId());
            }
        }
        return result;
    }


    /** Returns a collection of data Id for each chip inside this View. May be null. */
    /* package */ Collection<Long> getDataIds() {
        final Set<Long> result = new HashSet<Long>();
        RecipientChip [] chips = getSortedRecipients();
        if (chips != null) {
            for (RecipientChip chip : chips) {
                result.add(chip.getDataId());
            }
        }
        return result;
    }

    // Visible for testing.
    /* package */RecipientChip[] getSortedRecipients() {
        RecipientChip[] recips = getSpannable()
                .getSpans(0, getText().length(), RecipientChip.class);
        ArrayList<RecipientChip> recipientsList = new ArrayList<RecipientChip>(Arrays
                .asList(recips));
        final Spannable spannable = getSpannable();
        Collections.sort(recipientsList, new Comparator<RecipientChip>() {

            @Override
            public int compare(RecipientChip first, RecipientChip second) {
                int firstStart = spannable.getSpanStart(first);
                int secondStart = spannable.getSpanStart(second);
                if (firstStart < secondStart) {
                    return -1;
                } else if (firstStart > secondStart) {
                    return 1;
                } else {
                    return 0;
                }
            }
        });
        return recipientsList.toArray(new RecipientChip[recipientsList.size()]);
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        return false;
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
    }

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        return false;
    }

    /**
     * No chips are selectable.
     */
    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        return false;
    }

    // Visible for testing.
    /* package */ImageSpan getMoreChip() {
        MoreImageSpan[] moreSpans = getSpannable().getSpans(0, getText().length(),
                MoreImageSpan.class);
        return moreSpans != null && moreSpans.length > 0 ? moreSpans[0] : null;
    }

    /**
     * Create the more chip. The more chip is text that replaces any chips that
     * do not fit in the pre-defined available space when the
     * RecipientEditTextView loses focus.
     */
    // Visible for testing.
    /* package */ void createMoreChip() {
        if (!mShouldShrink) {
            return;
        }

        ImageSpan[] tempMore = getSpannable().getSpans(0, getText().length(), MoreImageSpan.class);
        if (tempMore.length > 0) {
            getSpannable().removeSpan(tempMore[0]);
        }
        RecipientChip[] recipients = getSortedRecipients();
        if (recipients == null || recipients.length <= CHIP_LIMIT) {
            mMoreChip = null;
            return;
        }
        Spannable spannable = getSpannable();
        int numRecipients = recipients.length;
        int overage = numRecipients - CHIP_LIMIT;
        String moreText = String.format(mMoreItem.getText().toString(), overage);
        TextPaint morePaint = new TextPaint(getPaint());
        morePaint.setTextSize(mMoreItem.getTextSize());
        morePaint.setColor(mMoreItem.getCurrentTextColor());
        int width = (int)morePaint.measureText(moreText) + mMoreItem.getPaddingLeft()
                + mMoreItem.getPaddingRight();
        int height = getLineHeight();
        Bitmap drawable = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(drawable);
        int adjustedHeight = height;
        Layout layout = getLayout();
        if (layout != null) {
            adjustedHeight -= layout.getLineDescent(0);
        }
        canvas.drawText(moreText, 0, moreText.length(), 0, adjustedHeight, morePaint);

        Drawable result = new BitmapDrawable(getResources(), drawable);
        result.setBounds(0, 0, width, height);
        MoreImageSpan moreSpan = new MoreImageSpan(result);
        // Remove the overage chips.
        if (recipients == null || recipients.length == 0) {
            Log.w(TAG,
                    "We have recipients. Tt should not be possible to have zero RecipientChips.");
            mMoreChip = null;
            return;
        }
        mRemovedSpans = new ArrayList<RecipientChip>();
        int totalReplaceStart = 0;
        int totalReplaceEnd = 0;
        Editable text = getText();
        for (int i = numRecipients - overage; i < recipients.length; i++) {
            mRemovedSpans.add(recipients[i]);
            if (i == numRecipients - overage) {
                totalReplaceStart = spannable.getSpanStart(recipients[i]);
            }
            if (i == recipients.length - 1) {
                totalReplaceEnd = spannable.getSpanEnd(recipients[i]);
            }
            if (mTemporaryRecipients == null || !mTemporaryRecipients.contains(recipients[i])) {
                int spanStart = spannable.getSpanStart(recipients[i]);
                int spanEnd = spannable.getSpanEnd(recipients[i]);
                recipients[i].setOriginalText(text.toString().substring(spanStart, spanEnd));
            }
            spannable.removeSpan(recipients[i]);
        }
        int end = Math.max(totalReplaceStart, totalReplaceEnd);
        int start = Math.min(totalReplaceStart, totalReplaceEnd);
        SpannableString chipText = new SpannableString(text.subSequence(start, end));
        chipText.setSpan(moreSpan, 0, chipText.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        text.replace(start, end, chipText);
        mMoreChip = moreSpan;
    }

    /**
     * Replace the more chip, if it exists, with all of the recipient chips it had
     * replaced when the RecipientEditTextView gains focus.
     */
    // Visible for testing.
    /*package*/ void removeMoreChip() {
        if (mMoreChip != null) {
            Spannable span = getSpannable();
            span.removeSpan(mMoreChip);
            mMoreChip = null;
            // Re-add the spans that were removed.
            if (mRemovedSpans != null && mRemovedSpans.size() > 0) {
                // Recreate each removed span.
                RecipientChip[] recipients = getSortedRecipients();
                // Start the search for tokens after the last currently visible
                // chip.
                if (recipients == null || recipients.length == 0) {
                    return;
                }
                int end = span.getSpanEnd(recipients[recipients.length - 1]);
                Editable editable = getText();
                for (RecipientChip chip : mRemovedSpans) {
                    int chipStart;
                    int chipEnd;
                    String token;
                    // Need to find the location of the chip, again.
                    token = (String) chip.getOriginalText();
                    // As we find the matching recipient for the remove spans,
                    // reduce the size of the string we need to search.
                    // That way, if there are duplicates, we always find the correct
                    // recipient.
                    chipStart = editable.toString().indexOf(token, end);
                    end = chipEnd = Math.min(editable.length(), chipStart + token.length());
                    // Only set the span if we found a matching token.
                    if (chipStart != -1) {
                        editable.setSpan(chip, chipStart, chipEnd,
                                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                    }
                }
                mRemovedSpans.clear();
            }
        }
    }

    /**
     * Show specified chip as selected. If the RecipientChip is just an email address,
     * selecting the chip will take the contents of the chip and place it at
     * the end of the RecipientEditTextView for inline editing. If the
     * RecipientChip is a complete contact, then selecting the chip
     * will change the background color of the chip, show the delete icon,
     * and a popup window with the address in use highlighted and any other
     * alternate addresses for the contact.
     * @param currentChip Chip to select.
     * @return A RecipientChip in the selected state or null if the chip
     * just contained an email address.
     */
    private RecipientChip selectChip(RecipientChip currentChip) {
        if (currentChip.getContactId() == RecipientEntry.INVALID_CONTACT) {
            CharSequence text = currentChip.getValue();
            Editable editable = getText();
            removeChip(currentChip);
            editable.append(text);
            setCursorVisible(true);
            setSelection(editable.length());
            return new RecipientChip(null, RecipientEntry.constructFakeEntry((String) text), -1);
        } else if (currentChip.getContactId() == RecipientEntry.GENERATED_CONTACT) {
            int start = getChipStart(currentChip);
            int end = getChipEnd(currentChip);
            getSpannable().removeSpan(currentChip);
            RecipientChip newChip;
            try {
                newChip = constructChipSpan(currentChip.getEntry(), start, true);
            } catch (NullPointerException e) {
                Log.e(TAG, e.getMessage(), e);
                return null;
            }
            Editable editable = getText();
            QwertyKeyListener.markAsReplaced(editable, start, end, "");
            if (start == -1 || end == -1) {
                Log.d(TAG, "The chip being selected no longer exists but should.");
            } else {
                editable.setSpan(newChip, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
            newChip.setSelected(true);
            if (newChip.getEntry().getContactId() == RecipientEntry.INVALID_CONTACT) {
                scrollLineIntoView(getLayout().getLineForOffset(getChipStart(newChip)));
            }
            showAddress(newChip, mAddressPopup, getWidth(), getContext());
            setCursorVisible(false);
            return newChip;
        } else {
            int start = getChipStart(currentChip);
            int end = getChipEnd(currentChip);
            getSpannable().removeSpan(currentChip);
            RecipientChip newChip;
            try {
                newChip = constructChipSpan(currentChip.getEntry(), start, true);
            } catch (NullPointerException e) {
                Log.e(TAG, e.getMessage(), e);
                return null;
            }
            Editable editable = getText();
            QwertyKeyListener.markAsReplaced(editable, start, end, "");
            if (start == -1 || end == -1) {
                Log.d(TAG, "The chip being selected no longer exists but should.");
            } else {
                editable.setSpan(newChip, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
            newChip.setSelected(true);
            if (newChip.getEntry().getContactId() == RecipientEntry.INVALID_CONTACT) {
                scrollLineIntoView(getLayout().getLineForOffset(getChipStart(newChip)));
            }
            showAlternates(newChip, mAlternatesPopup, getWidth(), getContext());
            setCursorVisible(false);
            return newChip;
        }
    }


    private void showAddress(final RecipientChip currentChip, final ListPopupWindow popup,
            int width, Context context) {
        int line = getLayout().getLineForOffset(getChipStart(currentChip));
        int bottom = calculateOffsetFromBottom(line);
        // Align the alternates popup with the left side of the View,
        // regardless of the position of the chip tapped.
        setEnabled(false);
        popup.setWidth(width);
        popup.setAnchorView(this);
        popup.setVerticalOffset(bottom);
        popup.setAdapter(createSingleAddressAdapter(currentChip));
        popup.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                unselectChip(currentChip);
                popup.dismiss();
            }
        });
        popup.show();
        ListView listView = popup.getListView();
        listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
        listView.setItemChecked(0, true);
    }

    /**
     * Remove selection from this chip. Unselecting a RecipientChip will render
     * the chip without a delete icon and with an unfocused background. This
     * is called when the RecipientChip no longer has focus.
     */
    private void unselectChip(RecipientChip chip) {
        int start = getChipStart(chip);
        int end = getChipEnd(chip);
        Editable editable = getText();
        mSelectedChip = null;
        if (start == -1 || end == -1) {
            Log.w(TAG,
                    "The chip doesn't exist or may be a chip a user was editing");
            setSelection(editable.length());
            commitDefault();
        } else {
            getSpannable().removeSpan(chip);
            QwertyKeyListener.markAsReplaced(editable, start, end, "");
            editable.removeSpan(chip);
            try {
                editable.setSpan(constructChipSpan(chip.getEntry(), start, false), start, end,
                        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            } catch (NullPointerException e) {
                Log.e(TAG, e.getMessage(), e);
            }
        }
        setCursorVisible(true);
        setSelection(editable.length());
        if (mAlternatesPopup != null && mAlternatesPopup.isShowing()) {
            mAlternatesPopup.dismiss();
        }
    }

    /**
     * Return whether a touch event was inside the delete target of
     * a selected chip. It is in the delete target if:
     * 1) the x and y points of the event are within the
     * delete assset.
     * 2) the point tapped would have caused a cursor to appear
     * right after the selected chip.
     * @return boolean
     */
    private boolean isInDelete(RecipientChip chip, int offset, float x, float y) {
        // Figure out the bounds of this chip and whether or not
        // the user clicked in the X portion.
        return chip.isSelected() && offset == getChipEnd(chip);
    }

    /**
     * Remove the chip and any text associated with it from the RecipientEditTextView.
     */
    // Visible for testing.
    /*pacakge*/ void removeChip(RecipientChip chip) {
        Spannable spannable = getSpannable();
        int spanStart = spannable.getSpanStart(chip);
        int spanEnd = spannable.getSpanEnd(chip);
        Editable text = getText();
        int toDelete = spanEnd;
        boolean wasSelected = chip == mSelectedChip;
        // Clear that there is a selected chip before updating any text.
        if (wasSelected) {
            mSelectedChip = null;
        }
        // Always remove trailing spaces when removing a chip.
        while (toDelete >= 0 && toDelete < text.length() && text.charAt(toDelete) == ' ') {
            toDelete++;
        }
        spannable.removeSpan(chip);
        text.delete(spanStart, toDelete);
        if (wasSelected) {
            clearSelectedChip();
        }
    }

    /**
     * Replace this currently selected chip with a new chip
     * that uses the contact data provided.
     */
    // Visible for testing.
    /*package*/ void replaceChip(RecipientChip chip, RecipientEntry entry) {
        boolean wasSelected = chip == mSelectedChip;
        if (wasSelected) {
            mSelectedChip = null;
        }
        int start = getChipStart(chip);
        int end = getChipEnd(chip);
        getSpannable().removeSpan(chip);
        Editable editable = getText();
        CharSequence chipText = createChip(entry, false);
        if (chipText != null) {
            if (start == -1 || end == -1) {
                Log.e(TAG, "The chip to replace does not exist but should.");
                editable.insert(0, chipText);
            } else {
                if (!TextUtils.isEmpty(chipText)) {
                    // There may be a space to replace with this chip's new
                    // associated
                    // space. Check for it
                    int toReplace = end;
                    while (toReplace >= 0 && toReplace < editable.length()
                            && editable.charAt(toReplace) == ' ') {
                        toReplace++;
                    }
                    editable.replace(start, toReplace, chipText);
                }
            }
        }
        setCursorVisible(true);
        if (wasSelected) {
            clearSelectedChip();
        }
    }

    /**
     * Handle click events for a chip. When a selected chip receives a click
     * event, see if that event was in the delete icon. If so, delete it.
     * Otherwise, unselect the chip.
     */
    public void onClick(RecipientChip chip, int offset, float x, float y) {
        if (chip.isSelected()) {
            if (isInDelete(chip, offset, x, y)) {
                removeChip(chip);
            } else {
                clearSelectedChip();
            }
        }
    }

    private boolean chipsPending() {
        return mPendingChipsCount > 0 || (mRemovedSpans != null && mRemovedSpans.size() > 0);
    }

    @Override
    public void removeTextChangedListener(TextWatcher watcher) {
        mTextWatcher = null;
        super.removeTextChangedListener(watcher);
    }

    private class RecipientTextWatcher implements TextWatcher {
        @Override
        public void afterTextChanged(Editable s) {
            // If the text has been set to null or empty, make sure we remove
            // all the spans we applied.
            if (TextUtils.isEmpty(s)) {
                // Remove all the chips spans.
                Spannable spannable = getSpannable();
                RecipientChip[] chips = spannable.getSpans(0, getText().length(),
                        RecipientChip.class);
                for (RecipientChip chip : chips) {
                    spannable.removeSpan(chip);
                }
                if (mMoreChip != null) {
                    spannable.removeSpan(mMoreChip);
                }
                return;
            }
            // Get whether there are any recipients pending addition to the
            // view. If there are, don't do anything in the text watcher.
            if (chipsPending()) {
                return;
            }
            // If the user is editing a chip, don't clear it.
            if (mSelectedChip != null
                    && mSelectedChip.getContactId() != RecipientEntry.INVALID_CONTACT) {
                setCursorVisible(true);
                setSelection(getText().length());
                clearSelectedChip();
            }
            int length = s.length();
            // Make sure there is content there to parse and that it is
            // not just the commit character.
            if (length > 1) {
                char last;
                int end = getSelectionEnd() == 0 ? 0 : getSelectionEnd() - 1;
                int len = length() - 1;
                if (end != len) {
                    last = s.charAt(end);
                } else {
                    last = s.charAt(len);
                }
                if (last == COMMIT_CHAR_SEMICOLON || last == COMMIT_CHAR_COMMA) {
                    commitByCharacter();
                } else if (last == COMMIT_CHAR_SPACE) {
                    // Check if this is a valid email address. If it is,
                    // commit it.
                    String text = getText().toString();
                    int tokenStart = mTokenizer.findTokenStart(text, getSelectionEnd());
                    String sub = text.substring(tokenStart, mTokenizer.findTokenEnd(text,
                            tokenStart));
                    if (!TextUtils.isEmpty(sub) && mValidator != null && mValidator.isValid(sub)) {
                        commitByCharacter();
                    }
                }
            }
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            // Do nothing.
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            // Do nothing.
        }
    }

    /**
     * Handles pasting a {@link ClipData} to this {@link RecipientEditTextView}.
     */
    private void handlePasteClip(ClipData clip) {
        removeTextChangedListener(mTextWatcher);

        if (clip != null && clip.getDescription().hasMimeType(ClipDescription.MIMETYPE_TEXT_PLAIN)){
            for (int i = 0; i < clip.getItemCount(); i++) {
                CharSequence paste = clip.getItemAt(i).getText();
                if (paste != null) {
                    int start = getSelectionStart();
                    int end = getSelectionEnd();
                    Editable editable = getText();
                    if (start >= 0 && end >= 0 && start != end) {
                        editable.append(paste, start, end);
                    } else {
                        editable.insert(end, paste);
                    }
                    handlePasteAndReplace();
                }
            }
        }

        mHandler.post(mAddTextWatcher);
    }

    @Override
    public boolean onTextContextMenuItem(int id) {
        if (id == android.R.id.paste) {
            ClipboardManager clipboard = (ClipboardManager) getContext().getSystemService(
                    Context.CLIPBOARD_SERVICE);
            handlePasteClip(clipboard.getPrimaryClip());
            return true;
        }
        return super.onTextContextMenuItem(id);
    }

    private void handlePasteAndReplace() {
        ArrayList<RecipientChip> created = handlePaste();
        if (created != null && created.size() > 0) {
            // Perform reverse lookups on the pasted contacts.
            IndividualReplacementTask replace = new IndividualReplacementTask();
            replace.execute(created);
        }
    }

    // Visible for testing.
    /* package */ArrayList<RecipientChip> handlePaste() {
        String text = getText().toString();
        int originalTokenStart = mTokenizer.findTokenStart(text, getSelectionEnd());
        String lastAddress = text.substring(originalTokenStart);
        int tokenStart = originalTokenStart;
        int prevTokenStart = tokenStart;
        RecipientChip findChip = null;
        ArrayList<RecipientChip> created = new ArrayList<RecipientChip>();
        if (tokenStart != 0) {
            // There are things before this!
            while (tokenStart != 0 && findChip == null) {
                prevTokenStart = tokenStart;
                tokenStart = mTokenizer.findTokenStart(text, tokenStart);
                findChip = findChip(tokenStart);
            }
            if (tokenStart != originalTokenStart) {
                if (findChip != null) {
                    tokenStart = prevTokenStart;
                }
                int tokenEnd;
                RecipientChip createdChip;
                while (tokenStart < originalTokenStart) {
                    tokenEnd = movePastTerminators(mTokenizer.findTokenEnd(text, tokenStart));
                    commitChip(tokenStart, tokenEnd, getText());
                    createdChip = findChip(tokenStart);
                    // +1 for the space at the end.
                    tokenStart = getSpannable().getSpanEnd(createdChip) + 1;
                    created.add(createdChip);
                }
            }
        }
        // Take a look at the last token. If the token has been completed with a
        // commit character, create a chip.
        if (isCompletedToken(lastAddress)) {
            Editable editable = getText();
            tokenStart = editable.toString().indexOf(lastAddress, originalTokenStart);
            commitChip(tokenStart, editable.length(), editable);
            created.add(findChip(tokenStart));
        }
        return created;
    }

    // Visible for testing.
    /* package */int movePastTerminators(int tokenEnd) {
        if (tokenEnd >= length()) {
            return tokenEnd;
        }
        char atEnd = getText().toString().charAt(tokenEnd);
        if (atEnd == COMMIT_CHAR_COMMA || atEnd == COMMIT_CHAR_SEMICOLON) {
            tokenEnd++;
        }
        // This token had not only an end token character, but also a space
        // separating it from the next token.
        if (tokenEnd < length() && getText().toString().charAt(tokenEnd) == ' ') {
            tokenEnd++;
        }
        return tokenEnd;
    }

    private class RecipientReplacementTask extends AsyncTask<Void, Void, Void> {
        private RecipientChip createFreeChip(RecipientEntry entry) {
            try {
                return constructChipSpan(entry, -1, false);
            } catch (NullPointerException e) {
                Log.e(TAG, e.getMessage(), e);
                return null;
            }
        }

        @Override
        protected Void doInBackground(Void... params) {
            if (mIndividualReplacements != null) {
                mIndividualReplacements.cancel(true);
            }
            // For each chip in the list, look up the matching contact.
            // If there is a match, replace that chip with the matching
            // chip.
            final ArrayList<RecipientChip> originalRecipients = new ArrayList<RecipientChip>();
            RecipientChip[] existingChips = getSortedRecipients();
            for (int i = 0; i < existingChips.length; i++) {
                originalRecipients.add(existingChips[i]);
            }
            if (mRemovedSpans != null) {
                originalRecipients.addAll(mRemovedSpans);
            }
            String[] addresses = new String[originalRecipients.size()];
            for (int i = 0; i < originalRecipients.size(); i++) {
                addresses[i] = createAddressText(originalRecipients.get(i).getEntry());
            }
            HashMap<String, RecipientEntry> entries = RecipientAlternatesAdapter
                    .getMatchingRecipients(getContext(), addresses);
            final ArrayList<RecipientChip> replacements = new ArrayList<RecipientChip>();
            for (final RecipientChip temp : originalRecipients) {
                RecipientEntry entry = null;
                if (RecipientEntry.isCreatedRecipient(temp.getEntry().getContactId())
                        && getSpannable().getSpanStart(temp) != -1) {
                    // Replace this.
                    entry = createValidatedEntry(entries.get(tokenizeAddress(temp.getEntry()
                            .getDestination())));
                }
                if (entry != null) {
                    replacements.add(createFreeChip(entry));
                } else {
                    replacements.add(temp);
                }
            }
            if (replacements != null && replacements.size() > 0) {
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        SpannableStringBuilder text = new SpannableStringBuilder(getText()
                                .toString());
                        Editable oldText = getText();
                        int start, end;
                        int i = 0;
                        for (RecipientChip chip : originalRecipients) {
                            start = oldText.getSpanStart(chip);
                            if (start != -1) {
                                end = oldText.getSpanEnd(chip);
                                oldText.removeSpan(chip);
                                // Leave a spot for the space!
                                RecipientChip replacement = replacements.get(i);
                                text.setSpan(replacement, start, end,
                                        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
                                replacement.setOriginalText(text.toString().substring(start, end));
                            }
                            i++;
                        }
                        originalRecipients.clear();
                        setText(text);
                    }
                });
            }
            return null;
        }
    }

    private class IndividualReplacementTask extends AsyncTask<Object, Void, Void> {
        @SuppressWarnings("unchecked")
        @Override
        protected Void doInBackground(Object... params) {
            // For each chip in the list, look up the matching contact.
            // If there is a match, replace that chip with the matching
            // chip.
            final ArrayList<RecipientChip> originalRecipients =
                (ArrayList<RecipientChip>) params[0];
            String[] addresses = new String[originalRecipients.size()];
            for (int i = 0; i < originalRecipients.size(); i++) {
                addresses[i] = createAddressText(originalRecipients.get(i).getEntry());
            }
            HashMap<String, RecipientEntry> entries = RecipientAlternatesAdapter
                    .getMatchingRecipients(getContext(), addresses);
            for (final RecipientChip temp : originalRecipients) {
                if (RecipientEntry.isCreatedRecipient(temp.getEntry().getContactId())
                        && getSpannable().getSpanStart(temp) != -1) {
                    // Replace this.
                    final RecipientEntry entry = createValidatedEntry(entries
                            .get(tokenizeAddress(temp.getEntry().getDestination()).toLowerCase()));
                    if (entry != null) {
                        mHandler.post(new Runnable() {
                            @Override
                            public void run() {
                                replaceChip(temp, entry);
                            }
                        });
                    }
                }
            }
            return null;
        }
    }


    /**
     * MoreImageSpan is a simple class created for tracking the existence of a
     * more chip across activity restarts/
     */
    private class MoreImageSpan extends ImageSpan {
        public MoreImageSpan(Drawable b) {
            super(b);
        }
    }

    @Override
    public boolean onDown(MotionEvent e) {
        return false;
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        // Do nothing.
        return false;
    }

    @Override
    public void onLongPress(MotionEvent event) {
        if (mSelectedChip != null) {
            return;
        }
        float x = event.getX();
        float y = event.getY();
        int offset = putOffsetInRange(getOffsetForPosition(x, y));
        RecipientChip currentChip = findChip(offset);
        if (currentChip != null) {
            if (mDragEnabled) {
                // Start drag-and-drop for the selected chip.
                startDrag(currentChip);
            } else {
                // Copy the selected chip email address.
                showCopyDialog(currentChip.getEntry().getDestination());
            }
        }
    }

    /**
     * Enables drag-and-drop for chips.
     */
    public void enableDrag() {
        mDragEnabled = true;
    }

    /**
     * Starts drag-and-drop for the selected chip.
     */
    private void startDrag(RecipientChip currentChip) {
        String address = currentChip.getEntry().getDestination();
        ClipData data = ClipData.newPlainText(address, address + COMMIT_CHAR_COMMA);

        // Start drag mode.
        startDrag(data, new RecipientChipShadow(currentChip), null, 0);

        // Remove the current chip, so drag-and-drop will result in a move.
        // TODO (phamm): consider readd this chip if it's dropped outside a target.
        removeChip(currentChip);
    }

    /**
     * Handles drag event.
     */
    @Override
    public boolean onDragEvent(DragEvent event) {
        switch (event.getAction()) {
            case DragEvent.ACTION_DRAG_STARTED:
                // Only handle plain text drag and drop.
                return event.getClipDescription().hasMimeType(ClipDescription.MIMETYPE_TEXT_PLAIN);
            case DragEvent.ACTION_DRAG_ENTERED:
                requestFocus();
                return true;
            case DragEvent.ACTION_DROP:
                handlePasteClip(event.getClipData());
                return true;
        }
        return false;
    }

    /**
     * Drag shadow for a {@link RecipientChip}.
     */
    private final class RecipientChipShadow extends DragShadowBuilder {
        private final RecipientChip mChip;

        public RecipientChipShadow(RecipientChip chip) {
            mChip = chip;
        }

        @Override
        public void onProvideShadowMetrics(Point shadowSize, Point shadowTouchPoint) {
            Rect rect = mChip.getDrawable().getBounds();
            shadowSize.set(rect.width(), rect.height());
            shadowTouchPoint.set(rect.centerX(), rect.centerY());
        }

        @Override
        public void onDrawShadow(Canvas canvas) {
            mChip.getDrawable().draw(canvas);
        }
    }

    private void showCopyDialog(final String address) {
        mCopyAddress = address;
        mCopyDialog.setTitle(address);
        mCopyDialog.setContentView(mCopyViewRes);
        mCopyDialog.setCancelable(true);
        mCopyDialog.setCanceledOnTouchOutside(true);
        mCopyDialog.findViewById(android.R.id.button1).setOnClickListener(this);
        mCopyDialog.setOnDismissListener(this);
        mCopyDialog.show();
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        // Do nothing.
        return false;
    }

    @Override
    public void onShowPress(MotionEvent e) {
        // Do nothing.
    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        // Do nothing.
        return false;
    }

    @Override
    public void onDismiss(DialogInterface dialog) {
        mCopyAddress = null;
    }

    @Override
    public void onClick(View v) {
        // Copy this to the clipboard.
        ClipboardManager clipboard = (ClipboardManager) getContext().getSystemService(
                Context.CLIPBOARD_SERVICE);
        clipboard.setPrimaryClip(ClipData.newPlainText("", mCopyAddress));
        mCopyDialog.dismiss();
    }
}