/*
 * 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.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.os.Message;
import android.text.Editable;
import android.text.Layout;
import android.text.Spannable;
import android.text.SpannableString;
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.util.AttributeSet;
import android.util.Log;
import android.view.ActionMode;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.ActionMode.Callback;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListPopupWindow;
import android.widget.ListView;
import android.widget.MultiAutoCompleteTextView;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

import java.util.ArrayList;

/**
 * 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 {

    private static final String TAG = "RecipientEditTextView";

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

    private static final int INVALID_CONTACT = -1;

    // TODO: get correct size from UX.
    private static final float MORE_WIDTH_FACTOR = 0.25f;

    private Drawable mChipBackground = null;

    private Drawable mChipDelete = null;

    private int mChipPadding;

    private Tokenizer mTokenizer;

    private Drawable mChipBackgroundPressed;

    private RecipientChip mSelectedChip;

    private int mChipDeleteWidth;

    private int mAlternatesLayout;

    private Bitmap mDefaultContactPhoto;

    private ImageSpan mMoreChip;

    private int mMoreString;

    private ArrayList<RecipientChip> mRemovedSpans;

    private float mChipHeight;

    private float mChipFontSize;

    private Validator mValidator;

    private Drawable mInvalidChipBackground;

    private Handler mHandler;

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

    private static final long DISMISS_DELAY = 300;

    private int mPendingChipsCount = 0;

    private static int sSelectedTextColor = -1;

    private static final char COMMIT_CHAR_COMMA = ',';

    private static final char COMMIT_CHAR_SEMICOLON = ';';

    public RecipientEditTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        if (sSelectedTextColor == -1) {
            sSelectedTextColor = context.getResources().getColor(android.R.color.white);
        }
        setSuggestionsEnabled(false);
        setOnItemClickListener(this);
        setCustomSelectionActionModeCallback(this);
        // When the user starts typing, make sure we unselect any selected
        // chips.
        addTextChangedListener(new TextWatcher() {
            @Override
            public void afterTextChanged(Editable s) {
                if (mSelectedChip != null) {
                    setCursorVisible(true);
                    setSelection(getText().length());
                    clearSelectedChip();
                }
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                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 = s.charAt(length() - 1);
                    if (last == COMMIT_CHAR_SEMICOLON || last == COMMIT_CHAR_COMMA) {
                        commitDefault();
                    }
                }
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                // Do nothing.
            }
        });
        mHandler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                if (msg.what == DISMISS) {
                    ((ListPopupWindow)msg.obj).dismiss();
                    return;
                }
                super.handleMessage(msg);
            }
        };
    }

    @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.
        Spannable span = getSpannable();
        int textLength = getText().length();
        RecipientChip[] chips = span.getSpans(start, textLength, RecipientChip.class);
        if (chips != null && chips.length > 0) {
            if (chips != null && chips.length > 0) {
                // Grab the last chip and set the cursor to after it.
                setSelection(Math.min(chips[chips.length - 1].getChipEnd() + 1, textLength));
            }
        }
        super.onSelectionChanged(start, end);
    }

    /**
     * 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) {
        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++;
            }
        }
    }

    @Override
    public void onFocusChanged(boolean hasFocus, int direction, Rect previous) {
        if (!hasFocus) {
            shrink();
            // Reset any pending chips as they would have been handled
            // when the field lost focus.
            mPendingChipsCount = 0;
        } else {
            expand();
        }
        super.onFocusChanged(hasFocus, direction, previous);
    }

    private void shrink() {
        if (mSelectedChip != null) {
            clearSelectedChip();
        } else {
            commitDefault();
        }
        mMoreChip = createMoreChip();
    }

    private void expand() {
        removeMoreChip();
        setCursorVisible(true);
        Editable text = getText();
        setSelection(text != null && text.length() > 0 ? text.length() : 0);
    }

    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;
        CharSequence ellipsizedText = ellipsizeText(contact.getDisplayName(), paint,
                calculateAvailableWidth(true) - deleteWidth);

        // 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);
            // Align the display text with where the user enters text.
            canvas.drawText(ellipsizedText, 0, ellipsizedText.length(), mChipPadding, height
                    - Math.abs(height - mChipFontSize)/2, paint);
            // Make the delete a square.
            mChipDelete.setBounds(width - deleteWidth, 0, width, height);
            mChipDelete.draw(canvas);
        } 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.
     */
    public Drawable getChipBackground(RecipientEntry contact) {
        return mValidator != null && mValidator.isValid(contact.getDestination()) ?
                mChipBackground : mInvalidChipBackground;
    }

    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;
        CharSequence ellipsizedText = ellipsizeText(contact.getDisplayName(), paint,
                calculateAvailableWidth(false) - iconWidth);
        // 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() != 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.
                Matrix matrix = new Matrix();
                RectF src = new RectF(0, 0, photo.getWidth(), photo.getHeight());
                RectF dst = new RectF(0, 0, iconWidth, height);
                matrix.setRectToRect(src, dst, Matrix.ScaleToFit.CENTER);
                canvas.drawBitmap(photo, matrix, paint);
            } else {
                // Don't leave any space for the icon. It isn't being drawn.
                iconWidth = 0;
            }

            // Align the display text with where the user enters text.
            canvas.drawText(ellipsizedText, 0, ellipsizedText.length(), mChipPadding + iconWidth,
                    height - Math.abs(height - mChipFontSize) / 2, paint);
        } else {
            Log.w(TAG, "Unable to draw a background for the chips as it was never set");
        }
        return tmpBitmap;
    }

    public 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();
        int line = 0;
        int lineTop = getTop();

        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);
        }

        // Get the location of the widget so we can properly offset
        // the anchor for each chip.
        int[] xy = new int[2];
        getLocationOnScreen(xy);
        // 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
     * 4) the position of the autocomplete view on the screen, taking into account
     * that any top padding will move this down visually
     */
    private int calculateLineBottom(int yOffset, int line, int chipHeight) {
        // Line offsets start at zero.
        int actualLine = line + 1;
        return yOffset + (actualLine * (chipHeight + getPaddingBottom())) + getPaddingTop();
    }

    /**
     * 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
     */
    public void setChipDimensions(Drawable chipBackground, Drawable chipBackgroundPressed,
            Drawable invalidChip, Drawable chipDelete, Bitmap defaultContact, int moreResource,
            int alternatesLayout, float chipHeight, float padding,
            float chipFontSize) {
        mChipBackground = chipBackground;
        mChipBackgroundPressed = chipBackgroundPressed;
        mChipDelete = chipDelete;
        mChipPadding = (int) padding;
        mAlternatesLayout = alternatesLayout;
        mDefaultContactPhoto = defaultContact;
        mMoreString = moreResource;
        mChipHeight = chipHeight;
        mChipFontSize = chipFontSize;
        mInvalidChipBackground = invalidChip;
    }

    @Override
    public void onSizeChanged(int width, int height, int oldw, int oldh) {
        super.onSizeChanged(width, height, oldw, oldh);
        // Check for any pending tokens created before layout had been completed
        // on the view.
        if (width != 0 && height != 0 && mPendingChipsCount > 0) {
            Editable editable = getText();
            // Tokenize!
            int startingPos = 0;
            while (startingPos < editable.length() && mPendingChipsCount > 0) {
                int tokenEnd = mTokenizer.findTokenEnd(editable, startingPos);
                int tokenStart = mTokenizer.findTokenStart(editable, tokenEnd);
                if (findChip(tokenStart) == null) {
                    // Always include seperators with the token to the left.
                    if (tokenEnd < editable.length() - 1
                            && editable.charAt(tokenEnd) == COMMIT_CHAR_COMMA) {
                        tokenEnd++;
                    }
                    startingPos = tokenEnd;
                    String token = (String) editable.toString().substring(tokenStart, tokenEnd);
                    int seperatorPos = token.indexOf(COMMIT_CHAR_COMMA);
                    if (seperatorPos != -1) {
                        token = token.substring(0, seperatorPos);
                    }
                    editable.replace(tokenStart, tokenEnd, createChip(RecipientEntry
                            .constructFakeEntry(token), false));
                }
                mPendingChipsCount--;
            }
            mPendingChipsCount = 0;
        }
    }

    @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:
            case KeyEvent.KEYCODE_TAB:
                if (event.hasNoModifiers()) {
                    if (commitDefault()) {
                        return true;
                    }
                }
                break;
        }
        return super.onKeyUp(keyCode, event);
    }

    /**
     * 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();
        boolean enough = enoughToFilter();
        boolean shouldSubmitAtPosition = false;
        int end = getSelectionEnd();
        int start = mTokenizer.findTokenStart(editable, end);
        if (enough) {
            RecipientChip[] chips = getSpannable().getSpans(start, end, RecipientChip.class);
            if ((chips == null || chips.length == 0)) {
                // There's something being filtered or typed that has not been
                // completed yet.
                shouldSubmitAtPosition = true;
            }
        }

        if (shouldSubmitAtPosition) {
            if (getAdapter().getCount() > 0) {
                // choose the first entry.
                submitItemAtPosition(0);
                dismissDropDown();
                return true;
            } else {
                String text = editable.toString().substring(start, end);
                clearComposingText();
                if (text != null && text.length() > 0 && !text.equals(" ")) {
                    text = removeCommitChars(text);
                    RecipientEntry entry = RecipientEntry.constructFakeEntry(text);
                    QwertyKeyListener.markAsReplaced(editable, start, end, "");
                    editable.replace(start, end, createChip(entry, false));
                    dismissDropDown();
                }
                return false;
            }
        }
        return false;
    }

    private String removeCommitChars(String text) {
        int commitCharPosition = text.indexOf(COMMIT_CHAR_COMMA);
        if (commitCharPosition != -1) {
            text = text.substring(0, commitCharPosition);
        }
        commitCharPosition = text.indexOf(COMMIT_CHAR_SEMICOLON);
        if (commitCharPosition != -1) {
            text = text.substring(0, commitCharPosition);
        }
        return text;
    }

    /**
     * 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) {
            mSelectedChip.onKeyDown(keyCode, event);
        }

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

        return super.onKeyDown(keyCode, event);
    }

    private Spannable getSpannable() {
        return (Spannable) getText();
    }

    /**
     * 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()) {
            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);
    }

    private void clearSelectedChip() {
        if (mSelectedChip != null) {
            mSelectedChip.unselectChip();
            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 (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_DOWN) {
            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 = currentChip.selectChip();
                    } else if (mSelectedChip == null) {
                        // Selection may have moved due to the tap event,
                        // but make sure we correctly reset selection to the
                        // end so that any unfinished chips are committed.
                        setSelection(getText().length());
                        commitDefault();
                        mSelectedChip = currentChip.selectChip();
                    } else {
                        mSelectedChip.onClick(this, offset, x, y);
                    }
                }
                chipWasSelected = true;
            }
        }
        if (action == MotionEvent.ACTION_UP && !chipWasSelected) {
            clearSelectedChip();
        }
        return handled;
    }

    // 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];
            if (chip.matchesChip(offset)) {
                return chip;
            }
        }
        return null;
    }

    private CharSequence createChip(RecipientEntry entry, boolean pressed) {
        String displayText = entry.getDestination();
        displayText = (String) mTokenizer.terminateToken(displayText);
        // 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 {
            chipText.setSpan(constructChipSpan(entry, start, pressed), 0, textLength,
                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        } 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 = (RecipientEntry) getAdapter().getItem(position);
        // If the display name and the address are the same, then make this
        // a fake recipient that is editable.
        if (TextUtils.equals(entry.getDisplayName(), entry.getDestination())) {
            entry = RecipientEntry.constructFakeEntry(entry.getDestination());
        }
        clearComposingText();

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

        Editable editable = getText();
        QwertyKeyListener.markAsReplaced(editable, start, end, "");
        editable.replace(start, end, createChip(entry, false));
    }

    /** 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 = getRecipients();
        if (chips != null) {
            for (RecipientChip chip : chips) {
                result.add(chip.getContactId());
            }
        }
        return result;
    }

    private RecipientChip[] getRecipients() {
        return getSpannable().getSpans(0, getText().length(), RecipientChip.class);
    }

    /** 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 = getRecipients();
        if (chips != null) {
            for (RecipientChip chip : chips) {
                result.add(chip.getDataId());
            }
        }
        return result;
    }


    @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;
    }

    /**
     * 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.
     */
    private ImageSpan createMoreChip() {
        RecipientChip[] recipients = getRecipients();
        if (recipients == null || recipients.length <= CHIP_LIMIT) {
            return null;
        }
        int numRecipients = recipients.length;
        int overage = numRecipients - CHIP_LIMIT;
        Editable text = getText();
        // TODO: get the correct size from visual design.
        int width = (int) Math.floor(getWidth() * MORE_WIDTH_FACTOR);
        int height = getLineHeight();
        Bitmap drawable = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(drawable);
        String moreText = getResources().getString(mMoreString, overage);
        canvas.drawText(moreText, 0, moreText.length(), 0, height - getLayout().getLineDescent(0),
                getPaint());

        Drawable result = new BitmapDrawable(getResources(), drawable);
        result.setBounds(0, 0, width, height);
        ImageSpan moreSpan = new ImageSpan(result);
        Spannable spannable = getSpannable();
        // Remove the overage chips.
        RecipientChip[] chips = spannable.getSpans(0, text.length(), RecipientChip.class);
        if (chips == null || chips.length == 0) {
            Log.w(TAG,
                "We have recipients. Tt should not be possible to have zero RecipientChips.");
            return null;
        }
        mRemovedSpans = new ArrayList<RecipientChip>(chips.length);
        int totalReplaceStart = 0;
        int totalReplaceEnd = 0;
        for (int i = numRecipients - overage; i < chips.length; i++) {
            mRemovedSpans.add(chips[i]);
            if (i == numRecipients - overage) {
                totalReplaceStart = chips[i].getChipStart();
            }
            if (i == chips.length - 1) {
                totalReplaceEnd = chips[i].getChipEnd();
            }
            chips[i].setPreviousChipStart(chips[i].getChipStart());
            chips[i].setPreviousChipEnd(chips[i].getChipEnd());
            spannable.removeSpan(chips[i]);
        }
        SpannableString chipText = new SpannableString(text.subSequence(totalReplaceStart,
                totalReplaceEnd));
        chipText.setSpan(moreSpan, 0, chipText.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        text.replace(totalReplaceStart, totalReplaceEnd, chipText);
        return moreSpan;
    }

    /**
     * Replace the more chip, if it exists, with all of the recipient chips it had
     * replaced when the RecipientEditTextView gains focus.
     */
    private 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.
                Editable editable = getText();
                SpannableString associatedText;
                for (RecipientChip chip : mRemovedSpans) {
                    int chipStart = chip.getPreviousChipStart();
                    int chipEnd = Math.min(editable.length(), chip.getPreviousChipEnd());
                    if (Log.isLoggable(TAG, Log.DEBUG) && chipEnd != chip.getPreviousChipEnd()) {
                        Log.d(TAG,
                                "Unexpectedly, the chip ended after the end of the editable text. "
                                        + "Chip End " + chip.getPreviousChipEnd()
                                        + "Editable length " + editable.length());
                    }
                    associatedText = new SpannableString(editable.subSequence(chipStart, chipEnd));
                    associatedText.setSpan(chip, 0, associatedText.length(),
                            Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                    editable.replace(chipStart, chipEnd, associatedText);
                }
                mRemovedSpans.clear();
            }
        }
    }

    /**
     * RecipientChip defines an ImageSpan that contains information relevant to
     * a particular recipient.
     */
    public class RecipientChip extends ImageSpan implements OnItemClickListener {
        private final CharSequence mDisplay;

        private final CharSequence mValue;

        private View mAnchorView;

        private final long mContactId;

        private final long mDataId;

        private RecipientEntry mEntry;

        private boolean mSelected = false;

        private RecipientAlternatesAdapter mAlternatesAdapter;

        private int mStart = -1;

        private int mEnd = -1;

        private ListPopupWindow mAlternatesPopup;

        public RecipientChip(Drawable drawable, RecipientEntry entry, int offset) {
            super(drawable);
            mDisplay = entry.getDisplayName();
            mValue = entry.getDestination();
            mContactId = entry.getContactId();
            mDataId = entry.getDataId();
            mEntry = entry;
            mAnchorView = new View(getContext());
            mAnchorView.setVisibility(View.GONE);
        }

        /**
         * Store the offset in the spannable where this RecipientChip
         * is currently being displayed.
         */
        public void setPreviousChipStart(int start) {
            mStart = start;
        }

        /**
         * Get the offset in the spannable where this RecipientChip
         * was currently being displayed. Use this to determine where
         * to place a RecipientChip that has been hidden when the
         * RecipientEditTextView loses focus.
         */
        public int getPreviousChipStart() {
            return mStart;
        }

        /**
         * Store the end offset in the spannable where this RecipientChip
         * is currently being displayed.
         */
        public void setPreviousChipEnd(int end) {
            mEnd = end;
        }

        /**
         * Get the end offset in the spannable where this RecipientChip
         * was currently being displayed. Use this to determine where
         * to place a RecipientChip that has been hidden when the
         * RecipientEditTextView loses focus.
         */
        public int getPreviousChipEnd() {
            return mEnd;
        }

        /**
         * 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.
         */
        public void unselectChip() {
            int start = getChipStart();
            int end = getChipEnd();
            Editable editable = getText();
            if (start == -1 || end == -1) {
                Log.e(TAG, "The chip being unselected no longer exists but should.");
            } else {
                getSpannable().removeSpan(this);
                QwertyKeyListener.markAsReplaced(editable, start, end, "");
                editable.replace(start, end, createChip(mEntry, false));
            }
            mSelectedChip = null;
            clearSelectedChip();
            setCursorVisible(true);
            setSelection(editable.length());
            if (mAlternatesPopup != null && mAlternatesPopup.isShowing()) {
                mAlternatesPopup.dismiss();
            }
        }

        /**
         * Show this 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.
         * @return A RecipientChip in the selected state or null if the chip
         * just contained an email address.
         */
        public RecipientChip selectChip() {
            if (mEntry.getContactId() != INVALID_CONTACT) {
                int start = getChipStart();
                int end = getChipEnd();
                getSpannable().removeSpan(this);
                RecipientChip newChip;
                CharSequence displayText = mTokenizer.terminateToken(mEntry.getDestination());
                // Always leave a blank space at the end of a chip.
                int textLength = displayText.length() - 1;
                SpannableString chipText = new SpannableString(displayText);
                try {
                    newChip = constructChipSpan(mEntry, start, true);
                    chipText.setSpan(newChip, 0, textLength,
                            Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
                } 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.replace(start, end, chipText);
                }
                setCursorVisible(false);
                newChip.setSelected(true);
                newChip.showAlternates();
                setCursorVisible(false);
                return newChip;
            } else {
                CharSequence text = getValue();
                Editable editable = getText();
                removeChip();
                editable.append(text);
                setCursorVisible(true);
                setSelection(editable.length());
                return null;
            }
        }

        /**
         * Handle key events for a chip. When the keyCode equals
         * KeyEvent.KEYCODE_DEL, this deletes the currently selected chip.
         */
        public void onKeyDown(int keyCode, KeyEvent event) {
            if (keyCode == KeyEvent.KEYCODE_DEL) {
                if (mAlternatesPopup != null && mAlternatesPopup.isShowing()) {
                    mAlternatesPopup.dismiss();
                }
                removeChip();
            }
        }

        /**
         * Remove this chip and any text associated with it from the RecipientEditTextView.
         */
        private void removeChip() {
            Spannable spannable = getSpannable();
            int spanStart = spannable.getSpanStart(this);
            int spanEnd = spannable.getSpanEnd(this);
            Editable text = getText();
            int toDelete = spanEnd;
            boolean wasSelected = this == 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() - 1 && text.charAt(toDelete) == ' ') {
                toDelete++;
            }
            spannable.removeSpan(this);
            text.delete(spanStart, toDelete);
            if (wasSelected) {
                clearSelectedChip();
            }
        }

        /**
         * Get the start offset of this chip in the view.
         */
        public int getChipStart() {
            return getSpannable().getSpanStart(this);
        }

        /**
         * Get the end offset of this chip in the view.
         */
        public int getChipEnd() {
            return getSpannable().getSpanEnd(this);
        }

        /**
         * Replace this currently selected chip with a new chip
         * that uses the contact data provided.
         */
        public void replaceChip(RecipientEntry entry) {
            boolean wasSelected = this == mSelectedChip;
            if (wasSelected) {
                mSelectedChip = null;
            }
            int start = getSpannable().getSpanStart(this);
            int end = getSpannable().getSpanEnd(this);
            getSpannable().removeSpan(this);
            Editable editable = getText();
            CharSequence chipText = createChip(entry, false);
            if (start == -1 || end == -1) {
                Log.e(TAG, "The chip to replace does not exist but should.");
                editable.insert(0, chipText);
            } else {
                editable.replace(start, end, chipText);
            }
            setCursorVisible(true);
            if (wasSelected) {
                clearSelectedChip();
            }
        }

        /**
         * Show all addresses associated with a contact.
         */
        private void showAlternates() {
            mAlternatesPopup = new ListPopupWindow(getContext());

            if (!mAlternatesPopup.isShowing()) {
                int line = getLayout().getLineForOffset(getChipStart());
                int[] xy = new int[2];
                getLocationOnScreen(xy);
                int bottom = calculateLineBottom(xy[1], line, (int) mChipHeight);
                mAnchorView.setBottom(bottom);
                mAnchorView.setTop(bottom);
                mAlternatesAdapter = new RecipientAlternatesAdapter(getContext(),
                        mEntry.getContactId(), mEntry.getDataId(), mAlternatesLayout);
                // Align the alternates popup with the left side of the View, regardless
                // of the position of the chip tapped.
                mAlternatesPopup.setAnchorView(mAnchorView);
                mAlternatesPopup.setAdapter(mAlternatesAdapter);
                mAlternatesPopup.setWidth(getWidth());
                mAlternatesPopup.setOnItemClickListener(this);
                mAlternatesPopup.show();
                ListView listView = mAlternatesPopup.getListView();
                listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
                listView.setItemChecked(mAlternatesAdapter.getCheckedItemPosition(), true);
            }
        }

        private void setSelected(boolean selected) {
            mSelected = selected;
        }

        /**
         * Get the text displayed in the chip.
         */
        public CharSequence getDisplay() {
            return mDisplay;
        }

        /**
         * Get the text value this chip represents.
         */
        public CharSequence getValue() {
            return mValue;
        }

        /**
         * See if 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.
         */
        private boolean isInDelete(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 mSelected && offset == getChipEnd();
        }

        /**
         * Return whether this chip contains the position passed in.
         */
        public boolean matchesChip(int offset) {
            int start = getChipStart();
            int end = getChipEnd();
            return (offset >= start && offset <= end);
        }

        /**
         * 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(View widget, int offset, float x, float y) {
            if (mSelected) {
                if (isInDelete(offset, x, y)) {
                    removeChip();
                } else {
                    clearSelectedChip();
                }
            }
        }

        @Override
        public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top,
                int y, int bottom, Paint paint) {
            // Shift the bounds of this span to where it is actually drawn on the screeen.
            super.draw(canvas, text, start, end, x, top, y, bottom, paint);
        }

        /**
         * Handle clicks to alternate addresses for a selected chip. If the user
         * selects an alternate, the chip is replaced with a new contact with the
         * new contact address information.
         */
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int position, long rowId) {
            Message delayed = Message.obtain(mHandler, DISMISS);
            delayed.obj = mAlternatesPopup;
            mHandler.sendMessageDelayed(delayed, DISMISS_DELAY);
            clearComposingText();
            replaceChip(mAlternatesAdapter.getRecipientEntry(position));
        }

        /**
         * Get the id of the contact associated with this chip.
         */
        public long getContactId() {
            return mContactId;
        }

        /**
         * Get the id of the data associated with this chip.
         */
        public long getDataId() {
            return mDataId;
        }
    }
}