android/content/ClipData.java

/**
 * Copyright (c) 2010, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.content;

import static android.content.ContentProvider.maybeAddUserId;

import android.content.res.AssetFileDescriptor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.StrictMode;
import android.text.Html;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.style.URLSpan;
import android.util.Log;

import com.android.internal.util.ArrayUtils;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

/**
 * Representation of a clipped data on the clipboard.
 *
 * <p>ClipData is a complex type containing one or more Item instances,
 * each of which can hold one or more representations of an item of data.
 * For display to the user, it also has a label.</p>
 *
 * <p>A ClipData contains a {@link ClipDescription}, which describes
 * important meta-data about the clip.  In particular, its
 * {@link ClipDescription#getMimeType(int) getDescription().getMimeType(int)}
 * must return correct MIME type(s) describing the data in the clip.  For help
 * in correctly constructing a clip with the correct MIME type, use
 * {@link #newPlainText(CharSequence, CharSequence)},
 * {@link #newUri(ContentResolver, CharSequence, Uri)}, and
 * {@link #newIntent(CharSequence, Intent)}.
 *
 * <p>Each Item instance can be one of three main classes of data: a simple
 * CharSequence of text, a single Intent object, or a Uri.  See {@link Item}
 * for more details.
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about using the clipboard framework, read the
 * <a href="{@docRoot}guide/topics/clipboard/copy-paste.html">Copy and Paste</a>
 * developer guide.</p>
 * </div>
 *
 * <a name="ImplementingPaste"></a>
 * <h3>Implementing Paste or Drop</h3>
 *
 * <p>To implement a paste or drop of a ClipData object into an application,
 * the application must correctly interpret the data for its use.  If the {@link Item}
 * it contains is simple text or an Intent, there is little to be done: text
 * can only be interpreted as text, and an Intent will typically be used for
 * creating shortcuts (such as placing icons on the home screen) or other
 * actions.
 *
 * <p>If all you want is the textual representation of the clipped data, you
 * can use the convenience method {@link Item#coerceToText Item.coerceToText}.
 * In this case there is generally no need to worry about the MIME types
 * reported by {@link ClipDescription#getMimeType(int) getDescription().getMimeType(int)},
 * since any clip item can always be converted to a string.
 *
 * <p>More complicated exchanges will be done through URIs, in particular
 * "content:" URIs.  A content URI allows the recipient of a ClipData item
 * to interact closely with the ContentProvider holding the data in order to
 * negotiate the transfer of that data.  The clip must also be filled in with
 * the available MIME types; {@link #newUri(ContentResolver, CharSequence, Uri)}
 * will take care of correctly doing this.
 *
 * <p>For example, here is the paste function of a simple NotePad application.
 * When retrieving the data from the clipboard, it can do either two things:
 * if the clipboard contains a URI reference to an existing note, it copies
 * the entire structure of the note into a new note; otherwise, it simply
 * coerces the clip into text and uses that as the new note's contents.
 *
 * {@sample development/samples/NotePad/src/com/example/android/notepad/NoteEditor.java
 *      paste}
 *
 * <p>In many cases an application can paste various types of streams of data.  For
 * example, an e-mail application may want to allow the user to paste an image
 * or other binary data as an attachment.  This is accomplished through the
 * ContentResolver {@link ContentResolver#getStreamTypes(Uri, String)} and
 * {@link ContentResolver#openTypedAssetFileDescriptor(Uri, String, android.os.Bundle)}
 * methods.  These allow a client to discover the type(s) of data that a particular
 * content URI can make available as a stream and retrieve the stream of data.
 *
 * <p>For example, the implementation of {@link Item#coerceToText Item.coerceToText}
 * itself uses this to try to retrieve a URI clip as a stream of text:
 *
 * {@sample frameworks/base/core/java/android/content/ClipData.java coerceToText}
 *
 * <a name="ImplementingCopy"></a>
 * <h3>Implementing Copy or Drag</h3>
 *
 * <p>To be the source of a clip, the application must construct a ClipData
 * object that any recipient can interpret best for their context.  If the clip
 * is to contain a simple text, Intent, or URI, this is easy: an {@link Item}
 * containing the appropriate data type can be constructed and used.
 *
 * <p>More complicated data types require the implementation of support in
 * a ContentProvider for describing and generating the data for the recipient.
 * A common scenario is one where an application places on the clipboard the
 * content: URI of an object that the user has copied, with the data at that
 * URI consisting of a complicated structure that only other applications with
 * direct knowledge of the structure can use.
 *
 * <p>For applications that do not have intrinsic knowledge of the data structure,
 * the content provider holding it can make the data available as an arbitrary
 * number of types of data streams.  This is done by implementing the
 * ContentProvider {@link ContentProvider#getStreamTypes(Uri, String)} and
 * {@link ContentProvider#openTypedAssetFile(Uri, String, android.os.Bundle)}
 * methods.
 *
 * <p>Going back to our simple NotePad application, this is the implementation
 * it may have to convert a single note URI (consisting of a title and the note
 * text) into a stream of plain text data.
 *
 * {@sample development/samples/NotePad/src/com/example/android/notepad/NotePadProvider.java
 *      stream}
 *
 * <p>The copy operation in our NotePad application is now just a simple matter
 * of making a clip containing the URI of the note being copied:
 *
 * {@sample development/samples/NotePad/src/com/example/android/notepad/NotesList.java
 *      copy}
 *
 * <p>Note if a paste operation needs this clip as text (for example to paste
 * into an editor), then {@link Item#coerceToText(Context)} will ask the content
 * provider for the clip URI as text and successfully paste the entire note.
 */
public class ClipData implements Parcelable {
    static final String[] MIMETYPES_TEXT_PLAIN = new String[] {
        ClipDescription.MIMETYPE_TEXT_PLAIN };
    static final String[] MIMETYPES_TEXT_HTML = new String[] {
        ClipDescription.MIMETYPE_TEXT_HTML };
    static final String[] MIMETYPES_TEXT_URILIST = new String[] {
        ClipDescription.MIMETYPE_TEXT_URILIST };
    static final String[] MIMETYPES_TEXT_INTENT = new String[] {
        ClipDescription.MIMETYPE_TEXT_INTENT };

    final ClipDescription mClipDescription;

    final Bitmap mIcon;

    final ArrayList<Item> mItems;

    /**
     * Description of a single item in a ClipData.
     *
     * <p>The types than an individual item can currently contain are:</p>
     *
     * <ul>
     * <li> Text: a basic string of text.  This is actually a CharSequence,
     * so it can be formatted text supported by corresponding Android built-in
     * style spans.  (Custom application spans are not supported and will be
     * stripped when transporting through the clipboard.)
     * <li> Intent: an arbitrary Intent object.  A typical use is the shortcut
     * to create when pasting a clipped item on to the home screen.
     * <li> Uri: a URI reference.  This may be any URI (such as an http: URI
     * representing a bookmark), however it is often a content: URI.  Using
     * content provider references as clips like this allows an application to
     * share complex or large clips through the standard content provider
     * facilities.
     * </ul>
     */
    public static class Item {
        final CharSequence mText;
        final String mHtmlText;
        final Intent mIntent;
        Uri mUri;

        /** @hide */
        public Item(Item other) {
            mText = other.mText;
            mHtmlText = other.mHtmlText;
            mIntent = other.mIntent;
            mUri = other.mUri;
        }

        /**
         * Create an Item consisting of a single block of (possibly styled) text.
         */
        public Item(CharSequence text) {
            mText = text;
            mHtmlText = null;
            mIntent = null;
            mUri = null;
        }

        /**
         * Create an Item consisting of a single block of (possibly styled) text,
         * with an alternative HTML formatted representation.  You <em>must</em>
         * supply a plain text representation in addition to HTML text; coercion
         * will not be done from HTML formated text into plain text.
         */
        public Item(CharSequence text, String htmlText) {
            mText = text;
            mHtmlText = htmlText;
            mIntent = null;
            mUri = null;
        }

        /**
         * Create an Item consisting of an arbitrary Intent.
         */
        public Item(Intent intent) {
            mText = null;
            mHtmlText = null;
            mIntent = intent;
            mUri = null;
        }

        /**
         * Create an Item consisting of an arbitrary URI.
         */
        public Item(Uri uri) {
            mText = null;
            mHtmlText = null;
            mIntent = null;
            mUri = uri;
        }

        /**
         * Create a complex Item, containing multiple representations of
         * text, Intent, and/or URI.
         */
        public Item(CharSequence text, Intent intent, Uri uri) {
            mText = text;
            mHtmlText = null;
            mIntent = intent;
            mUri = uri;
        }

        /**
         * Create a complex Item, containing multiple representations of
         * text, HTML text, Intent, and/or URI.  If providing HTML text, you
         * <em>must</em> supply a plain text representation as well; coercion
         * will not be done from HTML formated text into plain text.
         */
        public Item(CharSequence text, String htmlText, Intent intent, Uri uri) {
            if (htmlText != null && text == null) {
                throw new IllegalArgumentException(
                        "Plain text must be supplied if HTML text is supplied");
            }
            mText = text;
            mHtmlText = htmlText;
            mIntent = intent;
            mUri = uri;
        }

        /**
         * Retrieve the raw text contained in this Item.
         */
        public CharSequence getText() {
            return mText;
        }

        /**
         * Retrieve the raw HTML text contained in this Item.
         */
        public String getHtmlText() {
            return mHtmlText;
        }

        /**
         * Retrieve the raw Intent contained in this Item.
         */
        public Intent getIntent() {
            return mIntent;
        }

        /**
         * Retrieve the raw URI contained in this Item.
         */
        public Uri getUri() {
            return mUri;
        }

        /**
         * Turn this item into text, regardless of the type of data it
         * actually contains.
         *
         * <p>The algorithm for deciding what text to return is:
         * <ul>
         * <li> If {@link #getText} is non-null, return that.
         * <li> If {@link #getUri} is non-null, try to retrieve its data
         * as a text stream from its content provider.  If this succeeds, copy
         * the text into a String and return it.  If it is not a content: URI or
         * the content provider does not supply a text representation, return
         * the raw URI as a string.
         * <li> If {@link #getIntent} is non-null, convert that to an intent:
         * URI and return it.
         * <li> Otherwise, return an empty string.
         * </ul>
         *
         * @param context The caller's Context, from which its ContentResolver
         * and other things can be retrieved.
         * @return Returns the item's textual representation.
         */
//BEGIN_INCLUDE(coerceToText)
        public CharSequence coerceToText(Context context) {
            // If this Item has an explicit textual value, simply return that.
            CharSequence text = getText();
            if (text != null) {
                return text;
            }

            // If this Item has a URI value, try using that.
            Uri uri = getUri();
            if (uri != null) {

                // First see if the URI can be opened as a plain text stream
                // (of any sub-type).  If so, this is the best textual
                // representation for it.
                FileInputStream stream = null;
                try {
                    // Ask for a stream of the desired type.
                    AssetFileDescriptor descr = context.getContentResolver()
                            .openTypedAssetFileDescriptor(uri, "text/*", null);
                    stream = descr.createInputStream();
                    InputStreamReader reader = new InputStreamReader(stream, "UTF-8");

                    // Got it...  copy the stream into a local string and return it.
                    StringBuilder builder = new StringBuilder(128);
                    char[] buffer = new char[8192];
                    int len;
                    while ((len=reader.read(buffer)) > 0) {
                        builder.append(buffer, 0, len);
                    }
                    return builder.toString();

                } catch (SecurityException e) {
                    Log.w("ClipData", "Failure opening stream", e);

                } catch (FileNotFoundException e) {
                    // Unable to open content URI as text...  not really an
                    // error, just something to ignore.

                } catch (IOException e) {
                    // Something bad has happened.
                    Log.w("ClipData", "Failure loading text", e);
                    return e.toString();

                } finally {
                    if (stream != null) {
                        try {
                            stream.close();
                        } catch (IOException e) {
                        }
                    }
                }

                // If we couldn't open the URI as a stream, then the URI itself
                // probably serves fairly well as a textual representation.
                return uri.toString();
            }

            // Finally, if all we have is an Intent, then we can just turn that
            // into text.  Not the most user-friendly thing, but it's something.
            Intent intent = getIntent();
            if (intent != null) {
                return intent.toUri(Intent.URI_INTENT_SCHEME);
            }

            // Shouldn't get here, but just in case...
            return "";
        }
//END_INCLUDE(coerceToText)

        /**
         * Like {@link #coerceToHtmlText(Context)}, but any text that would
         * be returned as HTML formatting will be returned as text with
         * style spans.
         * @param context The caller's Context, from which its ContentResolver
         * and other things can be retrieved.
         * @return Returns the item's textual representation.
         */
        public CharSequence coerceToStyledText(Context context) {
            CharSequence text = getText();
            if (text instanceof Spanned) {
                return text;
            }
            String htmlText = getHtmlText();
            if (htmlText != null) {
                try {
                    CharSequence newText = Html.fromHtml(htmlText);
                    if (newText != null) {
                        return newText;
                    }
                } catch (RuntimeException e) {
                    // If anything bad happens, we'll fall back on the plain text.
                }
            }

            if (text != null) {
                return text;
            }
            return coerceToHtmlOrStyledText(context, true);
        }

        /**
         * Turn this item into HTML text, regardless of the type of data it
         * actually contains.
         *
         * <p>The algorithm for deciding what text to return is:
         * <ul>
         * <li> If {@link #getHtmlText} is non-null, return that.
         * <li> If {@link #getText} is non-null, return that, converting to
         * valid HTML text.  If this text contains style spans,
         * {@link Html#toHtml(Spanned) Html.toHtml(Spanned)} is used to
         * convert them to HTML formatting.
         * <li> If {@link #getUri} is non-null, try to retrieve its data
         * as a text stream from its content provider.  If the provider can
         * supply text/html data, that will be preferred and returned as-is.
         * Otherwise, any text/* data will be returned and escaped to HTML.
         * If it is not a content: URI or the content provider does not supply
         * a text representation, HTML text containing a link to the URI
         * will be returned.
         * <li> If {@link #getIntent} is non-null, convert that to an intent:
         * URI and return as an HTML link.
         * <li> Otherwise, return an empty string.
         * </ul>
         *
         * @param context The caller's Context, from which its ContentResolver
         * and other things can be retrieved.
         * @return Returns the item's representation as HTML text.
         */
        public String coerceToHtmlText(Context context) {
            // If the item has an explicit HTML value, simply return that.
            String htmlText = getHtmlText();
            if (htmlText != null) {
                return htmlText;
            }

            // If this Item has a plain text value, return it as HTML.
            CharSequence text = getText();
            if (text != null) {
                if (text instanceof Spanned) {
                    return Html.toHtml((Spanned)text);
                }
                return Html.escapeHtml(text);
            }

            text = coerceToHtmlOrStyledText(context, false);
            return text != null ? text.toString() : null;
        }

        private CharSequence coerceToHtmlOrStyledText(Context context, boolean styled) {
            // If this Item has a URI value, try using that.
            if (mUri != null) {

                // Check to see what data representations the content
                // provider supports.  We would like HTML text, but if that
                // is not possible we'll live with plan text.
                String[] types = null;
                try {
                    types = context.getContentResolver().getStreamTypes(mUri, "text/*");
                } catch (SecurityException e) {
                    // No read permission for mUri, assume empty stream types list.
                }
                boolean hasHtml = false;
                boolean hasText = false;
                if (types != null) {
                    for (String type : types) {
                        if ("text/html".equals(type)) {
                            hasHtml = true;
                        } else if (type.startsWith("text/")) {
                            hasText = true;
                        }
                    }
                }

                // If the provider can serve data we can use, open and load it.
                if (hasHtml || hasText) {
                    FileInputStream stream = null;
                    try {
                        // Ask for a stream of the desired type.
                        AssetFileDescriptor descr = context.getContentResolver()
                                .openTypedAssetFileDescriptor(mUri,
                                        hasHtml ? "text/html" : "text/plain", null);
                        stream = descr.createInputStream();
                        InputStreamReader reader = new InputStreamReader(stream, "UTF-8");

                        // Got it...  copy the stream into a local string and return it.
                        StringBuilder builder = new StringBuilder(128);
                        char[] buffer = new char[8192];
                        int len;
                        while ((len=reader.read(buffer)) > 0) {
                            builder.append(buffer, 0, len);
                        }
                        String text = builder.toString();
                        if (hasHtml) {
                            if (styled) {
                                // We loaded HTML formatted text and the caller
                                // want styled text, convert it.
                                try {
                                    CharSequence newText = Html.fromHtml(text);
                                    return newText != null ? newText : text;
                                } catch (RuntimeException e) {
                                    return text;
                                }
                            } else {
                                // We loaded HTML formatted text and that is what
                                // the caller wants, just return it.
                                return text.toString();
                            }
                        }
                        if (styled) {
                            // We loaded plain text and the caller wants styled
                            // text, that is all we have so return it.
                            return text;
                        } else {
                            // We loaded plain text and the caller wants HTML
                            // text, escape it for HTML.
                            return Html.escapeHtml(text);
                        }

                    } catch (SecurityException e) {
                        Log.w("ClipData", "Failure opening stream", e);

                    } catch (FileNotFoundException e) {
                        // Unable to open content URI as text...  not really an
                        // error, just something to ignore.

                    } catch (IOException e) {
                        // Something bad has happened.
                        Log.w("ClipData", "Failure loading text", e);
                        return Html.escapeHtml(e.toString());

                    } finally {
                        if (stream != null) {
                            try {
                                stream.close();
                            } catch (IOException e) {
                            }
                        }
                    }
                }

                // If we couldn't open the URI as a stream, then we can build
                // some HTML text with the URI itself.
                // probably serves fairly well as a textual representation.
                if (styled) {
                    return uriToStyledText(mUri.toString());
                } else {
                    return uriToHtml(mUri.toString());
                }
            }

            // Finally, if all we have is an Intent, then we can just turn that
            // into text.  Not the most user-friendly thing, but it's something.
            if (mIntent != null) {
                if (styled) {
                    return uriToStyledText(mIntent.toUri(Intent.URI_INTENT_SCHEME));
                } else {
                    return uriToHtml(mIntent.toUri(Intent.URI_INTENT_SCHEME));
                }
            }

            // Shouldn't get here, but just in case...
            return "";
        }

        private String uriToHtml(String uri) {
            StringBuilder builder = new StringBuilder(256);
            builder.append("<a href=\"");
            builder.append(Html.escapeHtml(uri));
            builder.append("\">");
            builder.append(Html.escapeHtml(uri));
            builder.append("</a>");
            return builder.toString();
        }

        private CharSequence uriToStyledText(String uri) {
            SpannableStringBuilder builder = new SpannableStringBuilder();
            builder.append(uri);
            builder.setSpan(new URLSpan(uri), 0, builder.length(),
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            return builder;
        }

        @Override
        public String toString() {
            StringBuilder b = new StringBuilder(128);

            b.append("ClipData.Item { ");
            toShortString(b);
            b.append(" }");

            return b.toString();
        }

        /** @hide */
        public void toShortString(StringBuilder b) {
            if (mHtmlText != null) {
                b.append("H:");
                b.append(mHtmlText);
            } else if (mText != null) {
                b.append("T:");
                b.append(mText);
            } else if (mUri != null) {
                b.append("U:");
                b.append(mUri);
            } else if (mIntent != null) {
                b.append("I:");
                mIntent.toShortString(b, true, true, true, true);
            } else {
                b.append("NULL");
            }
        }

        /** @hide */
        public void toShortSummaryString(StringBuilder b) {
            if (mHtmlText != null) {
                b.append("HTML");
            } else if (mText != null) {
                b.append("TEXT");
            } else if (mUri != null) {
                b.append("U:");
                b.append(mUri);
            } else if (mIntent != null) {
                b.append("I:");
                mIntent.toShortString(b, true, true, true, true);
            } else {
                b.append("NULL");
            }
        }
    }

    /**
     * Create a new clip.
     *
     * @param label Label to show to the user describing this clip.
     * @param mimeTypes An array of MIME types this data is available as.
     * @param item The contents of the first item in the clip.
     */
    public ClipData(CharSequence label, String[] mimeTypes, Item item) {
        mClipDescription = new ClipDescription(label, mimeTypes);
        if (item == null) {
            throw new NullPointerException("item is null");
        }
        mIcon = null;
        mItems = new ArrayList<Item>();
        mItems.add(item);
    }

    /**
     * Create a new clip.
     *
     * @param description The ClipDescription describing the clip contents.
     * @param item The contents of the first item in the clip.
     */
    public ClipData(ClipDescription description, Item item) {
        mClipDescription = description;
        if (item == null) {
            throw new NullPointerException("item is null");
        }
        mIcon = null;
        mItems = new ArrayList<Item>();
        mItems.add(item);
    }

    /**
     * Create a new clip.
     *
     * @param description The ClipDescription describing the clip contents.
     * @param items The items in the clip. Not that a defensive copy of this
     *     list is not made, so caution should be taken to ensure the
     *     list is not available for further modification.
     * @hide
     */
    public ClipData(ClipDescription description, ArrayList<Item> items) {
        mClipDescription = description;
        if (items == null) {
            throw new NullPointerException("item is null");
        }
        mIcon = null;
        mItems = items;
    }

    /**
     * Create a new clip that is a copy of another clip.  This does a deep-copy
     * of all items in the clip.
     *
     * @param other The existing ClipData that is to be copied.
     */
    public ClipData(ClipData other) {
        mClipDescription = other.mClipDescription;
        mIcon = other.mIcon;
        mItems = new ArrayList<Item>(other.mItems);
    }

    /**
     * Create a new ClipData holding data of the type
     * {@link ClipDescription#MIMETYPE_TEXT_PLAIN}.
     *
     * @param label User-visible label for the clip data.
     * @param text The actual text in the clip.
     * @return Returns a new ClipData containing the specified data.
     */
    static public ClipData newPlainText(CharSequence label, CharSequence text) {
        Item item = new Item(text);
        return new ClipData(label, MIMETYPES_TEXT_PLAIN, item);
    }

    /**
     * Create a new ClipData holding data of the type
     * {@link ClipDescription#MIMETYPE_TEXT_HTML}.
     *
     * @param label User-visible label for the clip data.
     * @param text The text of clip as plain text, for receivers that don't
     * handle HTML.  This is required.
     * @param htmlText The actual HTML text in the clip.
     * @return Returns a new ClipData containing the specified data.
     */
    static public ClipData newHtmlText(CharSequence label, CharSequence text,
            String htmlText) {
        Item item = new Item(text, htmlText);
        return new ClipData(label, MIMETYPES_TEXT_HTML, item);
    }

    /**
     * Create a new ClipData holding an Intent with MIME type
     * {@link ClipDescription#MIMETYPE_TEXT_INTENT}.
     *
     * @param label User-visible label for the clip data.
     * @param intent The actual Intent in the clip.
     * @return Returns a new ClipData containing the specified data.
     */
    static public ClipData newIntent(CharSequence label, Intent intent) {
        Item item = new Item(intent);
        return new ClipData(label, MIMETYPES_TEXT_INTENT, item);
    }

    /**
     * Create a new ClipData holding a URI.  If the URI is a content: URI,
     * this will query the content provider for the MIME type of its data and
     * use that as the MIME type.  Otherwise, it will use the MIME type
     * {@link ClipDescription#MIMETYPE_TEXT_URILIST}.
     *
     * @param resolver ContentResolver used to get information about the URI.
     * @param label User-visible label for the clip data.
     * @param uri The URI in the clip.
     * @return Returns a new ClipData containing the specified data.
     */
    static public ClipData newUri(ContentResolver resolver, CharSequence label,
            Uri uri) {
        Item item = new Item(uri);
        String[] mimeTypes = getMimeTypes(resolver, uri);
        return new ClipData(label, mimeTypes, item);
    }

    /**
     * Finds all applicable MIME types for a given URI.
     *
     * @param resolver ContentResolver used to get information about the URI.
     * @param uri The URI.
     * @return Returns an array of MIME types.
     */
    private static String[] getMimeTypes(ContentResolver resolver, Uri uri) {
        String[] mimeTypes = null;
        if ("content".equals(uri.getScheme())) {
            String realType = resolver.getType(uri);
            mimeTypes = resolver.getStreamTypes(uri, "*/*");
            if (realType != null) {
                if (mimeTypes == null) {
                    mimeTypes = new String[] { realType };
                } else if (!ArrayUtils.contains(mimeTypes, realType)) {
                    String[] tmp = new String[mimeTypes.length + 1];
                    tmp[0] = realType;
                    System.arraycopy(mimeTypes, 0, tmp, 1, mimeTypes.length);
                    mimeTypes = tmp;
                }
            }
        }
        if (mimeTypes == null) {
            mimeTypes = MIMETYPES_TEXT_URILIST;
        }
        return mimeTypes;
    }

    /**
     * Create a new ClipData holding an URI with MIME type
     * {@link ClipDescription#MIMETYPE_TEXT_URILIST}.
     * Unlike {@link #newUri(ContentResolver, CharSequence, Uri)}, nothing
     * is inferred about the URI -- if it is a content: URI holding a bitmap,
     * the reported type will still be uri-list.  Use this with care!
     *
     * @param label User-visible label for the clip data.
     * @param uri The URI in the clip.
     * @return Returns a new ClipData containing the specified data.
     */
    static public ClipData newRawUri(CharSequence label, Uri uri) {
        Item item = new Item(uri);
        return new ClipData(label, MIMETYPES_TEXT_URILIST, item);
    }

    /**
     * Return the {@link ClipDescription} associated with this data, describing
     * what it contains.
     */
    public ClipDescription getDescription() {
        return mClipDescription;
    }

    /**
     * Add a new Item to the overall ClipData container.
     * <p> This method will <em>not</em> update the list of available MIME types in the
     * {@link ClipDescription}. It should be used only when adding items which do not add new
     * MIME types to this clip. If this is not the case, use {@link #addItem(Item, ContentResolver)}
     * or call {@link #ClipData(CharSequence, String[], Item)} with a complete list of MIME types.
     * @param item Item to be added.
     */
    public void addItem(Item item) {
        if (item == null) {
            throw new NullPointerException("item is null");
        }
        mItems.add(item);
    }

    /**
     * Add a new Item to the overall ClipData container.
     * <p> Unlike {@link #addItem(Item)}, this method will update the list of available MIME types
     * in the {@link ClipDescription}.
     * @param item Item to be added.
     * @param resolver ContentResolver used to get information about the URI possibly contained in
     * the item.
     */
    public void addItem(Item item, ContentResolver resolver) {
        addItem(item);

        if (item.getHtmlText() != null) {
            mClipDescription.addMimeTypes(MIMETYPES_TEXT_HTML);
        } else if (item.getText() != null) {
            mClipDescription.addMimeTypes(MIMETYPES_TEXT_PLAIN);
        }

        if (item.getIntent() != null) {
            mClipDescription.addMimeTypes(MIMETYPES_TEXT_INTENT);
        }

        if (item.getUri() != null) {
            mClipDescription.addMimeTypes(getMimeTypes(resolver, item.getUri()));
        }
    }

    /** @hide */
    public Bitmap getIcon() {
        return mIcon;
    }

    /**
     * Return the number of items in the clip data.
     */
    public int getItemCount() {
        return mItems.size();
    }

    /**
     * Return a single item inside of the clip data.  The index can range
     * from 0 to {@link #getItemCount()}-1.
     */
    public Item getItemAt(int index) {
        return mItems.get(index);
    }

    /** @hide */
    public void setItemAt(int index, Item item) {
        mItems.set(index, item);
    }

    /**
     * Prepare this {@link ClipData} to leave an app process.
     *
     * @hide
     */
    public void prepareToLeaveProcess(boolean leavingPackage) {
        // Assume that callers are going to be granting permissions
        prepareToLeaveProcess(leavingPackage, Intent.FLAG_GRANT_READ_URI_PERMISSION);
    }

    /**
     * Prepare this {@link ClipData} to leave an app process.
     *
     * @hide
     */
    public void prepareToLeaveProcess(boolean leavingPackage, int intentFlags) {
        final int size = mItems.size();
        for (int i = 0; i < size; i++) {
            final Item item = mItems.get(i);
            if (item.mIntent != null) {
                item.mIntent.prepareToLeaveProcess(leavingPackage);
            }
            if (item.mUri != null && leavingPackage) {
                if (StrictMode.vmFileUriExposureEnabled()) {
                    item.mUri.checkFileUriExposed("ClipData.Item.getUri()");
                }
                if (StrictMode.vmContentUriWithoutPermissionEnabled()) {
                    item.mUri.checkContentUriWithoutPermission("ClipData.Item.getUri()",
                            intentFlags);
                }
            }
        }
    }

    /** {@hide} */
    public void prepareToEnterProcess() {
        final int size = mItems.size();
        for (int i = 0; i < size; i++) {
            final Item item = mItems.get(i);
            if (item.mIntent != null) {
                item.mIntent.prepareToEnterProcess();
            }
        }
    }

    /** @hide */
    public void fixUris(int contentUserHint) {
        final int size = mItems.size();
        for (int i = 0; i < size; i++) {
            final Item item = mItems.get(i);
            if (item.mIntent != null) {
                item.mIntent.fixUris(contentUserHint);
            }
            if (item.mUri != null) {
                item.mUri = maybeAddUserId(item.mUri, contentUserHint);
            }
        }
    }

    /**
     * Only fixing the data field of the intents
     * @hide
     */
    public void fixUrisLight(int contentUserHint) {
        final int size = mItems.size();
        for (int i = 0; i < size; i++) {
            final Item item = mItems.get(i);
            if (item.mIntent != null) {
                Uri data = item.mIntent.getData();
                if (data != null) {
                    item.mIntent.setData(maybeAddUserId(data, contentUserHint));
                }
            }
            if (item.mUri != null) {
                item.mUri = maybeAddUserId(item.mUri, contentUserHint);
            }
        }
    }

    @Override
    public String toString() {
        StringBuilder b = new StringBuilder(128);

        b.append("ClipData { ");
        toShortString(b);
        b.append(" }");

        return b.toString();
    }

    /** @hide */
    public void toShortString(StringBuilder b) {
        boolean first;
        if (mClipDescription != null) {
            first = !mClipDescription.toShortString(b);
        } else {
            first = true;
        }
        if (mIcon != null) {
            if (!first) {
                b.append(' ');
            }
            first = false;
            b.append("I:");
            b.append(mIcon.getWidth());
            b.append('x');
            b.append(mIcon.getHeight());
        }
        for (int i=0; i<mItems.size(); i++) {
            if (!first) {
                b.append(' ');
            }
            first = false;
            b.append('{');
            mItems.get(i).toShortString(b);
            b.append('}');
        }
    }

    /** @hide */
    public void toShortStringShortItems(StringBuilder b, boolean first) {
        if (mItems.size() > 0) {
            if (!first) {
                b.append(' ');
            }
            mItems.get(0).toShortString(b);
            if (mItems.size() > 1) {
                b.append(" ...");
            }
        }
    }

    /** @hide */
    public void collectUris(List<Uri> out) {
        for (int i = 0; i < mItems.size(); ++i) {
            ClipData.Item item = getItemAt(i);

            if (item.getUri() != null) {
                out.add(item.getUri());
            }

            Intent intent = item.getIntent();
            if (intent != null) {
                if (intent.getData() != null) {
                    out.add(intent.getData());
                }
                if (intent.getClipData() != null) {
                    intent.getClipData().collectUris(out);
                }
            }
        }
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        mClipDescription.writeToParcel(dest, flags);
        if (mIcon != null) {
            dest.writeInt(1);
            mIcon.writeToParcel(dest, flags);
        } else {
            dest.writeInt(0);
        }
        final int N = mItems.size();
        dest.writeInt(N);
        for (int i=0; i<N; i++) {
            Item item = mItems.get(i);
            TextUtils.writeToParcel(item.mText, dest, flags);
            dest.writeString(item.mHtmlText);
            if (item.mIntent != null) {
                dest.writeInt(1);
                item.mIntent.writeToParcel(dest, flags);
            } else {
                dest.writeInt(0);
            }
            if (item.mUri != null) {
                dest.writeInt(1);
                item.mUri.writeToParcel(dest, flags);
            } else {
                dest.writeInt(0);
            }
        }
    }

    ClipData(Parcel in) {
        mClipDescription = new ClipDescription(in);
        if (in.readInt() != 0) {
            mIcon = Bitmap.CREATOR.createFromParcel(in);
        } else {
            mIcon = null;
        }
        mItems = new ArrayList<Item>();
        final int N = in.readInt();
        for (int i=0; i<N; i++) {
            CharSequence text = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
            String htmlText = in.readString();
            Intent intent = in.readInt() != 0 ? Intent.CREATOR.createFromParcel(in) : null;
            Uri uri = in.readInt() != 0 ? Uri.CREATOR.createFromParcel(in) : null;
            mItems.add(new Item(text, htmlText, intent, uri));
        }
    }

    public static final Parcelable.Creator<ClipData> CREATOR =
        new Parcelable.Creator<ClipData>() {

            @Override
            public ClipData createFromParcel(Parcel source) {
                return new ClipData(source);
            }

            @Override
            public ClipData[] newArray(int size) {
                return new ClipData[size];
            }
        };
}