ClipData.java revision a14acd20b8d563319ea1a5974dca0e9a29f0aaef
1/**
2 * Copyright (c) 2010, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.content;
18
19import android.content.res.AssetFileDescriptor;
20import android.graphics.Bitmap;
21import android.net.Uri;
22import android.os.Parcel;
23import android.os.Parcelable;
24import android.os.StrictMode;
25import android.text.Html;
26import android.text.Spannable;
27import android.text.SpannableStringBuilder;
28import android.text.Spanned;
29import android.text.TextUtils;
30import android.text.style.URLSpan;
31import android.util.Log;
32
33import java.io.FileInputStream;
34import java.io.FileNotFoundException;
35import java.io.IOException;
36import java.io.InputStreamReader;
37import java.util.ArrayList;
38
39/**
40 * Representation of a clipped data on the clipboard.
41 *
42 * <p>ClippedData is a complex type containing one or Item instances,
43 * each of which can hold one or more representations of an item of data.
44 * For display to the user, it also has a label and iconic representation.</p>
45 *
46 * <p>A ClipData contains a {@link ClipDescription}, which describes
47 * important meta-data about the clip.  In particular, its
48 * {@link ClipDescription#getMimeType(int) getDescription().getMimeType(int)}
49 * must return correct MIME type(s) describing the data in the clip.  For help
50 * in correctly constructing a clip with the correct MIME type, use
51 * {@link #newPlainText(CharSequence, CharSequence)},
52 * {@link #newUri(ContentResolver, CharSequence, Uri)}, and
53 * {@link #newIntent(CharSequence, Intent)}.
54 *
55 * <p>Each Item instance can be one of three main classes of data: a simple
56 * CharSequence of text, a single Intent object, or a Uri.  See {@link Item}
57 * for more details.
58 *
59 * <div class="special reference">
60 * <h3>Developer Guides</h3>
61 * <p>For more information about using the clipboard framework, read the
62 * <a href="{@docRoot}guide/topics/clipboard/copy-paste.html">Copy and Paste</a>
63 * developer guide.</p>
64 * </div>
65 *
66 * <a name="ImplementingPaste"></a>
67 * <h3>Implementing Paste or Drop</h3>
68 *
69 * <p>To implement a paste or drop of a ClippedData object into an application,
70 * the application must correctly interpret the data for its use.  If the {@link Item}
71 * it contains is simple text or an Intent, there is little to be done: text
72 * can only be interpreted as text, and an Intent will typically be used for
73 * creating shortcuts (such as placing icons on the home screen) or other
74 * actions.
75 *
76 * <p>If all you want is the textual representation of the clipped data, you
77 * can use the convenience method {@link Item#coerceToText Item.coerceToText}.
78 * In this case there is generally no need to worry about the MIME types
79 * reported by {@link ClipDescription#getMimeType(int) getDescription().getMimeType(int)},
80 * since any clip item an always be converted to a string.
81 *
82 * <p>More complicated exchanges will be done through URIs, in particular
83 * "content:" URIs.  A content URI allows the recipient of a ClippedData item
84 * to interact closely with the ContentProvider holding the data in order to
85 * negotiate the transfer of that data.  The clip must also be filled in with
86 * the available MIME types; {@link #newUri(ContentResolver, CharSequence, Uri)}
87 * will take care of correctly doing this.
88 *
89 * <p>For example, here is the paste function of a simple NotePad application.
90 * When retrieving the data from the clipboard, it can do either two things:
91 * if the clipboard contains a URI reference to an existing note, it copies
92 * the entire structure of the note into a new note; otherwise, it simply
93 * coerces the clip into text and uses that as the new note's contents.
94 *
95 * {@sample development/samples/NotePad/src/com/example/android/notepad/NoteEditor.java
96 *      paste}
97 *
98 * <p>In many cases an application can paste various types of streams of data.  For
99 * example, an e-mail application may want to allow the user to paste an image
100 * or other binary data as an attachment.  This is accomplished through the
101 * ContentResolver {@link ContentResolver#getStreamTypes(Uri, String)} and
102 * {@link ContentResolver#openTypedAssetFileDescriptor(Uri, String, android.os.Bundle)}
103 * methods.  These allow a client to discover the type(s) of data that a particular
104 * content URI can make available as a stream and retrieve the stream of data.
105 *
106 * <p>For example, the implementation of {@link Item#coerceToText Item.coerceToText}
107 * itself uses this to try to retrieve a URI clip as a stream of text:
108 *
109 * {@sample frameworks/base/core/java/android/content/ClipData.java coerceToText}
110 *
111 * <a name="ImplementingCopy"></a>
112 * <h3>Implementing Copy or Drag</h3>
113 *
114 * <p>To be the source of a clip, the application must construct a ClippedData
115 * object that any recipient can interpret best for their context.  If the clip
116 * is to contain a simple text, Intent, or URI, this is easy: an {@link Item}
117 * containing the appropriate data type can be constructed and used.
118 *
119 * <p>More complicated data types require the implementation of support in
120 * a ContentProvider for describing and generating the data for the recipient.
121 * A common scenario is one where an application places on the clipboard the
122 * content: URI of an object that the user has copied, with the data at that
123 * URI consisting of a complicated structure that only other applications with
124 * direct knowledge of the structure can use.
125 *
126 * <p>For applications that do not have intrinsic knowledge of the data structure,
127 * the content provider holding it can make the data available as an arbitrary
128 * number of types of data streams.  This is done by implementing the
129 * ContentProvider {@link ContentProvider#getStreamTypes(Uri, String)} and
130 * {@link ContentProvider#openTypedAssetFile(Uri, String, android.os.Bundle)}
131 * methods.
132 *
133 * <p>Going back to our simple NotePad application, this is the implementation
134 * it may have to convert a single note URI (consisting of a title and the note
135 * text) into a stream of plain text data.
136 *
137 * {@sample development/samples/NotePad/src/com/example/android/notepad/NotePadProvider.java
138 *      stream}
139 *
140 * <p>The copy operation in our NotePad application is now just a simple matter
141 * of making a clip containing the URI of the note being copied:
142 *
143 * {@sample development/samples/NotePad/src/com/example/android/notepad/NotesList.java
144 *      copy}
145 *
146 * <p>Note if a paste operation needs this clip as text (for example to paste
147 * into an editor), then {@link Item#coerceToText(Context)} will ask the content
148 * provider for the clip URI as text and successfully paste the entire note.
149 */
150public class ClipData implements Parcelable {
151    static final String[] MIMETYPES_TEXT_PLAIN = new String[] {
152        ClipDescription.MIMETYPE_TEXT_PLAIN };
153    static final String[] MIMETYPES_TEXT_HTML = new String[] {
154        ClipDescription.MIMETYPE_TEXT_HTML };
155    static final String[] MIMETYPES_TEXT_URILIST = new String[] {
156        ClipDescription.MIMETYPE_TEXT_URILIST };
157    static final String[] MIMETYPES_TEXT_INTENT = new String[] {
158        ClipDescription.MIMETYPE_TEXT_INTENT };
159
160    final ClipDescription mClipDescription;
161
162    final Bitmap mIcon;
163
164    final ArrayList<Item> mItems;
165
166    /**
167     * Description of a single item in a ClippedData.
168     *
169     * <p>The types than an individual item can currently contain are:</p>
170     *
171     * <ul>
172     * <li> Text: a basic string of text.  This is actually a CharSequence,
173     * so it can be formatted text supported by corresponding Android built-in
174     * style spans.  (Custom application spans are not supported and will be
175     * stripped when transporting through the clipboard.)
176     * <li> Intent: an arbitrary Intent object.  A typical use is the shortcut
177     * to create when pasting a clipped item on to the home screen.
178     * <li> Uri: a URI reference.  This may be any URI (such as an http: URI
179     * representing a bookmark), however it is often a content: URI.  Using
180     * content provider references as clips like this allows an application to
181     * share complex or large clips through the standard content provider
182     * facilities.
183     * </ul>
184     */
185    public static class Item {
186        final CharSequence mText;
187        final String mHtmlText;
188        final Intent mIntent;
189        final Uri mUri;
190
191        /**
192         * Create an Item consisting of a single block of (possibly styled) text.
193         */
194        public Item(CharSequence text) {
195            mText = text;
196            mHtmlText = null;
197            mIntent = null;
198            mUri = null;
199        }
200
201        /**
202         * Create an Item consisting of a single block of (possibly styled) text,
203         * with an alternative HTML formatted representation.  You <em>must</em>
204         * supply a plain text representation in addition to HTML text; coercion
205         * will not be done from HTML formated text into plain text.
206         */
207        public Item(CharSequence text, String htmlText) {
208            mText = text;
209            mHtmlText = htmlText;
210            mIntent = null;
211            mUri = null;
212        }
213
214        /**
215         * Create an Item consisting of an arbitrary Intent.
216         */
217        public Item(Intent intent) {
218            mText = null;
219            mHtmlText = null;
220            mIntent = intent;
221            mUri = null;
222        }
223
224        /**
225         * Create an Item consisting of an arbitrary URI.
226         */
227        public Item(Uri uri) {
228            mText = null;
229            mHtmlText = null;
230            mIntent = null;
231            mUri = uri;
232        }
233
234        /**
235         * Create a complex Item, containing multiple representations of
236         * text, Intent, and/or URI.
237         */
238        public Item(CharSequence text, Intent intent, Uri uri) {
239            mText = text;
240            mHtmlText = null;
241            mIntent = intent;
242            mUri = uri;
243        }
244
245        /**
246         * Create a complex Item, containing multiple representations of
247         * text, HTML text, Intent, and/or URI.  If providing HTML text, you
248         * <em>must</em> supply a plain text representation as well; coercion
249         * will not be done from HTML formated text into plain text.
250         */
251        public Item(CharSequence text, String htmlText, Intent intent, Uri uri) {
252            if (htmlText != null && text == null) {
253                throw new IllegalArgumentException(
254                        "Plain text must be supplied if HTML text is supplied");
255            }
256            mText = text;
257            mHtmlText = htmlText;
258            mIntent = intent;
259            mUri = uri;
260        }
261
262        /**
263         * Retrieve the raw text contained in this Item.
264         */
265        public CharSequence getText() {
266            return mText;
267        }
268
269        /**
270         * Retrieve the raw HTML text contained in this Item.
271         */
272        public String getHtmlText() {
273            return mHtmlText;
274        }
275
276        /**
277         * Retrieve the raw Intent contained in this Item.
278         */
279        public Intent getIntent() {
280            return mIntent;
281        }
282
283        /**
284         * Retrieve the raw URI contained in this Item.
285         */
286        public Uri getUri() {
287            return mUri;
288        }
289
290        /**
291         * Turn this item into text, regardless of the type of data it
292         * actually contains.
293         *
294         * <p>The algorithm for deciding what text to return is:
295         * <ul>
296         * <li> If {@link #getText} is non-null, return that.
297         * <li> If {@link #getUri} is non-null, try to retrieve its data
298         * as a text stream from its content provider.  If this succeeds, copy
299         * the text into a String and return it.  If it is not a content: URI or
300         * the content provider does not supply a text representation, return
301         * the raw URI as a string.
302         * <li> If {@link #getIntent} is non-null, convert that to an intent:
303         * URI and return it.
304         * <li> Otherwise, return an empty string.
305         * </ul>
306         *
307         * @param context The caller's Context, from which its ContentResolver
308         * and other things can be retrieved.
309         * @return Returns the item's textual representation.
310         */
311//BEGIN_INCLUDE(coerceToText)
312        public CharSequence coerceToText(Context context) {
313            // If this Item has an explicit textual value, simply return that.
314            CharSequence text = getText();
315            if (text != null) {
316                return text;
317            }
318
319            // If this Item has a URI value, try using that.
320            Uri uri = getUri();
321            if (uri != null) {
322
323                // First see if the URI can be opened as a plain text stream
324                // (of any sub-type).  If so, this is the best textual
325                // representation for it.
326                FileInputStream stream = null;
327                try {
328                    // Ask for a stream of the desired type.
329                    AssetFileDescriptor descr = context.getContentResolver()
330                            .openTypedAssetFileDescriptor(uri, "text/*", null);
331                    stream = descr.createInputStream();
332                    InputStreamReader reader = new InputStreamReader(stream, "UTF-8");
333
334                    // Got it...  copy the stream into a local string and return it.
335                    StringBuilder builder = new StringBuilder(128);
336                    char[] buffer = new char[8192];
337                    int len;
338                    while ((len=reader.read(buffer)) > 0) {
339                        builder.append(buffer, 0, len);
340                    }
341                    return builder.toString();
342
343                } catch (FileNotFoundException e) {
344                    // Unable to open content URI as text...  not really an
345                    // error, just something to ignore.
346
347                } catch (IOException e) {
348                    // Something bad has happened.
349                    Log.w("ClippedData", "Failure loading text", e);
350                    return e.toString();
351
352                } finally {
353                    if (stream != null) {
354                        try {
355                            stream.close();
356                        } catch (IOException e) {
357                        }
358                    }
359                }
360
361                // If we couldn't open the URI as a stream, then the URI itself
362                // probably serves fairly well as a textual representation.
363                return uri.toString();
364            }
365
366            // Finally, if all we have is an Intent, then we can just turn that
367            // into text.  Not the most user-friendly thing, but it's something.
368            Intent intent = getIntent();
369            if (intent != null) {
370                return intent.toUri(Intent.URI_INTENT_SCHEME);
371            }
372
373            // Shouldn't get here, but just in case...
374            return "";
375        }
376//END_INCLUDE(coerceToText)
377
378        /**
379         * Like {@link #coerceToHtmlText(Context)}, but any text that would
380         * be returned as HTML formatting will be returned as text with
381         * style spans.
382         * @param context The caller's Context, from which its ContentResolver
383         * and other things can be retrieved.
384         * @return Returns the item's textual representation.
385         */
386        public CharSequence coerceToStyledText(Context context) {
387            CharSequence text = getText();
388            if (text instanceof Spanned) {
389                return text;
390            }
391            String htmlText = getHtmlText();
392            if (htmlText != null) {
393                try {
394                    CharSequence newText = Html.fromHtml(htmlText);
395                    if (newText != null) {
396                        return newText;
397                    }
398                } catch (RuntimeException e) {
399                    // If anything bad happens, we'll fall back on the plain text.
400                }
401            }
402
403            if (text != null) {
404                return text;
405            }
406            return coerceToHtmlOrStyledText(context, true);
407        }
408
409        /**
410         * Turn this item into HTML text, regardless of the type of data it
411         * actually contains.
412         *
413         * <p>The algorithm for deciding what text to return is:
414         * <ul>
415         * <li> If {@link #getHtmlText} is non-null, return that.
416         * <li> If {@link #getText} is non-null, return that, converting to
417         * valid HTML text.  If this text contains style spans,
418         * {@link Html#toHtml(Spanned) Html.toHtml(Spanned)} is used to
419         * convert them to HTML formatting.
420         * <li> If {@link #getUri} is non-null, try to retrieve its data
421         * as a text stream from its content provider.  If the provider can
422         * supply text/html data, that will be preferred and returned as-is.
423         * Otherwise, any text/* data will be returned and escaped to HTML.
424         * If it is not a content: URI or the content provider does not supply
425         * a text representation, HTML text containing a link to the URI
426         * will be returned.
427         * <li> If {@link #getIntent} is non-null, convert that to an intent:
428         * URI and return as an HTML link.
429         * <li> Otherwise, return an empty string.
430         * </ul>
431         *
432         * @param context The caller's Context, from which its ContentResolver
433         * and other things can be retrieved.
434         * @return Returns the item's representation as HTML text.
435         */
436        public String coerceToHtmlText(Context context) {
437            // If the item has an explicit HTML value, simply return that.
438            String htmlText = getHtmlText();
439            if (htmlText != null) {
440                return htmlText;
441            }
442
443            // If this Item has a plain text value, return it as HTML.
444            CharSequence text = getText();
445            if (text != null) {
446                if (text instanceof Spanned) {
447                    return Html.toHtml((Spanned)text);
448                }
449                return Html.escapeHtml(text);
450            }
451
452            text = coerceToHtmlOrStyledText(context, false);
453            return text != null ? text.toString() : null;
454        }
455
456        private CharSequence coerceToHtmlOrStyledText(Context context, boolean styled) {
457            // If this Item has a URI value, try using that.
458            if (mUri != null) {
459
460                // Check to see what data representations the content
461                // provider supports.  We would like HTML text, but if that
462                // is not possible we'll live with plan text.
463                String[] types = context.getContentResolver().getStreamTypes(mUri, "text/*");
464                boolean hasHtml = false;
465                boolean hasText = false;
466                if (types != null) {
467                    for (String type : types) {
468                        if ("text/html".equals(type)) {
469                            hasHtml = true;
470                        } else if (type.startsWith("text/")) {
471                            hasText = true;
472                        }
473                    }
474                }
475
476                // If the provider can serve data we can use, open and load it.
477                if (hasHtml || hasText) {
478                    FileInputStream stream = null;
479                    try {
480                        // Ask for a stream of the desired type.
481                        AssetFileDescriptor descr = context.getContentResolver()
482                                .openTypedAssetFileDescriptor(mUri,
483                                        hasHtml ? "text/html" : "text/plain", null);
484                        stream = descr.createInputStream();
485                        InputStreamReader reader = new InputStreamReader(stream, "UTF-8");
486
487                        // Got it...  copy the stream into a local string and return it.
488                        StringBuilder builder = new StringBuilder(128);
489                        char[] buffer = new char[8192];
490                        int len;
491                        while ((len=reader.read(buffer)) > 0) {
492                            builder.append(buffer, 0, len);
493                        }
494                        String text = builder.toString();
495                        if (hasHtml) {
496                            if (styled) {
497                                // We loaded HTML formatted text and the caller
498                                // want styled text, convert it.
499                                try {
500                                    CharSequence newText = Html.fromHtml(text);
501                                    return newText != null ? newText : text;
502                                } catch (RuntimeException e) {
503                                    return text;
504                                }
505                            } else {
506                                // We loaded HTML formatted text and that is what
507                                // the caller wants, just return it.
508                                return text.toString();
509                            }
510                        }
511                        if (styled) {
512                            // We loaded plain text and the caller wants styled
513                            // text, that is all we have so return it.
514                            return text;
515                        } else {
516                            // We loaded plain text and the caller wants HTML
517                            // text, escape it for HTML.
518                            return Html.escapeHtml(text);
519                        }
520
521                    } catch (FileNotFoundException e) {
522                        // Unable to open content URI as text...  not really an
523                        // error, just something to ignore.
524
525                    } catch (IOException e) {
526                        // Something bad has happened.
527                        Log.w("ClippedData", "Failure loading text", e);
528                        return Html.escapeHtml(e.toString());
529
530                    } finally {
531                        if (stream != null) {
532                            try {
533                                stream.close();
534                            } catch (IOException e) {
535                            }
536                        }
537                    }
538                }
539
540                // If we couldn't open the URI as a stream, then we can build
541                // some HTML text with the URI itself.
542                // probably serves fairly well as a textual representation.
543                if (styled) {
544                    return uriToStyledText(mUri.toString());
545                } else {
546                    return uriToHtml(mUri.toString());
547                }
548            }
549
550            // Finally, if all we have is an Intent, then we can just turn that
551            // into text.  Not the most user-friendly thing, but it's something.
552            if (mIntent != null) {
553                if (styled) {
554                    return uriToStyledText(mIntent.toUri(Intent.URI_INTENT_SCHEME));
555                } else {
556                    return uriToHtml(mIntent.toUri(Intent.URI_INTENT_SCHEME));
557                }
558            }
559
560            // Shouldn't get here, but just in case...
561            return "";
562        }
563
564        private String uriToHtml(String uri) {
565            StringBuilder builder = new StringBuilder(256);
566            builder.append("<a href=\"");
567            builder.append(Html.escapeHtml(uri));
568            builder.append("\">");
569            builder.append(Html.escapeHtml(uri));
570            builder.append("</a>");
571            return builder.toString();
572        }
573
574        private CharSequence uriToStyledText(String uri) {
575            SpannableStringBuilder builder = new SpannableStringBuilder();
576            builder.append(uri);
577            builder.setSpan(new URLSpan(uri), 0, builder.length(),
578                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
579            return builder;
580        }
581
582        @Override
583        public String toString() {
584            StringBuilder b = new StringBuilder(128);
585
586            b.append("ClipData.Item { ");
587            toShortString(b);
588            b.append(" }");
589
590            return b.toString();
591        }
592
593        /** @hide */
594        public void toShortString(StringBuilder b) {
595            if (mHtmlText != null) {
596                b.append("H:");
597                b.append(mHtmlText);
598            } else if (mText != null) {
599                b.append("T:");
600                b.append(mText);
601            } else if (mUri != null) {
602                b.append("U:");
603                b.append(mUri);
604            } else if (mIntent != null) {
605                b.append("I:");
606                mIntent.toShortString(b, true, true, true, true);
607            } else {
608                b.append("NULL");
609            }
610        }
611    }
612
613    /**
614     * Create a new clip.
615     *
616     * @param label Label to show to the user describing this clip.
617     * @param mimeTypes An array of MIME types this data is available as.
618     * @param item The contents of the first item in the clip.
619     */
620    public ClipData(CharSequence label, String[] mimeTypes, Item item) {
621        mClipDescription = new ClipDescription(label, mimeTypes);
622        if (item == null) {
623            throw new NullPointerException("item is null");
624        }
625        mIcon = null;
626        mItems = new ArrayList<Item>();
627        mItems.add(item);
628    }
629
630    /**
631     * Create a new clip.
632     *
633     * @param description The ClipDescription describing the clip contents.
634     * @param item The contents of the first item in the clip.
635     */
636    public ClipData(ClipDescription description, Item item) {
637        mClipDescription = description;
638        if (item == null) {
639            throw new NullPointerException("item is null");
640        }
641        mIcon = null;
642        mItems = new ArrayList<Item>();
643        mItems.add(item);
644    }
645
646    /**
647     * Create a new clip that is a copy of another clip.  This does a deep-copy
648     * of all items in the clip.
649     *
650     * @param other The existing ClipData that is to be copied.
651     */
652    public ClipData(ClipData other) {
653        mClipDescription = other.mClipDescription;
654        mIcon = other.mIcon;
655        mItems = new ArrayList<Item>(other.mItems);
656    }
657
658    /**
659     * Create a new ClipData holding data of the type
660     * {@link ClipDescription#MIMETYPE_TEXT_PLAIN}.
661     *
662     * @param label User-visible label for the clip data.
663     * @param text The actual text in the clip.
664     * @return Returns a new ClipData containing the specified data.
665     */
666    static public ClipData newPlainText(CharSequence label, CharSequence text) {
667        Item item = new Item(text);
668        return new ClipData(label, MIMETYPES_TEXT_PLAIN, item);
669    }
670
671    /**
672     * Create a new ClipData holding data of the type
673     * {@link ClipDescription#MIMETYPE_TEXT_HTML}.
674     *
675     * @param label User-visible label for the clip data.
676     * @param text The text of clip as plain text, for receivers that don't
677     * handle HTML.  This is required.
678     * @param htmlText The actual HTML text in the clip.
679     * @return Returns a new ClipData containing the specified data.
680     */
681    static public ClipData newHtmlText(CharSequence label, CharSequence text,
682            String htmlText) {
683        Item item = new Item(text, htmlText);
684        return new ClipData(label, MIMETYPES_TEXT_HTML, item);
685    }
686
687    /**
688     * Create a new ClipData holding an Intent with MIME type
689     * {@link ClipDescription#MIMETYPE_TEXT_INTENT}.
690     *
691     * @param label User-visible label for the clip data.
692     * @param intent The actual Intent in the clip.
693     * @return Returns a new ClipData containing the specified data.
694     */
695    static public ClipData newIntent(CharSequence label, Intent intent) {
696        Item item = new Item(intent);
697        return new ClipData(label, MIMETYPES_TEXT_INTENT, item);
698    }
699
700    /**
701     * Create a new ClipData holding a URI.  If the URI is a content: URI,
702     * this will query the content provider for the MIME type of its data and
703     * use that as the MIME type.  Otherwise, it will use the MIME type
704     * {@link ClipDescription#MIMETYPE_TEXT_URILIST}.
705     *
706     * @param resolver ContentResolver used to get information about the URI.
707     * @param label User-visible label for the clip data.
708     * @param uri The URI in the clip.
709     * @return Returns a new ClipData containing the specified data.
710     */
711    static public ClipData newUri(ContentResolver resolver, CharSequence label,
712            Uri uri) {
713        Item item = new Item(uri);
714        String[] mimeTypes = null;
715        if ("content".equals(uri.getScheme())) {
716            String realType = resolver.getType(uri);
717            mimeTypes = resolver.getStreamTypes(uri, "*/*");
718            if (mimeTypes == null) {
719                if (realType != null) {
720                    mimeTypes = new String[] { realType, ClipDescription.MIMETYPE_TEXT_URILIST };
721                }
722            } else {
723                String[] tmp = new String[mimeTypes.length + (realType != null ? 2 : 1)];
724                int i = 0;
725                if (realType != null) {
726                    tmp[0] = realType;
727                    i++;
728                }
729                System.arraycopy(mimeTypes, 0, tmp, i, mimeTypes.length);
730                tmp[i + mimeTypes.length] = ClipDescription.MIMETYPE_TEXT_URILIST;
731                mimeTypes = tmp;
732            }
733        }
734        if (mimeTypes == null) {
735            mimeTypes = MIMETYPES_TEXT_URILIST;
736        }
737        return new ClipData(label, mimeTypes, item);
738    }
739
740    /**
741     * Create a new ClipData holding an URI with MIME type
742     * {@link ClipDescription#MIMETYPE_TEXT_URILIST}.
743     * Unlike {@link #newUri(ContentResolver, CharSequence, Uri)}, nothing
744     * is inferred about the URI -- if it is a content: URI holding a bitmap,
745     * the reported type will still be uri-list.  Use this with care!
746     *
747     * @param label User-visible label for the clip data.
748     * @param uri The URI in the clip.
749     * @return Returns a new ClipData containing the specified data.
750     */
751    static public ClipData newRawUri(CharSequence label, Uri uri) {
752        Item item = new Item(uri);
753        return new ClipData(label, MIMETYPES_TEXT_URILIST, item);
754    }
755
756    /**
757     * Return the {@link ClipDescription} associated with this data, describing
758     * what it contains.
759     */
760    public ClipDescription getDescription() {
761        return mClipDescription;
762    }
763
764    /**
765     * Add a new Item to the overall ClipData container.
766     */
767    public void addItem(Item item) {
768        if (item == null) {
769            throw new NullPointerException("item is null");
770        }
771        mItems.add(item);
772    }
773
774    /** @hide */
775    public Bitmap getIcon() {
776        return mIcon;
777    }
778
779    /**
780     * Return the number of items in the clip data.
781     */
782    public int getItemCount() {
783        return mItems.size();
784    }
785
786    /**
787     * Return a single item inside of the clip data.  The index can range
788     * from 0 to {@link #getItemCount()}-1.
789     */
790    public Item getItemAt(int index) {
791        return mItems.get(index);
792    }
793
794    /**
795     * Prepare this {@link ClipData} to leave an app process.
796     *
797     * @hide
798     */
799    public void prepareToLeaveProcess() {
800        final int size = mItems.size();
801        for (int i = 0; i < size; i++) {
802            final Item item = mItems.get(i);
803            if (item.mIntent != null) {
804                item.mIntent.prepareToLeaveProcess();
805            }
806            if (item.mUri != null && StrictMode.vmFileUriExposureEnabled()) {
807                item.mUri.checkFileUriExposed("ClipData.Item.getUri()");
808            }
809        }
810    }
811
812    @Override
813    public String toString() {
814        StringBuilder b = new StringBuilder(128);
815
816        b.append("ClipData { ");
817        toShortString(b);
818        b.append(" }");
819
820        return b.toString();
821    }
822
823    /** @hide */
824    public void toShortString(StringBuilder b) {
825        boolean first;
826        if (mClipDescription != null) {
827            first = !mClipDescription.toShortString(b);
828        } else {
829            first = true;
830        }
831        if (mIcon != null) {
832            if (!first) {
833                b.append(' ');
834            }
835            first = false;
836            b.append("I:");
837            b.append(mIcon.getWidth());
838            b.append('x');
839            b.append(mIcon.getHeight());
840        }
841        for (int i=0; i<mItems.size(); i++) {
842            if (!first) {
843                b.append(' ');
844            }
845            first = false;
846            b.append('{');
847            mItems.get(i).toShortString(b);
848            b.append('}');
849        }
850    }
851
852    @Override
853    public int describeContents() {
854        return 0;
855    }
856
857    @Override
858    public void writeToParcel(Parcel dest, int flags) {
859        mClipDescription.writeToParcel(dest, flags);
860        if (mIcon != null) {
861            dest.writeInt(1);
862            mIcon.writeToParcel(dest, flags);
863        } else {
864            dest.writeInt(0);
865        }
866        final int N = mItems.size();
867        dest.writeInt(N);
868        for (int i=0; i<N; i++) {
869            Item item = mItems.get(i);
870            TextUtils.writeToParcel(item.mText, dest, flags);
871            dest.writeString(item.mHtmlText);
872            if (item.mIntent != null) {
873                dest.writeInt(1);
874                item.mIntent.writeToParcel(dest, flags);
875            } else {
876                dest.writeInt(0);
877            }
878            if (item.mUri != null) {
879                dest.writeInt(1);
880                item.mUri.writeToParcel(dest, flags);
881            } else {
882                dest.writeInt(0);
883            }
884        }
885    }
886
887    ClipData(Parcel in) {
888        mClipDescription = new ClipDescription(in);
889        if (in.readInt() != 0) {
890            mIcon = Bitmap.CREATOR.createFromParcel(in);
891        } else {
892            mIcon = null;
893        }
894        mItems = new ArrayList<Item>();
895        final int N = in.readInt();
896        for (int i=0; i<N; i++) {
897            CharSequence text = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
898            String htmlText = in.readString();
899            Intent intent = in.readInt() != 0 ? Intent.CREATOR.createFromParcel(in) : null;
900            Uri uri = in.readInt() != 0 ? Uri.CREATOR.createFromParcel(in) : null;
901            mItems.add(new Item(text, htmlText, intent, uri));
902        }
903    }
904
905    public static final Parcelable.Creator<ClipData> CREATOR =
906        new Parcelable.Creator<ClipData>() {
907
908            public ClipData createFromParcel(Parcel source) {
909                return new ClipData(source);
910            }
911
912            public ClipData[] newArray(int size) {
913                return new ClipData[size];
914            }
915        };
916}
917