/** * 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 java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; /** * Representation of a clipped data on the clipboard. * *

ClippedData is a complex type containing one or 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 and iconic representation.

* *

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)}. * *

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. * *

*

Developer Guides

*

For more information about using the clipboard framework, read the * Copy and Paste * developer guide.

*
* * *

Implementing Paste or Drop

* *

To implement a paste or drop of a ClippedData 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. * *

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. * *

More complicated exchanges will be done through URIs, in particular * "content:" URIs. A content URI allows the recipient of a ClippedData 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. * *

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} * *

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. * *

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} * * *

Implementing Copy or Drag

* *

To be the source of a clip, the application must construct a ClippedData * 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. * *

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. * *

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. * *

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} * *

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} * *

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 mItems; /** * Description of a single item in a ClippedData. * *

The types than an individual item can currently contain are:

* * */ public static class Item { final CharSequence mText; final String mHtmlText; final Intent mIntent; Uri 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 must * 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 * must 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. * *

The algorithm for deciding what text to return is: *

* * @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 (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("ClippedData", "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. * *

The algorithm for deciding what text to return is: *

* * @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 = context.getContentResolver().getStreamTypes(mUri, "text/*"); 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 (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("ClippedData", "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(""); builder.append(Html.escapeHtml(uri)); builder.append(""); 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(); 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(); mItems.add(item); } /** * 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(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 = null; if ("content".equals(uri.getScheme())) { String realType = resolver.getType(uri); mimeTypes = resolver.getStreamTypes(uri, "*/*"); if (mimeTypes == null) { if (realType != null) { mimeTypes = new String[] { realType, ClipDescription.MIMETYPE_TEXT_URILIST }; } } else { String[] tmp = new String[mimeTypes.length + (realType != null ? 2 : 1)]; int i = 0; if (realType != null) { tmp[0] = realType; i++; } System.arraycopy(mimeTypes, 0, tmp, i, mimeTypes.length); tmp[i + mimeTypes.length] = ClipDescription.MIMETYPE_TEXT_URILIST; mimeTypes = tmp; } } if (mimeTypes == null) { mimeTypes = MIMETYPES_TEXT_URILIST; } return new ClipData(label, mimeTypes, item); } /** * 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. */ public void addItem(Item item) { if (item == null) { throw new NullPointerException("item is null"); } mItems.add(item); } /** @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); } /** * Prepare this {@link ClipData} to leave an app process. * * @hide */ public void prepareToLeaveProcess() { 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(); } if (item.mUri != null && StrictMode.vmFileUriExposureEnabled()) { item.mUri.checkFileUriExposed("ClipData.Item.getUri()"); } } } /** @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 0) { if (!first) { b.append(' '); } mItems.get(0).toShortString(b); if (mItems.size() > 1) { b.append(" ..."); } } } @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(); final int N = in.readInt(); for (int i=0; i CREATOR = new Parcelable.Creator() { public ClipData createFromParcel(Parcel source) { return new ClipData(source); } public ClipData[] newArray(int size) { return new ClipData[size]; } }; }