PrintFileDocumentAdapter.java revision 19fba5d34a444ce145ab0d3a12c578d9d5d3f38c 
1/*
2 * Copyright (C) 2013 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.print;
18
19import android.content.Context;
20import android.os.AsyncTask;
21import android.os.Bundle;
22import android.os.CancellationSignal;
23import android.os.CancellationSignal.OnCancelListener;
24import android.os.ParcelFileDescriptor;
25import android.util.Log;
26
27import com.android.internal.R;
28
29import libcore.io.IoUtils;
30
31import java.io.File;
32import java.io.FileInputStream;
33import java.io.FileOutputStream;
34import java.io.IOException;
35import java.io.InputStream;
36import java.io.OutputStream;
37
38/**
39 * Adapter for printing PDF files. This class could be useful if you
40 * want to print a file and intercept when the system is ready
41 * spooling the data, so you can delete the file if it is a
42 * temporary one. To achieve this one must override {@link #onFinish()}
43 * and delete the file yourself.
44 */
45public class PrintFileDocumentAdapter extends PrintDocumentAdapter {
46
47    private static final String LOG_TAG = "PrintedFileDocumentAdapter";
48
49    private final Context mContext;
50
51    private final File mFile;
52
53    private final PrintDocumentInfo mDocumentInfo;
54
55    private WriteFileAsyncTask mWriteFileAsyncTask;
56
57    /**
58     * Constructor.
59     *
60     * @param context Context for accessing resources.
61     * @param file The PDF file to print.
62     * @param documentInfo The information about the printed file.
63     */
64    public PrintFileDocumentAdapter(Context context, File file,
65            PrintDocumentInfo documentInfo) {
66        if (file == null) {
67            throw new IllegalArgumentException("File cannot be null!");
68        }
69        if (documentInfo == null) {
70            throw new IllegalArgumentException("documentInfo cannot be null!");
71        }
72        mContext = context;
73        mFile = file;
74        mDocumentInfo = documentInfo;
75    }
76
77    @Override
78    public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes,
79            CancellationSignal cancellationSignal, LayoutResultCallback callback,
80            Bundle metadata) {
81        callback.onLayoutFinished(mDocumentInfo, false);
82    }
83
84    @Override
85    public void onWrite(PageRange[] pages, ParcelFileDescriptor destination,
86            CancellationSignal cancellationSignal, WriteResultCallback callback) {
87        mWriteFileAsyncTask = new WriteFileAsyncTask(destination, cancellationSignal, callback);
88        mWriteFileAsyncTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
89                (Void[]) null);
90    }
91
92    private final class WriteFileAsyncTask extends AsyncTask<Void, Void, Void> {
93
94        private final ParcelFileDescriptor mDestination;
95
96        private final WriteResultCallback mResultCallback;
97
98        private final CancellationSignal mCancellationSignal;
99
100        public WriteFileAsyncTask(ParcelFileDescriptor destination,
101                CancellationSignal cancellationSignal, WriteResultCallback callback) {
102            mDestination = destination;
103            mResultCallback = callback;
104            mCancellationSignal = cancellationSignal;
105            mCancellationSignal.setOnCancelListener(new OnCancelListener() {
106                @Override
107                public void onCancel() {
108                    cancel(true);
109                }
110            });
111        }
112
113        @Override
114        protected Void doInBackground(Void... params) {
115            InputStream in = null;
116            OutputStream out = new FileOutputStream(mDestination.getFileDescriptor());
117            final byte[] buffer = new byte[8192];
118            try {
119                in = new FileInputStream(mFile);
120                while (true) {
121                    if (isCancelled()) {
122                        break;
123                    }
124                    final int readByteCount = in.read(buffer);
125                    if (readByteCount < 0) {
126                        break;
127                    }
128                    out.write(buffer, 0, readByteCount);
129                }
130             } catch (IOException ioe) {
131                 Log.e(LOG_TAG, "Error writing data!", ioe);
132                 mResultCallback.onWriteFailed(mContext.getString(
133                         R.string.write_fail_reason_cannot_write));
134             } finally {
135                IoUtils.closeQuietly(in);
136                IoUtils.closeQuietly(out);
137            }
138            return null;
139        }
140
141        @Override
142        protected void onPostExecute(Void result) {
143            mResultCallback.onWriteFinished(new PageRange[] {PageRange.ALL_PAGES});
144        }
145
146        @Override
147        protected void onCancelled(Void result) {
148            mResultCallback.onWriteFailed(mContext.getString(
149                    R.string.write_fail_reason_cancelled));
150        }
151    }
152}
153
154