PDFDocMemory

1//---------------------------------------------------------------------------------------
2// Copyright (c) 2001-2019 by PDFTron Systems Inc. All Rights Reserved.
3// Consult legal.txt regarding legal and license information.
4//---------------------------------------------------------------------------------------
5
6package com.pdftron.android.pdfnetsdksamples.samples;
7
8import com.pdftron.android.pdfnetsdksamples.OutputListener;
9import com.pdftron.android.pdfnetsdksamples.PDFNetSample;
10import com.pdftron.android.pdfnetsdksamples.R;
11import com.pdftron.android.pdfnetsdksamples.util.Utils;
12import com.pdftron.common.PDFNetException;
13import com.pdftron.filters.FilterReader;
14import com.pdftron.filters.MappedFile;
15import com.pdftron.pdf.Element;
16import com.pdftron.pdf.ElementReader;
17import com.pdftron.pdf.ElementWriter;
18import com.pdftron.pdf.PDFDoc;
19import com.pdftron.pdf.Page;
20import com.pdftron.pdf.PageIterator;
21import com.pdftron.sdf.SDFDoc;
22
23import java.io.File;
24import java.io.FileInputStream;
25import java.io.FileNotFoundException;
26import java.io.FileOutputStream;
27import java.io.IOException;
28import java.util.ArrayList;
29
30public class PDFDocMemoryTest extends PDFNetSample {
31
32	private static OutputListener mOutputListener;
33
34	private static ArrayList<String> mFileList = new ArrayList<>();
35
36    public PDFDocMemoryTest() {
37        setTitle(R.string.sample_pdfdocmemory_title);
38        setDescription(R.string.sample_pdfdocmemory_description);
39    }
40
41	@Override
42	public void run(OutputListener outputListener) {
43		super.run(outputListener);
44		mOutputListener = outputListener;
45		mFileList.clear();
46		printHeader(outputListener);
47
48
49        // The following sample illustrates how to read/write a PDF document from/to
50        // a memory buffer.  This is useful for applications that work with dynamic PDF
51        // documents that don't need to be saved/read from a disk.
52        try {
53            // Read a PDF document in a memory buffer.
54            MappedFile file = new MappedFile((Utils.getAssetTempFile(INPUT_PATH + "tiger.pdf").getAbsolutePath()));
55            long file_sz = file.fileSize();
56
57            FilterReader file_reader = new FilterReader(file);
58
59            byte[] mem = new byte[(int) file_sz];
60
61            long bytes_read = file_reader.read(mem);
62            try (PDFDoc doc = new PDFDoc(mem)) {
63
64                doc.initSecurityHandler();
65                int num_pages = doc.getPageCount();
66
67                ElementWriter writer = new ElementWriter();
68                ElementReader reader = new ElementReader();
69                Element element;
70
71                // Create a duplicate of every page but copy only path objects
72
73                for (int i = 1; i <= num_pages; ++i) {
74                    PageIterator itr = doc.getPageIterator(2 * i - 1);
75                    Page current = itr.next();
76                    reader.begin(current);
77                    Page new_page = doc.pageCreate(current.getMediaBox());
78                    doc.pageInsert(itr, new_page);
79
80                    writer.begin(new_page);
81                    while ((element = reader.next()) != null)    // Read page contents
82                    {
83                        //if (element.getType() == Element.e_path)
84                        writer.writeElement(element);
85                    }
86
87                    writer.end();
88                    reader.end();
89                }
90
91                doc.save(Utils.createExternalFile("doc_memory_edit.pdf", mFileList).getAbsolutePath(), SDFDoc.SaveMode.REMOVE_UNUSED, null);
92
93                // Save the document to a memory buffer.
94
95                byte[] buf = doc.save(SDFDoc.SaveMode.REMOVE_UNUSED, null);
96                // doc.Save(buf, buf_sz, Doc::e_linearized, NULL);
97
98                // Write the contents of the buffer to the disk
99                {
100                    File outfile = new File(Utils.createExternalFile("doc_memory_edit.txt", mFileList).getAbsolutePath());
101                    // output "doc_memory_edit.txt"
102                    FileOutputStream fop = new FileOutputStream(outfile);
103                    if (!outfile.exists()) {
104                        outfile.createNewFile();
105                    }
106                    fop.write(buf);
107                    fop.flush();
108                    fop.close();
109                }
110
111                // Read some data from the file stored in memory
112                reader.begin(doc.getPage(1));
113                while ((element = reader.next()) != null) {
114                    if (element.getType() == Element.e_path) mOutputListener.print("Path, ");
115                }
116                reader.end();
117                
118                mOutputListener.println("\n\nDone. Result saved in doc_memory_edit.pdf and doc_memory_edit.txt ...");
119            }
120        }
121        catch (PDFNetException e)
122        {
123            mOutputListener.printError(e.getStackTrace());
124            mOutputListener.printError(e.getStackTrace());
125        }
126        catch (Exception e)
127        {
128            mOutputListener.printError(e.getStackTrace());
129        }
130
131		for (String file : mFileList) {
132			addToFileList(file);
133		}
134		printFooter(outputListener);
135	}
136
137}