package com.pdflib.cookbook.tet.tet_and_pdflib;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.pdflib.PDFlibException;
import com.pdflib.TET;
import com.pdflib.TETException;
import com.pdflib.pdflib;
/**
* Search term highlighting: Identify all occurrences of a particular word on
* the page, and make them visible with the "Highlight" annotation.
*
* Required software: TET 4 and PDFlib+PDI 8
*
* Required data: PDF document
*
*/
class highlight_search_terms {
/**
* Common search path for PDI and TET to find the input document.
*/
private static final String DOC_SEARCH_PATH = "../input";
/**
* Global option list. The program expects the "resource" directory parallel to
* the "java" directory.
*/
private static final String GLOBAL_OPTLIST = "searchpath={../resource/cmap ../resource/glyphlist "
+ DOC_SEARCH_PATH + "}";
/**
* Document specific option list.
*/
private static final String DOC_OPTLIST = "";
/**
* Page-specific option list.
*
* "contentanalysis={keephyphenglyphs}" is specified because we want to capture
* the geometry of hyphens as well, in order to be able to include them in the
* highlighting box.
*/
private static final String PAGE_OPTLIST = "granularity=word contentanalysis={keephyphenglyphs}";
/**
* The encoding in which the output is sent to System.out. For running the
* example in a Windows command window, you can set this for example to
* "windows-1252" for getting Latin-1 output.
*/
private static final String OUTPUT_ENCODING = System.getProperty("file.encoding");
/**
* For printing to System.out in the encoding specified via OUTPUT_ENCODING.
*/
private static PrintStream out;
/**
* The name of the input file
*/
private String infilename;
/**
* The name of the output file
*/
private String outfilename;
/**
* The search terms to highlight, specified as a regular expression. In the
* example we search for "XMP", "Metadata" and "PDFlib" in case insensitive
* mode. The "u" flag for Unicode-aware case folding is not strictly necessary
* but included for the general case.
*/
private static final Pattern SEARCH_TERM_REGEX = Pattern.compile("(?iu)XMP|Metadata|PDFlib");
/**
* Import the current page from the PDI import document and place it in the
* ouput document.
*
* @param p the pdflib object
* @param pdiHandle the PDI handle for the input document
* @param pageno the current page number
*
* @throws PDFlibException an error occurred in the PDFlib API
*/
private boolean importPdiPage(pdflib p, int pdiHandle, int pageno) throws PDFlibException {
/*
* The page size will be adjusted later to match the size of the input pages
*/
p.begin_page_ext(10, 10, "");
int pdiPage = p.open_pdi_page(pdiHandle, pageno, "");
if (pdiPage == -1) {
System.err.println("Error: " + p.get_errmsg());
return false;
}
/* Place the input page and adjust the page size */
p.fit_pdi_page(pdiPage, 0, 0, "adjustpage");
p.close_pdi_page(pdiPage);
return true;
}
/**
* Helper class to store rectangle data.
*/
private class rectangle {
rectangle(double llx, double lly, double urx, double ury) {
this.llx = llx;
this.lly = lly;
this.urx = urx;
this.ury = ury;
}
double llx;
double lly;
double urx;
double ury;
}
/**
* Process a page: Create a new page in the output document, place the page from
* the input document in the output document, and highlight all occurrences of
* the search term.
*
* @param tet TET object
* @param doc TET document handle
* @param p pdflib object
* @param pdiHandle PDI document handle
* @param pageno The current page number
* @throws TETException An error occurred in the TET API
* @throws PDFlibException An error occurred in the PDFlib API
*/
private void process_page(TET tet, final int doc, pdflib p, int pdiHandle, int pageno)
throws TETException, PDFlibException {
/*
* Copy page from input document to output document.
*/
importPdiPage(p, pdiHandle, pageno);
final int page = tet.open_page(doc, pageno, PAGE_OPTLIST);
if (page == -1) {
System.err.println("Error " + tet.get_errnum() + " in " + tet.get_apiname() + "(): "
+ tet.get_errmsg());
} else {
/* Retrieve all text fragments for the page */
for (String text = tet.get_text(page); text != null; text = tet.get_text(page)) {
/*
* Check whether this is text that we want to highlight.
*/
Matcher matcher = SEARCH_TERM_REGEX.matcher(text);
if (matcher.matches()) {
/*
* List for collecting the rectangles that belong to an instance of the search
* term
*/
List<rectangle> rectangles = new LinkedList<rectangle>();
String matchedText = matcher.group(0);
boolean first = true;
double llx = 0, lly = 0, urx = 0, ury = 0, lasty = 0;
/*
* Loop over all characters, watch the y position for a jump to detect a word
* that spreads over two lines
*/
while (tet.get_char_info(page) != -1) {
/*
* Get ascender and descender, which are expressed relative to a font scaling
* factor of 1000. Descender will be returned as a negative number, therefore it
* will be added to the baseline y position to get the lower left y value.
*/
final double descender =
tet.pcos_get_number(doc, "fonts[" + tet.fontid + "]/descender") / 1000;
final double ascender =
tet.pcos_get_number(doc, "fonts[" + tet.fontid + "]/ascender") / 1000;
if (first) {
llx = tet.x;
lasty = tet.y;
lly = tet.y + descender * tet.fontsize;
first = false;
} else if (lasty != tet.y) {
/*
* y value jumped, we have to start a new rectangle
*/
rectangles.add(new rectangle(llx, lly, urx, ury));
llx = tet.x;
lasty = tet.y;
lly = tet.y + descender * tet.fontsize;
}
urx = tet.x + tet.width;
ury = tet.y + ascender * tet.fontsize;
}
/*
* Add the last identified rectangle.
*/
rectangles.add(new rectangle(llx, lly, urx, ury));
/*
* Build the option list for the highlight annotation, including the
* "polylinelist" option that describes one or multiple rectangles for the
* highlighting annotation for the potentially hyphenated word.
*
* We still need the rectangle that surrounds the separate sub-rectangles of the
* annotation, for passing it to the function create_annotation(). To get the
* actual values, we start with impossible values and compute the minimum and
* maximum accross the relevant values.
*/
double minx = 1E10, miny = 1E10, maxx = -1, maxy = -1;
StringBuffer optlist = new StringBuffer(
"annotcolor {rgb 0.68 0.85 0.90} linewidth 1 ")
.append("title {TET/PDFlib Search Term Highlighting} ")
.append("contents {Search Term: ")
.append(matchedText).append("} ")
.append("polylinelist {");
Iterator<rectangle> i = rectangles.iterator();
while (i.hasNext()) {
/*
* The quadrilaterals have to be built in the following order: upper left corner
* -> upper right corner -> lower left corner -> lower right corner
*/
rectangle r = (rectangle) i.next();
minx = Math.min(minx, r.llx);
miny = Math.min(miny, r.lly);
maxx = Math.max(maxx, r.urx);
maxy = Math.max(maxy, r.ury);
optlist.append("{");
// upper left corner
optlist.append(r.llx).append(" ").append(r.ury);
// upper right corner
optlist.append(" ").append(r.urx).append(" ").append(r.ury);
// lower left corner
optlist.append(" ").append(r.llx).append(" ").append(r.lly);
// lower right corner
optlist.append(" ").append(r.urx).append(" ").append(r.lly);
optlist.append("} ");
}
optlist.append("}");
p.create_annotation(minx, miny, maxx, maxy, "Highlight", optlist.toString());
}
}
if (tet.get_errnum() != 0) {
System.err.println("Error " + tet.get_errnum() + " in " + tet.get_apiname()
+ "(): " + tet.get_errmsg());
}
/*
* Close page in the input and output documents.
*/
p.end_page_ext("");
tet.close_page(page);
}
}
private void execute() {
TET tet = null;
pdflib p = null;
int pageno = 0;
try {
tet = new TET();
tet.set_option(GLOBAL_OPTLIST);
p = new pdflib();
p.set_option("searchpath={" + DOC_SEARCH_PATH + "}");
if (p.begin_document(outfilename, "") == -1) {
System.err.println("Error: " + p.get_errmsg());
return;
}
/* add document info entries */
p.set_info("Creator", "Highlight Search Terms TET Cookbook Example");
p.set_info("Author", "PDFlib GmbH");
p.set_info("Title", infilename);
p.set_info("Subject",
"Search terms matched by " + "regular expression \"" + SEARCH_TERM_REGEX.pattern()
+ "\"");
int pdiHandle = p.open_pdi_document(infilename, "");
if (pdiHandle == -1) {
System.err.println("Error: " + p.get_errmsg());
return;
}
final int doc = tet.open_document(infilename, DOC_OPTLIST);
if (doc == -1) {
System.err.println("Error " + tet.get_errnum() + " in " + tet.get_apiname()
+ "(): " + tet.get_errmsg());
return;
}
/*
* Loop over pages in the document
*/
final int n_pages = (int) tet.pcos_get_number(doc, "length:pages");
for (pageno = 1; pageno <= n_pages; ++pageno) {
process_page(tet, doc, p, pdiHandle, pageno);
}
p.end_document("");
p.close_pdi_document(pdiHandle);
tet.close_document(doc);
} catch (TETException e) {
if (pageno == 0) {
System.err.println("Error " + e.get_errnum() + " in " + e.get_apiname()
+ "(): " + e.get_errmsg() + "\n");
} else {
System.err.println("Error " + e.get_errnum() + " in " + e.get_apiname()
+ "() on page " + pageno + ": " + e.get_errmsg() + "\n");
}
} catch (PDFlibException e) {
if (pageno == 0) {
System.err.println("Error " + e.get_errnum() + " in " + e.get_apiname()
+ "(): " + e.get_errmsg() + "\n");
} else {
System.err.println("Error " + e.get_errnum() + " in " + e.get_apiname()
+ "() on page " + pageno + ": " + e.get_errmsg() + "\n");
}
} finally {
tet.delete();
p.delete();
}
}
/**
* @param infilename the name of the file for which the file with highlighted
* text will be generated
* @param outfilename the name of the output file
*/
private highlight_search_terms(String infilename, String outfilename) {
this.infilename = infilename;
this.outfilename = outfilename;
}
public static void main(String[] args) throws UnsupportedEncodingException {
System.out.println("Using output encoding \"" + OUTPUT_ENCODING + "\"");
out = new PrintStream(System.out, true, OUTPUT_ENCODING);
if (args.length != 2) {
out.println("usage: highlight_search_terms <infilename> <outfilename>");
return;
}
highlight_search_terms t = new highlight_search_terms(args[0], args[1]);
t.execute();
}
}