textflow/keep_lines_together
Control the lines kept together on the page.
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/*
* Keep lines together:
* Control the lines kept together on the page
*
* Use the inline option "mark" of add/create_textflow() to mark certain
* positions in the Textflow. Use the "returnatmark" option fit_textflow() to
* return prematurely at the text position where the inline option "mark" has
* been defined with the specified number. The return reason string will be
* "_mark#", where # is the number of the appropriate mark.
* Use this feature to ensure that the text between two marks is always kept
* together in one fitbox.
*
* Required software: PDFlib/PDFlib+PDI/PPS 10
* Required data: none
*/
package com.pdflib.cookbook.pdflib.textflow;
import com.pdflib.pdflib;
import com.pdflib.PDFlibException;
public class keep_lines_together
{
public static void main (String argv[])
{
/* This is where the data files are. Adjust as necessary. */
String searchpath = "../input";
String outfile = "keep_lines_together.pdf";
String title = "Keep Lines Together";
pdflib p = null;
int tf = -1;
int exitcode = 0;
final int ystart = 700;
final int boxwidth = 210, boxheight = 110;
final int offset = 10;
final int xleft = 10;
final int xright = xleft + boxwidth + 80;
String result, optlist;
int lastmark = 0;
int y = ystart;
try {
p = new pdflib();
p.set_option("searchpath={" + searchpath + "}");
/* This means we must check return values of load_font() etc. */
p.set_option("errorpolicy=return");
/* Set an output path according to the name of the topic */
if (p.begin_document(outfile, "") == -1)
throw new Exception("Error: " + p.get_errmsg());
p.set_info("Creator", "PDFlib Cookbook");
p.set_info("Title", title);
/* Text to be created.
* Soft hyphens are indicated with the character reference "­"
* (character references are enabled by the "charref" option).
* The inline option "mark" is used to indicated text which should not
* be divided, i.e. all text between an equal and an odd mark number
* should be kept together in one fitbox.
*/
final String text =
"<mark=0>Have a look at our new paper plane models!" +
"<mark=1>" +
"<mark=2><nextline fillcolor={rgb 0.5 0.0 0.0}>Long Distance Glider:<nextline>" +
"With this paper rocket you can send all your messages even when " +
"sitting in a hall or in the cinema pretty near the back." +
"<mark=3>" +
"<mark=4><nextline fillcolor={rgb 0.0 0.5 0.0}>Giant Wing:<nextline>" +
"An unbelievable sailplane! It is ama­zingly robust and can " +
"even do aero­batics. But it best suited to gliding." +
"<mark=5>" +
"<mark=6><nextline fillcolor={rgb 0.8 0.4 0.1}>Cone Head Rocket:<nextline>" +
"This paper arrow can be thrown with big swing. We launched it " +
"from the roof of a hotel. It stayed in the air a long time and " +
"covered a considerable distance." +
"<mark=7>" +
"<mark=8><nextline fillcolor={rgb 0.0 0.5 0.5}>Super Dart:<nextline>" +
"The super dart can fly giant loops with a radius of 4 or 5 " +
"metres and cover very long distances. Its heavy cone point is " +
"slightly bowed upwards to get the lift required for loops." +
"<mark=9>" +
"<mark=10><nextline fillcolor={rgb 0.0 0.0 0.5}>German Bi-Plane:<nextline>" +
"Brand-new and ready for take-off. If you have lessons in the " +
"history of aviation you can show your interest by letting it " +
"land on your teacher's desk.<mark=11>";
/* Maximum number of the mark defined in the Textflow */
int maxmark = 11;
p.begin_page_ext(0, 0, "width=a4.width height=a4.height");
/* Output some descriptive text */
String topts = "fontname=NotoSerif-Bold fontsize=14 ";
p.fit_textline("Fit Textflow without considering",
xleft, y + 30, topts);
p.fit_textline("marks", xleft, y + 15, topts);
p.fit_textline("Fit Textflow using \"returnatmark\"", xright, y + 30,
topts);
p.fit_textline("to keep lines together", xright, y + 15, topts);
/* Option list to create the Textflow.
* "avoidemptybegin" deletes empty lines at the beginning of a fitbox.
* "charref" enables the substitution of numeric and character entity
* or glyph name references, e.g. of the character reference "­"
* for a soft hyphen.
*/
optlist = "fontname=NotoSerif-Regular fontsize=12 " +
"alignment=justify leading=120% charref avoidemptybegin";
/* ------------------------------------------------------------------
* First, output the text without considering any marks, i.e. without
* keeping lines together
* ------------------------------------------------------------------
*/
/* Create the Textflow */
tf = p.create_textflow(text, optlist);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
do
{
/* Set the line width used for the border around the fitbox of the
* Textflow displayed with the "showborder" option.
*/
p.setlinewidth(0.3);
/* Fit the Textflow */
result = p.fit_textflow(tf, xleft, y, xleft + boxwidth,
y - boxheight, "showborder");
y -= boxheight + offset;
/* "_stop" means that the Textflow has been fit completely */
} while (!result.equals("_stop") &&
!result.equals("_boxempty"));
/* -------------------------------------------------------------------
* Now, output the text with keeping lines together by considering the
* marks
* -------------------------------------------------------------------
*/
/* Create the Textflow again */
tf = p.create_textflow(text, optlist);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Set the starting point for the first fitbox */
y = ystart;
/* Loop until all of the text is placed; create new fitboxes on the
* page as long as more text needs to be placed.
*/
do
{
/* Set the line width used for the border around the fitbox of the
* Textflow displayed with the "showborder" option.
*/
p.setlinewidth(0.3);
/* Option list for fitting the Textflow.
* "showborder" is used to illustrate the fitbox borders for
* testing.
* "blind" is used to fit the Textflow in "blind" mode. All
* calculations will be done but the Textflow will not actually be
* placed.
*/
optlist = "showborder blind";
/* Fit the Textflow in "blind" mode to find out up to which mark
* the text will fit into the fitbox.
*/
result = p.fit_textflow(tf, xright, y, xright + boxwidth,
y - boxheight, optlist);
lastmark = (int) p.info_textflow(tf, "lastmark");
/* An even mark number indicates the start of a text section to be
* kept together. Reset it to the last odd mark number which
* indicates the end of a text section.
*/
if (lastmark%2 == 0) {
--lastmark;
}
/* Now actually fit the Textflow. To rewind the Textflow status
* to before the last call to fit_textflow() use "rewind=-1".
*/
optlist = "showborder returnatmark=" + lastmark + " rewind=-1";
result = p.fit_textflow(tf, xright, y, xright + boxwidth,
y - boxheight, optlist);
y -= boxheight + offset;
/* _stop means that the Textflow has been fit completely.
* _mark# with # equals "maxmark" defined above means that the maximum
* mark number defined in the Textflow has been reached.
*/
} while (!result.equals("_stop") &&
!result.equals("_boxempty") &&
!result.equals("_mark" + maxmark));
/* _boxempty" happens if the box is too small to hold any text */
if (result.equals( "_boxempty")) {
throw new Exception ("Error: Textflow box too small");
}
p.end_page_ext("");
p.delete_textflow(tf);
p.end_document("");
} catch (PDFlibException e){
System.err.println("PDFlib exception occurred:");
System.err.println("[" + e.get_errnum() + "] " + e.get_apiname()
+ ": " + e.get_errmsg());
exitcode = 1;
} catch (Exception e) {
System.err.println(e);
exitcode = 1;
} finally {
if (p != null) {
p.delete();
}
System.exit(exitcode);
}
}
}