text_output/transparent_part_of_text
Transparent part of text: Create transparent text and highlight it with transparent rectangles
Use the "opacityfill" and "opacitystroke" options of create_gstate() to create an explicit graphics state with transparency settings. Place a transparent text line in two different ways. First use set_gstate() to set the explicit graphics state before placing the text line. Second use the "gstate" option of fit_textline(). Output a Textflow with one word highlighted with a transparent rectangle using the "gstate" suboption of the "matchbox" option of add_textflow(). Output a transparent Textflow with one word surrounded by the transparent borders of a rectangle using the "gstate" suboption of the "matchbox" option and the "gstate" option of add_textflow().
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* Transparent part of text:
* Create transparent text and highlight it with transparent rectangles
*
* Use the "opacityfill" and "opacitystroke" options of create_gstate() to
* create an explicit graphics state with transparency settings.
* Place a transparent text line in two different ways.
* First use set_gstate() to set the explicit graphics state before placing the
* text line.
* Second use the "gstate" option of fit_textline().
* Output a Textflow with one word highlighted with a transparent rectangle
* using the "gstate" suboption of the "matchbox" option of add_textflow().
* Output a transparent Textflow with one word surrounded by the transparent
* borders of a rectangle using the "gstate" suboption of the "matchbox" option
* and the "gstate" option of add_textflow().
*
* Required software: PDFlib Lite/PDFlib/PDFlib+PDI/PPS 7
* Required data: image file
*/
package com.pdflib.cookbook.pdflib.text_output;
import com.pdflib.pdflib;
import com.pdflib.PDFlibException;
public class transparent_part_of_text
{
/* Check whether the required minimum PDFlib version is available */
private static boolean required_pdflib_version_available(
pdflib p, int version)
throws PDFlibException, Exception {
double major = p.get_value("major", 0);
double minor = p.get_value("minor", 0);
double revision = p.get_value("revision", 0);
if (major*100 + minor*10 + revision < version) {
return false;
}
else {
return true;
}
}
public static void main (String argv[])
{
/* This is where the data files are. Adjust as necessary. */
String searchpath = "../input";
String outfile = "transparent_part_of_text.pdf";
String title = "Transparent Part of Text";
pdflib p = null;
/* Required minimum PDFlib version */
final int requiredversion = 800;
final String requiredvstr = "8.0.0";
String imagefile = "nesrin.jpg";
String text, optlist, mopts, gopts, result;
int image, gstate, font, tf = -1;
try {
p = new pdflib();
p.set_parameter("SearchPath", searchpath);
/* This means we must check return values of load_font() etc. */
p.set_parameter("errorpolicy", "return");
if (p.begin_document(outfile, "") == -1)
throw new Exception("Error: " + p.get_errmsg());
p.set_info("Creator", "PDFlib Cookbook");
p.set_info("Title", title + " $Revision: 1.6 $");
/* Load image */
image = p.load_image("auto", imagefile, "");
if (image == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Load the font; for PDFlib Lite: change "unicode" to "winansi" */
font = p.load_font("Helvetica-Bold", "unicode", "");
if (font == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Start page */
p.begin_page_ext(842, 595, "");
/* Draw a yellow background rectangle */
p.setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
p.rect(0, 0, 842, 595);
p.fill();
/* Output a background image */
p.fit_image(image, 50, 50, "");
/* Save the current graphics state. The save/restore of the current
* state is not necessarily required, but it will help you get back to
* a graphics state without any transparency.
*/
p.save();
/* Create an extended graphics state with transparency set to 50%, using
* create_gstate() with the "opacityfill" option set to 0.5.
*/
gstate = p.create_gstate("opacityfill=.5");
/* Apply the extended graphics state */
p.set_gstate(gstate);
/* Display some text which will be transparent according to the
* graphics state set
*/
p.setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
p.fit_textline("Page 1: My favorite holiday photo", 100, 100,
"font=" + font + " fontsize=40");
/* Restore the current graphics state */
p.restore();
p.end_page_ext("");
/* -----------------
* The following code will only be executed if the minimum required PDFlib
* version is available
* -----------------
*/
/* If the minimum required version is not available output a page with
* an appropriate comment
*/
if (!required_pdflib_version_available(p, requiredversion)) {
p.begin_page_ext(842, 595, "");
optlist = "font=" + font + " fontsize=14 ";
p.fit_textline("Page 2: PDFlib " + requiredvstr + " specific " +
"output is omitted since a lower PDFlib version has been used",
50, 470, optlist);
p.end_page_ext("");
}
/* If the minimum required version is available proceed as desired */
else {
/* Start page */
p.begin_page_ext(842, 595, "");
/* Draw a yellow background rectangle */
p.setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
p.rect(0, 0, 842, 595);
p.fill();
/* Output a background image */
p.fit_image(image, 50, 50, "");
/* ------------------------------
* Output a transparent text line
* ------------------------------
*/
/* Create an explicit graphics state with the transparency for fill
* operations set to 40%
*/
gstate = p.create_gstate("opacityfill=0.4");
/* Display a text line with the explicit graphics state applied. The
* text will appear transparent.
*/
optlist =
"font=" + font + " fontsize=40 " +
"fillcolor={rgb 1 0.9 0.58} " +
"gstate=" + gstate;
p.fit_textline("Page 2: My favorite holiday photo", 100, 470,
optlist);
/* --------------------------------------------------------
* Output a Textflow with the word "favorite" filled with a
* transparent rectangle
* --------------------------------------------------------
*/
/* Create an explicit graphics state with the transparency for fill
* operations set to 40%
*/
gstate = p.create_gstate("opacityfill=0.4");
/* Define the general Textflow options */
optlist =
"fontname=Helvetica-Bold fontsize=30 encoding=unicode " +
"leading=120% charref fillcolor={rgb 1 0.9 0.58} ";
/* Add parts of the Textflow */
text = "Here you can see my ";
tf = p.add_textflow(tf, text, optlist);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Use the "matchbox" option to define a matchbox rectangle to be
* filled on parts of the Textflow. To fill the rectangle
* transparently the matchbox is provided with the graphics state
* created above.
*/
mopts = "matchbox={name=mymatchbox boxheight={ascender descender}" +
" fillcolor={rgb 1 0.9 0.58} gstate=" + gstate +
" offsetleft=-4 offsetright=4 offsettop=4} ";
/* Use the "gstate" option to apply the explicit graphics state
* defined above
*/
gopts = "gstate=" + gstate;
/* Add a part of the Textflow with the "matchbox" and "gstate"
* options. That part of the text will be filled with a transparent
* rectangle and will appear transparent.
*/
text = "favorite";
tf = p.add_textflow(tf, text, optlist + mopts + gopts);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Define the "matchbox=end" option to end the matchbox */
mopts = "matchbox=end ";
/* Create another explicit graphics state with no transparency */
gstate = p.create_gstate("opacityfill=1");
/* Use the "gstate" option to apply the explicit graphics state
* defined above
*/
gopts = "gstate=" + gstate;
/* Add parts of the text with the "matchbox=end" option applied.
* The matchbox rectangle will end before the text to be added.
* The text will not appear transparent any more.
*/
text = " holiday photo.";
tf = p.add_textflow(tf, text, optlist + mopts + gopts);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
result = p.fit_textflow(tf, 100, 200, 300, 400, "");
if (!result.equals("_stop"))
{
/* Check for errors or more text to be placed */
}
p.delete_textflow(tf);
/* -----------------------------------------------------------------
* Output a transparent Textflow with the word "favorite" surrounded
* by the transparent borders of a rectangle.
* -----------------------------------------------------------------
*/
tf = -1;
/* Create an explicit graphics state with transparency for stroking
* and filling set to 40%
*/
gstate = p.create_gstate("opacitystroke=0.4 opacityfill=0.4");
/* Define the general Textflow options including the graphics state
* defined above
*/
optlist =
"fontname=Helvetica-Bold fontsize=30 encoding=unicode " +
"leading=120% charref fillcolor={rgb 1 0.9 0.58} " +
"gstate=" + gstate;
/* Add parts of the Textflow */
text = "This is my ";
tf = p.add_textflow(tf, text, optlist);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Use the "matchbox" option for defining a matchbox rectangle to be
* stroked around parts of the Textflow. To stroke the rectangle
* transparently the matchbox is provided with the graphics state
* created above.
*/
mopts = " matchbox={name=mymatchbox gstate=" + gstate +
" boxheight={ascender descender} linecap=projecting" +
" borderwidth=3 strokecolor={rgb 1 0.9 0.58}" +
" offsetleft=-4 offsetright=4 offsettop=4}";
/* Add a part of the Textflow with the matchbox option */
text = "favorite";
tf = p.add_textflow(tf, text, optlist + mopts);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
/* Define the "matchbox=end" option to end the matchbox */
mopts = " matchbox=end";
/* Add parts of the text with the "matchbox=end" option.
* The matchbox rectangle will end before the text to be added.
*/
text = " holiday photo.";
tf = p.add_textflow(tf, text, optlist + mopts);
if (tf == -1)
throw new Exception("Error: " + p.get_errmsg());
result = p.fit_textflow(tf, 650, 100, 780, 280, "");
if (!result.equals("_stop"))
{
/* Check for errors or more text to be placed */
}
p.delete_textflow(tf);
p.end_page_ext("");
}
/* ---------------
* The previous code has only been executed if the minimum required PDFlib
* version is available
* ---------------
*/
p.end_document("");
} catch (PDFlibException e) {
System.err.print("PDFlib exception occurred:\n");
System.err.print("[" + e.get_errnum() + "] " + e.get_apiname() +
": " + e.get_errmsg() + "\n");
} catch (Exception e) {
System.err.println(e.toString());
} finally {
if (p != null) {
p.delete();
}
}
}
}