Reputation: 85
My Text file contains these contents:
public class MyC{
public void MyMethod()
{
System.out.println("My method has been accessed");
System.out.println("hi");
}
}
I want to underline the first line public class MyC{
red when I load the text file in the JTextPane
. Can someone guide me on this? I tried looking at http://docs.oracle.com/javase/7/docs/api/javax/swing/text/Highlighter.html but it is using positions. I cant figure out how to do it.
This is what I have so far:
public class ReadDemo {
// read the file into the pane
static void readin(String fn, JTextComponent pane) {
try {
FileReader fr = new FileReader(fn);
pane.read(fr, null);
fr.close();
}
catch (IOException e) {
System.err.println(e);
}
}
public static void main(String args[]) {
final JFrame frame = new JFrame("Testing");
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
// set up the text pane, either a JTextArea or JTextPane
final JTextComponent textpane = new JTextArea();
//final JTextComponent textpane = new JTextPane();
// set up a scroll pane for the text pane
final JScrollPane pane = new JScrollPane(textpane);
pane.setPreferredSize(new Dimension(600, 600));
// set up the file chooser
String cwd = System.getProperty("user.dir");
final JFileChooser jfc = new JFileChooser(cwd);
final JLabel elapsed = new JLabel("Elapsed time: ");
JButton filebutton = new JButton("Choose File");
filebutton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (jfc.showOpenDialog(frame) !=
JFileChooser.APPROVE_OPTION)
return;
File f = jfc.getSelectedFile();
// record the current time and read the file
final long s_time = System.currentTimeMillis();
frame.setCursor(Cursor.getPredefinedCursor(
Cursor.WAIT_CURSOR));
readin(f.toString(), textpane);
// wait for read to complete and update time
SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame.setCursor(Cursor.
getPredefinedCursor(
Cursor.DEFAULT_CURSOR));
long t = System.currentTimeMillis() -
s_time;
elapsed.setText("Elapsed time: " + t);
}
});
}
});
JPanel buttonpanel = new JPanel();
buttonpanel.add(filebutton);
buttonpanel.add(elapsed);
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add("North", buttonpanel);
panel.add("East", pane);
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
}
}
Upvotes: 2
Views: 728
Reputation: 7854
you can try like this:
static void readin(String fn, JTextComponent pane) {
try {
FileReader fr = new FileReader(fn);
pane.read(fr, null);
fr.close();
Highlighter hilit = new DefaultHighlighter();
Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter(Color.yellow);
pane.setHighlighter(hilit);
hilit.addHighlight(0, pane.getText().indexOf("\n"), painter);
}
catch (IOException e) {
System.err.println(e);
} catch (BadLocationException e) {
e.printStackTrace();
}
}
point is you can get index for the first line end and use it while adding highlight.
For any line/s, you can try:
static void readin(String fn, JTextComponent pane) {
try {
FileReader fr = new FileReader(fn);
pane.read(fr, null);
fr.close();
Highlighter hilit = new DefaultHighlighter();
Highlighter.HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter(Color.yellow);
pane.setHighlighter(hilit);
hilit.addHighlight(getLineEndIdx(pane.getText(), 4), getLineEndIdx(pane.getText(), 8 ), painter);
}
catch (IOException e) {
System.err.println(e);
} catch (BadLocationException e) {
e.printStackTrace();
}
}
private static int getLineEndIdx(String text, int lineNo) {
int lineEndIdx = 0;
for(int i = 1; i <= lineNo && lineEndIdx + 1 < text.length(); i++)
{
lineEndIdx = text.indexOf('\n', lineEndIdx + 1) ;
}
return lineEndIdx;
}
you can also improve it further...
Upvotes: 3
Reputation: 57381
Use javax.swing.text.Utilities.getRowStart()/getRowEnd()
to obtain the offsets for Highlighter
Upvotes: 3