Print string to Caret position in JEditorPane when Ctrl+C is pressed

Question

I'm trying to print out a certain string to the current caret position in a JEditorPane when CTRL+C is pressed. I'm not sure how to handle two key events and print to current caret position. The APIs do not do a good job of describing them. I figure it would go something like this:

@Override 
public void keyPressed( KeyEvent e) {
    if((e.getKeyChar()==KeyEvent.VK_CONTROL) && (e.getKeyChar()==KeyEvent.VK_C))
        //JEditorPane.getCaretPosition();
        //BufferedWriter bw = new BufferedWriter();
        //JEditorPane.write(bw.write("desired string"));
}

Can someone tell me if this would work?

Sticks · Accepted Answer · 2012-07-16T17:57:14.297

The keyChar for that event will never be equal to both VK_CONTROL and VK_C at the same time. What you want to do is check for the CONTROL key as a modifier to the event. If you want to insert or append text into the editor pane it is probably better to grab the underlying Document object that contains the text and then insert the text into that. If you know that the key event in this context could only have originated from your editor pane you could do something like the following:

if (e.getKeyCode() == KeyEvent.VK_C &&
       (e.getModifiers() & KeyEvent.CTRL_MASK) == KeyEvent.CTRL_MASK) {
    JEditorPane editorPane = (JEditorPane) e.getComponent();
    int caretPos = editorPane.getCaretPosition();
    try {
        editorPane.getDocument().insertString(caretPos, "desired string", null);
    } catch(BadLocationException ex) {
        ex.printStackTrace();
    }
}

Here is a full example:

import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.text.BadLocationException;

public class EditorPaneEx {

public static void main(String[] args) {
    JFrame frame = new JFrame();
    JEditorPane editorPane = new JEditorPane();
    editorPane.addKeyListener(new KeyAdapter() {
        @Override
        public void keyPressed(KeyEvent ev) {
            if (ev.getKeyCode() == KeyEvent.VK_C
                    && (ev.getModifiers() & KeyEvent.CTRL_MASK) == KeyEvent.CTRL_MASK) {
                JEditorPane editorPane = (JEditorPane) ev.getComponent();
                int caretPos = editorPane.getCaretPosition();
                try {
                    editorPane.getDocument().insertString(caretPos,
                            "desired string", null);
                } catch (BadLocationException ex) {
                    ex.printStackTrace();
                }
            }
        }
    });
    frame.add(editorPane);
    frame.pack();
    frame.setVisible(true);
}

}

When I ran it in the debugger, it caught the KeyEvent and went to the keyPressed() method but didn't do anything and I didn't get any errors. I used the global JEditorPane that I initialized at the beginning of the program instead of creating a new instance like you did. Do you know why it still might not be doing anything? — ridecontrol53, Jul 16 '12 at 17:16
Oops, that's what I get when coding from memory. I put the wrong constant for the modifier - if you use the one that is there now it will work. — Sticks, Jul 16 '12 at 17:58
Thanks so much. Works great. Thats kind of weird though how put the whole `keyPressed()` method inside `addKeyListener()` . — ridecontrol53, Jul 16 '12 at 18:57

Print string to Caret position in JEditorPane when Ctrl+C is pressed

1 Answers1