Ms_Joe Ms_Joe -3 years ago 100
Java Question

Highlight a text on specific line in JTextArea using Start and End Offset

Am having a method that highlights all the occurrences of a word in a Text Area. Is there any way to use start and end offset to highlight the word only in that line.

My current codes.

public static void highlight(JTextComponent textComp, String pattern) {

try {
Highlighter hilite = textComp.getHighlighter();
javax.swing.text.Document doc = textComp.getDocument();
String text = doc.getText(0, doc.getLength());
int pos = 0;

// Search for pattern
while ((pos = text.indexOf(pattern, pos)) >= 0) {
// Create highlighter using private painter and apply around pattern
hilite.addHighlight(pos, pos + pattern.length(), painter2);
pos += pattern.length();
}
} catch (BadLocationException e) {
}
}


This is called on a JButton action performed:

highlight(textArea_1, "in");


The result:
enter image description here

I tried using the Start and End Offset Method but with no luck.I tried to highlight "in" on line 6 only.Any Help on this much appreciated.

static int iline =6;

public static void highlight(JTextComponent textComp, String pattern) {

try {
Highlighter hilite = textComp.getHighlighter();
javax.swing.text.Document doc = textComp.getDocument();
int start =((JTextArea) textComp).getLineStartOffset(iline);
int end = ((JTextArea) textComp).getLineEndOffset(iline);
String text = doc.getText(start,end);
int pos = start;

// Search for pattern
while ((pos = text.indexOf(pattern, pos)) >= start) {
// Create highlighter using private painter and apply around pattern
hilite.addHighlight(pos, pos + pattern.length(), painter2);
pos += pattern.length();
}
} catch (BadLocationException e) {
}
}

Answer Source

Got it to work Thanks @camickr

Code:

public static void highlight(JTextComponent textComp, String pattern) {

    try {
        Highlighter hilite = textComp.getHighlighter();

        String text = textComp.getText();
        String line =null;
        int start = 0;
        int end;
        int totalLines = ((JTextArea) textComp).getLineCount();
        for (int i=0; i < totalLines; i++) {

            if(i==5){ //Line Numbers Decrement by 1
            start = ((JTextArea) textComp).getLineStartOffset(i);
            end   = ((JTextArea) textComp).getLineEndOffset(i);
            line = text.substring(start, end);
            System.out.println("My Line: " + line);
            System.out.println("Start Position of Line: " + start);
            System.out.println("End Position of Line: " + end);
            }
        }
        int pos = start;

        // Search for pattern
        if ((pos =text.indexOf(pattern, pos)) >= start) {
            // Create highlighter using private painter and apply around pattern
            hilite.addHighlight(pos, pos + pattern.length(), painter2);
            pos += pattern.length();
        }
    } catch (BadLocationException e) {
    }
}
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