import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import javax.swing.event.*;

import javax.swing.text.*;

/*

* Class to manage the protection of text and to highlight the protected

* text within a text component. This class has two functions:

*

* a) notify the ProtectedDocument class of the text to be protected.

* b) notify the ProtectedHighlighter class of the text to be protected.

*/

public class ProtectedTextComponent

{

private JTextComponent component;

private ProtectedHighlighter highlighter;

private ProtectedDocument document;

/**

* Specify the component to be protected. The text will be highlighted

* using the default color

*/

public ProtectedTextComponent(JTextComponent component)

{

this(component, null);

}

/**

* Specify the component to be protected. The text will be highlighted

* using the specified color

*/

public ProtectedTextComponent(JTextComponent component, Color color)

{

this.component = component;

// Handles updates to the Document and caret movement

document = new ProtectedDocument(component);

// Handles highlighting of the protected text

highlighter = new ProtectedHighlighter(component, color);

}

/**

* Protect a range of characters

*

* @param start starting offset

* @param end ending offset

*/

public void protectText(int start, int end)

{

document.protect(start, end);

highlighter.addHighlight(start, end + 1);

}

/**

* Protect an entire line

*

* @param line the line to protect

*/

public void protectLine(int line)

{

protectLines(line, line);

}

/**

* Protect a range of lines

*

* @param firstLine first line in the range

* @param lastLine last line in the range

*/

public void protectLines(int firstLine, int lastLine)

{

Element root = component.getDocument().getDefaultRootElement();

firstLine = Math.max(firstLine, 0);

firstLine = Math.min(firstLine, root.getElementCount() - 1);

Element firstElement = root.getElement( firstLine );

lastLine = Math.max(lastLine, 0);

lastLine = Math.min(lastLine, root.getElementCount() - 1);

Element lastElement = root.getElement( lastLine );

int start = firstElement.getStartOffset();

int end = lastElement.getEndOffset();

document.protect(start - 1, end - 1);

highlighter.addHighlight(start, end);

}

}