org.fife.ui.rtextarea.RDocumentCharSequence Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rsyntaxtextarea Show documentation

RSyntaxTextArea is the syntax highlighting text editor for Swing applications. Features include syntax highlighting for 40+ languages, code folding, code completion, regex find and replace, macros, code templates, undo/redo, line numbering and bracket matching.

There is a newer version: 3.5.2

Show newest version

/*
 * 06/30/2012
 *
 * RDocumentCharSequence.java - Iterator over a portion of an RTextArea's
 * document.
 *
 * This library is distributed under a modified BSD license.  See the included
 * LICENSE file for details.
 */
package org.fife.ui.rtextarea;

import javax.swing.text.BadLocationException;


/**
 * Allows iterating over a portion of an RDocument.  This is of
 * course not thread-safe, so should only be used on the EDT or with external
 * synchronization.
 *
 * @author Robert Futrell
 * @version 1.0
 */
class RDocumentCharSequence implements CharSequence {

	private RDocument doc;
	private int start;
	private int end;


	/**
	 * Creates a CharSequence representing the text in a document
	 * from the specified offset to the end of that document.
	 *
	 * @param doc The document.
	 * @param start The starting offset in the document, inclusive.
	 */
	RDocumentCharSequence(RDocument doc, int start) {
		this(doc, start, doc.getLength());
	}


	/**
	 * Constructor.
	 *
	 * @param doc The document.
	 * @param start The starting offset in the document, inclusive.
	 * @param end the ending offset in the document, exclusive.
	 */
	RDocumentCharSequence(RDocument doc, int start, int end) {
		this.doc = doc;
		this.start = start;
		this.end = end;
	}


	@Override
	public char charAt(int index) {
		if (index<0 || index>=length()) {
			throw new IndexOutOfBoundsException("Index " + index +
					" is not in range [0-" + length() + ")");
		}
		try {
			return doc.charAt(start+index);
		} catch (BadLocationException ble) {
			throw new IndexOutOfBoundsException(ble.toString());
		}
	}


	@Override
	public int length() {
		return end - start;
	}


	@Override
	public CharSequence subSequence(int start, int end) {
		if (start<0) {
			throw new IndexOutOfBoundsException("start must be >= 0 (" +
					start + ")");
		}
		else if (end<0) {
			throw new IndexOutOfBoundsException("end must be >= 0 (" +
					end + ")");
		}
		else if (end>length()) {
			throw new IndexOutOfBoundsException("end must be <= " +
					length() + " (" + end + ")");
		}
		else if (start>end) {
			throw new IndexOutOfBoundsException("start (" + start +
					") cannot be > end (" + end + ")");
		}
		int newStart = this.start + start;
		int newEnd = this.start + end;
		return new RDocumentCharSequence(doc, newStart, newEnd);
	}


	@Override
	public String toString() {
		try {
			return doc.getText(start, length());
		} catch (BadLocationException ble) { // Never happens
			ble.printStackTrace();
			return "";
		}
	}

}