void backspaceOrUnindent()
{
	if(buffer.isReadOnly())
	{
		Toolkit.getDefaultToolkit().beep();
		return;
	}

	int line = textArea.getCaretLine();
	int lineStart = textArea.getLineStartOffset(line);
	int caret = textArea.getCaretPosition();

	// if at line start or linestart + 1, backspace as normal
	if(lineStart+1 >= caret)
	{
		textArea.backspace();
		return;
	}

	char[] text = buffer.getText(lineStart,(caret-lineStart)-1).toCharArray();

	// Check that we've only got whitespace.
	// If any non-whitespace found, backspace as normal.
	for(int i=0; i < text.length; i++)
	{
		if(text[i] != ' ' && text[i] != '\t')
		{
			textArea.backspace();
			return;
		}
	}

	textArea.shiftIndentLeft();
}

backspaceOrUnindent();