AbstractGutterComponent.java

/*
 * 02/17/2009
 *
 * AbstractGutterComponent.java - A component that can be displayed in a Gutter.
 * Copyright (C) 2009 Robert Futrell
 * robert_futrell at users.sourceforge.net
 * http://fifesoft.com/rsyntaxtextarea
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA.
 */
package org.fife.ui.rtextarea;

import java.awt.Container;
import java.awt.Rectangle;
import java.awt.Shape;
import javax.swing.JComponent;
import javax.swing.event.DocumentEvent;
import javax.swing.text.View;

/**
 * A component that can be displayed in a {@link Gutter}.
 * 
 * @author Robert Futrell
 * @version 1.0
 */
abstract class AbstractGutterComponent extends JComponent {

    /**
     * The text area whose lines we are marking with icons.
     */
    protected RTextArea textArea;

    /**
     * The number of lines in the text area.
     */
    protected int currentLineCount;

    /**
     * Constructor.
     * 
     * @param textArea
     *            The text area.
     */
    public AbstractGutterComponent(RTextArea textArea) {
        setTextArea(textArea);
    }

    /**
     * Returns the bounds of a child view as a rectangle, since <code>View</code>s tend to use <code>Shape</code>.
     * 
     * @param parent
     *            The parent view of the child whose bounds we're getting.
     * @param line
     *            The index of the child view.
     * @param editorRect
     *            Returned from the text area's <code>getVisibleEditorRect</code> method.
     * @return The child view's bounds.
     */
    protected static final Rectangle getChildViewBounds(View parent, int line,
            Rectangle editorRect) {
        Shape alloc = parent.getChildAllocation(line, editorRect);
        if (alloc == null) {
            // WrappedSyntaxView can have this when made so small it's
            // no longer visible
            return new Rectangle();
        }
        return alloc instanceof Rectangle ? (Rectangle) alloc :
                alloc.getBounds();
    }

    /**
     * Returns the parent <code>Gutter</code> component.
     * 
     * @return The parent <code>Gutter</code>.
     */
    protected Gutter getGutter() {
        Container parent = getParent();
        return (parent instanceof Gutter) ? (Gutter) parent : null;
    }

    /**
     * Called when text is inserted to or removed from the text area. Implementations can take this opportunity to
     * repaint, revalidate, etc.
     * 
     * @param e
     *            The document event.
     */
    abstract void handleDocumentEvent(DocumentEvent e);

    /**
     * Called when the line heights of the text area change. This is usually the result of one or more of the fonts in
     * the editor changing.
     */
    abstract void lineHeightsChanged();

    /**
     * Sets the text area being displayed. Subclasses can override, but should call the super implementation.
     * 
     * @param textArea
     *            The text area.
     */
    public void setTextArea(RTextArea textArea) {
        this.textArea = textArea;
        int lineCount = textArea == null ? 0 : textArea.getLineCount();
        if (currentLineCount != lineCount) {
            currentLineCount = lineCount;
            repaint();
        }
    }

}