source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rtextarea/AbstractGutterComponent.java@ 25584

/*
 * 02/17/2009
 *
 * AbstractGutterComponent.java - A component that can be displayed in a Gutter.
 * 
 * This library is distributed under a modified BSD license.  See the included
 * RSyntaxTextArea.License.txt file for details.
 */
package org.fife.ui.rtextarea;

import java.awt.Container;
import java.awt.Rectangle;
import java.awt.Shape;
import javax.swing.JPanel;
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 JPanel {

    /**
     * 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();
        }
    }


}