DrawableBox.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 John Krasnay and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     John Krasnay - initial API and implementation
 *******************************************************************************/
package net.sf.vex.layout;

import net.sf.vex.core.ColorResource;
import net.sf.vex.core.Drawable;
import net.sf.vex.core.FontMetrics;
import net.sf.vex.core.FontResource;
import net.sf.vex.core.Graphics;
import net.sf.vex.core.Rectangle;
import net.sf.vex.css.Styles;
import net.sf.vex.dom.Element;

/**
 * An inline box that draws a Drawable object. The drawable is drawn relative
 * to the text baseline, therefore it should draw using mostly negative y-coordinates.
 */
public class DrawableBox extends AbstractBox implements InlineBox {

    public static final byte NO_MARKER = 0;
    public static final byte START_MARKER = 1;
    public static final byte END_MARKER = 2;
    
    private Drawable drawable;
    private Element element;
    private byte marker;
    
    /**
     * Class constructor.
     * @param drawable Drawable to draw.
     * @param element Element whose styles determine the color of the drawable.
     */
    public DrawableBox(Drawable drawable, Element element) {
        this(drawable, element, NO_MARKER);
    }
    
    /**
     * Class constructor. This constructor is called when creating a 
     * DrawableBox that represents the start or end marker of an
     * inline element.
     * @param drawable Drawable to draw.
     * @param element Element whose styles determine the color of the drawable.
     * @param marker which marker should be drawn. Must be one of NO_MARKER,
     * START_MARKER, or END_MARKER.
     */
    public DrawableBox(Drawable drawable, Element element, byte marker) {
        this.drawable = drawable;
        this.element = element;
        this.marker = marker;
        Rectangle bounds = drawable.getBounds();
        this.setWidth(bounds.getWidth());
        this.setHeight(bounds.getHeight());
    }
    
    /**
     * @see net.sf.vex.layout.InlineBox#getBaseline()
     */
    public int getBaseline() {
        return 0;
    }

    /**
     * Returns the element that controls the styling for this text element.
     */
    public Element getElement() {
        return this.element;
    }
    
    public boolean isEOL() {
        return false;
    }
    
    /**
     * @see net.sf.vex.layout.InlineBox#split(net.sf.vex.layout.LayoutContext, int, boolean)
     */
    public Pair split(LayoutContext context, int maxWidth, boolean force) {
        return new Pair(null, this);
    }

    /**
     * Draw the drawable. The foreground color of the context's Graphics is
     * set before calling the drawable's draw method.
     */
    public void paint(LayoutContext context, int x, int y) {
        
        Graphics g = context.getGraphics();
        Styles styles = context.getStyleSheet().getStyles(this.element);
        
        boolean drawSelected = false;
        if (this.marker == START_MARKER) {
            drawSelected = 
                this.getElement().getStartOffset() >= context.getSelectionStart()
                && this.getElement().getStartOffset() + 1 <= context.getSelectionEnd();
        } else if (this.marker == END_MARKER) {
            drawSelected = 
                this.getElement().getEndOffset() >= context.getSelectionStart()
                && this.getElement().getEndOffset() + 1 <= context.getSelectionEnd();
        }
        
        FontResource font = g.createFont(styles.getFont());
        ColorResource color = g.createColor(styles.getColor());
        
        FontResource oldFont = g.setFont(font);
        ColorResource oldColor = g.setColor(color);
        
        FontMetrics fm = g.getFontMetrics();
        
        if (drawSelected) {
            Rectangle bounds = this.drawable.getBounds();
            g.setColor(g.getSystemColor(ColorResource.SELECTION_BACKGROUND));
            g.fillRect(x + bounds.getX(), y - fm.getAscent(), bounds.getWidth(), styles.getLineHeight());
            g.setColor(g.getSystemColor(ColorResource.SELECTION_FOREGROUND));
        }
        
        this.drawable.draw(g, x, y);
        
        g.setFont(oldFont);
        g.setColor(oldColor);
        font.dispose();
        color.dispose();
    }

    /**
     * @see java.lang.Object#toString()
     */
    public String toString() {
        return "[shape]";
    }

}