swingx-master/swingx-painters/src/main/java/org/jdesktop/swingx/painter/AbstractAreaPainter.java
/*
 * $Id$
 *
 * Copyright 2006 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

package org.jdesktop.swingx.painter;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;

import org.jdesktop.swingx.painter.effects.AreaEffect;
import org.jdesktop.swingx.util.PaintUtils;

/**
 * The abstract base class for all painters that fill a vector path area.  This
 * includes Shapes, Rectangles, Text, and the MattePainter
 * which fills in the entire background of a component.  The defining
 * feature of AbstractAreaPainter subclasses
 * is that they implement the provideShape() method which returns
 * the outline shape of the area that this
 * painter will fill. Subclasses must implement the provideShape() method.
 *
 * The AbstractAreaPainter provides support for the following common painting properties
 *
 * <ul>
 * <li>fillPaint</li>
 * <li>paintStretched</li>
 * <li>borderPaint</li>
 * <li>borderWidth</li>
 * <li>style</li>
 * </ul>
 *
 * The AbstractAreaPainter also provides support for path effects like dropshadows and glows.
 *
 * @author joshua@marinacci.org
 */
@SuppressWarnings("nls")
public abstract class AbstractAreaPainter<T> extends AbstractLayoutPainter<T> {
    
    /**
     * Different available fill styles. BOTH indicates that both the outline,
     * and the fill should be painted. This is the default. FILLED indicates that
     * the shape should be filled, but no outline painted. OUTLINE specifies that
     * the shape should be outlined, but not filled. NONE indicates that neither
     * the fill area nor the outline should be painted.
     */
    public enum Style {BOTH, FILLED, OUTLINE,
        /**
         * {@code NONE} has different semantics that {@link AbstractAreaPainter#setVisible(boolean)
         * setVisible(false)}. With {@code setVisible(false)}, nothing is painted. With style
         * {@code NONE}, any {@link AreaEffect effects} are still painted.
         */
        NONE}
    
    // controls if the paint should be stretched to fill the available area
    private boolean stretchPaint;
    
    private AreaEffect[] areaEffects = new AreaEffect[0];
    
    private Style style = Style.BOTH;
    /**
     * The stroke width to use when painting. If null, the default Stroke for
     * the Graphics2D is used
     */
    private float borderWidth;
    
    /**
     * The paint to use when filling the shape
     */
    private Paint fillPaint;
    
    /**
     * The Paint to use when stroking the shape (drawing the outline). If null,
     * then the component foreground color is used
     */
    private Paint borderPaint;
    
    /**
     * Creates a new instance of AbstractAreaPainter
     */
    public AbstractAreaPainter() {
        fillPaint = Color.RED;
    }
    
    /**
     * Creates a new instance of AbstractAreaPainter
     * @param paint the default paint to fill this area painter with
     */
    public AbstractAreaPainter(Paint paint) {
        this.fillPaint = paint;
    }
    
    /**
     * Gets the current fill paint. This is the Paint object that will be used to fill the path area.
     * @return Gets the Paint being used. May be null
     */
    public Paint getFillPaint() {
        return fillPaint;
    }
    
    /**
     * Sets the Paint to use. This is the Paint object that will be used to fill the path area. If null, nothing is painted
     * @param p the Paint to use
     */
    public void setFillPaint(Paint p) {
        Paint old = getFillPaint();
        this.fillPaint = p;
        setDirty(true);
        firePropertyChange("fillPaint", old, getFillPaint());
    }
    
    /**
     * Indicates if the paint will be snapped. This means that the paint will be scaled and aligned along the 4 axis of (horizontal, vertical,
     * and both diagonals). Snapping allows the paint to be stretched across the component when it is drawn, even if the component is
     * resized. This setting is only used for gradient paints. It will have no effect on Color or Texture paints.
     * @return the current value of the snapPaint property
     */
    public boolean isPaintStretched() {
        return stretchPaint;
    }
    
    /**
     * Specifies whether this Painter should attempt to resize the Paint to fit the area being painted.
     * For example, if true, then a gradient specified as (0, 0), (1, 0) would stretch horizontally such that
     * the beginning of the gradient is on the left edge of the painted region, and the end of the gradient
     * is at the right edge of the painted region.
     * Specifically, if true, the resizePaint method will be called to perform the actual resizing of the Paint
     * @param paintStretched true if the paint should be stretched, false otherwise.
     */
    public void setPaintStretched(boolean paintStretched) {
        boolean old = this.isPaintStretched();
        this.stretchPaint = paintStretched;
        setDirty(true);
        firePropertyChange("paintStretched", old, isPaintStretched());
    }
    
    /**
     * The Paint to use for stroking the shape (painting the outline).
     * Can be a Color, GradientPaint, TexturePaint, or any other kind of Paint.
     * If null, the component foreground is used.
     *
     * @param p the Paint to use for stroking the shape. May be null.
     */
    public void setBorderPaint(Paint p) {
        Paint old = getBorderPaint();
        this.borderPaint = p;
        setDirty(true);
        firePropertyChange("borderPaint", old, getBorderPaint());
    }
    
    /**
     * Gets the current Paint to use for stroking the shape (painting the outline).
     * Can be a Color, GradientPaint, TexturePaint, or any other kind of Paint.
     * If null, the component foreground is used.
     * @return the Paint used when stroking the shape. May be null
     */
    public Paint getBorderPaint() {
        return borderPaint;
    }
    
    /**
     * The shape can be filled or simply stroked (outlined), or both or none. By default,
     * the shape is both filled and stroked. This property specifies the strategy to
     * use.
     * @param s the Style to use. If null, Style.BOTH is used
     */
    public void setStyle(Style s) {
        Style old = getStyle();
        this.style = s == null ? Style.BOTH : s;
        setDirty(true);
        firePropertyChange("style", old, getStyle());
    }
    
    /**
     * Gets the current Style. The shape can be filled or simply stroked (outlined), or both or none. By default,
     * the shape is both filled and stroked. This property specifies the strategy to
     * use.
     * @return the Style used
     */
    public Style getStyle() {
        return style;
    }
    
    /**
     * Sets the border width to use for painting. If null, then the default Graphics2D
     * stroke will be used.  The stroke will be centered on the actual shape outline.
     * @param s the Stroke to fillPaint with
     */
    public void setBorderWidth(float s) {
        float old = getBorderWidth();
        this.borderWidth = s;
        setDirty(true);
        firePropertyChange("borderWidth", old, getBorderWidth());
    }
    
    /**
     * Gets the current border width.
     * @return the Stroke to use for painting
     */
    public float getBorderWidth() {
        return borderWidth;
    }
    
    /**
     * Resizes the given Paint. By default, only Gradients, LinearGradients, and RadialGradients are resized
     * in this method. If you have special resizing needs, override this method. This
     * method is mainly used to make gradient paints resize with the component this
     * painter is attached to. This method is internal to the painter api and should
     * not be called elsewhere. It is used by the paintStretched property and
     * painter subclasses. In the future it may be made public for use by other classes.
     * If this happens it should probably be turned into a static utility method.
     */
    Paint calculateSnappedPaint(Paint p, int width, int height) {
        return PaintUtils.resizeGradient(p, width, height);
    }
    
    /**
     * Returns the outline shape of this painter. Subclasses must implement this method. This shape
     * will be used for filling, stroking, and clipping.
     * @return the outline shape of this painter
     * @param g graphics
     * @param comp The Object this painter will be painted on.
     * @param width the width to paint
     * @param height the height to paint
     */
    protected abstract Shape provideShape(Graphics2D g, T comp, int width, int height);
    
    /**
     * Sets the path effects to be drawn on this painter. Set this to null in order to remove all installed effects.
     * @param areaEffects the effects to apply to this painter
     */
    public void setAreaEffects(AreaEffect... areaEffects) {
        AreaEffect[] old = getAreaEffects();
        this.areaEffects = new AreaEffect[areaEffects == null ? 0 : areaEffects.length];
        if (areaEffects != null) {
            System.arraycopy(areaEffects, 0, this.areaEffects, 0, this.areaEffects.length);
        }
        setDirty(true);
        firePropertyChange("areaEffects", old, getAreaEffects());
    }
    
    /**
     * Gets the current set of path effects applied to this painter. Returned array is guarantied to be not null.
     * @return the effects applied to this path painter
     */
    public AreaEffect[] getAreaEffects() {
        AreaEffect[] results = new AreaEffect[areaEffects.length];
        System.arraycopy(areaEffects, 0, results, 0, results.length);
        return results;
    }
    
}
