001: /*
002: * $Id: AbstractGradientPainter.java,v 1.3 2006/03/24 02:36:08 rbair Exp $
003: *
004: * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
005: * Santa Clara, California 95054, U.S.A. All rights reserved.
006: *
007: * This library is free software; you can redistribute it and/or
008: * modify it under the terms of the GNU Lesser General Public
009: * License as published by the Free Software Foundation; either
010: * version 2.1 of the License, or (at your option) any later version.
011: *
012: * This library is distributed in the hope that it will be useful,
013: * but WITHOUT ANY WARRANTY; without even the implied warranty of
014: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015: * Lesser General Public License for more details.
016: *
017: * You should have received a copy of the GNU Lesser General Public
018: * License along with this library; if not, write to the Free Software
019: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
020: */
021:
022: package org.jdesktop.swingx.painter.gradient;
023:
024: import java.awt.Graphics2D;
025: import java.awt.Paint;
026: import javax.swing.JComponent;
027: import org.jdesktop.swingx.painter.AbstractPainter;
028: import org.jdesktop.swingx.util.Resize;
029:
030: /**
031: * <p>An abstract base class from which the various gradient oriented painter
032: * classes extend. Gradient based painters perform an important task beyond what
033: * a MattePainter with a GradientPaint will do -- they resize the gradient to
034: * fit the Component regardless of its dimensions.</p>
035: *
036: * <p>AbstractGradientPainter has a resize property of type Resize that specifies
037: * whether the gradient should be resized horizontally, vertically, in both directions
038: * or not at all (in which case you should really probably be using MattePainter).
039: * Subclasses must implement calculateSizedPaint to return a new gradient paint
040: * instance that is resized in the proper ways. If no Paint is returned from
041: * this method call, then nothing is painted.</p>
042: *
043: * <p>By default, the resize property is set to BOTH.</p>
044: *
045: * <p>In order for resizing to work properly with GradientPaint, LinearGradientPaint,
046: * and RadialGradientPaint, it is necessary that the various control points used in
047: * these paints be specified in such a manner that they can be reliably resized.
048: * For example, BasicGradientPainter takes GradientPaints who's point1 and point2
049: * properties are specified between 0 and 1, representing at what percentage of
050: * the distance from the origin the gradient begins and ends. Thus, if I created
051: * a GradientPaint like this:
052: * <pre><code>
053: * GradientPaint gp = new GradientPaint(
054: * new Point2D.Double(.2d, 0),
055: * Color.BLUE,
056: * new Point2D.Double(.8d, 0),
057: * Color.WHITE);
058: * </code></pre>
059: *
060: * then when painted, the gradient will start with a BLUE at 20% of the width of
061: * the component, and finish with WHITE at 80% of the width of the component.</p>
062: *
063: * <p>See the various subclasses for more detailed examples.</p>
064: *
065: * @author rbair
066: */
067: public abstract class AbstractGradientPainter extends AbstractPainter {
068: /**
069: * Indicates in which direction (vertical, horizontal, both, none) to
070: * resize the gradient paint prior to painting
071: */
072: private Resize resize = Resize.BOTH;
073:
074: /**
075: * Creates a new instance of AbstractGradientPainter
076: */
077: public AbstractGradientPainter() {
078: }
079:
080: /**
081: * @inheritDoc
082: */
083: public void paintBackground(Graphics2D g, JComponent component) {
084: Paint p = calculateSizedPaint(component.getWidth(), component
085: .getHeight());
086: if (p != null) {
087: g.setPaint(p);
088: g.fillRect(0, 0, component.getWidth(), component
089: .getHeight());
090: }
091: }
092:
093: /**
094: * @return a calculated Paint that fits within the given width/height. May
095: * be null.
096: *
097: * @param width the width used to calculate the new paint size
098: * @param height the height used to calculate the new paint size
099: */
100: protected abstract Paint calculateSizedPaint(int width, int height);
101:
102: /**
103: * @return a value indicating how the paint will be resized to fit the
104: * component dimensions. Never returns null.
105: */
106: public Resize getResize() {
107: return resize;
108: }
109:
110: /**
111: * Specifies how the paint will be resized based on the component dimensions.
112: *
113: * @param resize the new Resize value. May be null. If null, set to Resize.BOTH.
114: */
115: public void setResize(Resize resize) {
116: Resize old = getResize();
117: boolean rh = isResizeHorizontal();
118: boolean rv = isResizeVertical();
119:
120: this .resize = resize == null ? Resize.BOTH : resize;
121:
122: firePropertyChange("resize", old, getResize());
123: firePropertyChange("resizeHorizontal", rh, isResizeHorizontal());
124: firePropertyChange("resizeVertical", rv, isResizeVertical());
125: }
126:
127: /**
128: * @return true if getResize() returns BOTH or HORIZONTAL.
129: */
130: protected boolean isResizeHorizontal() {
131: Resize r = getResize();
132: return r == Resize.BOTH || r == Resize.HORIZONTAL;
133: }
134:
135: /**
136: * @return true if getResize() returns BOTH or VERTICAL.
137: */
138: protected boolean isResizeVertical() {
139: Resize r = getResize();
140: return r == Resize.BOTH || r == Resize.VERTICAL;
141: }
142: }
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