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Java/ZZDrawing.java

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+/*   
+ZZDrawing.java
+ *    
+ *    Copyright (c) 2000, Ted Nelson and Tuomas Lukka
+ *
+ *    You may use and distribute under the terms of either the GNU Lesser
+ *    General Public License, either version 2 of the license or,
+ *    at your choice, any later version. Alternatively, you may use and
+ *    distribute under the terms of the XPL.
+ *
+ *    See the LICENSE.lgpl and LICENSE.xpl files for the specific terms of 
+ *    the licenses.
+ *
+ *    This software 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 README
+ *    file for more details.
+ *
+ */
+/*
+ * Written by Tuomas Lukka
+ */
+package org.gzigzag;
+import java.awt.*;
+
+/** An abstraction of improved drawing primitives.
+ * We are aiming for Java 1.1, but for instance Java2D provides
+ * many features we'd like to use, if present.
+ * Normally, simply testing <pre>g instanceof Graphics2D</pre>
+ * would be sufficient but we want to also be able to <em>compile</em>
+ * with only the 1.1 libraries available, so we cannot do that.
+ * Also, we want to be able to hook up to e.g. OpenGL without 
+ * having to create a full Java2D implementation there.
+ * <p>
+ * This class is used to abstract out any graphics operations that
+ * are not in java.awt.Graphics. The default of this class is that
+ * each operation is a no-op (unless otherwise specified).
+ * All code should function reasonably under such an assumption.
+ * Subclasses of this object are allowed to implement operations
+ * in any way they like.
+ * <p>
+ * TODO: Should make it possible to get drawing parameters
+ * from either system
+ * properties (possibly preferable) or the ZZ structure.
+ */
+
+public class ZZDrawing {
+public static final String rcsid = "$Id: ZZDrawing.java,v 1.6 2001/03/26 12:41:00 tjl Exp $";
+
+    /** Get a human-readable string identifying the ZZDrawing
+     * instance and the settings.
+     */
+    public String getType() {
+	return "Default 1.1 API -compliant version: no antialiasing or rotation";
+    }
+
+    /** The default instance of ZZDrawing for others to use.
+     */
+    static public final ZZDrawing instance = createInstance();
+    private boolean qEnabled = true;
+
+    /** Create an instance.
+     */
+    static public ZZDrawing createInstance() {
+	ZZDrawing ret = null;
+	Class g2d = null, zzdj2d = null;
+	try {
+	    g2d = Class.forName("java.awt.Graphics2D");
+	    zzdj2d = Class.forName("org.gzigzag.ZZDrawingJ2D");
+	    ret = (ZZDrawing)zzdj2d.newInstance();
+	} catch(Exception e) {
+	    ZZLogger.exc(e);
+	    if(g2d != null) {
+		ZZLogger.log("Graphics2D found but support not compiled in.");
+	    }
+	}
+	if(ret == null) ret = new ZZDrawing();
+	return ret;
+    }
+
+    /** Set rendering so that the graphics context will draw
+     * over translucently, with the given alpha.
+     */
+    public void setAlpha(Graphics g, float alpha) {
+    }
+
+    /** Set good rendering quality.
+     * XXX Should take a parameter.
+     */
+    public void setQuality(Graphics g) {
+    }
+
+    /** Return true if it makes any difference. */
+    public boolean enableQuality(boolean t) {
+	qEnabled = t;
+	return false;
+    }
+    public boolean qualityEnabled() { return qEnabled; }
+
+    /** Set the defaults. To be called on all
+     * Graphics objects used.
+     */
+    public void setDefaults(Graphics g0) {
+    }
+}
+