svn commit: r822864 - /incubator/pivot/trunk/wtk/src/org/apache/pivot/wtk/effects/RotationDecorator.java

[tv...@apache.org]

Author: tvolkert
Date: Wed Oct  7 19:31:35 2009
New Revision: 822864

URL: http://svn.apache.org/viewvc?rev=822864&view=rev
Log:
Added RotationDecorator

Added:
    incubator/pivot/trunk/wtk/src/org/apache/pivot/wtk/effects/RotationDecorator.java

Added: incubator/pivot/trunk/wtk/src/org/apache/pivot/wtk/effects/RotationDecorator.java
URL: http://svn.apache.org/viewvc/incubator/pivot/trunk/wtk/src/org/apache/pivot/wtk/effects/RotationDecorator.java?rev=822864&view=auto
==============================================================================
--- incubator/pivot/trunk/wtk/src/org/apache/pivot/wtk/effects/RotationDecorator.java (added)
+++ incubator/pivot/trunk/wtk/src/org/apache/pivot/wtk/effects/RotationDecorator.java Wed Oct  7 19:31:35 2009
@@ -0,0 +1,106 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to you under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except in
+ * compliance with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.pivot.wtk.effects;
+
+import java.awt.Graphics2D;
+import java.awt.geom.AffineTransform;
+
+import org.apache.pivot.wtk.Bounds;
+import org.apache.pivot.wtk.Component;
+
+/**
+ * Decorator that rotates a component about its center.
+ */
+public class RotationDecorator implements Decorator {
+    private double theta;
+
+    /**
+     * Creates a new rotation decorator with the default theta value (zero).
+     */
+    public RotationDecorator() {
+        this(0d);
+    }
+
+    /**
+     * Creates a new rotation decorator with the specified theta value.
+     *
+     * @param theta
+     * The rotation angle, in radians.
+     */
+    public RotationDecorator(double theta) {
+        setTheta(theta);
+    }
+
+    /**
+     * Gets the rotation angle, in radians.
+     */
+    public double getTheta() {
+        return theta;
+    }
+
+    /**
+     * Sets the rotation angle, in radians.
+     */
+    public void setTheta(double theta) {
+        this.theta = theta;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Graphics2D prepare(Component component, Graphics2D graphics) {
+        graphics.rotate(theta, component.getWidth() * 0.5, component.getHeight() * 0.5);
+        return graphics;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void update() {
+        // No-op
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Bounds getBounds(Component component) {
+        int width = component.getWidth();
+        int height = component.getHeight();
+
+        double sinTheta = Math.abs(Math.sin(theta));
+        double cosTheta = Math.abs(Math.cos(theta));
+
+        int transformedWidth = (int)Math.ceil((height * sinTheta) + (width * cosTheta));
+        int transformedHeight = (int)Math.ceil((height * cosTheta) + (width * sinTheta));
+        int transformedX = (int)Math.floor((width - transformedWidth) * 0.5);
+        int transformedY = (int)Math.floor((height - transformedHeight) * 0.5);
+
+        return new Bounds(transformedX, transformedY, transformedWidth, transformedHeight);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public AffineTransform getTransform(Component component) {
+        return AffineTransform.getRotateInstance(theta, component.getWidth() * 0.5,
+            component.getHeight() * 0.5);
+    }
+}