Ant example source code file (Rotate.java)

This example Ant source code file (Rotate.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

awt, bufferedimage, drawoperation, drawoperation, graphics2d, half_circle, image, imageoperation, imageoperation, interpolationnearest, parameterblock, planarimage, planarimage, rotate, transformoperation, transformoperation

The Rotate.java source code

/*
 *  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.tools.ant.types.optional.image;

import javax.media.jai.PlanarImage;
import javax.media.jai.InterpolationNearest;
import javax.media.jai.JAI;
import java.awt.image.renderable.ParameterBlock;
import java.awt.image.BufferedImage;
import java.awt.Graphics2D;

/**
 * ImageOperation to rotate an image by a certain degree
 *
 * @see org.apache.tools.ant.taskdefs.optional.image.Image
 */
public class Rotate extends TransformOperation implements DrawOperation {
    private static final float HALF_CIRCLE = 180.0F;

    // CheckStyle:VisibilityModifier OFF - bc
    protected float angle = 0.0F;
    // CheckStyle:VisibilityModifier ON

    /**
     * Sets the angle of rotation in degrees.
     * @param ang The angle at which to rotate the image
     */
    public void setAngle(String ang) {
        angle = Float.parseFloat(ang);
    }


    /**
     * Rotate an image.
     * @param image the image to rotate.
     * @return the rotated image.
     */
    public PlanarImage performRotate(PlanarImage image) {
        float tAngle = (float) (angle * (Math.PI / HALF_CIRCLE));
        ParameterBlock pb = new ParameterBlock();
        pb.addSource(image);
        pb.add(0.0F);
        pb.add(0.0F);
        pb.add(tAngle);
        pb.add(new InterpolationNearest());
        return JAI.create("Rotate", pb, null);
    }


    /**
     * Performs the image rotation when being handled as a TransformOperation.
     * @param image The image to perform the transformation on.
     * @return the transformed image.
     */
    public PlanarImage executeTransformOperation(PlanarImage image) {
        BufferedImage bi = null;
        Graphics2D graphics = null;
        for (int i = 0; i < instructions.size(); i++) {
            ImageOperation instr = ((ImageOperation) instructions.elementAt(i));
            if (instr instanceof DrawOperation) {
                // If this TransformOperation has DrawOperation children
                // then Rotate the first child and return.
                System.out.println("Execing Draws");
                PlanarImage op = ((DrawOperation) instr).executeDrawOperation();
                image = performRotate(op);
                return image;
            } else if (instr instanceof TransformOperation) {
                bi = image.getAsBufferedImage();
                graphics = (Graphics2D) bi.getGraphics();
                System.out.println("Execing Transforms");
                image = ((TransformOperation) instr)
                    .executeTransformOperation(PlanarImage.wrapRenderedImage(bi));
                bi = image.getAsBufferedImage();
            }
        }
        System.out.println("Execing as TransformOperation");
        image = performRotate(image);
        System.out.println(image);
        return image;
    }

    /**
     *  Performs the image rotation when being handled as a DrawOperation.
     *  It absolutely requires that there be a DrawOperation nested beneath it,
     *  but only the FIRST DrawOperation will be handled since it can only return
     *  ONE image.
     * @return the image.
     */
    public PlanarImage executeDrawOperation() {
        for (int i = 0; i < instructions.size(); i++) {
            ImageOperation instr = ((ImageOperation) instructions.elementAt(i));
            if (instr instanceof DrawOperation) {
                // If this TransformOperation has DrawOperation children
                // then Rotate the first child and return.
                PlanarImage op = ((DrawOperation) instr).executeDrawOperation();
                op = performRotate(op);
                return op;
            }
        }
        return null;
    }

}