io.wcm.handler.media.impl.DummyImageServlet.java Source code

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Here is the source code for io.wcm.handler.media.impl.DummyImageServlet.java

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/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2014 wcm.io
 * %%
 * Licensed 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.
 * #L%
 */
package io.wcm.handler.media.impl;

import io.wcm.handler.url.suffix.SuffixParser;
import io.wcm.wcm.commons.contenttype.FileExtension;

import java.awt.Color;
import java.io.IOException;

import javax.jcr.RepositoryException;

import org.apache.commons.lang3.StringUtils;
import org.apache.felix.scr.annotations.sling.SlingServlet;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;

import com.day.cq.wcm.commons.AbstractImageServlet;
import com.day.image.Font;
import com.day.image.Layer;
import com.day.image.font.AbstractFont;

/**
 * Servlet which is used to render a dummy image with information about the size of the image and media format.
 * Note: most of the values used for scaling are the result of experiments, how the image looks nice.
 */
@SlingServlet(resourceTypes = "/apps/wcm-io/handler/media/components/dummyImage", extensions = FileExtension.PNG)
public final class DummyImageServlet extends AbstractImageServlet {
    private static final long serialVersionUID = 1L;

    /**
     * Dummy image content path
     */
    public static final String PATH = "/apps/wcm-io/handler/media/content/dummyImage";

    /**
     * Suffix for width
     */
    public static final String SUFFIX_WIDTH = "width";

    /**
     * Suffix for height
     */
    public static final String SUFFIX_HEIGHT = "height";

    /**
     * Suffix for Name of mediaformat (optional)
     */
    public static final String SUFFIX_MEDIA_FORMAT_NAME = "mf";

    @Override
    protected Layer createLayer(ImageContext ctx) throws RepositoryException, IOException {
        SuffixParser parser = new SuffixParser(ctx.request);
        int width = parser.get(SUFFIX_WIDTH, 0);
        int height = parser.get(SUFFIX_HEIGHT, 0);
        String name = parser.get(SUFFIX_MEDIA_FORMAT_NAME, String.class);

        // validate with/height
        if (width < 1 || height < 1) {
            return new Layer(1, 1, null);
        }

        Layer textLayer = getTextLayer(width, height, name);

        int x = (width - textLayer.getWidth()) / 2;
        int y = (height - textLayer.getHeight()) / 2;

        Layer layer = new Layer(width, height, Color.GRAY);

        // we now build a grey box for the text which is slightly bigger than the text
        int backgroundOffset = width / 120;
        Layer textBackground = new Layer(textLayer.getWidth() + (backgroundOffset * 2),
                textLayer.getHeight() + (backgroundOffset * 2), Color.DARK_GRAY);
        layer.blit(textBackground, x - backgroundOffset, y - backgroundOffset, textBackground.getWidth(),
                textBackground.getHeight(), 0, 0);

        // now we can add the text
        layer.blit(textLayer, x, y, textLayer.getWidth(), textLayer.getHeight(), 0, 0);
        return layer;
    }

    private Layer getTextLayer(int width, int height, String name) {
        String text = (StringUtils.isNotEmpty(name) ? name + "\n" : "") + width + " x " + height;
        Font font = new Font("Arial", width / 30);
        int align = AbstractFont.ALIGN_BASE | AbstractFont.ALIGN_CENTER | AbstractFont.TTANTIALIASED;
        Layer ret = new Layer(1, 1, null);
        ret.setPaint(Color.WHITE);
        ret.drawText(0, 0, 0, 0, text, font, align, 0, 0);
        return ret;
    }

    @Override
    protected boolean checkModifiedSince(SlingHttpServletRequest pReq, SlingHttpServletResponse pResp) {
        return false;
    }

}