CropImage.java

package com.celements.photo.image;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xwiki.component.annotation.Component;
import org.xwiki.component.annotation.Requirement;
import org.xwiki.context.Execution;

import com.xpn.xwiki.XWikiContext;
import com.xpn.xwiki.XWikiException;
import com.xpn.xwiki.api.Document;
import com.xpn.xwiki.doc.XWikiAttachment;
import com.xpn.xwiki.doc.XWikiDocument;

@Component
public class CropImage implements ICropImage {
  
  private static final Log LOGGER = LogFactory.getFactory().getInstance(CropImage.class);

  @Requirement
  Execution execution;

  private XWikiContext getContext() {
    return (XWikiContext) execution.getContext().getProperty("xwikicontext");
  }
  
  public void crop(BufferedImage img, int x, int y, int w, int h, String type, 
      OutputStream out)  {
    BufferedImage buffCropped = img;
    w = Math.min(w, (img.getWidth()-x));
    h = Math.min(h, (img.getHeight()-y));
    if((x < img.getWidth()) && (y < img.getHeight())) {
      buffCropped = img.getSubimage(x, y, w, h);
    }
    (new GenerateThumbnail()).encodeImage(out, buffCropped, img, type);
  }

  public OutputStream crop(XWikiAttachment xAtt, int x, int y, int w, int h) {
    OutputStream out = new ByteArrayOutputStream();
    crop(xAtt, x, y, w, h, out);
    return out;
  }

  public OutputStream crop(Document doc, String filename, int x, int y, int w, int h,
      OutputStream out) {
    XWikiAttachment xAtt = getAttachment(doc, filename);
    if(xAtt != null){
      return crop((XWikiAttachment)xAtt.clone(), x, y, w, h, out);
    }
    return null;
  }

    public OutputStream crop(XWikiAttachment xAtt, int x, int y, int w, int h,
        OutputStream out) {
    try {
      InputStream in = xAtt.getContentInputStream(getContext());
      BufferedImage img = new GenerateThumbnail().decodeImage(in);
      in.close();
      crop(img, x, y, w, h, xAtt.getMimeType(getContext()), out);
    } catch (XWikiException e) {
      LOGGER.error("Error getting attachment content and decoding it into an " +
          "BufferedImage", e);
    } catch (IOException e) {
      LOGGER.error("Error in input our output stream.", e);
    }
    return out;
  }
  
  XWikiAttachment getAttachment(Document srcDoc, String filename) {
    XWikiAttachment xAtt = null;
    if(srcDoc != null) {
      try {
        XWikiDocument xDoc = getContext().getWiki().getDocument(
            srcDoc.getDocumentReference(),getContext());
        xAtt = xDoc.getAttachment(filename);
      } catch (XWikiException e) {
        LOGGER.error("Exception getting XWikiDocument with crop Attachment", e);
      }
    }
    return xAtt;
  }

  public void outputCroppedImage(Document srcDoc, String srcFilename, int x, int y,
      int w, int h) {
    XWikiAttachment xAtt = getAttachment(srcDoc, srcFilename);
    if(xAtt != null){
      try {
        getContext().getResponse().setContentType("image/png");//output is always png
        crop((XWikiAttachment)xAtt.clone(), x, y, w, h, getContext().getResponse(
            ).getOutputStream());
      } catch (IOException e) {
        LOGGER.error("Error writing cropped image to response stream.", e);
      }
    }
  }
}