Package org.apache.poi.sl.draw

Interface ImageRenderer

All Known Implementing Classes:
BitmapImageRenderer, HwmfImageRenderer
public interface ImageRenderer
Classes can implement this interfaces to support other formats, for example, use Apache Batik to render WMF (since POI 4.0, there's an internal WMF/EMF/EMF+ renderer in POI), PICT can be rendered using Apple QuickTime API for Java: 
 
 public class MyImageRendener implements ImageRendener {
     InputStream data;

     public boolean drawImage(Graphics2D graphics,Rectangle2D anchor,Insets clip) {
         // draw image
       DataInputStream is = new DataInputStream(data);
       org.apache.batik.transcoder.wmf.tosvg.WMFRecordStore wmfStore =
               new org.apache.batik.transcoder.wmf.tosvg.WMFRecordStore();
       try {
           wmfStore.read(is);
       } catch (IOException e){
           return;
       }

       float scale = (float)anchor.width/wmfStore.getWidthPixels();

       org.apache.batik.transcoder.wmf.tosvg.WMFPainter painter =
               new org.apache.batik.transcoder.wmf.tosvg.WMFPainter(wmfStore, 0, 0, scale);
       graphics.translate(anchor.x, anchor.y);
       painter.paint(graphics);
     }

     public void loadImage(InputStream data, String contentType) throws IOException {
         if ("image/wmf".equals(contentType)) {
             this.data = data;
             // use Apache Batik to handle WMF
         } else {
             super.loadImage(data,contentType);
         }
     }
 }
and then pass this class to your instance of java.awt.Graphics2D: 
 
 graphics.setRenderingHint(Drawable.IMAGE_RENDERER, new MyImageRendener());

  • Method Details

    • canRender

      boolean canRender(String contentType)
      Determines if this image renderer implementation supports the given contentType
      Parameters:
      contentType - the image content type
      Returns:
      if the content type is supported

    • loadImage

      void loadImage(InputStream data, String contentType) throws IOException
      Load and buffer the image
      Parameters:
      data - the raw image stream
      contentType - the content type
      Throws:
      IOException

    • loadImage

      void loadImage(byte[] data, String contentType) throws IOException
      Load and buffer the image
      Parameters:
      data - the raw image bytes
      contentType - the content type
      Throws:
      IOException

    • getNativeBounds

      Rectangle2D getNativeBounds()
      Returns:
      the format-specific / not-normalized bounds of the image

    • getBounds

      Rectangle2D getBounds()
      Returns:
      the bounds of the buffered image in pixel

    • getDimension

      default Dimension2D getDimension()
      Returns:
      the dimension of the buffered image in pixel

    • setAlpha

      void setAlpha(double alpha)
      Parameters:
      alpha - the alpha [0..1] to be added to the image (possibly already containing an alpha channel)

    • getImage

      BufferedImage getImage()
      Returns:
      the image as buffered image or null if image could not be loaded

    • getImage

      BufferedImage getImage(Dimension2D dim)
      Parameters:
      dim - the dimension in pixels of the returned image
      Returns:
      the image as buffered image or null if image could not be loaded
      Since:
      POI 3.15-beta2

    • drawImage

      boolean drawImage(Graphics2D graphics, Rectangle2D anchor)
      Render picture data into the supplied graphics
      Returns:
      true if the picture data was successfully rendered

    • drawImage

      boolean drawImage(Graphics2D graphics, Rectangle2D anchor, Insets clip)
      Render picture data into the supplied graphics
      Returns:
      true if the picture data was successfully rendered

    • getGenericRecord

      default GenericRecord getGenericRecord()

    • setDefaultCharset

      default void setDefaultCharset(Charset defaultCharset)
      Sets the default charset to render text elements. Opposed to other windows libraries in POI this simply defaults to Windows-1252.
      Parameters:
      defaultCharset - the default charset

    • setCacheInput

      default void setCacheInput(boolean enable)
      Dis-/Enables caching of input data for later retrieval. Opposed to getImage(), which returns a BufferedImage, the cached image can be later used to embedded the original, unmodified data
      Parameters:
      enable - dis-/enables caching - this is an optional operation. false removes already cached data

    • getCachedImage

      default byte[] getCachedImage()
      Returns:
      the cached image data

    • getCachedContentType

      default String getCachedContentType()
      Returns:
      the cached content type