org.apache.poi.sl.draw

Interface ImageRenderer

All Known Implementing Classes:

BitmapImageRenderer, HemfImageRenderer, HemfPlusGDIImageRenderer, HwmfImageRenderer, SVGImageRenderer

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 Summary

Modifier and Type	Method and Description
boolean	canRender(java.lang.String contentType) Determines if this image renderer implementation supports the given contentType
boolean	drawImage(java.awt.Graphics2D graphics, java.awt.geom.Rectangle2D anchor) Render picture data into the supplied graphics
boolean	drawImage(java.awt.Graphics2D graphics, java.awt.geom.Rectangle2D anchor, java.awt.Insets clip) Render picture data into the supplied graphics
java.awt.geom.Rectangle2D	getBounds()
default java.lang.String	getCachedContentType()
default byte[]	getCachedImage()
default java.awt.geom.Dimension2D	getDimension()
default GenericRecord	getGenericRecord()
java.awt.image.BufferedImage	getImage()
java.awt.image.BufferedImage	getImage(java.awt.geom.Dimension2D dim)
java.awt.geom.Rectangle2D	getNativeBounds()
void	loadImage(byte[] data, java.lang.String contentType) Load and buffer the image
void	loadImage(java.io.InputStream data, java.lang.String contentType) Load and buffer the image
void	setAlpha(double alpha)
default void	setCacheInput(boolean enable) Dis-/Enables caching of input data for later retrieval.
default void	setDefaultCharset(java.nio.charset.Charset defaultCharset) Sets the default charset to render text elements.

Method Detail

canRender

boolean canRender(java.lang.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(java.io.InputStream data,
               java.lang.String contentType)
        throws java.io.IOException

Load and buffer the image

Parameters:

data - the raw image stream

contentType - the content type

Throws:

java.io.IOException

loadImage

void loadImage(byte[] data,
               java.lang.String contentType)
        throws java.io.IOException

Load and buffer the image

Parameters:

data - the raw image bytes

contentType - the content type

Throws:

java.io.IOException

getNativeBounds

java.awt.geom.Rectangle2D getNativeBounds()

Returns:

the format-specific / not-normalized bounds of the image

getBounds

java.awt.geom.Rectangle2D getBounds()

Returns:

the bounds of the buffered image in pixel

getDimension

default java.awt.geom.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

java.awt.image.BufferedImage getImage()

Returns:

the image as buffered image or null if image could not be loaded

getImage

java.awt.image.BufferedImage getImage(java.awt.geom.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(java.awt.Graphics2D graphics,
                  java.awt.geom.Rectangle2D anchor)

Render picture data into the supplied graphics

Returns:

true if the picture data was successfully rendered

drawImage

boolean drawImage(java.awt.Graphics2D graphics,
                  java.awt.geom.Rectangle2D anchor,
                  java.awt.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(java.nio.charset.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 java.lang.String getCachedContentType()

Returns:

the cached content type