Bug 199834 Enable access to IContent object in IReportItemPresentation layer
In IReportItemPresentation layer, the extended item may want to access properties from current IContent object, for example, bookmark, content style. So we need expose the content object in this layer.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/presentation/LocalizedContentVisitor.java
return formats;
		}
		return "PNG;GIF;JPG;BMP;"; 
	}
	private String getImageCacheID( IContent content )
	{
		StringBuffer buffer = new StringBuffer( );
		buffer.append( content.getInstanceID( ).toUniqueString( ) );
		buffer.append( getChartResolution( ) );
		buffer.append( getChartFormats( ) );
		buffer.append( locale );
		return buffer.toString( );
	}
	
	private IContent processCachedImage( IForeignContent content,
			CachedImage cachedImage )
	{
		IImageContent imageObj = getReportContent( ).createImageContent(
				content );
		imageObj.setParent( content.getParent( ) );
		
		imageObj.setImageSource( IImageContent.IMAGE_FILE );
		imageObj.setURI( cachedImage.getURL( ) );
		imageObj.setMIMEType( cachedImage.getMIMEType( ) );
		imageObj.setImageMap( cachedImage.getImageMap( ) );
		imageObj.setAltText( content.getAltText( ) );
		imageObj.setAltTextKey( content.getAltTextKey( ) );
		processImage( imageObj );
		return imageObj;
	}