Bug 149922 Image builder - URI and file source type are treated as same
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ImageHandle.java
{
		String source = DesignChoiceConstants.IMAGE_REF_TYPE_URL;
		setURIProperty( uri, source );
	}
	/**
	 * Sets the image uri property. The source type is
	 * <code>IMAGE_REF_TYPE_FILE</code>, and will automatically set in this
	 * method.
	 * 
	 * @param file
	 *            the file to be set.
	 * @throws SemanticException
	 *             if the property is locked.
	 */
	public void setFile( String file ) throws SemanticException
	{
		String source = DesignChoiceConstants.IMAGE_REF_TYPE_FILE;
		setURIProperty( file, source );
	}
	/**
	 * Sets the image uri property. The source type is
	 * <code>IMAGE_REF_TYPE_FILE</code> or <code>IMAGE_REF_TYPE_FILE</code>.
	 * 
	 * @param prop
	 *            uri property
	 * @param source
	 *            image reference property
	 * @throws SemanticException
	 */
	private void setURIProperty( String prop, String source )