Bug 132645 Mouse Double Click/URL Redirect on Y series of Line Chart does not work
Decription: Add a interactivity on line chart, mouse double click/URL Redirect on Y Series, does not work. Steps to reproduce: 1.Add a line chart, bind with valid dataset. 2.In the "Format Chart" tab, add a interactivity on "Value(Y) Series", the type is "Mouse Double Click", and the action is set "URL Redirect". 3.Preview in layout, click on the Y Series, interactivity does not work.
chart/org.eclipse.birt.chart.device.extension/src/org/eclipse/birt/chart/device/image/JavaxImageIOWriter.java
* Returns true if the image type supports transparency
	 * false otherwise
	 * @return
	 */
	protected boolean supportsTransparency( )
	{
		return true;
	}
	JavaxImageIOWriter( )
	{
		
		ImageIO.setUseCache( false );
	}
	/**
	 * Updates the writer's parameters.
	 * 
	 * @param iwp
	 */
	protected void updateWriterParameters( ImageWriteParam iwp )
	{
		
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.chart.device.IImageMapEmitter#getMimeType()
	 */
	public abstract String getMimeType( );
	/*
	 * (non-Javadoc)