Bug 212291 SWT Chart render engine always uses 96 DPI(Display) resolution
chart/org.eclipse.birt.chart.device.swt/src/org/eclipse/birt/chart/device/swt/SwtTextMetrics.java
{
		return gc.isDisposed( );
	}
	protected Font getFont( )
	{
		if ( null == font )
		{
			font = (Font) ids.createFont( la.getCaption( ).getFont( ) );
		}
		return font;
	}
	/**
	 * 
	 * @param fm
	 * @return
	 */
	public final double getHeight( )
	{
		gc.setFont( getFont( ) );
		final int iHeight = gc.textExtent( "X" ).y; 
		return iHeight;
	}
	/**
	 * 
	 * @param fm
	 * @return
	 */
	public final double getDescent( )
	{
		gc.setFont( getFont( ) );