Bug 178519 Problems in multi-rows header
Please see the attachments.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/PDFBlockStackingLM.java
IStyle contentStyle = content.getComputedStyle( );
			return PropertyUtil.getLineHeight( contentStyle.getLineHeight( ));
		}
		return 0;
	}
	public String getTextAlign( )
	{
		if ( content != null )
		{
			IStyle contentStyle = content.getComputedStyle( );
			return contentStyle.getTextAlign( );
		}
		return null;
	}
	public int getTextIndent( )
	{
		if ( content != null )
		{
			IStyle contentStyle = content.getComputedStyle( );
			return getDimensionValue( contentStyle
					.getProperty( StyleConstants.STYLE_TEXT_INDENT ), maxAvaWidth );
		}
		return 0;
	}
	protected void cancelChildren( )
	{
		if ( child != null )
		{
			child.cancel( );
		}