Bug 180249 BPS39 - Centralized Chart Engine API
Centralized and clearer Engine API -Create one single entry point class ChartEngine in an api package so it's easy to find (with access to IGenerator, Serializer, Device Renderers) -Create a new IGenerator interface instead of exposing the Generator class.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/factory/Generator.java
ScriptHandler sh = new ScriptHandler( );
		rtc.setScriptHandler( sh );
		sh.setScriptClassLoader( iscl );
		sh.setScriptContext( csc );
		
		if ( externalContext != null
				&& externalContext.getScriptable( ) != null )
		{
			sh.init( externalContext.getScriptable( ) );
		}
		else
		{
			sh.init( null );
		}
		sh.setRunTimeModel( cmRunTime );
		final String sScriptContent = cmRunTime.getScript( );
		if ( sScriptContent != null )
		{
			sh.register( sScriptContent );
		}
		
		
		/*
		 * ScriptHandler.callFunction( sh, ScriptHandler.ON_PREPARE, cmRunTime,
		 * rtc.getScriptContext( ) );
		 */
		return rtc;
	}
	/**
	 * Builds and computes preferred sizes of various chart components offscreen