Bug 312859 The list of operator for Chart filter does not provide 30 visible items
chart/org.eclipse.birt.chart.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/dialogs/ChartCubeFilterConditionBuilder.java
private String fCurrentExpr = ""; 
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.dialogs.Dialog#createContents(org.eclipse.swt.widgets.Composite)
	 */
	protected Control createDialogArea( Composite parent )
	{
		UIUtil.bindHelp( parent,
				IHelpContextIds.INSERT_EDIT_FILTER_CONDITION_DIALOG_ID );
		Composite area = (Composite) super.createDialogArea( parent );
		Composite contents = new Composite( area, SWT.NONE );
		contents.setLayoutData( new GridData( GridData.FILL_BOTH ) );
		contents.setLayout( new GridLayout( ) );
		this.setTitle( title );
		this.setMessage( message );
		getShell( ).setText( title );
		applyDialogFont( contents );
		initializeDialogUnits( area );
		createFilterConditionContent( contents );
		return area;
	}
	protected void createFilterConditionContent( Composite innerParent )
	{
		Composite anotherParent = new Composite( innerParent, SWT.NONE );
		GridData gd = new GridData( GridData.FILL_HORIZONTAL );
		anotherParent.setLayoutData( gd );
		GridLayout glayout = new GridLayout( 4, false );
		anotherParent.setLayout( glayout );
		Label lb = new Label( anotherParent, SWT.NONE );