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
import org.eclipse.birt.chart.reportitem.ui.ChartExpressionButtonUtil;
import org.eclipse.birt.chart.reportitem.ui.ChartReportItemUIUtil;
import org.eclipse.birt.chart.reportitem.ui.views.attributes.provider.ChartCubeFilterExpressionProvider;
import org.eclipse.birt.chart.ui.swt.interfaces.IExpressionButton;
import org.eclipse.birt.chart.ui.swt.interfaces.IUIServiceProvider;
import org.eclipse.birt.chart.ui.swt.wizard.ChartWizardContext;
import org.eclipse.birt.chart.util.ChartExpressionUtil.ExpressionCodec;
import org.eclipse.birt.core.exception.BirtException;
import org.eclipse.birt.data.engine.olap.api.query.IBaseCubeQueryDefinition;
import org.eclipse.birt.data.engine.olap.api.query.ICubeQueryDefinition;
import org.eclipse.birt.report.data.adapter.api.DataRequestSession;
import org.eclipse.birt.report.data.adapter.api.DataSessionContext;
import org.eclipse.birt.report.data.adapter.api.IModelAdapter;
import org.eclipse.birt.report.data.adapter.api.IModelAdapter.ExpressionLocation;
import org.eclipse.birt.report.designer.internal.ui.util.IHelpContextIds;
import org.eclipse.birt.report.designer.internal.ui.util.UIUtil;
import org.eclipse.birt.report.designer.internal.ui.util.WidgetUtil;
import org.eclipse.birt.report.designer.nls.Messages;
import org.eclipse.birt.report.designer.ui.dialogs.ExpressionBuilder;
import org.eclipse.birt.report.designer.ui.dialogs.ExpressionProvider;
import org.eclipse.birt.report.designer.ui.dialogs.FilterConditionBuilder;
import org.eclipse.birt.report.designer.ui.dialogs.IExpressionProvider;
import org.eclipse.birt.report.designer.ui.dialogs.SelectValueDialog;
import org.eclipse.birt.report.designer.ui.newelement.DesignElementFactory;
import org.eclipse.birt.report.designer.ui.views.attributes.providers.ChoiceSetFactory;
import org.eclipse.birt.report.designer.util.AlphabeticallyComparator;
import org.eclipse.birt.report.designer.util.DEUtil;
import org.eclipse.birt.report.model.api.DataItemHandle;
import org.eclipse.birt.report.model.api.DesignElementHandle;
import org.eclipse.birt.report.model.api.Expression;