Bug 151959 inappropriate screen operation
steps to reproduce: - create a report - add a grid item (3x3) - switch to Outline view - expand the grid item to see its rows and cells - select the grid item, and drag it into any of its own cell expected behavior: - is it an invalid screen operation? if it is, it should be banned actual behavior: - the grid item was disappeared surprisingly
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
import org.eclipse.birt.report.model.api.core.IDesignElement;
import org.eclipse.birt.report.model.api.core.IStructure;
import org.eclipse.birt.report.model.api.core.Listener;
import org.eclipse.birt.report.model.api.core.UserPropertyDefn;
import org.eclipse.birt.report.model.api.elements.ReportDesignConstants;
import org.eclipse.birt.report.model.api.elements.structures.PropertyMask;
import org.eclipse.birt.report.model.api.metadata.IElementDefn;
import org.eclipse.birt.report.model.api.metadata.IObjectDefn;
import org.eclipse.birt.report.model.api.metadata.ISlotDefn;
import org.eclipse.birt.report.model.api.metadata.PropertyValueException;
import org.eclipse.birt.report.model.api.util.StringUtil;
import org.eclipse.birt.report.model.api.validators.SimpleListValidator;
import org.eclipse.birt.report.model.api.validators.StructureListValidator;
import org.eclipse.birt.report.model.api.validators.UnsupportedElementValidator;
import org.eclipse.birt.report.model.elements.ElementVisitor;
import org.eclipse.birt.report.model.elements.Library;
import org.eclipse.birt.report.model.elements.ListingElement;
import org.eclipse.birt.report.model.elements.MasterPage;
import org.eclipse.birt.report.model.elements.ReportDesign;
import org.eclipse.birt.report.model.elements.TemplateElement;
import org.eclipse.birt.report.model.elements.TemplateParameterDefinition;
import org.eclipse.birt.report.model.elements.Theme;
import org.eclipse.birt.report.model.elements.interfaces.IDesignElementModel;
import org.eclipse.birt.report.model.elements.strategy.CopyForPastePolicy;
import org.eclipse.birt.report.model.elements.strategy.CopyPolicy;
import org.eclipse.birt.report.model.i18n.ThreadResources;
import org.eclipse.birt.report.model.metadata.BooleanPropertyType;
import org.eclipse.birt.report.model.metadata.ElementDefn;
import org.eclipse.birt.report.model.metadata.ElementPropertyDefn;
import org.eclipse.birt.report.model.metadata.ElementRefPropertyType;