This document contains the release notes for recent major releases of Sirius. See also the release notes from previous versions for details about older releases.
org.eclipse.sirius.properties.core.api.SiriusInputDescriptor and
org.eclipse.sirius.properties.core.internal.SiriusToolServices classes allows to use the list of selected elements in order to exploit additional informations. It is now possible to retrieve the list of selected elements via an aql expression like
aql:input.getSelectedOriginalSelections(), the list of semantic elements with
aql:input.getSelectedSemanticElements() and the list of contexts with
aql:input.getContextSelections().
org.eclipse.sirius.properties.core.api.SiriusInputDescriptor class has been modified to handle the selection of many elements by creating a list of SiriusContext. This enhancement allows to access the list of selected semantic elements with
org.eclipse.sirius.properties.core.api.SiriusInputDescriptor.getSemanticElements() and the list of original selected objects with
org.eclipse.sirius.properties.core.api.SiriusInputDescriptor.getOriginalSelections().
Shift key is pressed during using the
left arrow key, a collapse all is done instead of a simple collapse. This is the same for expand with
Shift +
right arrow key. You can refer to
navigation documentation for more details.
org.eclipse.sirius.ui.restoreBehaviorEnablingDirectEditOnAlphanumericKey to true
org.eclipse.sirius.ui.enableCreatedElementsConstraintInSelectElementsListener has been added to allow to ignore the “created elements” constraint when the
SelectDRepresentationElementsListener is called to select elements after a tool execution. In other words, this allows to select an element that is not created during the tool execution. The default value of the system property is
true. It must be set to
false to ignore the constraint.
org.eclipse.sirius.diagram.ui.business.internal.migration.WorkspaceImageGMFBoundsMigrationParticipant migration participant has been modified to fix the previous version
15.0.0.202201261500 . The corresponding version, stored in attribute version of viewpoint:DAnalysis of the aird file, is
15.0.0.202209061200.
Minor release to avoid errors thrown during indirect deletion of edges whose label is selected (deletion done from outside the diagram editor or from a custom command).
com.ibm.icu has been removed.
edgeView and
otherEnd are now also available during precondition evaluation of a reconnect tool. Before, these variables were available only during the reconnection tool execution.
org.eclipse.sirius
org.eclipse.sirius.business.api.helper.task.TaskHelper.checkPrecondition(EObject, AbstractToolDescription, Map<String, EObject>, boolean, boolean) has been added to factorize code for the evaluation of a tool precondition.
org.eclipse.sirius.common
org.eclipse.sirius.common.tools.api.interpreter.VariableType.fromVariableTypes(VariableType...) has been added to create a new VariableType from a list of other VariableTypes, ie a concatenation without duplicate.
org.eclipse.sirius.diagram
edgeView and
otherEnd is now available in
org.eclipse.sirius.diagram.tools.api.interpreter.IInterpreterSiriusDiagramVariables. Before, it was duplicated constants in several classes.
org.eclipse.sirius.diagram.ui.enableEmbeddedSVGInSVGExport to
false.
org.eclipse.sirius.model, re-exported by
org.eclipse.sirius
org.eclipse.sirius.diagram.model, re-exported by
org.eclipse.sirius.diagram
org.eclipse.sirius.diagram.sequence.model, re-exported by
org.eclipse.sirius.diagram.sequence
org.eclipse.sirius.table.model, re-exported by
org.eclipse.sirius.table
org.eclipse.sirius.tree.model, re-exported by
org.eclipse.sirius.tree
org.eclipse.sirius.diagram.ui.disableArrangeAtOpeningChanges to
true. You can also create a specific bugzilla to explain the problem. This system property is temporary and will be removed in one or two versions.
org.eclipse.sirius.diagram.ui.disableHStackContainerNewBehavior to
true. You can also create a specific bugzilla to explain the problem. This system property is temporary and will be removed in one or two versions.
org.eclipse.sirius.ext.base.Option<T> helper type has been deprecated for removal. It will be progressively replaced by the standard
java.util.Optional type in our APIs.
org.eclipse.sirius.workflow.* and
org.eclipse.sirius.editor.workflow plug-ins.
org.eclipse.sirius.server.* plug-ins.
org.eclipse.sirius.business.api.query.DRepresentationDescriptorQuery.isRepresentationReachable(boolean) was added to allow it to load the representation in order to verify that the representation element is reachable, not just its resource. To benefit from this new method,
org.eclipse.sirius.business.api.query.DRepresentationDescriptorQuery.isRepresentationValid(boolean) and
org.eclipse.sirius.business.api.query.DRepresentationDescriptorQuery.DRepresentationDescriptorValidityAdapter.triggerRepresentationValidation(boolean) were also created. These new methods (with a parameter value true) can be used in tests, but should not be used by the “Model explorer” view otherwise there would be no more lazy loading of representations.
org.eclipse.sirius
org.eclipse.sirius.business.api.image.ImageManager and
org.eclipse.sirius.business.api.image.Base64ImageHelper have been added to support image management such as image creation from base64 string or image path serialization.
org.eclipse.sirius.business.api.query.SiriusReferenceFinderCache has been added. This cache allows to avoid redundant computing to find impacted DRepresentationDescriptors returned by
org.eclipse.sirius.business.api.query.SiriusReferenceFinder.getImpactedRepresentationDescriptors.
org.eclipse.sirius.business.api.query.SiriusReferenceFinder.CACHE is a convenience to use
org.eclipse.sirius.business.api.query.SiriusReferenceFinderCache.
org.eclipse.sirius.viewpoint.SiriusPlugin has been renamed to
org.eclipse.sirius.tools.api.SiriusPlugin
org.eclipse.sirius.viewpoint.Messages has been renamed to
org.eclipse.sirius.tools.api.Messages
org.eclipse.sirius.business.api.helper.ViewpointUtil has been deprecated,
org.eclipse.sirius.model.business.api.helper.ViewpointUtil from plugin
org.eclipse.sirius.model should be used instead.
org.eclipse.sirius.business.api.resource.ResourceDescriptor has been moved to
org.eclipse.sirius.model plugin alongside with code generated from Sirius metamodel as it is one of its data type.
org.eclipse.sirius.business.api.resource has been renamed to
org.eclipse.sirius.business.api.resource.support. Impacted classes are
org.eclipse.sirius.business.api.resource.support.LoadEMFResource and
org.eclipse.sirius.business.api.resource.support.WorkspaceDragAndDropSupport.
org.eclipse.sirius.tools.api.ui.color.EnvironmentSystemColorFactory has been moved to
org.eclipse.sirius.model plugin.
org.eclipse.sirius.business.api.session.danalysis.DAnalysisSelector.selectSmartlyAnalysisForAddedResource(Resource, Collection<DAnalysis>) and
org.eclipse.sirius.business.api.session.danalysis.DAnalysisSessionHelper.selectAnalysis(Resource, Collection<DAnalysis>, DAnalysisSelector) have been deprecated for removal in a future version.
org.eclipse.sirius.common
org.eclipse.sirius.common.tools.api.resource.FileProvider.exists(IPath) and
org.eclipse.sirius.common.tools.api.resource.IFileGetter.exists(IPath) have been added to know if a path leads to an existing file.
org.eclipse.sirius.diagram
org.eclipse.sirius.diagram.DiagramPlugin has been renamed to
org.eclipse.sirius.diagram.tools.api.DiagramPlugin.
org.eclipse.sirius.diagram.Messages has been renamed to
org.eclipse.sirius.diagram.tools.api.Messages.
eventShouldTriggerArrange(OperationHistoryEvent) in
org.eclipse.sirius.diagram.business.api.diagramtype.IDiagramDescriptionProvider This method is used to avoid an arrange to be launch for a specific event if it is not necessary for a specific diagram description.
org.eclipse.sirius.diagram.business.api.helper.graphicalfilters.HideFilterHelper.hideLabel(DDiagramElement, Map<EObject, List<Integer>>) has been added in order to hide a list of labels of a diagram element. This is dedicated to DEdge that can have up to 3 labels. The list of Integer correspond to the VisualID of the corresponding edge label edit part.
org.eclipse.sirius.diagram.business.api.helper.graphicalfilters.HideFilterHelper.revealLabel(DDiagramElement, Map<EObject, List<Integer>>) has been added in order to reveal a list of labels of a diagram element. This is dedicated to DEdge that can have up to 3 labels. The list of Integer correspond to the VisualID of the corresponding edge label edit part.
org.eclipse.sirius.diagram.tools.api.command.IDiagramCommandFactory.buildHideLabelSelectionCommand(Set<EObject>, Map<EObject, List<Integer>>) has been added to forward the labels of an edge to hide to the command.
org.eclipse.sirius.diagram.tools.api.command.IDiagramCommandFactory.buildRevealLabelSelectionCommand(DDiagramElement, Map<EObject, List<Integer>>) has been added to forward the labels of an edge to reveal to the command.
org.eclipse.sirius.diagram.tools.api.command.view.HideDDiagramElementLabel.HideDDiagramElementLabel(TransactionalEditingDomain, Set<?>, Map<EObject, List<Integer>>) has a new constructor in order to give the list of labels of an edge to hide.
org.eclipse.sirius.diagram.tools.api.command.view.RevealDDiagramElementsLabel.RevealDDiagramElementsLabel(TransactionalEditingDomain, Set<DDiagramElement>, Map<EObject, List<Integer>>) has a new constructor in order to give the list of labels of an edge to reveal.
org.eclipse.sirius.diagram.business.api.query.DDiagramElementQuery.hasAnyHiddenLabel() has been added in order to check if at least one label of a DDiagramElement is hidden.
org.eclipse.sirius.diagram.business.api.query.DDiagramElementQuery.areAllLabelsHidden() has been added in order to check if at all labels of a DDiagramElement are hidden.
org.eclipse.sirius.diagram.business.api.query.DDiagramElementQuery.areAllLabelsHidden(List<Integer>) has been added in order to check if at all labels of the given collection concerning a DDiagramElement are hidden.
org.eclipse.sirius.diagram.business.api.query.DDiagramElementQuery.isLabelHidden(int) has been added in order to check if one label in particular of a DDiagramElement is hidden.
org.eclipse.sirius.diagram.business.api.query.DEdgeQuery.howManyLabels() has been added in order to return how many labels an edge has.
org.eclipse.sirius.diagram.business.api.query.DEdgeQuery.areAllLabelsHidden() has been added in order to check if at all labels of a DEdge are hidden.
org.eclipse.sirius.diagram.model
DiagramDescription::allTools operation has been removed from the Diagram metamodel. The corresponding method has been removed from generated code. Calls to
org.eclipse.sirius.diagram.description.DiagramDescription.getAllTools() should be replaced by
new org.eclipse.sirius.diagram.business.api.query.DiagramDescriptionQuery(diagramDescription).getAllTools().
DiagramDescription::allEdgeMappings operation has been removed from the Diagram metamodel. The corresponding method has been removed from generated code. Calls to
org.eclipse.sirius.diagram.description.DiagramDescription.getAllEdgeMappings() should be replaced by
org.eclipse.sirius.diagram.business.internal.metamodel.helper.ContentHelper.getAllEdgeMappings(diagramDescription, false) alongside with the getAllNodeMappings and getAllContainerMappings methods.
org.eclipse.sirius.diagram.ui
org.eclipse.sirius.diagram.ui.business.api.image.WorkspaceImageHelper has been added, it includes most of the methods that previously existed in
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectorService. The affected methods are:
org.eclipse.sirius.diagram.ui.business.api.image.WorkspaceImageHelper.updateStyle(BasicLabelStyle, String), which was previously
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectorService.updateStyle(BasicLabelStyle, String).
org.eclipse.sirius.diagram.ui.business.api.image.WorkspaceImageHelper.updateWorkspacePath(BasicLabelStyle, String), which was previously
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectorService.updateWorkspacePath(BasicLabelStyle, String).
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectionDialog has been added to replace the
org.eclipse.sirius.common.ui.tools.api.resource.WorkspaceResourceDialogWithFilter dialog which was used to select a background image for a diagram element.
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectionDialog now provides a new simpler and more complete UI.
org.eclipse.sirius.diagram.ui.business.api.image.ITreeImagesContentProvider has been added to allow the implementation of an
org.eclipse.jface.viewers.ITreeContentProvider that can be used by
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectionDialog to retrieve image information.
org.eclipse.sirius.diagram.ui.business.api.image.ImageFiltersUtils provides the filter used by the TreeViewer in the
ImageSelectionDialog as well as various utility methods to identify the supported image formats.
org.eclipse.sirius.diagram.ui.business.api.image.GallerySelectable provides an implementation of
org.eclipse.sirius.diagram.ui.tools.internal.dialogs.widgets.gallery.Gallery which allows to select items in the gallery. This is mostly used in tests.
GallerySelectable allows to use the
org.eclipse.sirius.diagram.ui.tools.internal.dialogs.widgets.gallery.Gallery in
ImageSelectionDialog implementations.
org.eclipse.sirius.diagram.ui.tools.api.editor.DDiagramEditor:
enableFireNotification() to enable the fire notification, ie it causes the editor to fire selection changed notification to all listeners when
SelectionManager#fireSelectionChanged() is called, and
disableFireNotification() to disable it. It is used internally, among others, to disable the notification during a drag’n’drop of an element or during the reconnection of an edge.
org.eclipse.sirius.diagram.ui now depends on GMF Runtime 1.14.0, which itself uses Apache Batik 1.14.0 to support SVG (both rendering SVG images on diagrams and exporting diagrams to SVG files). As a result, exporting diagrams to PDF is not supported anymore (as GMF Runtime 1.14.0 itself has dropped support for this).
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelector has been modified to support multiple image selection. The enum
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelector.SelectionMode can be used to define the selection mode supported:
MONO_SELECTION for a single selection or
MULTI_SELECTION for a multiple selection. The method
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelector.selectImages(EObject, SelectionMode) has been updated to handle this selection mode as a parameter and now returns the list of selected images as a
List<String>.
org.eclipse.sirius.diagram.ui.business.api.image.WorkspaceImageSelector has been modified to implement the interface
ImageSelector and the update of its
ImageSelector.selectImages(EObject, SelectionMode) method.
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectorService has been split in a new lighter
ImageSelectorService which aims to get an
ImageSelector. The other methods have been moved to
org.eclipse.sirius.diagram.ui.business.api.image.WorkspaceImageHelper.
org.eclipse.sirius.diagram.ui.tools.internal.util.EditPartQuery.getVisualID() has been added in order to return the VisualID field value if there is one.
org.eclipse.sirius.diagram.ui.tools.api.figure.FigureQuery.edgeLabelViewConstantToVisualID(int) has been added in order to convert LabelViewConstant values to the equivalent VisualID from the label edit parts.
org.eclipse.sirius.diagram.ui.tools.api.figure.SiriusWrapLabelWithAttachment.getLocationField() was added in order to have a public access to the location value.
org.eclipse.sirius.diagram.ui.business.api.provider.DEdgeBeginLabelItemProvider,
org.eclipse.sirius.diagram.ui.business.api.provider.DEdgeEndLabelItemProvider and
org.eclipse.sirius.diagram.ui.business.api.provider.DEdgeLabelItemProvider methods equals and hashCode have been overridden in order to differentiate them in an HashSet.
org.eclipse.sirius.common.ui
org.eclipse.sirius.common.ui.tools.api.resource.WorkspaceResourceDialogWithFilter is now deprecated. The use of
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectionDialog is now favored to provide a dialog to select a background image of a diagram element.
org.eclipse.sirius.diagram.sequence
org.eclipse.sirius.diagram.sequence.util.Range has been moved to
org.eclipse.sirius.diagram.sequence.business.api.util.Range
org.eclipse.sirius.diagram.sequence.util.Pair has been moved to
org.eclipse.sirius.diagram.sequence.business.api.util.Pair
org.eclipse.sirius.diagram.sequence.Messages has been moved to
org.eclipse.sirius.diagram.sequence.tool.internal.Messages.
org.eclipse.sirius.tests.swtbot.support
org.eclipse.sirius.tests.swtbot.support.api.editor.SWTBotSiriusHelper.selectGalleryItem(SWTBot, String) has been added in order to select an item in the Gallery in the new
org.eclipse.sirius.diagram.ui.business.api.image.ImageSelectionDialog.
org.eclipse.sirius.tests.swtbot.support.api.condition.CheckNbVisibleElementsInGallery has been added to avoid tests failing because of images that have not finished loading.
org.eclipse.sirius.tests.swtbot.support.api.AbstractSiriusSwtBotGefTestCase.getNbStatusInErrorLog() has been removed. It is not reliable (sometimes the number of elements returned is 0 instead of the real number). It should be replaced by
doesAnErrorOccurs() and
doesAWarningOccurs().
org.eclipse.sirius.tests.junit.support
org.eclipse.sirius.tests.support.api.SiriusTestCase.copyAllFiles(String, String, String) and
org.eclipse.sirius.tests.support.api.EclipseTestsSupportHelper.copyDirectory(String, String) have been added to ease to the copy of the test files from the test plugin to the junit workspace.
org.eclipse.sirius.diagram.ui.business.internal.migration.WorkspaceImageGMFBoundsMigrationParticipant migration participant, the size of these nodes was recomputed according to the Size Computation Expression defined in the VSM. The corresponding version, stored in attribute version of viewpoint:DAnalysis of the aird file, is
15.0.0.202201261500.
org.eclipse.sirius.diagram
org.eclipse.sirius.diagram.tools.api.command.IDiagramCommandFactory to support the new z-order actions on edges. The returned commands are currently only used by new actions for edges but they also manage nodes (same code than in existing GMF commands).
buildBringToFrontCommand(List<? extends View>): Build a command that is able to bring to the front many elements. These elements, nodes or edges, must be of the same type and have the same parent.
buildSendToBackCommand(List<? extends View>: Build a command that is able to send to the back many elements. These elements, nodes or edges, must be of the same type and have the same parent.
buildBringForwardCommand(List<? extends View>): Build a command that is able to bring forward many elements. These elements, nodes or edges, must be of the same type and have the same parent.
buildSendBackwardCommand(List<? extends View>): Build a command that is able to send backward many elements. These elements, nodes or edges, must be of the same type and have the same parent.
org.eclipse.sirius.diagram.tools.api.command.view.BringForwardElements
org.eclipse.sirius.diagram.tools.api.command.view.BringToFrontElements
org.eclipse.sirius.diagram.tools.api.command.view.SendBackwardElements
org.eclipse.sirius.diagram.tools.api.command.view.SendToBackElements
org.eclipse.sirius.diagram.ui
org.eclipse.sirius.diagram.ui.edit.api.part.AbstractDDiagramEditPart.refreshChildren() has been overridden to redraw the edges figures according to the order of the GMF edges.
org.eclipse.sirius.diagram.ui.business.internal.migration.SetChangeIdMigrationParticipant sets a random changeId if it didn’t already exist. The corresponding version, stored in attribute version of viewpoint:DAnalysis of the aird file, is
14.6.0.202110251100.
org.eclipse.sirius.diagram.ui.business.internal.migration.NoteShapeDefaultLabelAlignmentMigrationParticipant has been updated to repair Notes with a potential wrong vertical label alignment. This problem can occur since Sirius 6.3.2 used in a collaborative environment, Obeo Designer Team Edition or Team For Capella for example. The corresponding version, stored in the attribute version of viewpoint:DAnalysis of the aird file, is
14.5.1.202106111100 (migration added in Sirius 6.5.1).
aird file, select “Properties”, and in the dialog go to the “Sirius settings” section. The preferences are stored in the project scope and associated to the aird file. For more details, refer the
documentation .
CellEditor tool is available for feature column mapping of edition table. It allows to define a specific
org.eclipse.jface.viewers.CellEditor to edit a cell (see
documentation for more details).
order, despite this problem, to have a satisfactory layout result. This new behavior has been tested with
ELK Layered algorithm with option
Node Placement Strategy
set to
NETWORK_SIMPLEX. There is no guarantee with other kind of layouts. All cases are not supported. Further additional developments are needed to support more. There are probably still some constructions not correctly handled but it is a first step. As example, the edges with label(s) have not been tested. Here is a list of supported/tested cases:
diagram:targetSemanticId is added on SVG elements to reference the target semantic id on which the graphical element is based on. This option can be activated programmatically or by setting a preference. See the details below:
org.eclipse.sirius.diagram.ui.tools.api.part.DiagramEditPartService.DiagramEditPartService(boolean) has been added to make it possible to activate the semantic traceability during the SVG export. Note that this constructor will also be called by
org.eclipse.sirius.ui.business.api.dialect.DialectUIServices.exportWithResult with the
ExportFormat as parameter, which own the
SemanticTraceabilityEnabled value.
org.eclipse.sirius.ui.business.api.dialect.ExportFormat,
setSemanticTraceabilityEnabled(boolean) and
isSemanticTraceabilityEnabled() have been added to specify through the ExportFormat if the traceability should be enabled.
org.eclipse.sirius.ui.business.api.preferences.SiriusUIPreferencesKeys.PREF_EXPORT_SEMANTIC_TRACEABILITY has been added to make it possible to activate the traceability on representation export. This will activate the traceability for any export by using the user interface (through the export specific wizard) or by calling the
ExportAction. Direct calls to the
DialectUIServices.exportWithResult are not impacted.
org.eclipse.sirius
org.eclipse.sirius.business.api.session.SiriusPreferences has been added to get preferences related to a Sirius Session that is to a main aird file. An instance of this API can be accessed with
org.eclipse.sirius.business.api.session.Session.getSiriusPreferences(). Both
org.eclipse.sirius.business.api.preferences.SiriusPreferencesKeys.PREF_AUTO_REFRESH and
org.eclipse.sirius.ui.business.api.preferences.SiriusUIPreferencesKeys.PREF_REFRESH_ON_REPRESENTATION_OPENING
should not be used any more by clients with Eclipse preference API but
org.eclipse.sirius.business.api.session.SiriusPreferences.isAutoRefresh() and
org.eclipse.sirius.business.api.session.SiriusPreferences.isRefreshAtRepresentationOpening() should be used instead.
The reason is that the implementation of
SiriusPreferences wraps the logic of getting or storing the preferences on a ProjectScope.
org.eclipse.sirius.tools.api.ui.RefreshHelper.isAutoRefresh() has been removed. Clients should call
Session.getPreferences.isAutoRefresh() or
new DRepresentationQuery(DRpresentation).isAutoRefresh() instead.
org.eclipse.sirius.diagram.ui.tools.api.properties.PropertiesService,
org.eclipse.sirius.tools.api.ui.property.IPropertiesProvider and
org.eclipse.sirius.diagram.ui.tools.internal.properties.SiriusDiagramEditorPropertiesProvider have been removed. Clients should call
Session.getPreferences.isAutoRefresh() or
new DRepresentationQuery(DRpresentation).isAutoRefresh() instead.
org.eclipse.sirius.diagram.ui
org.eclipse.sirius.diagram.ui.tools.api.format.AbstractSiriusFormatDataManager.logUnhandledDiagramElementKindMessage(Object) has been added to mutualize the code concerning the log of a warning for
Object not managed by the
SiriusLayoutDataManager. This method avoids to log a message for
DNodeListElement, as it is expected that nothing is stored in LayoutDataManager for
DNodeListElement as their location and size are constrained by their parents.
org.eclipse.sirius.ui
org.eclipse.sirius.ui.business.api.dialect.DialectUIManager.isRefreshActivatedOnRepresentationOpening() has been removed. Use
org.eclipse.sirius.business.api.session.SiriusPreferences.isRefreshAtRepresentationOpening() instead.
org.eclipse.sirius.ecore.extender
org.eclipse.sirius.ecore.extender.business.api.permission.IPermissionAuthority.getLockedObjects() has been added the get all the locked objects.
org.eclipse.sirius.ext.gmf.runtime
org.eclipse.sirius.ext.gmf.runtime.gef.ui.figures.IFigureWithoutLabels has been created so that a Figure, that implements this API, can provide its bounds without considering its labels. The method
org.eclipse.sirius.ext.gmf.runtime.editparts.GraphicalHelper.getAbsoluteBoundsWithoutLabelsIn100Percent(GraphicalEditPart) has been added to get the rectangle bounds without taking labels into account. This is used, in particular, to compute the bendpoints of an edge when the source or the target of the edge is an edge.