org.eclipse.gmf.runtime.diagram.ui.editpolicies
Class CanonicalEditPolicy

java.lang.Object
  org.eclipse.gef.editpolicies.AbstractEditPolicy
      org.eclipse.gmf.runtime.diagram.ui.editpolicies.CanonicalEditPolicy

All Implemented Interfaces:

EditPolicy, NotificationListener, RequestConstants

public abstract class CanonicalEditPolicy

extends AbstractEditPolicy

implements NotificationListener

The base canonical editpolicy class. This edit policy will register itself with the model server to receive semantic events fired to its host editpart. It will create, if necessary, notation elements for all semantic elements inserted into the host element or delete the notation element for the semantic element removed from the host element.

This editpolicy will create the necessary notation element by simply returning a CreateCommand.

See Also:

CanonicalEditPolicy.refreshSemanticChildren(), will create or delete notation elements as required., CanonicalEditPolicy.getCreateViewCommand(CreateRequest), CanonicalEditPolicy.shouldDeleteView(View)

Nested Class Summary

protected static class

CanonicalEditPolicy.CanonicalElementAdapter Adds String.class adaptablity to return a factory hint.

Field Summary

Fields inherited from interface org.eclipse.gef.EditPolicy

COMPONENT_ROLE, CONNECTION_BENDPOINTS_ROLE, CONNECTION_ENDPOINTS_ROLE, CONNECTION_ROLE, CONTAINER_ROLE, DIRECT_EDIT_ROLE, GRAPHICAL_NODE_ROLE, LAYOUT_ROLE, NODE_ROLE, PRIMARY_DRAG_ROLE, SELECTION_FEEDBACK_ROLE, TREE_CONTAINER_ROLE

Fields inherited from interface org.eclipse.gef.RequestConstants

REQ_ADD, REQ_ALIGN, REQ_ALIGN_CHILDREN, REQ_CLONE, REQ_CONNECTION_END, REQ_CONNECTION_START, REQ_CREATE, REQ_CREATE_BENDPOINT, REQ_DELETE, REQ_DELETE_DEPENDANT, REQ_DIRECT_EDIT, REQ_MOVE, REQ_MOVE_BENDPOINT, REQ_MOVE_CHILDREN, REQ_OPEN, REQ_ORPHAN, REQ_ORPHAN_CHILDREN, REQ_RECONNECT_SOURCE, REQ_RECONNECT_TARGET, REQ_RESIZE, REQ_RESIZE_CHILDREN, REQ_SELECTION, REQ_SELECTION_HOVER

Constructor Summary

CanonicalEditPolicy()

Method Summary

void	activate() Registers with the model server to receive semantic events targeted to the host editpart.
protected boolean	addListenerFilter(java.lang.String filterId, NotificationListener listener, EObject element) Adds a listener filter by adding the given listener to a passed notifier.
protected boolean	addListenerFilter(java.lang.String filterId, NotificationListener listener, EObject element, EStructuralFeature feature) Adds a listener filter by adding the given listener to a passed notifier.
protected java.util.List	cleanCanonicalSemanticChildren(java.util.Collection viewChildren, java.util.Collection semanticChildren) Synchronizes the semanticChildren the viewChildren to discover if any of the semanticChildren don't have a corresponding view.
protected java.util.List	createViews(java.util.List eObjects) Creates a View element for each of the supplied semantic elements.
void	deactivate() Unregisters all registered model server listeners.
protected boolean	deleteViews(java.util.Iterator views) Deletes a list of views.
void	enableRefresh(boolean enable) Disables the editpolicy.
protected void	executeCommand(Command cmd) Executes the supplied command inside an unchecked action
protected CanonicalStyle	getCanonicalStyle() gets the canonical style that may be installed on the host shape compartment view.
protected Command	getCreateViewCommand(CreateRequest request) Returns a CreateCommand for each view descriptor contained in the supplied request without forwarding create requests to the host editpart.
protected ICommand	getCreateViewCommand(CreateViewRequest.ViewDescriptor descriptor)
protected CreateViewRequest	getCreateViewRequest(java.util.List descriptors) Return a create view request.
protected java.lang.String	getDefaultFactoryHint() Returns the default factory hint.
protected Command	getDeleteViewCommand(View view) gets a Command to delete the supplied View.
protected java.lang.String	getFactoryHint(IAdaptable elementAdapter) Clients may override this method to return an appropriate factory hint for the supplied semantic element.
protected java.lang.String	getFactoryHint(IAdaptable elementAdapter, java.lang.String defaultHint) Return a factory hint to assign to this element.
static java.util.List	getRegisteredEditPolicies(EObject element) Returns the Canonical EditPolicies mapped to the supplied element.
static java.util.List	getRegisteredEditPolicies(EObject element, java.lang.Class clazz) Returns the enabled Canonical EditPolicies mapped to the supplied element that are an instance of the supplied clazz.
protected abstract java.util.List	getSemanticChildrenList() Return the host's semantic children.
EObject	getSemanticHost() Return the semantic element to be listened to by this editpolicy.
protected java.util.List	getViewChildren() Return the host's model children.
protected CreateViewRequest.ViewDescriptor	getViewDescriptor(EObject element) Convenience method to create a view descriptor.
protected CreateViewRequest.ViewDescriptor	getViewDescriptor(IAdaptable elementAdapter, java.lang.Class viewKind, java.lang.String hint, int index) Return a view descriptor.
EditPartViewer	getViewer()
protected int	getViewIndexFor(EObject semanticChild) This method tries to locate the position that the view will be inserted into it's parent.
protected java.util.List	getViewReferers(EObject element) Return a list of all the notation elements mapped to the supplied semantic element.
protected void	handleNotificationEvent(Notification event) Handles NotificationEvent and resynchronizes the canonical container if the event should be handled.
protected IGraphicalEditPart	host()
boolean	isActive() check is this edit policy is active or not
boolean	isEnabled() Return true if the editpolicy is enabled and its host is visible; otherwise false.
protected boolean	isHostStillValid() Return true if the host is active and its view has not been deleted; otherwise false
protected void	makeViewsImmutable(java.util.List createdViews) Sets views as being immutable, meaning that they are unmodifiable as non-persisted views.
protected void	makeViewsMutable(java.util.List createdViews) Sets state on views to allow for modification without changing their non-persisted status.
void	notifyChanged(Notification notification) Event callback: filters out non IElementEvent events.
protected void	postProcessRefreshSemantic(java.util.List viewDescriptors) Allow for post processing of the refresh semantic to set the view mutable state and allow subclasses to add functionality.
void	refresh() Resynchronize the canonical container.
protected void	refreshOnActivate() Refresh that is called on activate of the editpolicy to ensure that all relevant editparts can receive canonically created connections.
protected void	refreshSemantic() Redirects the call to CanonicalEditPolicy.refreshSemanticChildren().
protected java.util.List	refreshSemanticChildren() Updates the set of children views so that it is in sync with the semantic children.
protected void	removeListenerFilter(java.lang.String filterId) Removes a listener previously added with the given id
protected EObject	resolveSemanticElement() Convenience method to return the host's semantic element.
void	setEnable(boolean enable) Sets enable(aBoolean) on all the edit policies of the semantic host.
void	setHost(EditPart host) Asserts that the supplied host is an IGraphicalEditPart instance.
protected boolean	shouldDeleteView(View view) returns true to always delete a view if required.
protected boolean	shouldHandleNotificationEvent(Notification event) Determines if the the NotificationEvent should be handled / processed by the editpolicy.

Methods inherited from class org.eclipse.gef.editpolicies.AbstractEditPolicy

debugFeedback, eraseSourceFeedback, eraseTargetFeedback, getCommand, getHost, getTargetEditPart, showSourceFeedback, showTargetFeedback, toString, understandsRequest

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

CanonicalEditPolicy

public CanonicalEditPolicy()

Method Detail

getRegisteredEditPolicies

public static java.util.List getRegisteredEditPolicies(EObject element)

Returns the Canonical EditPolicies mapped to the supplied element. Canonical EditPolicies are mapped to their CanonicalEditPolicy.getSemanticHost() as the key. A single key may have multiple editpolicies registered against it.

Parameters:

element - a semantic element

Returns:

a unmodifiable list of semantic editpolicies listening to the supplied element

getRegisteredEditPolicies

public static java.util.List getRegisteredEditPolicies(EObject element,
                                                       java.lang.Class clazz)

Returns the enabled Canonical EditPolicies mapped to the supplied element that are an instance of the supplied clazz. Canonical EditPolicies are mapped to their CanonicalEditPolicy.getSemanticHost()as the key. A single key may have multiple editpolicies registered against it.

Parameters:

element - a semantic element

clazz - a class type

Returns:

an unmodifiable list of semantic editpolicies listening to the supplied element

setHost

public void setHost(EditPart host)

Asserts that the supplied host is an IGraphicalEditPart instance.

Specified by:

setHost in interface EditPolicy

host

protected final IGraphicalEditPart host()

Returns:

(IGraphicalEditPart)host().

getSemanticChildrenList

protected abstract java.util.List getSemanticChildrenList()

Return the host's semantic children.

Returns:

a list of semantic children.

getDefaultFactoryHint

protected java.lang.String getDefaultFactoryHint()

Returns the default factory hint.

Returns:

host().getView().getSemanticType()

getFactoryHint

protected java.lang.String getFactoryHint(IAdaptable elementAdapter,
                                          java.lang.String defaultHint)

Return a factory hint to assign to this element. The supplied default hint is used if no hint can be found.

Parameters:

elementAdapter - adapter that adapts to EObject.

defaultHint - a default factory hint (typically the host's factory hint).

Returns:

a factory hint.

See Also:

CanonicalEditPolicy.getFactoryHint(IAdaptable)

getFactoryHint

protected java.lang.String getFactoryHint(IAdaptable elementAdapter)

Clients may override this method to return an appropriate factory hint for the supplied semantic element. Returning null will set the factory hint to the host editpart's factory hint.

Parameters:

elementAdapter - adapter that adapts to EObject.

Returns:

null.

See Also:

CanonicalEditPolicy.getFactoryHint(IAdaptable, String)

deleteViews

protected final boolean deleteViews(java.util.Iterator views)

Deletes a list of views. The views will be deleted iff their semantic element has also been deleted.

Parameters:

views - an iterator on a list of views.

Returns:

true if the host editpart should be refreshed; either one one of the supplied views was deleted or has been reparented.

getDeleteViewCommand

protected Command getDeleteViewCommand(View view)

gets a Command to delete the supplied View.

Parameters:

view - view to use

Returns:

command

shouldDeleteView

protected boolean shouldDeleteView(View view)

returns true to always delete a view if required.

Parameters:

view - to consider

Returns:

true or false

getViewReferers

protected java.util.List getViewReferers(EObject element)

Return a list of all the notation elements mapped to the supplied semantic element.

Parameters:

element - to use

Returns:

list of Views

getViewIndexFor

protected int getViewIndexFor(EObject semanticChild)

This method tries to locate the position that the view will be inserted into it's parent. The position is determined by the position of the semantic element. If the semantic element is not found the view will be appended to it's parent.

Parameters:

semanticChild -

Returns:

position where the view should be inserted

createViews

protected final java.util.List createViews(java.util.List eObjects)

Creates a View element for each of the supplied semantic elements.

Parameters:

eObjects - list of semantic element

Returns:

a list of IAdaptable that adapt to View.

executeCommand

protected void executeCommand(Command cmd)

Executes the supplied command inside an unchecked action

Parameters:

cmd - command that can be executed (i.e., cmd.canExecute() == true)

getCreateViewCommand

protected Command getCreateViewCommand(CreateRequest request)

Returns a CreateCommand for each view descriptor contained in the supplied request without forwarding create requests to the host editpart.

Parameters:

request - a create request

Returns:

command create view command(s)

getCreateViewCommand

protected ICommand getCreateViewCommand(CreateViewRequest.ViewDescriptor descriptor)

Parameters:

descriptor -

Returns:

ICommand to create a view given a descriptor

getCreateViewRequest

protected CreateViewRequest getCreateViewRequest(java.util.List descriptors)

Return a create view request.

Parameters:

descriptors - a CreateViewRequest.ViewDescriptor list.

Returns:

a create request

getViewDescriptor

protected CreateViewRequest.ViewDescriptor getViewDescriptor(IAdaptable elementAdapter,
                                                             java.lang.Class viewKind,
                                                             java.lang.String hint,
                                                             int index)

Return a view descriptor.

Parameters:

elementAdapter - semantic element

viewKind - type of view to create

hint - factory hint

index - index

Returns:

a create non-persisted view descriptor

getViewDescriptor

protected CreateViewRequest.ViewDescriptor getViewDescriptor(EObject element)

Convenience method to create a view descriptor. Will call CanonicalEditPolicy.getViewDescriptor(IAdaptable, Class, String, int)

Parameters:

element - semantic element.

Returns:

view descriptor

activate

public void activate()

Registers with the model server to receive semantic events targeted to the host editpart. By default, this editpolicy will receive events fired to the semantic element mapped to the host editpart. Clients wanting to listen to another semantic element should override CanonicalEditPolicy.getSemanticHost()

Specified by:

activate in interface EditPolicy

See Also:

CanonicalEditPolicy.deactivate()

refreshOnActivate

protected void refreshOnActivate()

Refresh that is called on activate of the editpolicy to ensure that all relevant editparts can receive canonically created connections.

isEnabled

public boolean isEnabled()

Return true if the editpolicy is enabled and its host is visible; otherwise false.

Returns:

true

enableRefresh

public void enableRefresh(boolean enable)

Disables the editpolicy. While disabled, the editpolicy will not perform any refreshes.

Parameters:

enable -

setEnable

public void setEnable(boolean enable)

Sets enable(aBoolean) on all the edit policies of the semantic host.

Parameters:

enable -

isActive

public final boolean isActive()

check is this edit policy is active or not

Returns:

true if the this editpart has already been activated; otherwise false.

getSemanticHost

public EObject getSemanticHost()

Return the semantic element to be listened to by this editpolicy.

Returns:

host().getView().resolveSemanticElement() by default.

deactivate

public void deactivate()

Unregisters all registered model server listeners.

Specified by:

deactivate in interface EditPolicy

See Also:

CanonicalEditPolicy.activate()

addListenerFilter

protected boolean addListenerFilter(java.lang.String filterId,
                                    NotificationListener listener,
                                    EObject element)

Adds a listener filter by adding the given listener to a passed notifier. The supplied listener will not be added to there is already a listener registered against the supplied filterId

Parameters:

filterId - A unique filter id (within the same editpart instance)

listener - A listener instance

Returns:

true if the listener was added, otherwise false

Throws:

java.lang.NullPointerException - if either filterId or listner parameters are null.

addListenerFilter

protected boolean addListenerFilter(java.lang.String filterId,
                                    NotificationListener listener,
                                    EObject element,
                                    EStructuralFeature feature)

Adds a listener filter by adding the given listener to a passed notifier. The supplied listener will not be added to there is already a listener registered against the supplied filterId

Parameters:

filterId - A unique filter id (within the same editpart instance)

listener - A listener instance

Returns:

true if the listener was added, otherwise false

Throws:

java.lang.NullPointerException - if either filterId or listner parameters are null.

removeListenerFilter

protected void removeListenerFilter(java.lang.String filterId)

Removes a listener previously added with the given id

Parameters:

filterId - the filter id

notifyChanged

public final void notifyChanged(Notification notification)

Event callback: filters out non IElementEvent events.

Specified by:

notifyChanged in interface NotificationListener

Parameters:

notification - the notification object

isHostStillValid

protected final boolean isHostStillValid()

Return true if the host is active and its view has not been deleted; otherwise false

Returns:

true or false

handleNotificationEvent

protected void handleNotificationEvent(Notification event)

Handles NotificationEvent and resynchronizes the canonical container if the event should be handled.

Parameters:

event - NotificationEvent to handle.

shouldHandleNotificationEvent

protected boolean shouldHandleNotificationEvent(Notification event)

Determines if the the NotificationEvent should be handled / processed by the editpolicy.

Parameters:

event - NotificationEvent to check

Returns:

true if event should be handled, false otherwise.

getViewChildren

protected java.util.List getViewChildren()

Return the host's model children.

Returns:

list of Views

refresh

public final void refresh()

Resynchronize the canonical container.

refreshSemantic

protected void refreshSemantic()

Redirects the call to CanonicalEditPolicy.refreshSemanticChildren().

makeViewsMutable

protected final void makeViewsMutable(java.util.List createdViews)

Sets state on views to allow for modification without changing their non-persisted status.

Parameters:

createdViews - List of view adapters that were created during the CanonicalEditPolicy.refreshSemantic() operation

makeViewsImmutable

protected final void makeViewsImmutable(java.util.List createdViews)

Sets views as being immutable, meaning that they are unmodifiable as non-persisted views. Any subsequent change to an immutable view will force the view to be persisted.

Parameters:

createdViews - List of view adapters that were created during the CanonicalEditPolicy.refreshSemantic() operation

refreshSemanticChildren

protected final java.util.List refreshSemanticChildren()

Updates the set of children views so that it is in sync with the semantic children. This method is called in response to notification from the model.

The update is performed by comparing the exising views with the set of semantic children returned from CanonicalEditPolicy.getViewChildren(). Views whose semantic element no longer exists are removed. New semantic children have their View created. Subclasses must override getSemanticChildren().

Unlike AbstractEditPart#refreshChildren(), this refresh will not reorder the view list to ensure both it and the semantic children are in the same order since it is possible that this edit policy will handle a specifc subset of the host's views.

The host is refreshed if a view has created or deleted as a result of this refresh.

Returns:

List of new View objects that were created as a result of the synchronization

cleanCanonicalSemanticChildren

protected final java.util.List cleanCanonicalSemanticChildren(java.util.Collection viewChildren,
                                                              java.util.Collection semanticChildren)

Synchronizes the semanticChildren the viewChildren to discover if any of the semanticChildren don't have a corresponding view. Any semanticChildren that do have a view are removed from the list.

Parameters:

viewChildren - List of View elements that already exist in the container.

semanticChildren - List of semantic elements that are candidates for synchronization

Returns:

List of orphans views that should be deleted from the container.

postProcessRefreshSemantic

protected void postProcessRefreshSemantic(java.util.List viewDescriptors)

Allow for post processing of the refresh semantic to set the view mutable state and allow subclasses to add functionality.

Parameters:

viewDescriptors - List of IAdaptable that adapt to View

resolveSemanticElement

protected final EObject resolveSemanticElement()

Convenience method to return the host's semantic element. Same as calling host().getView().resolveSemanticElement();

Returns:

an EObject

getCanonicalStyle

protected CanonicalStyle getCanonicalStyle()

gets the canonical style that may be installed on the host shape compartment view.

Returns:

CanonicalStyle

getViewer

public final EditPartViewer getViewer()