/**
* Copyright (c) 2002-2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v2.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v20.html
*
* Contributors:
* IBM - Initial API and implementation
*/
package org.eclipse.emf.edit.command;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.ListIterator;
import org.eclipse.emf.common.command.Command;
import org.eclipse.emf.common.command.CommandWrapper;
import org.eclipse.emf.common.command.CompoundCommand;
import org.eclipse.emf.common.command.IdentityCommand;
import org.eclipse.emf.common.command.StrictCompoundCommand;
import org.eclipse.emf.common.util.BasicEList;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EGenericType;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.ecore.EcorePackage;
import org.eclipse.emf.ecore.util.ExtendedMetaData;
import org.eclipse.emf.edit.EMFEditPlugin;
import org.eclipse.emf.edit.domain.EditingDomain;
/**
* The set command logically acts upon an owner object to set a particular feature to a specified value or to unset a feature.
* The static create methods delegate command creation to {@link EditingDomain#createCommand EditingDomain.createCommand},
* which may or may not result in the actual creation of an instance of this class.
*
*
* The implementation of this class is low-level and EMF specific;
* it allows a value to be set to a single-valued feature of an owner,
* i.e., it is equivalent of the call
*
* ((EObject)object).eSet((EStructuralFeature)feature, value);
*
* or to
*
* ((EObject)object).eUnset((EStructuralFeature)feature);
*
* if the value is {@link #UNSET_VALUE}.
*
* Setting a feature that is a bidirectional reference with a multiplicity-many reverse or with a
* multiplicity-1 reverse that is already set (on value), is not undoable.
* In this case, the SetCommand static create function will not return an instance of this class, but
* instead will return a compound command (e.g., a {@link RemoveCommand} followed by an {@link AddCommand}
* for the other end of the relation) which could not be undone.
*
* The exception to the above is when an empty list is being set to empty or unset. Such commands are undoable
* and represent the only way to toggle whether the feature is set.
*
* When setting a containment (or container) feature, we always assume that the object that will be
* contained is not already in a container, but take no action in this class to ensure this is the case.
*
* A set command is an {@link OverrideableCommand}.
*/
public class SetCommand extends AbstractOverrideableCommand
{
/**
* Specify this as the value in order to unset a feature. Note that this value can be specified for
* a multiplicity-1 feature or for a multiplicity-many feature with no index given. Unsetting a single
* value within a list is not possible.
*/
public static final Object UNSET_VALUE = new Object();
/**
* This creates a command to set the owner's feature to the specified value.
*/
public static Command create(EditingDomain domain, final Object owner, Object feature, Object value)
{
return create(domain, owner, feature, value, CommandParameter.NO_INDEX);
}
/**
* This creates a command to set the owner's feature to the specified value at the specified index.
*/
public static Command create(EditingDomain domain, final Object owner, Object feature, Object value, int index)
{
// If the feature is a bidirectional reference with a multiplicity-many reverse, a composite reverse,
// or a multiplicity-1 reverse that is already set (on value), then we'll switch things around and
// execute this command a little differently, because otherwise it's not undoable.
//
if (owner instanceof EObject && ((EObject)owner).eClass().getEAllReferences().contains(feature))
{
EReference eReference = (EReference)feature;
if (eReference.isMany() && index == CommandParameter.NO_INDEX)
{
// We never directly set a multiplicity-many feature to a list directly. Instead, we remove the old values
// values, move the values that remain, and insert the new values. If all old values are removed, we'll still
// set it to an empty list, or unset it, as appropriate.
//
List values = value == UNSET_VALUE ? Collections.EMPTY_LIST : (List)value;
List oldValues = (List)((EObject)owner).eGet(eReference);
CompoundCommand compound = null;
compound =
new CompoundCommand(CompoundCommand.LAST_COMMAND_ALL, LABEL, DESCRIPTION)
{
@Override
public Collection getAffectedObjects()
{
return Collections.singleton(owner);
}
};
if (!oldValues.isEmpty())
{
if (!values.isEmpty())
{
List removedValues = new BasicEList.FastCompare(oldValues);
removedValues.removeAll(values);
// If we aren't simply removing all the old values...
//
if (!removedValues.equals(oldValues))
{
// If there are values to remove, append a command for them.
//
if (!removedValues.isEmpty())
{
compound.append(RemoveCommand.create(domain, owner, feature, new BasicEList(removedValues)));
}
// Determine the values that will remain and move them into the right order, if necessary.
//
EList remainingValues = new BasicEList.FastCompare(oldValues);
remainingValues.removeAll(removedValues);
int count = -1;
for (Object object : values)
{
int position = remainingValues.indexOf(object);
if (position != -1 && position != ++count)
{
compound.append(MoveCommand.create(domain, owner, feature, object, count));
remainingValues.move(count, position);
}
}
// Determine the values to be added and add them at the right position.
//
List addedValues = new BasicEList.FastCompare(values);
addedValues.removeAll(remainingValues);
if (!addedValues.isEmpty())
{
int addIndex = remainingValues.size();
for (ListIterator i = values.listIterator(values.size()); i.hasPrevious(); )
{
Object object = i.previous();
if (addedValues.contains(object))
{
compound.append(AddCommand.create(domain, owner, feature, object, addIndex));
}
else
{
--addIndex;
}
}
}
return compound;
}
}
compound.append(RemoveCommand.create(domain, owner, feature, new BasicEList(oldValues)));
}
if (!values.isEmpty())
{
compound.append(AddCommand.create(domain, owner, feature, values));
}
else if (value == UNSET_VALUE && eReference.isUnsettable())
{
compound.append(domain.createCommand(SetCommand.class, new CommandParameter(owner, feature, value)));
}
else if (eReference.isUnsettable() && compound.getCommandList().isEmpty())
{
return domain.createCommand(SetCommand.class, new CommandParameter(owner, feature, value));
}
else if (compound.getCommandList().isEmpty())
{
return IdentityCommand.INSTANCE;
}
return compound;
} // end setting whole list
else if (eReference.getEOpposite() != null)
{
EReference eOtherEnd = eReference.getEOpposite();
if (eOtherEnd.isMany())
{
if (eReference.isMany())
{
// For a many-to-many association, the command can only be undoable if the value or owner is last in its
// respective list, since the undo will include an inverse add. So, if the value is last, but the owner is
// not, we create an undoable compound command that removes from the opposite end and then inserts the new
// value.
//
EList list = (EList)((EObject)owner).eGet(eReference);
if (index == list.size() - 1)
{
EObject oldValue = (EObject)list.get(index);
EList oppositeList = (EList)oldValue.eGet(eOtherEnd);
if (oppositeList.get(oppositeList.size() - 1) != owner)
{
CompoundCommand compound =
new CompoundCommand(CompoundCommand.LAST_COMMAND_ALL, LABEL, DESCRIPTION)
{
@Override
public Collection getAffectedObjects()
{
return Collections.singleton(owner);
}
};
compound.append(RemoveCommand.create(domain, oldValue, eOtherEnd, owner));
compound.append(AddCommand.create(domain, owner, feature, value));
return compound;
}
}
}
else
{
// For a 1-to-many association, doing the set as a remove and add from the other end will make it undoable.
// In particular, if there is an existing non-null value, we first need to remove it from the other end, so
// that it will be reinserted at the correct index on undo.
//
Object oldValue = ((EObject)owner).eGet(eReference);
if (value == null || value == UNSET_VALUE)
{
if (oldValue == null)
{ // (value == null) && (oldValue == null)
// A simple set/unset will suffice.
//
return domain.createCommand(SetCommand.class, new CommandParameter(owner, eReference, value));
}
else
{ // (value == null) && (oldValue != null)
// Remove owner from the old value and unset if necessary.
//
Command removeCommand = RemoveCommand.create(domain, oldValue, eOtherEnd, Collections.singleton(owner));
if (value != UNSET_VALUE || !eReference.isUnsettable())
{
return removeCommand;
}
else
{
CompoundCommand compound = new CompoundCommand(LABEL, DESCRIPTION);
compound.append(removeCommand);
compound.append(domain.createCommand(SetCommand.class, new CommandParameter(owner, eReference, value)));
return compound;
}
}
}
else
{ // ((value != null)
Command addCommand =
new CommandWrapper(AddCommand.create(domain, value, eOtherEnd, Collections.singleton(owner)))
{
@Override
public Collection getAffectedObjects()
{
return Collections.singleton(owner);
}
};
if (oldValue == null)
{ // (value != null) && (oldValue == null)
// Add owner to new value.
//
return addCommand;
}
else
{ // ((value != null) && (oldValue != null))
// Need a compound command to remove owner from old value and add it to new value.
//
CompoundCommand compound = new CompoundCommand(CompoundCommand.LAST_COMMAND_ALL, LABEL, DESCRIPTION);
compound.append(RemoveCommand.create(domain, oldValue, eOtherEnd, Collections.singleton(owner)));
compound.append(addCommand);
return compound;
}
}
}
}
else if (eOtherEnd.isContainment())
{
if (value != null && value != UNSET_VALUE)
{
// For consistency, we always set 1-1 container relations from the container end.
//
return
new CommandWrapper(SetCommand.create(domain, value, eOtherEnd, owner))
{
@Override
public Collection getResult()
{
return Collections.singleton(owner);
}
@Override
public Collection getAffectedObjects()
{
return Collections.singleton(owner);
}
};
}
}
else
{
// For a many-to-1 or 1-to-1 association, if the opposite reference on the new value is already set to
// something, we need a compound command that first explicitly removes that reference, so that it will be
// restored in the undo.
//
if (value instanceof EObject)
{
EObject otherEObject = (EObject)((EObject)value).eGet(eOtherEnd);
if (otherEObject != null)
{
CompoundCommand compound =
new CompoundCommand(CompoundCommand.LAST_COMMAND_ALL)
{
@Override
public boolean canUndo()
{
return true;
}
};
if (eReference.isMany())
{
// For a many-to-1, we use SetCommand.create() to create the command to remove the opposite reference;
// a RemoveCommand on its opposite will actually result.
//
compound.append(SetCommand.create(domain, value, eOtherEnd, null));
}
else
{
// For a 1-to-1, we can directly create a SetCommand.
//
compound.append
(domain.createCommand
(SetCommand.class,
eOtherEnd.isChangeable() ?
new CommandParameter(value, eOtherEnd, null) :
new CommandParameter(otherEObject, eReference, null)));
}
compound.append(domain.createCommand(SetCommand.class, new CommandParameter(owner, eReference, value, index)));
return compound;
}
}
}
}
}
return domain.createCommand(SetCommand.class, new CommandParameter(owner, feature, value, index));
}
/**
* This caches the label.
*/
protected static final String LABEL = EMFEditPlugin.INSTANCE.getString("_UI_SetCommand_label");
/**
* This caches the description.
*/
protected static final String DESCRIPTION = EMFEditPlugin.INSTANCE.getString("_UI_SetCommand_description");
/**
* This is the owner object upon which the command will act.
*/
protected EObject owner;
/**
* This is the feature of the owner object upon the command will act.
*/
protected EStructuralFeature feature;
/**
* If non-null, this is the list in which the command will set a value.
* If null, feature is single-valued or no index was specified.
*/
protected EList ownerList;
/**
* This is the value to be set.
*/
protected Object value;
/**
* This is the old value of the feature which must be restored during undo.
*/
protected Object oldValue;
/**
* This is the position at which the object will be set.
*/
protected int index;
/**
* This specified whether or not this command can be undone.
*/
protected boolean canUndo = true;
/**
* This is any remove commands needed to clear this many valued list or to update the opposite properly.
*/
protected Command removeCommand;
/**
* This constructs a primitive command to set the owner's feature to the specified value.
*/
public SetCommand(EditingDomain domain, EObject owner, EStructuralFeature feature, Object value)
{
super(domain, LABEL, DESCRIPTION);
// Initialize all the fields from the command parameter.
//
this.owner = owner;
this.feature = feature;
this.value = value;
this.index = CommandParameter.NO_INDEX;
}
/**
* This constructs a primitive command to set the owner's feature to the specified value at the given index.
*/
public SetCommand(EditingDomain domain, EObject owner, EStructuralFeature feature, Object value, int index)
{
super(domain, LABEL, DESCRIPTION);
// Initialize all the fields from the command parameter.
//
this.owner = owner;
this.feature = feature;
this.value = value;
this.index = index;
if (index != CommandParameter.NO_INDEX)
{
ownerList = getOwnerList(owner, feature);
}
}
/**
* This returns the owner object upon which the command will act.
*/
public EObject getOwner()
{
return owner;
}
/**
* This returns the feature of the owner object upon the command will act.
*/
public EStructuralFeature getFeature()
{
return feature;
}
/**
* If the command will set a single value in a list, this returns the list in which it will set; null otherwise.
*/
public EList getOwnerList()
{
return ownerList;
}
/**
* This returns the position at which the objects will be added.
*/
public int getIndex()
{
return index;
}
/**
* This returns the value to be set.
*/
public Object getValue()
{
return value;
}
/**
* This returns the old value of the feature which must be restored during undo.
*/
public Object getOldValue()
{
return oldValue;
}
protected static final EcorePackage ecorePackage = EcorePackage.eINSTANCE;
@Override
protected boolean prepare()
{
boolean result = false;
// If there is an owner.
//
if (owner != null)
{
if (domain.isReadOnly(owner.eResource()))
{
return false;
}
// Get the owner's meta object.
//
EClass eClass = owner.eClass();
// Is the feature an attribute of the owner...
//
EList eAllStructuralFeatures = eClass.getEAllStructuralFeatures();
if (eAllStructuralFeatures.contains(feature) ||
feature != null && eAllStructuralFeatures.contains(ExtendedMetaData.INSTANCE.getAffiliation(eClass, feature)))
{
// If must be of this type then.
//
EGenericType eType = eClass.getFeatureType(feature);
if (ownerList != null)
{
// Setting at an index. Make sure the index is valid, the type is valid, and the value isn't already in a
// unique feature. Record the old value.
//
if (index >= 0 && index < ownerList.size() && eType.isInstance(value) &&
(!feature.isUnique() || !ownerList.contains(value)))
{
oldValue = ownerList.get(index);
result = true;
}
}
else if (feature.isMany())
{
// If the attribute is set, record it's old value.
//
if (owner.eIsSet(feature))
{
oldValue = new BasicEList((EList)owner.eGet(feature));
// oldValue = owner.eGet(feature);
}
else
{
oldValue = UNSET_VALUE;
}
if (value == UNSET_VALUE)
{
result = true;
}
else if (value instanceof Collection)
{
Collection collection = (Collection)value;
result = true;
for (Object object : collection)
{
if (!eType.isInstance(object))
{
result = false;
break;
}
}
}
}
else
{
// If the attribute is set, record it's old value.
//
if (owner.eIsSet(feature))
{
oldValue = owner.eGet(feature);
}
else
{
oldValue = UNSET_VALUE;
}
result = value == null || value == UNSET_VALUE || eType.isInstance(value);
}
// Make sure the container is not being put into a contained object.
//
if (result && feature instanceof EReference && ((EReference)feature).isContainment())
{
for (EObject container = owner; container != null; container = container.eContainer())
{
if (value == container)
{
result = false;
break;
}
}
}
}
}
return result;
}
@Override
public void doExecute()
{
if (feature instanceof EReference)
{
EReference eReference = (EReference)feature;
// Check whether there is an opposite that needs attention.
//
if (eReference.getEOpposite() != null)
{
// Because of the old factoring approach in the create method,
// it might be the case that the state of the old value has changed by the time we get here,
// and in that case, we don't want to duplicate the removals in this code.
//
if (oldValue instanceof Collection)
{
oldValue = new BasicEList((Collection)owner.eGet(feature));
}
else if (oldValue != UNSET_VALUE && index == CommandParameter.NO_INDEX)
{
oldValue = owner.eGet(feature);
}
EReference eOtherEnd = eReference.getEOpposite();
if (eOtherEnd.isMany())
{
// If the other end is a many, then we should remove the owner from the old value's opposite feature so that undo will put it back.
//
if (oldValue instanceof Collection)
{
@SuppressWarnings("unchecked")
Collection oldValues = (Collection)oldValue;
if (!oldValues.isEmpty())
{
CompoundCommand compoundCommand = new CompoundCommand();
for (EObject oldValueObject : oldValues)
{
compoundCommand.appendIfCanExecute(new RemoveCommand(domain, oldValueObject, eOtherEnd, owner));
}
removeCommand = compoundCommand;
}
}
else if (oldValue instanceof EObject)
{
removeCommand = new RemoveCommand(domain, (EObject)oldValue, eOtherEnd, owner);
}
}
else
{
// If the other end is single, then we should unset the owner from the old value's opposite feature so that undo will put it back.
//
if (value instanceof Collection)
{
@SuppressWarnings("unchecked")
Collection newValues = (Collection)value;
if (!newValues.isEmpty())
{
CompoundCommand compoundCommand = new CompoundCommand();
for (EObject newValueObject : newValues)
{
compoundCommand.appendIfCanExecute(new SetCommand(domain, newValueObject, eOtherEnd, UNSET_VALUE));
EObject otherEObject = (EObject)newValueObject.eGet(eOtherEnd);
if (otherEObject != null)
{
compoundCommand.appendIfCanExecute
(eOtherEnd.isChangeable() ?
new SetCommand(domain, newValueObject, eOtherEnd, UNSET_VALUE) :
new RemoveCommand(domain, otherEObject, eReference, newValueObject));
}
}
removeCommand = compoundCommand;
}
}
else if (value instanceof EObject)
{
EObject eObject = (EObject)value;
EObject otherEObject = (EObject)eObject.eGet(eOtherEnd);
if (otherEObject != null)
{
removeCommand =
eOtherEnd.isChangeable() ?
new SetCommand(domain, eObject, eOtherEnd, UNSET_VALUE) :
new SetCommand(domain, otherEObject, eReference, UNSET_VALUE);
}
}
}
if (removeCommand != null)
{
if (removeCommand.canExecute())
{
removeCommand.execute();
}
else
{
removeCommand = null;
}
}
}
}
// Either set or unset the feature.
//
if (ownerList != null)
{
if (removeCommand == null || ownerList.size() > index && ownerList.get(index) == oldValue)
{
ownerList.set(index, value);
}
else
{
ownerList.add(index, value);
}
}
else if (value == UNSET_VALUE)
{
owner.eUnset(feature);
}
else
{
owner.eSet(feature, value);
}
// Update the containing map, if necessary.
//
updateEMap(owner, feature);
}
@Override
public boolean doCanUndo()
{
return canUndo;
}
@Override
public void doUndo()
{
if (removeCommand != null)
{
removeCommand.undo();
}
// Either set or unset the old value.
//
if (ownerList != null)
{
if (removeCommand == null || !ownerList.contains(oldValue))
{
ownerList.set(index, oldValue);
}
else
{
ownerList.remove(value);
ownerList.move(index, oldValue);
}
}
else if (oldValue == UNSET_VALUE)
{
owner.eUnset(feature);
}
else
{
owner.eSet(feature, oldValue);
}
// Update the containing map, if necessary.
//
updateEMap(owner, feature);
}
@Override
public void doRedo()
{
if (removeCommand != null)
{
removeCommand.redo();
}
// Either set or unset the feature.
//
if (ownerList != null)
{
if (removeCommand == null || ownerList.size() > index && ownerList.get(index) == oldValue)
{
ownerList.set(index, value);
}
else
{
ownerList.add(index, value);
}
}
else if (value == UNSET_VALUE)
{
owner.eUnset(feature);
}
else
{
owner.eSet(feature, value);
}
// Update the containing map, if necessary.
//
updateEMap(owner, feature);
}
@Override
public Collection doGetResult()
{
return Collections.singleton(owner);
}
@Override
public Collection doGetAffectedObjects()
{
return Collections.singleton(owner);
}
/**
* This gives an abbreviated name using this object's own class' name, without package qualification,
* followed by a space separated list of field:value pairs.
*/
@Override
public String toString()
{
StringBuilder result = new StringBuilder(super.toString());
result.append(" (owner: " + owner + ")");
result.append(" (feature: " + feature + ")");
if (ownerList != null)
{
result.append(" (ownerList: " + ownerList + ")");
result.append(" (index: " + index + ")");
}
result.append(" (value: " + value + ")");
result.append(" (oldValue: " + oldValue + ")");
return result.toString();
}
protected static class PessimisticStrictCompoundCommand extends StrictCompoundCommand
{
public PessimisticStrictCompoundCommand(String label, String description)
{
super(label, description);
isPessimistic = true;
}
}
}
