/**
* Copyright (c) 2002-2010 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM - Initial API and implementation
*/
package org.eclipse.emf.edit.command;
import java.util.Collection;
import java.util.Collections;
import org.eclipse.emf.common.command.Command;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.edit.EMFEditPlugin;
import org.eclipse.emf.edit.domain.EditingDomain;
/**
* The move command logically acts upon an owner object that has a collection-based feature
* containing an object that is to be moved to a new position within the collection.
* The static create method delegates command creation to {@link EditingDomain#createCommand EditingDomain.createCommand},
* which may or may not result in the actual creation of an instance of this class.
* Like all the low level commands in this package, the move command is undoable.
*
* <p>
* The implementation of this class is low-level and EMF specific;
* it allows an object to be moved to a new position within a many-valued feature of an owner,
* i.e., it is equivalent of the call
* <pre>
* ((EList)((EObject)owner).eGet((EStructuralFeature)feature)).move(index, object);
* </pre>
*
* <p>
* It can also be used as an equivalent to the call
* <pre>
* ((EList)extent).move(index, object);
* </pre>
* which is how root objects are moved within the contents of a resource.
* Like all the low-level commands in this package, the move command is undoable.
*
* <p>
* A move command is an {@link OverrideableCommand}.
*/
public class MoveCommand extends AbstractOverrideableCommand
{
/**
* This creates a command to move particular value to a particular index in the specified feature of the owner.
* The feature will often be null because the domain will deduce it.
*/
public static Command create(EditingDomain domain, Object owner, Object feature, Object value, int index)
{
return domain.createCommand(MoveCommand.class, new CommandParameter(owner, feature, value, index));
}
/**
* This caches the label.
*/
protected static final String LABEL = EMFEditPlugin.INSTANCE.getString("_UI_MoveCommand_label");
/**
* This caches the description.
*/
protected static final String DESCRIPTION = EMFEditPlugin.INSTANCE.getString("_UI_MoveCommand_description");
/**
* This caches the description for a list-based command.
*/
protected static final String DESCRIPTION_FOR_LIST = EMFEditPlugin.INSTANCE.getString("_UI_MoveCommand_description_for_list");
/**
* This is the owner object upon which the command will act.
* It could be null in the case that we are dealing with an {@link org.eclipse.emf.common.util.EList}.
*/
protected EObject owner;
/**
* This is the feature of the owner object upon the command will act.
* It could be null, in the case that we are dealing with an {@link org.eclipse.emf.common.util.EList}.
*/
protected EStructuralFeature feature;
/**
* This is the list in which the command will move an object.
*/
protected EList<Object> ownerList;
/**
* This is the value being moved within the owner list.
*/
protected Object value;
/**
* This is the position to which the object will be moved.
*/
protected int index;
/**
* This is the original position to which the object will be moved upon undo.
*/
protected int oldIndex;
/**
* This constructs a primitive command to move a particular value to a particular index
* of the specified many-valued feature of the owner.
*/
public MoveCommand(EditingDomain domain, EObject owner, EStructuralFeature feature, Object value, int index)
{
super(domain, LABEL, DESCRIPTION);
this.owner = owner;
this.feature = feature;
this.value = value;
this.index = index;
ownerList = getOwnerList(this.owner, feature);
oldIndex = -1;
}
/**
* This constructs a primitive command to move a value at a particular index to another particular index
* of the specified many-valued feature of the owner.
* @since 2.7
*/
public MoveCommand(EditingDomain domain, EObject owner, EStructuralFeature feature, int sourceIndex, int targetIndex)
{
super(domain, LABEL, DESCRIPTION);
this.owner = owner;
this.feature = feature;
index = targetIndex;
oldIndex = sourceIndex;
ownerList = getOwnerList(this.owner, feature);
if (ownerList != null && ownerList.size() > sourceIndex && sourceIndex >= 0)
{
value = ownerList.get(sourceIndex);
}
}
/**
* This constructs a primitive command to move a particular value to a particular index of the specified extent.
*/
public MoveCommand(EditingDomain domain, EList<?> list, Object value, int index)
{
super(domain, LABEL, DESCRIPTION_FOR_LIST);
this.value = value;
this.index = index;
oldIndex = -1;
@SuppressWarnings("unchecked")
EList<Object> untypedList = (EList<Object>)list;
ownerList = untypedList;
}
/**
* This constructs a primitive command to move a value at a particular index to another particular index of the specified extent.
* @since 2.7
*/
public MoveCommand(EditingDomain domain, EList<?> list, int sourceIndex, int targetIndex)
{
super(domain, LABEL, DESCRIPTION_FOR_LIST);
if (list != null && list.size() > sourceIndex && sourceIndex >= 0)
{
value = list.get(sourceIndex);
}
index = targetIndex;
oldIndex = sourceIndex;
@SuppressWarnings("unchecked")
EList<Object> untypedList = (EList<Object>)list;
ownerList = untypedList;
}
/**
* This returns the owner object upon which the command will act.
* It could be null in the case that we are dealing with an {@link org.eclipse.emf.common.util.EList}.
*/
public EObject getOwner()
{
return owner;
}
/**
* This returns the feature of the owner object upon the command will act.
* It could be null, in the case that we are dealing with an {@link org.eclipse.emf.common.util.EList}.
*/
public EStructuralFeature getFeature()
{
return feature;
}
/**
* This returns the list in which the command will move an object.
*/
public EList<Object> getOwnerList()
{
return ownerList;
}
/**
* This returns the value being moved.
*/
public Object getValue()
{
return value;
}
/**
* This returns the position to which the value will be moved.
*/
public int getIndex()
{
return index;
}
/**
* This returns the original position to which the object will be moved upon undo.
*/
public int getOldIndex()
{
return oldIndex;
}
@Override
protected boolean prepare()
{
// Return whether there is a list and the indices are within range.
//
boolean result =
ownerList != null &&
index >= 0 &&
index < ownerList.size() &&
(oldIndex == -1 ? ownerList.contains(value) : oldIndex >= 0 && oldIndex < ownerList.size()) &&
(owner == null || !domain.isReadOnly(owner.eResource()));
return result;
}
@Override
public void doExecute()
{
if (oldIndex == -1)
{
oldIndex = ownerList.indexOf(value);
}
ownerList.move(index, oldIndex);
}
@Override
public void doUndo()
{
ownerList.move(oldIndex, index);
}
@Override
public void doRedo()
{
ownerList.move(index, oldIndex);
}
@Override
public Collection<?> doGetResult()
{
return Collections.singleton(value);
}
@Override
public Collection<?> doGetAffectedObjects()
{
return Collections.singleton(value);
}
/**
* This gives an abbreviated name using this object's own class' name, without package qualification,
* followed by a space separated list of <tt>field:value</tt> pairs.
*/
@Override
public String toString()
{
StringBuffer result = new StringBuffer(super.toString());
result.append(" (owner: " + owner + ")");
result.append(" (feature: " + feature + ")");
result.append(" (ownerList: " + ownerList + ")");
result.append(" (value: " + value + ")");
result.append(" (index: " + index + ")");
result.append(" (oldIndex: " + oldIndex + ")");
return result.toString();
}
}