/*******************************************************************************
* Copyright (c) 2001, 2007 Oracle 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:
* Oracle Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jst.pagedesigner.editpolicies;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.draw2d.IFigure;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.Request;
import org.eclipse.gef.editpolicies.GraphicalEditPolicy;
import org.eclipse.gef.requests.DropRequest;
import org.eclipse.gef.requests.GroupRequest;
import org.eclipse.jst.jsf.common.dom.TagIdentifier;
import org.eclipse.jst.jsf.core.internal.tld.TagIdentifierFactory;
import org.eclipse.jst.pagedesigner.editors.palette.IDropSourceData;
import org.eclipse.jst.pagedesigner.editors.palette.ITagDropSourceData;
import org.eclipse.jst.pagedesigner.elementedit.ElementEditFactoryRegistry;
import org.eclipse.jst.pagedesigner.elementedit.IElementEdit;
import org.eclipse.jst.pagedesigner.itemcreation.ItemCreationRequest;
import org.eclipse.jst.pagedesigner.parts.NodeEditPart;
import org.eclipse.jst.pagedesigner.validation.caret.IPositionMediator;
import org.eclipse.jst.pagedesigner.validation.caret.DropActionData.DropData;
import org.eclipse.jst.pagedesigner.viewer.DefaultDropLocationStrategy;
import org.eclipse.jst.pagedesigner.viewer.DesignPosition;
import org.eclipse.jst.pagedesigner.viewer.IDropLocationStrategy;
/**
* @author cbateman
*
*/
public abstract class DropEditPolicy extends GraphicalEditPolicy
{
private List _feedbackFigures;
/**
* @param r
* @return a mediator that can validate valid model drops into the
* host's edit part
*/
protected IPositionMediator createDropChildValidator(DropRequest r)
{
// sub-class may override to customize the drop container validator
return null;
}
/**
* @param r
* @return the appropriate design position for the drop request
*/
protected abstract DesignPosition findPosition(DropRequest r);
/**
* @param data
* @return a default validation mediator to be used if nothing custom is provided
*/
protected abstract IPositionMediator createDefaultDropChildValidator(DropData data);
/**
* @param r
* @return the validator to be used to validate the 'request' to drop
* the edit parts specified by 'r' into this policy's host edit part
*/
protected final IPositionMediator getDropChildValidator(DropRequest r)
{
IPositionMediator mediator = createDropChildValidator(r);
if (mediator == null)
{
DropData data = createDropData(r);
if (data == null)
{
return null;
}
mediator = createDefaultDropChildValidator(data);
}
return mediator;
}
/**
* @param request
* @return the data about the drop request
*/
protected DropData createDropData(DropRequest request)
{
if (request instanceof GroupRequest)
{
List editParts = ((GroupRequest)request).getEditParts();
// TODO: currently we only support one drop item
if (editParts.size() > 0)
{
EditPart part = (EditPart) editParts.get(0);
if (part instanceof NodeEditPart)
{
NodeEditPart nodePart = (NodeEditPart) part;
TagIdentifier tagId = nodePart.getTagIdentifier();
if (tagId != null)
{
List tagIds = new ArrayList();
tagIds.add(tagId);
return new DropData(tagIds);
}
}
}
}
else if (request instanceof ItemCreationRequest)
{
IDropSourceData creationProvider =
((ItemCreationRequest)request).getTagCreationProvider();
String tagName = creationProvider.getId();
if (creationProvider instanceof ITagDropSourceData)
{
tagName = ((ITagDropSourceData)creationProvider).getTagName();
}
TagIdentifier tagId =
TagIdentifierFactory.
createJSPTagWrapper(creationProvider.getNamespace(),
tagName);
List tagIds = new ArrayList();
tagIds.add(tagId);
return new DropData(tagIds);
}
return null;
}
/**
* @param r
* @return the drop location strategy
*/
protected final IDropLocationStrategy createDropLocationStrategy(DropRequest r)
{
DropData dropData = createDropData(r);
if (dropData != null && dropData.getTagIdentifiers().size() > 0)
{
// TODO: only supporting single item drop currently
TagIdentifier tagIdentifier =
(TagIdentifier) dropData.getTagIdentifiers().get(0);
IElementEdit elementEdit =
ElementEditFactoryRegistry.getInstance()
.createElementEdit(tagIdentifier);
// element edit not guaranteed to exist
if (elementEdit != null)
{
IDropLocationStrategy strategy =
elementEdit.getDropRequestorLocationStrategy(tagIdentifier, getHost().getViewer());
if (strategy != null)
{
return strategy;
}
}
}
// by default, return the default strategy
return new DefaultDropLocationStrategy(getHost().getViewer());
}
/*
* (non-Javadoc)
*
* @see org.eclipse.gef.editpolicies.AbstractEditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
*/
public void eraseTargetFeedback(Request request) {
if (_feedbackFigures != null)
{
for (final Iterator it = _feedbackFigures.iterator(); it.hasNext();)
{
final IFigure figure = (IFigure) it.next();
if (figure != null)
{
removeFeedback(figure);
}
}
_feedbackFigures.clear();
_feedbackFigures = null;
}
}
public void showTargetFeedback(Request request)
{
if (request instanceof DropRequest)
{
DesignPosition position = findPosition((DropRequest)request);
if (position != null) {
// erase any prior feedback
eraseTargetFeedback(request);
// add figures to feedback layer and save them in _feedbackFigures
// for later.
_feedbackFigures = createDropLocationStrategy((DropRequest)request).showTargetFeedback(getHost(), position, (DropRequest)request);
}
}
}
}