/*******************************************************************************
* Copyright (c) 2000, 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 Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.gef.editparts;
import java.util.Iterator;
import java.util.List;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.eclipse.swt.widgets.Widget;
import org.eclipse.gef.DragTracker;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.Request;
import org.eclipse.gef.TreeEditPart;
/**
* Default implementation for {@link TreeEditPart}s used in GEF
* {@link org.eclipse.gef.ui.parts.TreeViewer}s.
* <P>
* This is an implementation class, and the documentation here is targeted at
* <em>subclassing</em> this class. Callers of public API should refer to the
* interface's documentation.
*/
public abstract class AbstractTreeEditPart extends AbstractEditPart implements
TreeEditPart {
/**
* Either a Tree or TreeItem
*/
protected Widget widget;
private boolean expanded;
/**
* Constructs a new EditPart with the specified model.
*
* @param model
* the model
*/
public AbstractTreeEditPart(Object model) {
setModel(model);
}
/**
* Default constructor
*/
public AbstractTreeEditPart() {
}
/**
* Implemented to assign the child its
* {@link TreeEditPart#setWidget(Widget) widget}. Subclasses should not call
* or override this method.
*
* @see AbstractEditPart#addChildVisual(EditPart, int)
*/
protected void addChildVisual(EditPart childEditPart, int index) {
Widget widget = getWidget();
TreeItem item;
if (widget instanceof Tree)
item = new TreeItem((Tree) widget, 0, index);
else
item = new TreeItem((TreeItem) widget, 0, index);
((TreeEditPart) childEditPart).setWidget(item);
}
/**
* Convenience method that returns <code>true</code> if the widget is a
* TreeItem and is safe to use.
*
* @return <code>true</code> if the widget is a <code>TreeItem</code> and is
* not disposed
*/
protected final boolean checkTreeItem() {
return !(widget == null || widget.isDisposed() || widget instanceof Tree);
}
/**
* Override this method to install the EditPolicies for your EditPart.
*
* @see AbstractEditPart#createEditPolicies()
*/
protected void createEditPolicies() {
}
/**
* @see EditPart#getDragTracker(Request)
*/
public DragTracker getDragTracker(Request req) {
return null;
}
/**
* Override this method to return the <code>Image</code> for this EditPart's
* {@link #widget}. This method is called from {@link #refreshVisuals()}.
*
* @return the Image to be displayed in the TreeItem
*/
protected Image getImage() {
return null;
}
/**
* Override this method to return the String to be used in this EditPart's
* {@link #widget}. This method is called from {@link #refreshVisuals()}.
*
* @return the String to be displayed by the TreeItem
*/
protected String getText() {
return getClass().getName();
}
/**
* @see TreeEditPart#getWidget()
*/
public Widget getWidget() {
return widget;
}
/**
* By default, this method will apply an <code>Image</code> and
* <code>String</code> to the widget if it is a <code>TreeItem</code>.
* Subclasses should override {@link #getImage()} and {@link #getText()} to
* provide the <code>Image</code> and <code>String</code> used.
* <P>
* Subclasses might extend this method if they also want to change the
* TreeItem's foreground or background color.
*
* @see AbstractEditPart#refreshVisuals()
*/
protected void refreshVisuals() {
setWidgetImage(getImage());
setWidgetText(getText());
}
/**
* Disposes the child's <code>widget</code> and sets it to <code>null</code>
* .
*
* @see AbstractEditPart#removeChildVisual(EditPart)
*/
protected void removeChildVisual(EditPart childEditPart) {
TreeEditPart treeEditPart = (TreeEditPart) childEditPart;
treeEditPart.getWidget().dispose();
treeEditPart.setWidget(null);
}
/**
* @see AbstractEditPart#reorderChild(EditPart, int)
*/
protected void reorderChild(EditPart editpart, int index) {
super.reorderChild(editpart, index);
// Reordering assigns a new Widget to the child. Call refresh() to
// update widget.
editpart.refresh();
}
/**
* Sets the {@link #widget}.
*
* @see org.eclipse.gef.TreeEditPart#setWidget(Widget)
*/
public void setWidget(Widget widget) {
List children = getChildren();
if (widget != null) {
widget.setData(this);
if (widget instanceof TreeItem) {
final TreeItem item = (TreeItem) widget;
item.addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent e) {
expanded = item.getExpanded();
}
});
}
for (int i = 0; i < children.size(); i++) {
TreeEditPart tep = (TreeEditPart) children.get(i);
if (widget instanceof TreeItem)
tep.setWidget(new TreeItem((TreeItem) widget, 0));
else
tep.setWidget(new TreeItem((Tree) widget, 0));
// We have just assigned a new TreeItem to the EditPart
tep.refresh();
}
if (widget instanceof TreeItem)
((TreeItem) widget).setExpanded(expanded);
} else {
Iterator iter = getChildren().iterator();
while (iter.hasNext())
((TreeEditPart) iter.next()).setWidget(null);
}
this.widget = widget;
}
/**
* Sets a specified <code>Image</code> into the widget iff it is a
* <code>TreeItem</code>.
*
* @param image
* the Image
*/
protected final void setWidgetImage(Image image) {
if (checkTreeItem())
((TreeItem) getWidget()).setImage(image);
}
/**
* Sets a specified <code>String</code> into the widget iff it is a
* <code>TreeItem</code>.
*
* @param text
* the String
*/
protected final void setWidgetText(String text) {
if (checkTreeItem())
((TreeItem) getWidget()).setText(text);
}
}