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/*******************************************************************************
* Copyright (c) 2012 BestSolution.at 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:
* Tom Schindl<tom.schindl@bestsolution.at> - initial API and implementation
*******************************************************************************/
package org.eclipse.fx.ui.databinding;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.core.databinding.observable.list.IListChangeListener;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.list.ListChangeEvent;
import org.eclipse.core.databinding.observable.list.ListDiffVisitor;
import org.eclipse.jdt.annotation.NonNull;
import javafx.collections.ObservableList;
import javafx.scene.control.TreeItem;
/**
* Utility to setup a tree
*/
public class TreeUtil {
/**
* Create a tree model backed by the given {@link ObservableFactory}
*
* @param root
* the root of the model
* @param factory
* the factory to create children
* @param <T>
* the the item value type
* @return the tree item backed by the given root model instance
*/
@NonNull
public static <T> TreeItem<T> createModel(@NonNull T root, @NonNull ObservableFactory<T> factory) {
return new TreeItemImpl<T>(root, factory);
}
/**
* Factory to create child observables
*
* @param <T>
* the type
*/
public interface ObservableFactory<T> {
/**
* Create an observable list for the parent element
*
* @param parent
* the parent
* @return the list
*/
public IObservableList createObservable(@NonNull T parent);
}
static class TreeItemImpl<T> extends TreeItem<T> {
private IObservableList list;
@NonNull
ObservableFactory<T> factory;
private boolean hasLoadedChildren = false;
public TreeItemImpl(@NonNull T element, @NonNull ObservableFactory<T> factory) {
setValue(element);
this.factory = factory;
this.list = factory.createObservable(element);
getChildren().add(new TreeItem<>());
expandedProperty().addListener((o) -> {
if( isExpanded() ) {
if( ! this.hasLoadedChildren ) {
loadChildren();
}
}
});
}
// @Override
// public ObservableList<TreeItem<T>> getChildren() {
// if (this.hasLoadedChildren == false) {
// loadChildren();
// }
// return super.getChildren();
// }
// @Override
// public boolean isLeaf() {
// if( this.hasLoadedChildren ) {
// loadChildren();
// }
// return super.isLeaf();
// }
// public boolean isLeaf() {
// if (this.hasLoadedChildren == false) {
// loadChildren();
// }
// return super.getChildren().isEmpty();
// }
@SuppressWarnings("null")
private void loadChildren() {
this.hasLoadedChildren = true;
if (this.list != null) {
final ObservableList<@NonNull TreeItem<@NonNull T>> itemList = getChildren();
this.list.addListChangeListener(new IListChangeListener() {
@Override
public void handleListChange(ListChangeEvent event) {
event.diff.accept(new ListDiffVisitor() {
@Override
public void handleRemove(int index, Object element) {
if (itemList.size() < index) {
TreeItem<T> t = itemList.get(index);
if (t.getValue() == element) {
itemList.remove(index);
} else {
Iterator<TreeItem<T>> it = itemList.iterator();
while (it.hasNext()) {
if (it.next().getValue() == element) {
it.remove();
break;
}
}
}
}
}
@SuppressWarnings({ "unchecked" })
@Override
public void handleAdd(int index, Object element) {
if (itemList.size() > index) {
itemList.add(index, new TreeItemImpl<@NonNull T>((T) element, TreeItemImpl.this.factory));
} else {
itemList.add(new TreeItemImpl<@NonNull T>((T) element, TreeItemImpl.this.factory));
}
}
@Override
public void handleMove(int oldIndex, int newIndex, Object element) {
TreeItem<T> item = getChildren().remove(oldIndex);
getChildren().add(newIndex,item);
}
});
}
});
List<TreeItemImpl<@NonNull T>> l = new ArrayList<>(this.list.size());
for (Object o : this.list) {
@SuppressWarnings("unchecked")
T t = (T) o;
l.add(new TreeItemImpl<@NonNull T>(t, this.factory));
}
itemList.setAll(l);
} else {
getChildren().clear();
}
}
}
}
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