// Copyright 2011 Palantir Technologies
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.palantir.ptoss.cinch.swing;
import java.beans.IntrospectionException;
import java.lang.reflect.Field;
import java.util.Collection;
import java.util.List;
import java.util.Set;
import javax.swing.DefaultListModel;
import javax.swing.JList;
import javax.swing.ListModel;
import javax.swing.table.DefaultTableModel;
import org.apache.commons.lang.ArrayUtils;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.palantir.ptoss.cinch.core.BindableModel;
import com.palantir.ptoss.cinch.core.Binding;
import com.palantir.ptoss.cinch.core.BindingContext;
import com.palantir.ptoss.cinch.core.ModelUpdate;
import com.palantir.ptoss.cinch.core.WiringHarness;
import com.palantir.ptoss.cinch.swing.Bound.Wiring;
import com.palantir.ptoss.util.Mutator;
/**
* <p>
* Wires up a {@link JList} to a {@link List} in a {@link BindableModel}. Whenever the contents of
* the bound List change (and the BindableModel's update is called) the JList's model will be
* swapped out with a new model with the new contents. Selection of values is maintained between
* model swaps.
* <p>
* This bindings is only one way. The JList will modify itself to reflect the contents of the List
* in the BindableModel. However, changes to the JList's model after that will not be reflected
* in the model. The idea here is that if the user takes some action to remove an item from the
* list then that should be accomplished by removing an item from the underlying BindableModel,
* not the JList.
* <p>
* Implementation notes: a {@link DefaultTableModel} is used to back the JList. Maintaining
* selection between model swaps is simply done with {@link Object#equals(Object)} comparisons.
*/
public class JListWiringHarness implements WiringHarness<Bound, Field> {
public Collection<Binding> wire(Bound bound, BindingContext context, Field field)
throws IllegalAccessException, IntrospectionException {
JList list = context.getFieldObject(field, JList.class);
Mutator mutator = Mutator.create(context, bound.to());
return ImmutableList.of(bindJList(bound, mutator, list));
}
private Binding bindJList(final Bound bound, final Mutator mutator, final JList list) {
final List<Object> ons = BindingContext.getOnObjects(bound.on(), mutator.getModel());
Binding binding = new Binding() {
public <T extends Enum<?> & ModelUpdate> void update(T... changed) {
if (!BindingContext.isOn(ons, changed)) {
return;
}
try {
updateListModel(list, (List<?>)mutator.get());
} catch (Exception ex) {
Wiring.logger.error("exception in JList binding", ex);
}
}
};
mutator.getModel().bind(binding);
return binding;
}
private static void updateListModel(JList list, List<?> newContents) {
if (newContents == null) {
newContents = ImmutableList.of();
}
ListModel oldModel = list.getModel();
List<Object> old = Lists.newArrayListWithExpectedSize(oldModel.getSize());
for (int i = 0; i < oldModel.getSize(); i++) {
old.add(oldModel.getElementAt(i));
}
if (old.equals(newContents)) {
return;
}
Object[] selected = list.getSelectedValues();
DefaultListModel listModel = new DefaultListModel();
for (Object obj : newContents) {
listModel.addElement(obj);
}
list.setModel(listModel);
List<Integer> newIndices = Lists.newArrayListWithCapacity(selected.length);
Set<Object> selectedSet = Sets.newHashSet(selected);
for (int i = 0; i < listModel.size(); i++) {
if (selectedSet.contains(listModel.elementAt(i))) {
newIndices.add(i);
}
}
list.setSelectedIndices(ArrayUtils.toPrimitive(newIndices.toArray(new Integer[0])));
}
}