/**
* Copyright 2014 ArcBees Inc.
*
* 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.arcbees.chosen.client.gwt;
import java.util.Objects;
import com.arcbees.chosen.client.ChosenOptions;
import com.google.common.base.Preconditions;
import com.google.gwt.editor.client.IsEditor;
import com.google.gwt.editor.client.adapters.TakesValueEditor;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.text.shared.Renderer;
import com.google.gwt.user.client.ui.HasValue;
import com.google.gwt.view.client.ProvidesKey;
import com.google.gwt.view.client.SimpleKeyProvider;
public class ChosenValueListBox<T> extends BaseChosenValueListBox<T> implements IsEditor<TakesValueEditor<T>>,
HasValue<T> {
private final Renderer<T> renderer;
private TakesValueEditor<T> editor;
private T value;
/**
* @throws java.lang.NullPointerException if {@code renderer} is null
*/
public ChosenValueListBox(Renderer<T> renderer) {
this(renderer, new ChosenOptions());
}
/**
* @throws java.lang.NullPointerException if {@code renderer} is null
* @throws java.lang.NullPointerException if {@code options} is null
*/
public ChosenValueListBox(Renderer<T> renderer, ChosenOptions options) {
this(renderer, new SimpleKeyProvider<T>(), options);
}
/**
* @throws java.lang.NullPointerException if {@code renderer} is null
* @throws java.lang.NullPointerException if {@code keyProvider} is null
*/
public ChosenValueListBox(Renderer<T> renderer, ProvidesKey<T> keyProvider) {
this(renderer, keyProvider, new ChosenOptions());
}
/**
* @throws java.lang.NullPointerException if {@code renderer} is null
* @throws java.lang.NullPointerException if {@code keyProvider} is null
* @throws java.lang.NullPointerException if {@code options} is null
*/
public ChosenValueListBox(Renderer<T> renderer, ProvidesKey<T> keyProvider, ChosenOptions options) {
super(keyProvider, options);
Preconditions.checkNotNull(renderer);
this.renderer = renderer;
}
@Override
public HandlerRegistration addValueChangeHandler(ValueChangeHandler<T> handler) {
return addHandler(handler, ValueChangeEvent.getType());
}
@Override
public TakesValueEditor<T> asEditor() {
if (editor == null) {
editor = TakesValueEditor.of(this);
}
return editor;
}
/**
* Get the selected value of the component
*
* @return
*/
@Override
public T getValue() {
return value;
}
/**
* Set the value of the component. This method throws an IllegalStateException if the value isn't part of the
* accepted values.
* <p/>
* You can only pass {#code null} to reset the value of the component if and only if @{code null} is in the
* accepted values list.
* <p/>
* See {@link #acceptValue(Object)} in order to test if a value can be accepted by the component.
*/
@Override
public void setValue(T newValue) {
setValue(newValue, false);
}
/**
* Set the value of the component. This method throws an IllegalStateException if the value isn't part of the
* accepted values.
* <p/>
* See {@link #acceptValue(Object)} in order to test if a value can be accepted by the component.
* <p/>
* If the {@code fireEvent} is set to true, a {@link com.google.gwt.event.logical.shared.ValueChangeEvent} will be
* fired.
*/
@Override
public void setValue(T newValue, boolean fireEvents) {
setValue(newValue, fireEvents, true);
}
@Override
protected void deselectValue(T value) {
// never happen in single selection mode
}
@Override
protected void selectValue(T value) {
setValue(value, true, false);
}
@Override
protected ChosenListBox createChosenListBox(ChosenOptions options) {
return new ChosenListBox(options);
}
@Override
protected void updateChosenListBox() {
Object key = keyProvider.getKey(value);
Integer index = valueKeyToIndex.get(key);
if (index != null) {
getChosenListBox().setSelectedIndex(index);
} else {
value = null; // the value is not in the accepted values list anymore.
getChosenListBox().setSelectedIndex(-1);
}
}
@Override
protected void addItemToChosenListBox(T value) {
getChosenListBox().addItem(renderer.render(value));
}
private void setValue(T newValue, boolean fireEvents, boolean update) {
Preconditions.checkState(acceptValue(newValue), "This value is not in the acceptable values " +
"list of this component");
if (Objects.equals(newValue, value)) {
return;
}
T before = value;
value = newValue;
if (update) {
updateChosenListBox();
}
if (fireEvents) {
ValueChangeEvent.fireIfNotEqual(this, before, value);
}
}
}