com.google.gwt.view.client.NoSelectionModel.java Source code

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Here is the source code for com.google.gwt.view.client.NoSelectionModel.java

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/*
 * Copyright 2010 Google 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.google.gwt.view.client;

import com.google.gwt.view.client.SelectionModel.AbstractSelectionModel;

/**
 * A selection model that does not allow selection, but fires selection change
 * events. Use this model if you want to know when a user selects an item, but
 * do not want the view to update based on the selection.
 * 
 * @param <T> the record data type
 */
public class NoSelectionModel<T> extends AbstractSelectionModel<T> {

    private Object lastKey;
    private T lastSelection;

    /**
     * Constructs a NoSelectionModel without a key provider.
     */
    public NoSelectionModel() {
        super(null);
    }

    /**
     * Constructs a NoSelectionModel with the given key provider.
     *
     * @param keyProvider an instance of ProvidesKey<T>, or null if the record
     *        object should act as its own key
     */
    public NoSelectionModel(ProvidesKey<T> keyProvider) {
        super(keyProvider);
    }

    /**
     * Gets the object that was last selected.
     * 
     * @return the last selected object
     */
    public T getLastSelectedObject() {
        return lastSelection;
    }

    public boolean isSelected(T object) {
        return false;
    }

    public void setSelected(T object, boolean selected) {
        Object key = getKey(object);
        if (selected) {
            lastSelection = object;
            lastKey = key;
        } else if (lastKey != null && lastKey.equals(key)) {
            lastSelection = null;
            lastKey = null;
        }
        scheduleSelectionChangeEvent();
    }
}