com.tasktop.c2c.server.common.web.client.widgets.chooser.SingleValueChooser.java Source code

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Here is the source code for com.tasktop.c2c.server.common.web.client.widgets.chooser.SingleValueChooser.java

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/*******************************************************************************
 * Copyright (c) 2010, 2012 Tasktop Technologies
 * Copyright (c) 2010, 2011 SpringSource, a division of VMware
 * 
 * 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:
 *     Tasktop Technologies - initial API and implementation
 ******************************************************************************/
package com.tasktop.c2c.server.common.web.client.widgets.chooser;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import com.google.gwt.editor.client.Editor;
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.user.client.ui.HasValue;
import com.google.gwt.user.client.ui.SuggestOracle;

/**
 * @author David Green (Tasktop Technologies Inc.)
 * @author Lucas Panjer (Tasktop Technologies Inc.)
 * 
 */
public class SingleValueChooser<T> extends AbstractValueChooser<T> implements HasValue<T>, IsEditor<Editor<T>> {
    public SingleValueChooser(SuggestOracle suggest) {
        super(suggest);
    }

    private T value;

    public T getValue() {
        return value;
    }

    public void setValue(T value) {
        this.value = value;
        updateUi();
    }

    @Override
    protected void addValue(T value) {
        if (this.value == null || !this.value.equals(value)) {
            setValue(value);
            fireValueChanged();
        }
    }

    @Override
    public void removeValue(Object value) {
        setValue(null);
        fireValueChanged();
    }

    @Override
    protected List<T> getValues() {
        if (value == null) {
            return Collections.emptyList();
        }
        return Collections.singletonList(value);
    }

    @Override
    public void fireValueChanged() {
        ValueChangeEvent.fire(this, getValue());
    }

    @Override
    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<T> handler) {
        return addHandler(handler, ValueChangeEvent.getType());
    }

    public void setOriginalValue(T value) {
        if (value == null) {
            setOriginalValues(new ArrayList<T>());
        } else {
            setOriginalValues(Collections.singletonList(value));
        }
    }

    private Editor<T> editor = null;

    @Override
    public Editor<T> asEditor() {
        if (editor == null) {
            editor = TakesValueEditor.of(this);
        }
        return editor;
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.google.gwt.user.client.ui.HasValue#setValue(java.lang.Object, boolean)
     */
    @Override
    public void setValue(T value, boolean fireEvents) {
        setValue(value);
        if (fireEvents) {
            fireValueChanged();
        }
    }

}