ButtonGroup.java :  » Apache-Harmony-Java-SE » javax-package » javax » swing » Java Open Source

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 javax.swing;

import java.io.Serializable;
import java.util.Enumeration;
import java.util.Vector;

public class ButtonGroup implements Serializable {
    private static final long serialVersionUID = 4259076101881721375L;

    protected Vector<AbstractButton> buttons = new Vector<AbstractButton>();

    private ButtonModel selection;

    public void add(final AbstractButton button) {
        if (button == null) {
            return;
        }
        
        buttons.add(button);

        ButtonModel model = button.getModel();
        if (button.isSelected()) {
            if (selection != null && model != selection) {
                button.setSelected(false);
            } else {
                selection = model;
            }
        }
        model.setGroup(this);
    }

    public int getButtonCount() {
        return buttons.size();
    }

    public Enumeration<javax.swing.AbstractButton> getElements() {
        return buttons.elements();
    }

    public ButtonModel getSelection() {
        return selection;
    }

    public boolean isSelected(final ButtonModel model) {
        return (model == selection);
    }

    public void remove(final AbstractButton button) {
        if (button == null) {
            return;
        }

        buttons.remove(button);
        ButtonModel model = button.getModel();
        if (selection == model) {
            selection = null;
        }
        model.setGroup(null);
    }

    public void setSelected(final ButtonModel model, final boolean selected) {
        if (!selected || model == null || selection == model) {
            return;
        }
        if (!model.isSelected()) {
            model.setSelected(true);
        }
        ButtonModel prevSelection = selection;
        selection = model;
        if (prevSelection != null) {
            prevSelection.setSelected(false);
        }
    }
}