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package javax.swing;

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

The default model for combo boxes.
Author:Arnaud Weber, Tom Santos
Type parameters:
  • <E> – the type of the elements of this model
Since:1.2
/** * The default model for combo boxes. * * @param <E> the type of the elements of this model * * @author Arnaud Weber * @author Tom Santos * @since 1.2 */
@SuppressWarnings("serial") // Superclass is not serializable across versions public class DefaultComboBoxModel<E> extends AbstractListModel<E> implements MutableComboBoxModel<E>, Serializable { Vector<E> objects; Object selectedObject;
Constructs an empty DefaultComboBoxModel object.
/** * Constructs an empty DefaultComboBoxModel object. */
public DefaultComboBoxModel() { objects = new Vector<E>(); }
Constructs a DefaultComboBoxModel object initialized with an array of objects.
Params:
  • items – an array of Object objects
/** * Constructs a DefaultComboBoxModel object initialized with * an array of objects. * * @param items an array of Object objects */
public DefaultComboBoxModel(final E[] items) { objects = new Vector<E>(items.length); int i,c; for ( i=0,c=items.length;i<c;i++ ) objects.addElement(items[i]); if ( getSize() > 0 ) { selectedObject = getElementAt( 0 ); } }
Constructs a DefaultComboBoxModel object initialized with a vector.
Params:
  • v – a Vector object ...
/** * Constructs a DefaultComboBoxModel object initialized with * a vector. * * @param v a Vector object ... */
public DefaultComboBoxModel(Vector<E> v) { objects = v; if ( getSize() > 0 ) { selectedObject = getElementAt( 0 ); } } // implements javax.swing.ComboBoxModel
Set the value of the selected item. The selected item may be null.
Params:
  • anObject – The combo box value or null for no selection.
/** * Set the value of the selected item. The selected item may be null. * * @param anObject The combo box value or null for no selection. */
public void setSelectedItem(Object anObject) { if ((selectedObject != null && !selectedObject.equals( anObject )) || selectedObject == null && anObject != null) { selectedObject = anObject; fireContentsChanged(this, -1, -1); } } // implements javax.swing.ComboBoxModel public Object getSelectedItem() { return selectedObject; } // implements javax.swing.ListModel public int getSize() { return objects.size(); } // implements javax.swing.ListModel public E getElementAt(int index) { if ( index >= 0 && index < objects.size() ) return objects.elementAt(index); else return null; }
Returns the index-position of the specified object in the list.
Params:
  • anObject – the object to return the index of
Returns:an int representing the index position, where 0 is the first position
/** * Returns the index-position of the specified object in the list. * * @param anObject the object to return the index of * @return an int representing the index position, where 0 is * the first position */
public int getIndexOf(Object anObject) { return objects.indexOf(anObject); } // implements javax.swing.MutableComboBoxModel public void addElement(E anObject) { objects.addElement(anObject); fireIntervalAdded(this,objects.size()-1, objects.size()-1); if ( objects.size() == 1 && selectedObject == null && anObject != null ) { setSelectedItem( anObject ); } } // implements javax.swing.MutableComboBoxModel public void insertElementAt(E anObject,int index) { objects.insertElementAt(anObject,index); fireIntervalAdded(this, index, index); } // implements javax.swing.MutableComboBoxModel public void removeElementAt(int index) { if ( getElementAt( index ) == selectedObject ) { if ( index == 0 ) { setSelectedItem( getSize() == 1 ? null : getElementAt( index + 1 ) ); } else { setSelectedItem( getElementAt( index - 1 ) ); } } objects.removeElementAt(index); fireIntervalRemoved(this, index, index); } // implements javax.swing.MutableComboBoxModel public void removeElement(Object anObject) { int index = objects.indexOf(anObject); if ( index != -1 ) { removeElementAt(index); } }
Empties the list.
/** * Empties the list. */
public void removeAllElements() { if ( objects.size() > 0 ) { int firstIndex = 0; int lastIndex = objects.size() - 1; objects.removeAllElements(); selectedObject = null; fireIntervalRemoved(this, firstIndex, lastIndex); } else { selectedObject = null; } }
Adds all of the elements present in the collection.
Params:
  • c – the collection which contains the elements to add
Throws:
/** * Adds all of the elements present in the collection. * * @param c the collection which contains the elements to add * @throws NullPointerException if {@code c} is null */
public void addAll(Collection<? extends E> c) { if (c.isEmpty()) { return; } int startIndex = getSize(); objects.addAll(c); fireIntervalAdded(this, startIndex, getSize() - 1); }
Adds all of the elements present in the collection, starting from the specified index.
Params:
  • index – index at which to insert the first element from the specified collection
  • c – the collection which contains the elements to add
Throws:
/** * Adds all of the elements present in the collection, starting * from the specified index. * * @param index index at which to insert the first element from the * specified collection * @param c the collection which contains the elements to add * @throws ArrayIndexOutOfBoundsException if {@code index} does not * fall within the range of number of elements currently held * @throws NullPointerException if {@code c} is null */
public void addAll(int index, Collection<? extends E> c) { if (index < 0 || index > getSize()) { throw new ArrayIndexOutOfBoundsException("index out of range: " + index); } if (c.isEmpty()) { return; } objects.addAll(index, c); fireIntervalAdded(this, index, index + c.size() - 1); } }