diff options
Diffstat (limited to 'libjava/classpath/javax/swing/DefaultComboBoxModel.java')
| -rw-r--r-- | libjava/classpath/javax/swing/DefaultComboBoxModel.java | 172 |
1 files changed, 105 insertions, 67 deletions
diff --git a/libjava/classpath/javax/swing/DefaultComboBoxModel.java b/libjava/classpath/javax/swing/DefaultComboBoxModel.java index b48b968d697..ea261a33bbf 100644 --- a/libjava/classpath/javax/swing/DefaultComboBoxModel.java +++ b/libjava/classpath/javax/swing/DefaultComboBoxModel.java @@ -1,5 +1,5 @@ /* DefaultComboBoxModel.java -- - Copyright (C) 2002, 2004 Free Software Foundation, Inc. + Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. @@ -41,13 +41,14 @@ import java.io.Serializable; import java.util.Arrays; import java.util.Vector; +import javax.swing.event.ListDataEvent; + /** - * The default implementation of {@link MutableComboBoxModel}. - * This model keeps track - * of elements contained in the JComboBox as well as the current combo box - * selection. Whenever selection in the JComboBox changes, the ComboBoxModel - * will fire ListDataEvents to ComboBox's ListDataListeners. + * A model that stores a list of elements and a selected item (which may be + * <code>null</code>). Changes to the model are signalled to listeners using + * {@link ListDataEvent}. This model is designed for use by the + * {@link JComboBox} component. * * @author Andrew Selkirk * @author Olga Rodimina @@ -59,17 +60,17 @@ public class DefaultComboBoxModel extends AbstractListModel private static final long serialVersionUID = 6698657703676921904L; /** - * List containing items in the combo box + * Storage for the elements in the model's list. */ private Vector list; /** - * Currently selected item in the combo box list + * The selected item (<code>null</code> indicates no selection). */ private Object selectedItem = null; /** - * Constructor DefaultComboBoxModel. Create empty JComboBox. + * Creates a new model, initially empty. */ public DefaultComboBoxModel() { @@ -77,64 +78,92 @@ public class DefaultComboBoxModel extends AbstractListModel } /** - * Constructs new DefaultComboBoxModel object and initializes its item list - * to values in the given array. + * Creates a new model and initializes its item list to the values in the + * given array. The selected item is set to the first item in the array, or + * <code>null</code> if the array length is zero. * - * @param items array containing items of the combo box. + * @param items an array containing items for the model (<code>null</code> + * not permitted). + * + * @throws NullPointerException if <code>items</code> is <code>null</code>. */ public DefaultComboBoxModel(Object[] items) { list = new Vector(Arrays.asList(items)); + if (list.size() > 0) + selectedItem = list.get(0); } /** - * Consturcts new DefaultComboBoxModel object and initializes its item list - * to values in the given vector. + * Creates a new model and initializes its item list to the values in the + * given vector. The selected item is set to the first item in the vector, + * or <code>null</code> if the vector length is zero. * - * @param vector Vector containing items for this combo box. + * @param vector a vector containing items for the model (<code>null</code> + * not permitted). + * + * @throws NullPointerException if <code>vector</code> is <code>null</code>. */ public DefaultComboBoxModel(Vector vector) { this.list = vector; + if (vector.size() > 0) + selectedItem = vector.get(0); } /** - * This method adds element to the combo box list. It fires ListDataEvent - * indicating that component was added to the combo box to all of the - * JComboBox's registered ListDataListeners. + * Adds an element to the model's item list and sends a {@link ListDataEvent} + * to all registered listeners. If the new element is the first item added + * to the list, it is set as the selected item. * - * @param object item to add to the combo box list + * @param object item to add to the model's item list. */ public void addElement(Object object) { list.add(object); - fireIntervalAdded(this, list.size() - 1, list.size()); + fireIntervalAdded(this, list.size() - 1, list.size() - 1); + if (list.size() == 1) + setSelectedItem(object); } /** - * This method removes element at the specified index from the combo box - * list. It fires ListDataEvent indicating that component was removed from - * the combo box list to all of the JComboBox's registered - * ListDataListeners. + * Removes the element at the specified index from the model's item list + * and sends a {@link ListDataEvent} to all registered listeners. If the + * element removed was the selected item, then the preceding element becomes + * the new selected item (or the next element, if there is no preceding + * element). * - * @param index index specifying location of the element to remove in the - * combo box list. + * @param index the index of the item to remove. + * + * @throws ArrayIndexOutOfBoundsException if <code>index</code> is out of + * bounds. */ public void removeElementAt(int index) { + int selected = getIndexOf(selectedItem); list.remove(index); + if (selected == index) // choose a new selected item + { + if (selected > 0) + selectedItem = getElementAt(selected - 1); + else + selectedItem = getElementAt(selected); + } fireIntervalRemoved(this, index, index); } /** - * This method inserts given object to the combo box list at the specified - * index. It fires ListDataEvent indicating that component was inserted to - * the combo box list to all of the JComboBox's registered - * ListDataListeners. + * Adds an element at the specified index in the model's item list + * and sends a {@link ListDataEvent} to all registered listeners. * * @param object element to insert * @param index index specifing position in the list where given element * should be inserted. + * + * @throws ArrayIndexOutOfBoundsException if <code>index</code> is out of + * bounds. + * + * @see #addElement(Object) */ public void insertElementAt(Object object, int index) { @@ -143,11 +172,13 @@ public class DefaultComboBoxModel extends AbstractListModel } /** - * Removes given object from the combo box list. It fires ListDataEvent - * indicating that component was removed from the combo box list to all of - * the JComboBox's registered ListDataListeners. + * Removes an element from the model's item list and sends a + * {@link ListDataEvent} to all registered listeners. If the item to be + * removed is the current selected item, a new selected item will be set. + * If the element is not found in the model's item list, this method does + * nothing. * - * @param object Element that will be removed from the combo box list + * @param object the element to remove. */ public void removeElement(Object object) { @@ -157,21 +188,25 @@ public class DefaultComboBoxModel extends AbstractListModel } /** - * Removes all the items from the JComboBox's item list. It fires - * ListDataEvent indicating that all the elements were removed from the - * combo box list to all of the JComboBox's registered ListDataListeners. + * Removes all the items from the model's item list, resets and selected item + * to <code>null</code>, and sends a {@link ListDataEvent} to all registered + * listeners. */ public void removeAllElements() { - list.clear(); - int listSize = getSize(); - fireIntervalAdded(this, 0, listSize); + selectedItem = null; + int size = getSize(); + if (size > 0) + { + list.clear(); + fireIntervalRemoved(this, 0, size - 1); + } } /** - * Returns number of items in the combo box list + * Returns the number of items in the model's item list. * - * @return number of items in the combo box list + * @return The number of items in the model's item list. */ public int getSize() { @@ -179,32 +214,32 @@ public class DefaultComboBoxModel extends AbstractListModel } /** - * Selects given object in the combo box list. This method fires - * ListDataEvent to all registered ListDataListeners of the JComboBox. The - * start and end index of the event is set to -1 to indicate combo box's - * selection has changed, and not its contents. - * - * <p>If the given object is not contained in the combo box list then nothing - * happens.</p> + * Sets the selected item for the model and sends a {@link ListDataEvent} to + * all registered listeners. The start and end index of the event is set to + * -1 to indicate the model's selection has changed, and not its contents. * - * @param object item to select in the JComboBox + * @param object the new selected item (<code>null</code> permitted). */ public void setSelectedItem(Object object) { - - // Updates the selected item only if the given object - // is null or in the list (this is how the JDK behaves). - if(object == null || list.contains(object)) { - selectedItem = object; - fireContentsChanged(this, -1, -1); - } - + if (selectedItem == null) + { + if (object == null) + return; + } + else + { + if (selectedItem.equals(object)) + return; + } + selectedItem = object; + fireContentsChanged(this, -1, -1); } /** - * Returns currently selected item in the combo box list + * Returns the selected item. * - * @return currently selected item in the combo box list + * @return The selected item (possibly <code>null</code>). */ public Object getSelectedItem() { @@ -212,24 +247,27 @@ public class DefaultComboBoxModel extends AbstractListModel } /** - * Returns element in the combo box list located at the given index + * Returns the element at the specified index in the model's item list. * - * @param index specifying location of the element in the list + * @param index the element index. * - * @return return element in the combo box list located at the given index + * @return The element at the specified index in the model's item list, or + * <code>null</code> if the <code>index</code> is outside the bounds + * of the list. */ public Object getElementAt(int index) { + if (index < 0 || index >= list.size()) + return null; return list.elementAt(index); } /** - * Returns index of the specified object in the combo box list. + * Returns the index of the specified element in the model's item list. * - * @param object element to look for in the combo box list . + * @param object the element. * - * @return Index specifying position of the specified element in combo box - * list. + * @return The index of the specified element in the model's item list. */ public int getIndexOf(Object object) { |