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Diffstat (limited to 'libjava/classpath/java/awt/Choice.java')
| -rw-r--r-- | libjava/classpath/java/awt/Choice.java | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/libjava/classpath/java/awt/Choice.java b/libjava/classpath/java/awt/Choice.java new file mode 100644 index 00000000000..5075ea92d83 --- /dev/null +++ b/libjava/classpath/java/awt/Choice.java @@ -0,0 +1,638 @@ +/* Choice.java -- Java choice button widget. + Copyright (C) 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.awt; + +import java.awt.event.ItemEvent; +import java.awt.event.ItemListener; +import java.awt.peer.ChoicePeer; +import java.io.Serializable; +import java.util.EventListener; +import java.util.Vector; + +import javax.accessibility.Accessible; +import javax.accessibility.AccessibleAction; +import javax.accessibility.AccessibleContext; +import javax.accessibility.AccessibleRole; + +/** + * This class implements a drop down choice list. + * + * @author Aaron M. Renn (arenn@urbanophile.com) + */ +public class Choice extends Component + implements ItemSelectable, Serializable, Accessible +{ + +/* + * Static Variables + */ + +// Serialization constant +private static final long serialVersionUID = -4075310674757313071L; + +/*************************************************************************/ + +/* + * Instance Variables + */ + +/** + * @serial A list of items for the choice box, which can be <code>null</code>. + * This is package-private to avoid an accessor method. + */ +Vector pItems = new Vector(); + +/** + * @serial The index of the selected item in the choice box. + */ +private int selectedIndex = -1; + +// Listener chain +private ItemListener item_listeners; + +/** + * This class provides accessibility support for the + * combo box. + * + * @author Jerry Quinn (jlquinn@optonline.net) + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + */ + protected class AccessibleAWTChoice + extends AccessibleAWTComponent + implements AccessibleAction + { + + /** + * Serialization constant to match JDK 1.5 + */ + private static final long serialVersionUID = 7175603582428509322L; + + /** + * Default constructor which simply calls the + * super class for generic component accessibility + * handling. + */ + public AccessibleAWTChoice() + { + super(); + } + + /** + * Returns an implementation of the <code>AccessibleAction</code> + * interface for this accessible object. In this case, the + * current instance is simply returned (with a more appropriate + * type), as it also implements the accessible action as well as + * the context. + * + * @return the accessible action associated with this context. + * @see javax.accessibility.AccessibleAction + */ + public AccessibleAction getAccessibleAction() + { + return this; + } + + /** + * Returns the role of this accessible object. + * + * @return the instance of <code>AccessibleRole</code>, + * which describes this object. + * @see javax.accessibility.AccessibleRole + */ + public AccessibleRole getAccessibleRole() + { + return AccessibleRole.COMBO_BOX; + } + + /** + * Returns the number of actions associated with this accessible + * object. In this case, it is the number of choices available. + * + * @return the number of choices available. + * @see javax.accessibility.AccessibleAction#getAccessibleActionCount() + */ + public int getAccessibleActionCount() + { + return pItems.size(); + } + + /** + * Returns a description of the action with the supplied id. + * In this case, it is the text used in displaying the particular + * choice on-screen. + * + * @param i the id of the choice whose description should be + * retrieved. + * @return the <code>String</code> used to describe the choice. + * @see javax.accessibility.AccessibleAction#getAccessibleActionDescription(int) + */ + public String getAccessibleActionDescription(int i) + { + return (String) pItems.get(i); + } + + /** + * Executes the action with the specified id. In this case, + * calling this method provides the same behaviour as would + * choosing a choice from the list in a visual manner. + * + * @param i the id of the choice to select. + * @return true if a valid choice was specified. + * @see javax.accessibility.AccessibleAction#doAccessibleAction(int) + */ + public boolean doAccessibleAction(int i) + { + if (i < 0 || i >= pItems.size()) + return false; + + Choice.this.processItemEvent(new ItemEvent(Choice.this, + ItemEvent.ITEM_STATE_CHANGED, + this, ItemEvent.SELECTED)); + return true; + } + } + +/*************************************************************************/ + +/* + * Constructors + */ + + /** + * Initializes a new instance of <code>Choice</code>. + * + * @exception HeadlessException If GraphicsEnvironment.isHeadless() + * returns true + */ + public Choice() + { + if (GraphicsEnvironment.isHeadless()) + throw new HeadlessException (); + } + +/*************************************************************************/ + +/* + * Instance Methods + */ + +/** + * Returns the number of items in the list. + * + * @return The number of items in the list. + */ +public int +getItemCount() +{ + return countItems (); +} + +/*************************************************************************/ + +/** + * Returns the number of items in the list. + * + * @return The number of items in the list. + * + * @deprecated This method is deprecated in favor of <code>getItemCount</code>. + */ +public int +countItems() +{ + return(pItems.size()); +} + +/*************************************************************************/ + +/** + * Returns the item at the specified index in the list. + * + * @param index The index into the list to return the item from. + * + * @exception ArrayIndexOutOfBoundsException If the index is invalid. + */ +public String +getItem(int index) +{ + return((String)pItems.elementAt(index)); +} + +/*************************************************************************/ + +/** + * Adds the specified item to this choice box. + * + * @param item The item to add. + * + * @exception NullPointerException If the item's value is null + * + * @since 1.1 + */ +public synchronized void +add(String item) +{ + if (item == null) + throw new NullPointerException ("item must be non-null"); + + pItems.addElement(item); + + int i = pItems.size () - 1; + if (peer != null) + { + ChoicePeer cp = (ChoicePeer) peer; + cp.add (item, i); + } + else if (selectedIndex == -1) + select(0); +} + +/*************************************************************************/ + +/** + * Adds the specified item to this choice box. + * + * This method is oboslete since Java 2 platform 1.1. Please use @see add + * instead. + * + * @param item The item to add. + * + * @exception NullPointerException If the item's value is equal to null + */ +public synchronized void +addItem(String item) +{ + add(item); +} + +/*************************************************************************/ + +/** Inserts an item into this Choice. Existing items are shifted + * upwards. If the new item is the only item, then it is selected. + * If the currently selected item is shifted, then the first item is + * selected. If the currently selected item is not shifted, then it + * remains selected. + * + * @param item The item to add. + * @param index The index at which the item should be inserted. + * + * @exception IllegalArgumentException If index is less than 0 + */ +public synchronized void +insert(String item, int index) +{ + if (index < 0) + throw new IllegalArgumentException ("index may not be less then 0"); + + if (index > getItemCount ()) + index = getItemCount (); + + pItems.insertElementAt(item, index); + + if (peer != null) + { + ChoicePeer cp = (ChoicePeer) peer; + cp.add (item, index); + } + else if (selectedIndex == -1 || selectedIndex >= index) + select(0); +} + +/*************************************************************************/ + +/** + * Removes the specified item from the choice box. + * + * @param item The item to remove. + * + * @exception IllegalArgumentException If the specified item doesn't exist. + */ +public synchronized void +remove(String item) +{ + int index = pItems.indexOf(item); + if (index == -1) + throw new IllegalArgumentException ("item \"" + + item + "\" not found in Choice"); + remove(index); +} + +/*************************************************************************/ + +/** + * Removes the item at the specified index from the choice box. + * + * @param index The index of the item to remove. + * + * @exception IndexOutOfBoundsException If the index is not valid. + */ +public synchronized void +remove(int index) +{ + if ((index < 0) || (index > getItemCount())) + throw new IllegalArgumentException("Bad index: " + index); + + pItems.removeElementAt(index); + + if (peer != null) + { + ChoicePeer cp = (ChoicePeer) peer; + cp.remove (index); + } + else + { + if (getItemCount() == 0) + selectedIndex = -1; + else if (index == selectedIndex) + select(0); + } + + if (selectedIndex > index) + --selectedIndex; +} + +/*************************************************************************/ + +/** + * Removes all of the objects from this choice box. + */ +public synchronized void +removeAll() +{ + if (getItemCount() <= 0) + return; + + pItems.removeAllElements (); + + if (peer != null) + { + ChoicePeer cp = (ChoicePeer) peer; + cp.removeAll (); + } + + selectedIndex = -1; +} + +/*************************************************************************/ + +/** + * Returns the currently selected item, or null if no item is + * selected. + * + * @return The currently selected item. + */ +public synchronized String +getSelectedItem() +{ + return (selectedIndex == -1 + ? null + : ((String)pItems.elementAt(selectedIndex))); +} + +/*************************************************************************/ + +/** + * Returns an array with one row containing the selected item. + * + * @return An array containing the selected item. + */ +public synchronized Object[] +getSelectedObjects() +{ + if (selectedIndex == -1) + return null; + + Object[] objs = new Object[1]; + objs[0] = pItems.elementAt(selectedIndex); + + return(objs); +} + +/*************************************************************************/ + +/** + * Returns the index of the selected item. + * + * @return The index of the selected item. + */ +public int +getSelectedIndex() +{ + return(selectedIndex); +} + +/*************************************************************************/ + +/** + * Forces the item at the specified index to be selected. + * + * @param index The index of the row to make selected. + * + * @exception IllegalArgumentException If the specified index is invalid. + */ +public synchronized void +select(int index) +{ + if ((index < 0) || (index > getItemCount())) + throw new IllegalArgumentException("Bad index: " + index); + + this.selectedIndex = index; + if (peer != null) + { + ChoicePeer cp = (ChoicePeer) peer; + cp.select (index); + } +} + +/*************************************************************************/ + +/** + * Forces the named item to be selected. + * + * @param item The item to be selected. + * + * @exception IllegalArgumentException If the specified item does not exist. + */ +public synchronized void +select(String item) +{ + int index = pItems.indexOf(item); + if (index >= 0) + select(index); +} + +/*************************************************************************/ + +/** + * Creates the native peer for this object. + */ +public void +addNotify() +{ + if (peer == null) + peer = getToolkit ().createChoice (this); + super.addNotify (); +} + +/*************************************************************************/ + +/** + * Adds the specified listener to the list of registered listeners for + * this object. + * + * @param listener The listener to add. + */ +public synchronized void +addItemListener(ItemListener listener) +{ + item_listeners = AWTEventMulticaster.add(item_listeners, listener); +} + +/*************************************************************************/ + +/** + * Removes the specified listener from the list of registered listeners for + * this object. + * + * @param listener The listener to remove. + */ +public synchronized void +removeItemListener(ItemListener listener) +{ + item_listeners = AWTEventMulticaster.remove(item_listeners, listener); +} + +/*************************************************************************/ + +/** + * Processes this event by invoking <code>processItemEvent()</code> if the + * event is an instance of <code>ItemEvent</code>, otherwise the event + * is passed to the superclass. + * + * @param event The event to process. + */ +protected void +processEvent(AWTEvent event) +{ + if (event instanceof ItemEvent) + processItemEvent((ItemEvent)event); + else + super.processEvent(event); +} + +/*************************************************************************/ + +/** + * Processes item event by dispatching to any registered listeners. + * + * @param event The event to process. + */ +protected void +processItemEvent(ItemEvent event) +{ + if (item_listeners != null) + item_listeners.itemStateChanged(event); +} + +void +dispatchEventImpl(AWTEvent e) +{ + if (e.id <= ItemEvent.ITEM_LAST + && e.id >= ItemEvent.ITEM_FIRST + && (item_listeners != null + || (eventMask & AWTEvent.ITEM_EVENT_MASK) != 0)) + processEvent(e); + else + super.dispatchEventImpl(e); +} + +/*************************************************************************/ + +/** + * Returns a debugging string for this object. + * + * @return A debugging string for this object. + */ +protected String +paramString() +{ + return ("selectedIndex=" + selectedIndex + "," + super.paramString()); +} + + /** + * Returns an array of all the objects currently registered as FooListeners + * upon this Choice. FooListeners are registered using the addFooListener + * method. + * + * @exception ClassCastException If listenerType doesn't specify a class or + * interface that implements java.util.EventListener. + * + * @since 1.3 + */ + public EventListener[] getListeners (Class listenerType) + { + if (listenerType == ItemListener.class) + return AWTEventMulticaster.getListeners (item_listeners, listenerType); + + return super.getListeners (listenerType); + } + + /** + * Returns all registered item listeners. + * + * @since 1.4 + */ + public ItemListener[] getItemListeners () + { + return (ItemListener[]) getListeners (ItemListener.class); + } + + /** + * Gets the AccessibleContext associated with this <code>Choice</code>. + * The context is created, if necessary. + * + * @return the associated context + */ + public AccessibleContext getAccessibleContext() + { + /* Create the context if this is the first request */ + if (accessibleContext == null) + accessibleContext = new AccessibleAWTChoice(); + return accessibleContext; + } +} // class Choice |