diff options
Diffstat (limited to 'libjava/classpath/java/awt/MenuComponent.java')
| -rw-r--r-- | libjava/classpath/java/awt/MenuComponent.java | 1302 |
1 files changed, 1302 insertions, 0 deletions
diff --git a/libjava/classpath/java/awt/MenuComponent.java b/libjava/classpath/java/awt/MenuComponent.java new file mode 100644 index 000000000..fb0f14eb0 --- /dev/null +++ b/libjava/classpath/java/awt/MenuComponent.java @@ -0,0 +1,1302 @@ +/* MenuComponent.java -- Superclass of all AWT menu components + Copyright (C) 1999, 2000, 2002, 2003, 2004, 2005, 2006 + 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.FocusEvent; +import java.awt.event.FocusListener; +import java.awt.peer.MenuComponentPeer; +import java.io.Serializable; +import java.util.Locale; + +import javax.accessibility.Accessible; +import javax.accessibility.AccessibleComponent; +import javax.accessibility.AccessibleContext; +import javax.accessibility.AccessibleRole; +import javax.accessibility.AccessibleSelection; +import javax.accessibility.AccessibleStateSet; + +/** + * This is the superclass of all menu AWT widgets. + * + * @author Aaron M. Renn (arenn@urbanophile.com) + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + */ +public abstract class MenuComponent implements Serializable +{ + +//Serialization Constant + private static final long serialVersionUID = -4536902356223894379L; + + /** + * The font for this component. + * + * @see #getFont() + * @see #setFont(java.awt.Font) + * @serial the component's font. + */ + private Font font; + + /** + * The name of the component. + * + * @see #getName() + * @see #setName(String) + * @serial the component's name. + */ + private String name; + + /** + * The parent of this component. + * + * @see #getParent() + * @see #setParent(java.awt.MenuContainer) + * @serial ignored. + */ + transient MenuContainer parent; + + /** + * The native peer for this component. + * + * @see #getPeer() + * @see #setPeer(java.awt.peer.MenuComponentPeer) + * @serial ignored. + */ + transient MenuComponentPeer peer; + + /** + * The synchronization locking object for this component. + * + * @serial ignored. + */ + private transient Object tree_lock = this; + + /** + * The toolkit for this object. + * + * @see #getToolkit() + * @serial ignored. + */ + private static transient Toolkit toolkit = Toolkit.getDefaultToolkit(); + + /** + * The accessible context for this component. + * + * @see #getAccessibleContext() + * @serial the accessibility information for this component. + */ + AccessibleContext accessibleContext; + + /** + * Was the name of the component set? This value defaults + * to false and becomes true after a call to <code>setName()</code>. + * Please note that this does not guarantee that name will then + * be non-null, as this may be the value passed to <code>setName()</code>. + * + * @see #setName(String) + * @serial true if the name value has been explicitly set by calling + * <code>setName()</code>. + */ + private boolean nameExplicitlySet; + + /** + * Does this component handle new events? Events will be handled + * by this component if this is true. Otherwise, they will be forwarded + * up the component hierarchy. This implementation does not use this + * variable; it is merely provided for serialization compatability. + * + * @see #dispatchEvent(AWTEvent) + * @serial true if events are to be processed locally. Unused. + */ + private boolean newEventsOnly; + + /** + * The focus listener chain handler which deals with focus events for + * the accessible context of this component. + * + * @see AccessibleAWTMenuComponent#addFocusListener(java.awt.event.FocusListener) + * @serial ignored. + * This is package-private to avoid an accessor method. + */ + transient FocusListener focusListener; + + /** + * Default constructor for subclasses. + * + * @throws HeadlessException ff GraphicsEnvironment.isHeadless() is true + */ + public MenuComponent() + { + if (GraphicsEnvironment.isHeadless()) + throw new HeadlessException(); + } + +/** + * Returns the font in use for this component. + * + * @return the font for this component + */ + public Font getFont() + { + if (font != null) + return font; + + if (parent != null) + return parent.getFont(); + + return null; + } + + /** + * Sets the font for this component to the specified font. + * + * @param font the new font for this component + */ + public void setFont(Font font) + { + this.font = font; + } + + /** + * Returns the name of this component. + * + * @return the name of this component + */ + public String getName() + { + if (name == null && ! nameExplicitlySet) + name = generateName(); + return name; + } + + /** + * Subclasses should override this to return unique component names like + * "menuitem0". + * + * @return the generated name for this menu component + */ + String generateName() + { + // MenuComponent is abstract. + return null; + } + + /** + * Sets the name of this component to the specified name. + * + * @param name the new name of this component + */ + public void setName(String name) + { + this.name = name; + nameExplicitlySet = true; + } + + /** + * Returns the parent of this component. + * + * @return the parent of this component + */ + public MenuContainer getParent() + { + return parent; + } + + /** + * Sets the parent of this component. + * + * @param parent the parent to set + */ + final void setParent(MenuContainer parent) + { + this.parent = parent; + } + + /** + * Returns the native windowing system peer for this component. + * + * @return the peer for this component + * + * @deprecated + */ + public MenuComponentPeer getPeer() + { + return peer; + } + + /** + * Sets the peer for this component. + * + * @param peer the peer to set + */ + final void setPeer(MenuComponentPeer peer) + { + this.peer = peer; + } + + /** + * Destroys this component's native peer + */ + public void removeNotify() + { + if (peer != null) + peer.dispose(); + peer = null; + } + + /** + * Returns the toolkit in use for this component. + * + * @return the toolkit for this component + */ + final Toolkit getToolkit() + { + return toolkit; + } + + /** + * Returns the object used for synchronization locks on this component + * when performing tree and layout functions. + * + * @return the synchronization lock for this component + */ + protected final Object getTreeLock() + { + return tree_lock; + } + + /** + * Sets the sync lock object for this component. + * + * @param treeLock the sync lock to set + */ + final void setTreeLock(Object treeLock) + { + this.tree_lock = treeLock; + } + + /** + * AWT 1.0 event dispatcher. + * + * @return true if the event was dispatched, false otherwise + * + * @deprecated Deprecated in favor of <code>dispatchEvent()</code>. + */ + public boolean + postEvent(Event event) + { + boolean retVal = false; + MenuContainer parent = getParent(); + if (parent != null) + retVal = parent.postEvent(event); + + return retVal; + } + + /** + * Sends this event to this component or a subcomponent for processing. + * + * @param event The event to dispatch + */ + public final void dispatchEvent(AWTEvent event) + { + // Convert AWT 1.1 event to AWT 1.0 event. + Event oldStyleEvent = Component.translateEvent(event); + if (oldStyleEvent != null) + { + postEvent(oldStyleEvent); + } + + // See comment in Component.dispatchEvent(). + dispatchEventImpl(event); + } + + /** + * Implementation of dispatchEvent. Allows trusted package classes + * to dispatch additional events first. This implementation first + * translates <code>event</code> to an AWT 1.0 event and sends the + * result to {@link #postEvent}. The event is then + * passed on to {@link #processEvent} for local processing. + * + * @param event the event to dispatch + */ + void dispatchEventImpl(AWTEvent event) + { + // Do local processing. + processEvent(event); + } + + /** + * Processes the specified event. In this class, this method simply + * calls one of the more specific event handlers. + * + * @param event the event to process + */ + protected void processEvent(AWTEvent event) + { + // Pass a focus event to the focus listener for + // the accessibility context. + if (event instanceof FocusEvent) + { + if (focusListener != null) + { + switch (event.id) + { + case FocusEvent.FOCUS_GAINED: + focusListener.focusGained((FocusEvent) event); + break; + case FocusEvent.FOCUS_LOST: + focusListener.focusLost((FocusEvent) event); + break; + } + } + } + } + + /** + * Returns a string representation of this component. + * + * @return a string representation of this component + */ + public String toString() + { + return getClass().getName() + "[" + paramString() + "]"; + } + + /** + * Returns a debugging string for this component + */ + protected String paramString() + { + return "name=" + getName(); + } + + /** + * Gets the AccessibleContext associated with this <code>MenuComponent</code>. + * As an abstract class, we return null. Concrete subclasses should return + * their implementation of the accessibility context. + * + * @return null + */ + public AccessibleContext getAccessibleContext() + { + return null; + } + + /** + * This class provides a base for the accessibility support of menu + * components. + * + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + */ + protected abstract class AccessibleAWTMenuComponent + extends AccessibleContext + implements Serializable, AccessibleComponent, AccessibleSelection + { + + /** + * Compatible with JDK 1.4.2 revision 5 + */ + private static final long serialVersionUID = -4269533416223798698L; + + /** + * This is the default constructor. It should be called by + * concrete subclasses to ensure necessary groundwork is completed. + */ + protected AccessibleAWTMenuComponent() + { + // Nothing to do here. + } + + /** + * Replaces or supplements the component's selection with the + * <code>Accessible</code> child at the supplied index. If + * the component supports multiple selection, the child is + * added to the current selection. Otherwise, the current + * selection becomes the specified child. If the child is + * already selected, nothing happens. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @param index the index of the specified child within a + * zero-based list of the component's children + */ + public void addAccessibleSelection(int index) + { + // Subclasses with children should implement this. + } + + /** + * Registers the specified focus listener to receive + * focus events from this component. + * + * @param listener the new focus listener + */ + public void addFocusListener(FocusListener listener) + { + // Chain the new focus listener to the existing chain + // of focus listeners. Each new focus listener is + // coupled via multicasting to the existing chain. + focusListener = AWTEventMulticaster.add(focusListener, listener); + } + + /** + * Clears the component's current selection. Following + * the calling of this method, no children of the component + * will be selected. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + */ + public void clearAccessibleSelection() + { + // Nothing to do here. + } + + /** + * Returns true if the specified point lies within the + * component. The supplied co-ordinates are assumed to + * be relative to the co-ordinate system of the component + * itself. Thus, the point (0,0) is the upper left corner + * of this component. + * <br /> + * <br /> + * Please note that this method depends on a correctly implemented + * version of the <code>getBounds()</code> method. Subclasses + * must provide the bounding rectangle via <code>getBounds()</code> + * in order for this method to work. + * + * @param point the point to check against this component + * @return true if the point is within this component + * @see #getBounds() + */ + public boolean contains(Point point) + { + // We can simply return the result of a + // test for containment in the bounding rectangle. + return getBounds().contains(point); + } + + /** + * Returns the <code>Accessible</code> child of this component present + * at the specified point. The supplied co-ordinates are + * assumed to be relative to the co-ordinate system of this + * component (the parent of any returned accessible). Thus, + * the point (0,0) is the upper left corner of this menu + * component. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @param point the point at which the returned accessible + * is located + * @return null + */ + public Accessible getAccessibleAt(Point point) + { + return null; + } + + /** + * Returns the <code>Accessible</code> child at the supplied + * index within the list of children of this component. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @param index the index of the <code>Accessible</code> child + * to retrieve + * + * @return null + */ + public Accessible getAccessibleChild(int index) + { + return null; + } + + /** + * Returns the number of children of this component which + * implement the <code>Accessible</code> interface. If + * all children of this component are accessible, then + * the returned value will be the same as the number of + * children. + * <br /> + * <br /> + * + * @return 0 + */ + public int getAccessibleChildrenCount() + { + return 0; + } + + /** + * Retrieves the <code>AccessibleComponent</code> associated + * with this accessible context and its component. As the + * context itself implements <code>AccessibleComponent</code>, + * this is the return value. + * + * @return the context itself + */ + public AccessibleComponent getAccessibleComponent() + { + return this; + } + + /** + * Returns the accessible name for this menu component. This + * is the name given to the component, which may be null if + * not set using <code>setName()</code>. + * <br /> + * <br /> + * The name is not the most appropriate description of this + * object. Subclasses should preferably provide a more + * accurate description. For example, a File menu could + * have the description `Lists commands related to the + * file system'. + * + * @return a description of the component. Currently, + * this is just the contents of the name property + * + * @see MenuComponent#setName(String) + */ + public String getAccessibleDescription() + { + return MenuComponent.this.getName(); + } + + /** + * Retrieves the index of this component within its parent. + * If no parent exists, -1 is returned. + * + * @return -1 as the parent, a <code>MenuContainer</code> + * is not <code>Accessible</code> + */ + public int getAccessibleIndexInParent() + { + return -1; + } + + /** + * Returns the accessible name of this component. This + * is the name given to the component, which may be null if + * not set using <code>setName()</code>. + * <br /> + * <br /> + * The name property is not the most suitable string to return + * for this method. The string should be localized, and + * relevant to the operation of the component. For example, + * it could be the text of a menu item. However, this can + * not be used at this level of abstraction, so it is the + * responsibility of subclasses to provide a more appropriate + * name. + * + * @return a localized name for this component. Currently, this + * is just the contents of the name property + * + * @see MenuComponent#setName(String) + */ + public String getAccessibleName() + { + return MenuComponent.this.getName(); + } + + /** + * Returns the <code>Accessible</code> parent of this component. + * As the parent of a <code>MenuComponent</code> is a + * <code>MenuContainer</code>, which doesn't implement + * <code>Accessible</code>, this method returns null. + * + * @return null + */ + public Accessible getAccessibleParent() + { + return null; + } + + /** + * Returns the accessible role of this component. + * <br /> + * <br /> + * The abstract implementation of this method returns + * <code>AccessibleRole.AWT_COMPONENT</code>, + * as the abstract component has no specific role. This + * method should be overridden by concrete subclasses, so + * as to return an appropriate role for the component. + * + * @return <code>AccessibleRole.AWT_COMPONENT</code> + */ + public AccessibleRole getAccessibleRole() + { + return AccessibleRole.AWT_COMPONENT; + } + + /** + * Retrieves the <code>AccessibleSelection</code> associated + * with this accessible context and its component. As the + * context itself implements <code>AccessibleSelection</code>, + * this is the return value. + * + * @return the context itself + */ + public AccessibleSelection getAccessibleSelection() + { + return this; + } + + /** + * Retrieves the <code>Accessible</code> selected child + * at the specified index. If there are no selected children + * or the index is outside the range of selected children, + * null is returned. Please note that the index refers + * to the index of the child in the list of <strong>selected + * children</strong>, and not the index of the child in + * the list of all <code>Accessible</code> children. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @param index the index of the selected <code>Accessible</code> + * child + */ + public Accessible getAccessibleSelection(int index) + { + return null; + } + + /** + * Returns a count of the number of <code>Accessible</code> + * children of this component which are currently selected. + * If there are no children currently selected, 0 is returned. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @return 0 + */ + public int getAccessibleSelectionCount() + { + return 0; + } + + /** + * Retrieves the current state of this component + * in an accessible form. For example, a given component + * may be visible, selected, disabled, etc. + * <br /> + * <br /> + * As this class tells us virtually nothing about the component, + * except for its name and font, no state information can be + * provided. This implementation thus returns an empty + * state set, and it is left to concrete subclasses to provide + * a more acceptable and relevant state set. Changes to these + * properties also need to be handled using + * <code>PropertyChangeListener</code>s. + * + * @return an empty <code>AccessibleStateSet</code> + */ + public AccessibleStateSet getAccessibleStateSet() + { + return new AccessibleStateSet(); + } + + /** + * Returns the background color of the component, or null + * if this property is unsupported. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply returns the + * default system background color used for rendering menus. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @return the default system background color for menus + * + * @see #setBackground(java.awt.Color) + */ + public Color getBackground() + { + return SystemColor.menu; + } + + /** + * Returns a <code>Rectangle</code> which represents the + * bounds of this component. The returned rectangle has the + * height and width of the component's bounds, and is positioned + * at a location relative to this component's parent, the + * <code>MenuContainer</code>. null is returned if bounds + * are not supported by the component. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply returns null. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @return null + * + * @see #setBounds(java.awt.Rectangle) + */ + public Rectangle getBounds() + { + return null; + } + + /** + * Returns the <code>Cursor</code> displayed when the pointer + * is positioned over this component. Alternatively, null + * is returned if the component doesn't support the cursor + * property. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply returns the default + * system cursor. Concrete subclasses which handle the drawing + * of an onscreen menu component may override this method and provide + * the appropriate information. + * + * @return the default system cursor + * + * @see #setCursor(java.awt.Cursor) + */ + public Cursor getCursor() + { + return Cursor.getDefaultCursor(); + } + + /** + * Returns the <code>Font</code> used for text created by this component. + * + * @return the current font + * + * @see #setFont(java.awt.Font) + */ + public Font getFont() + { + return MenuComponent.this.getFont(); + } + + /** + * Retrieves information on the rendering and metrics of the supplied + * font. If font metrics are not supported by this component, null + * is returned. + * <br /> + * <br /> + * The abstract implementation of this method simply uses the toolkit + * to obtain the <code>FontMetrics</code>. Concrete subclasses may + * find it more efficient to invoke their peer class directly, if one + * is available. + * + * @param font the font about which to retrieve rendering and metric + * information + * + * @return the metrics of the given font, as provided by the system + * toolkit + * + * @throws NullPointerException if the supplied font was null + */ + public FontMetrics getFontMetrics(Font font) + { + return MenuComponent.this.getToolkit().getFontMetrics(font); + } + + /** + * Returns the foreground color of the component, or null + * if this property is unsupported. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply returns the + * default system text color used for rendering menus. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @return the default system text color for menus + * + * @see #setForeground(java.awt.Color) + */ + public Color getForeground() + { + return SystemColor.menuText; + } + + /** + * Returns the locale currently in use by this component. + * <br /> + * <br /> + * This abstract class has no property relating to the + * locale used by the component, so this method simply + * returns the default locale for the current instance + * of the Java Virtual Machine (JVM). Concrete subclasses + * which maintain such a property should override this method + * and provide the locale information more accurately. + * + * @return the default locale for this JVM instance + */ + public Locale getLocale() + { + return Locale.getDefault(); + } + + /** + * Returns the location of the component, with co-ordinates + * relative to the parent component and using the co-ordinate + * space of the screen. Thus, the point (0,0) is the upper + * left corner of the parent component. + * <br /> + * <br /> + * Please note that this method depends on a correctly implemented + * version of the <code>getBounds()</code> method. Subclasses + * must provide the bounding rectangle via <code>getBounds()</code> + * in order for this method to work. + * + * @return the location of the component, relative to its parent + * + * @see #setLocation(java.awt.Point) + */ + public Point getLocation() + { + // Simply return the location of the bounding rectangle. + return getBounds().getLocation(); + } + + /** + * Returns the location of the component, with co-ordinates + * relative to the screen. Thus, the point (0,0) is the upper + * left corner of the screen. null is returned if the component + * is either not on screen or if this property is unsupported. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply returns null. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @return the location of the component, relative to the screen + */ + public Point getLocationOnScreen() + { + return null; + } + + /** + * Returns the size of the component. + * <br /> + * <br /> + * Please note that this method depends on a correctly implemented + * version of the <code>getBounds()</code> method. Subclasses + * must provide the bounding rectangle via <code>getBounds()</code> + * in order for this method to work. + * + * @return the size of the component + * + * @see #setSize(java.awt.Dimension) + */ + public Dimension getSize() + { + // Simply return the size of the bounding rectangle. + return getBounds().getSize(); + } + + /** + * Returns true if the accessible child specified by the supplied index + * is currently selected. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @param index the index of the accessible child to check for selection + * + * @return false + */ + public boolean isAccessibleChildSelected(int index) + { + return false; + } + + /** + * Returns true if this component is currently enabled. + * <br /> + * <br /> + * As this abstract component has no properties related to + * its enabled or disabled state, the implementation of this + * method is left to subclasses. + * + * @return false + * + * @see #setEnabled(boolean) + */ + public boolean isEnabled() + { + return false; + } + + /** + * Returns true if this component is included in the traversal + * of the current focus from one component to the other. + * <br /> + * <br /> + * As this abstract component has no properties related to + * its ability to accept the focus, the implementation of this + * method is left to subclasses. + * + * @return false + */ + public boolean isFocusTraversable() + { + return false; + } + + /** + * Returns true if the component is being shown on screen. + * A component is determined to be shown if it is visible, + * and each parent component is also visible. Please note + * that, even when a component is showing, it may still be + * obscured by other components in front. This method only + * determines if the component is being drawn on the screen. + * <br /> + * <br /> + * As this abstract component and its parent have no properties + * relating to visibility, the implementation of this method is + * left to subclasses. + * + * @return false + * + * @see #isVisible() + */ + public boolean isShowing() + { + return false; + } + + /** + * Returns true if the component is visible. A component may + * be visible but not drawn on the screen if one of its parent + * components is not visible. To determine if the component is + * actually drawn on screen, <code>isShowing()</code> should be + * used. + * <br /> + * <br /> + * As this abstract component has no properties relating to its + * visibility, the implementation of this method is left to subclasses. + * + * @return false + * + * @see #isShowing() + * @see #setVisible(boolean) + */ + public boolean isVisible() + { + return false; + } + + /** + * Removes the accessible child specified by the supplied index from + * the list of currently selected children. If the child specified + * is not selected, nothing happens. + * <br /> + * <br /> + * As the existence of children can not be determined from + * this abstract class, the implementation of this method + * is left to subclasses. + * + * @param index the index of the <code>Accessible</code> child + */ + public void removeAccessibleSelection(int index) + { + // Subclasses with children should implement this. + } + + /** + * Removes the specified focus listener from the list of registered + * focus listeners for this component. + * + * @param listener the listener to remove + */ + public void removeFocusListener(FocusListener listener) + { + // Remove the focus listener from the chain. + focusListener = AWTEventMulticaster.remove(focusListener, listener); + } + + /** + * Requests that this component gains focus. This depends on the + * component being focus traversable. + * <br /> + * <br /> + * As this abstract component has no properties relating to its + * focus traversability, or access to a peer with request focusing + * abilities, the implementation of this method is left to subclasses. + */ + public void requestFocus() + { + // Ignored. + } + + /** + * Selects all <code>Accessible</code> children of this component which + * it is possible to select. The component needs to support multiple + * selections. + * <br /> + * <br /> + * This abstract component provides a simplistic implementation of this + * method, which ignores the ability of the component to support multiple + * selections and simply uses <code>addAccessibleSelection</code> to + * add each <code>Accessible</code> child to the selection. The last + * <code>Accessible</code> component is thus selected for components + * which don't support multiple selections. Concrete implementations should + * override this with a more appopriate and efficient implementation, which + * properly takes into account the ability of the component to support multiple + * selections. + */ + public void selectAllAccessibleSelection() + { + // Simply call addAccessibleSelection() on all accessible children. + for (int a = 0; a < getAccessibleChildrenCount(); ++a) + { + addAccessibleSelection(a); + } + } + + /** + * Sets the background color of the component to that specified. + * Unspecified behaviour occurs when null is given as the new + * background color. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply ignores the supplied + * color and continues to use the default system color. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @param color the new color to use for the background + * + * @see #getBackground() + */ + public void setBackground(Color color) + { + // Ignored. + } + + /** + * Sets the height and width of the component, and its position + * relative to this component's parent, to the values specified + * by the supplied rectangle. Unspecified behaviour occurs when + * null is given as the new bounds. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply ignores the new + * rectangle and continues to return null from <code>getBounds()</code>. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @param rectangle a rectangle which specifies the new bounds of + * the component + * + * @see #getBounds() + */ + public void setBounds(Rectangle rectangle) + { + // Ignored. + } + + /** + * Sets the <code>Cursor</code> used when the pointer is positioned over the + * component. Unspecified behaviour occurs when null is given as the new + * cursor. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply ignores the new cursor + * and continues to return the default system cursor. Concrete + * subclasses which handle the drawing of an onscreen menu component + * may override this method and provide the appropriate information. + * + * @param cursor the new cursor to use + * + * @see #getCursor() + */ + public void setCursor(Cursor cursor) + { + // Ignored. + } + + /** + * Sets the enabled/disabled state of this component. + * <br /> + * <br /> + * As this abstract component has no properties related to + * its enabled or disabled state, the implementation of this + * method is left to subclasses. + * + * @param enabled true if the component should be enabled, + * false otherwise + * + * @see #isEnabled() + */ + public void setEnabled(boolean enabled) + { + // Ignored. + } + + /** + * Sets the <code>Font</code> used for text created by this component. + * Unspecified behaviour occurs when null is given as the new + * font. + * + * @param font the new font to use for text. + * @see #getFont() + */ + public void setFont(Font font) + { + // Call the method of the enclosing component. + MenuComponent.this.setFont(font); + } + + /** + * Sets the foreground color of the component to that specified. + * Unspecified behaviour occurs when null is given as the new + * background color. + * <br /> + * <br /> + * This abstract class knows nothing about how the component + * is drawn on screen, so this method simply ignores the supplied + * color and continues to return the default system text color used + * for rendering menus. + * Concrete subclasses which handle the drawing of an onscreen + * menu component should override this method and provide + * the appropriate information. + * + * @param color the new foreground color + * + * @see #getForeground() + */ + public void setForeground(Color color) + { + // Ignored. + } + + /** + * Sets the location of the component, with co-ordinates + * relative to the parent component and using the co-ordinate + * space of the screen. Thus, the point (0,0) is the upper + * left corner of the parent component. + * <br /> + * <br /> + * Please note that this method depends on a correctly implemented + * version of the <code>getBounds()</code> method. Subclasses + * must provide the bounding rectangle via <code>getBounds()</code> + * in order for this method to work. + * + * @param point the location of the component, relative to its parent + * + * @see #getLocation() + */ + public void setLocation(Point point) + { + getBounds().setLocation(point); + } + + /** + * Sets the size of the component. + * <br /> + * <br /> + * Please note that this method depends on a correctly implemented + * version of the <code>getBounds()</code> method. Subclasses + * must provide the bounding rectangle via <code>getBounds()</code> + * in order for this method to work. + * + * @param size the new size of the component + * + * @see #getSize() + */ + public void setSize(Dimension size) + { + getBounds().setSize(size); + } + + /** + * Sets the visibility state of the component. A component may + * be visible but not drawn on the screen if one of its parent + * components is not visible. To determine if the component is + * actually drawn on screen, <code>isShowing()</code> should be + * used. + * <br /> + * <br /> + * As this abstract component has no properties relating to its + * visibility, the implementation of this method is left to subclasses. + * + * @param visibility the new visibility of the component -- true if + * the component is visible, false if not + * + * @see #isShowing() + * @see #isVisible() + */ + public void setVisible(boolean visibility) + { + // Ignored. + } + + } + +} |