--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/awt/ContainerOrderFocusTraversalPolicy.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,583 @@
+/*
+ * Copyright 2000-2003 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package java.awt;
+
+import java.util.logging.*;
+import java.util.List;
+import java.util.ArrayList;
+
+/**
+ * A FocusTraversalPolicy that determines traversal order based on the order
+ * of child Components in a Container. From a particular focus cycle root, the
+ * policy makes a pre-order traversal of the Component hierarchy, and traverses
+ * a Container's children according to the ordering of the array returned by
+ * <code>Container.getComponents()</code>. Portions of the hierarchy that are
+ * not visible and displayable will not be searched.
+ * <p>
+ * By default, ContainerOrderFocusTraversalPolicy implicitly transfers focus
+ * down-cycle. That is, during normal forward focus traversal, the Component
+ * traversed after a focus cycle root will be the focus-cycle-root's default
+ * Component to focus. This behavior can be disabled using the
+ * <code>setImplicitDownCycleTraversal</code> method.
+ * <p>
+ * By default, methods of this class with return a Component only if it is
+ * visible, displayable, enabled, and focusable. Subclasses can modify this
+ * behavior by overriding the <code>accept</code> method.
+ * <p>
+ * This policy takes into account <a
+ * href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal
+ * policy providers</a>. When searching for first/last/next/previous Component,
+ * if a focus traversal policy provider is encountered, its focus traversal
+ * policy is used to perform the search operation.
+ *
+ * @author David Mendenhall
+ *
+ * @see Container#getComponents
+ * @since 1.4
+ */
+public class ContainerOrderFocusTraversalPolicy extends FocusTraversalPolicy
+ implements java.io.Serializable
+{
+ private static final Logger log = Logger.getLogger("java.awt.ContainerOrderFocusTraversalPolicy");
+
+ final private int FORWARD_TRAVERSAL = 0;
+ final private int BACKWARD_TRAVERSAL = 1;
+
+ /*
+ * JDK 1.4 serialVersionUID
+ */
+ private static final long serialVersionUID = 486933713763926351L;
+
+ private boolean implicitDownCycleTraversal = true;
+
+ /**
+ * Used by getComponentAfter and getComponentBefore for efficiency. In
+ * order to maintain compliance with the specification of
+ * FocusTraversalPolicy, if traversal wraps, we should invoke
+ * getFirstComponent or getLastComponent. These methods may be overriden in
+ * subclasses to behave in a non-generic way. However, in the generic case,
+ * these methods will simply return the first or last Components of the
+ * sorted list, respectively. Since getComponentAfter and
+ * getComponentBefore have already built the list before determining
+ * that they need to invoke getFirstComponent or getLastComponent, the
+ * list should be reused if possible.
+ */
+ transient private Container cachedRoot;
+ transient private List cachedCycle;
+
+ /*
+ * We suppose to use getFocusTraversalCycle & getComponentIndex methods in order
+ * to divide the policy into two parts:
+ * 1) Making the focus traversal cycle.
+ * 2) Traversing the cycle.
+ * The 1st point assumes producing a list of components representing the focus
+ * traversal cycle. The two methods mentioned above should implement this logic.
+ * The 2nd point assumes implementing the common concepts of operating on the
+ * cycle: traversing back and forth, retrieving the initial/default/first/last
+ * component. These concepts are described in the AWT Focus Spec and they are
+ * applied to the FocusTraversalPolicy in general.
+ * Thus, a descendant of this policy may wish to not reimplement the logic of
+ * the 2nd point but just override the implementation of the 1st one.
+ * A striking example of such a descendant is the javax.swing.SortingFocusTraversalPolicy.
+ */
+ /*protected*/ private List<Component> getFocusTraversalCycle(Container aContainer) {
+ List<Component> cycle = new ArrayList<Component>();
+ enumerateCycle(aContainer, cycle);
+ return cycle;
+ }
+ /*protected*/ private int getComponentIndex(List<Component> cycle, Component aComponent) {
+ return cycle.indexOf(aComponent);
+ }
+
+ private void enumerateCycle(Container container, List cycle) {
+ if (!(container.isVisible() && container.isDisplayable())) {
+ return;
+ }
+
+ cycle.add(container);
+
+ Component[] components = container.getComponents();
+ for (int i = 0; i < components.length; i++) {
+ Component comp = components[i];
+ if (comp instanceof Container) {
+ Container cont = (Container)comp;
+
+ if (!cont.isFocusCycleRoot() && !cont.isFocusTraversalPolicyProvider()) {
+ enumerateCycle(cont, cycle);
+ continue;
+ }
+ }
+ cycle.add(comp);
+ }
+ }
+
+ private Container getTopmostProvider(Container focusCycleRoot, Component aComponent) {
+ Container aCont = aComponent.getParent();
+ Container ftp = null;
+ while (aCont != focusCycleRoot && aCont != null) {
+ if (aCont.isFocusTraversalPolicyProvider()) {
+ ftp = aCont;
+ }
+ aCont = aCont.getParent();
+ }
+ if (aCont == null) {
+ return null;
+ }
+ return ftp;
+ }
+
+ /*
+ * Checks if a new focus cycle takes place and returns a Component to traverse focus to.
+ * @param comp a possible focus cycle root or policy provider
+ * @param traversalDirection the direction of the traversal
+ * @return a Component to traverse focus to if {@code comp} is a root or provider
+ * and implicit down-cycle is set, otherwise {@code null}
+ */
+ private Component getComponentDownCycle(Component comp, int traversalDirection) {
+ Component retComp = null;
+
+ if (comp instanceof Container) {
+ Container cont = (Container)comp;
+
+ if (cont.isFocusCycleRoot()) {
+ if (getImplicitDownCycleTraversal()) {
+ retComp = cont.getFocusTraversalPolicy().getDefaultComponent(cont);
+
+ if (retComp != null && log.isLoggable(Level.FINE)) {
+ log.fine("### Transfered focus down-cycle to " + retComp +
+ " in the focus cycle root " + cont);
+ }
+ } else {
+ return null;
+ }
+ } else if (cont.isFocusTraversalPolicyProvider()) {
+ retComp = (traversalDirection == FORWARD_TRAVERSAL ?
+ cont.getFocusTraversalPolicy().getDefaultComponent(cont) :
+ cont.getFocusTraversalPolicy().getLastComponent(cont));
+
+ if (retComp != null && log.isLoggable(Level.FINE)) {
+ log.fine("### Transfered focus to " + retComp + " in the FTP provider " + cont);
+ }
+ }
+ }
+ return retComp;
+ }
+
+ /**
+ * Returns the Component that should receive the focus after aComponent.
+ * aContainer must be a focus cycle root of aComponent or a focus traversal policy provider.
+ * <p>
+ * By default, ContainerOrderFocusTraversalPolicy implicitly transfers
+ * focus down-cycle. That is, during normal forward focus traversal, the
+ * Component traversed after a focus cycle root will be the focus-cycle-
+ * root's default Component to focus. This behavior can be disabled using
+ * the <code>setImplicitDownCycleTraversal</code> method.
+ * <p>
+ * If aContainer is <a href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus
+ * traversal policy provider</a>, the focus is always transferred down-cycle.
+ *
+ * @param aContainer a focus cycle root of aComponent or a focus traversal policy provider
+ * @param aComponent a (possibly indirect) child of aContainer, or
+ * aContainer itself
+ * @return the Component that should receive the focus after aComponent, or
+ * null if no suitable Component can be found
+ * @throws IllegalArgumentException if aContainer is not a focus cycle
+ * root of aComponent or focus traversal policy provider, or if either aContainer or
+ * aComponent is null
+ */
+ public Component getComponentAfter(Container aContainer, Component aComponent) {
+ if (log.isLoggable(Level.FINE)) log.fine("### Searching in " + aContainer + " for component after " + aComponent);
+
+ if (aContainer == null || aComponent == null) {
+ throw new IllegalArgumentException("aContainer and aComponent cannot be null");
+ }
+ if (!aContainer.isFocusTraversalPolicyProvider() && !aContainer.isFocusCycleRoot()) {
+ throw new IllegalArgumentException("aContainer should be focus cycle root or focus traversal policy provider");
+
+ } else if (aContainer.isFocusCycleRoot() && !aComponent.isFocusCycleRoot(aContainer)) {
+ throw new IllegalArgumentException("aContainer is not a focus cycle root of aComponent");
+ }
+
+ synchronized(aContainer.getTreeLock()) {
+
+ if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
+ return null;
+ }
+
+ // Before all the ckecks below we first see if it's an FTP provider or a focus cycle root.
+ // If it's the case just go down cycle (if it's set to "implicit").
+ Component comp = getComponentDownCycle(aComponent, FORWARD_TRAVERSAL);
+ if (comp != null) {
+ return comp;
+ }
+
+ // See if the component is inside of policy provider.
+ Container provider = getTopmostProvider(aContainer, aComponent);
+ if (provider != null) {
+ if (log.isLoggable(Level.FINE)) {
+ log.fine("### Asking FTP " + provider + " for component after " + aComponent);
+ }
+
+ // FTP knows how to find component after the given. We don't.
+ FocusTraversalPolicy policy = provider.getFocusTraversalPolicy();
+ Component afterComp = policy.getComponentAfter(provider, aComponent);
+
+ // Null result means that we overstepped the limit of the FTP's cycle.
+ // In that case we must quit the cycle, otherwise return the component found.
+ if (afterComp != null) {
+ if (log.isLoggable(Level.FINE)) log.fine("### FTP returned " + afterComp);
+ return afterComp;
+ }
+ aComponent = provider;
+ }
+
+ List<Component> cycle = getFocusTraversalCycle(aContainer);
+
+ if (log.isLoggable(Level.FINE)) log.fine("### Cycle is " + cycle + ", component is " + aComponent);
+
+ int index = getComponentIndex(cycle, aComponent);
+
+ if (index < 0) {
+ if (log.isLoggable(Level.FINE)) {
+ log.fine("### Didn't find component " + aComponent + " in a cycle " + aContainer);
+ }
+ return getFirstComponent(aContainer);
+ }
+
+ for (index++; index < cycle.size(); index++) {
+ comp = cycle.get(index);
+ if (accept(comp)) {
+ return comp;
+ } else if ((comp = getComponentDownCycle(comp, FORWARD_TRAVERSAL)) != null) {
+ return comp;
+ }
+ }
+
+ if (aContainer.isFocusCycleRoot()) {
+ this.cachedRoot = aContainer;
+ this.cachedCycle = cycle;
+
+ comp = getFirstComponent(aContainer);
+
+ this.cachedRoot = null;
+ this.cachedCycle = null;
+
+ return comp;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns the Component that should receive the focus before aComponent.
+ * aContainer must be a focus cycle root of aComponent or a <a
+ * href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal policy
+ * provider</a>.
+ *
+ * @param aContainer a focus cycle root of aComponent or focus traversal policy provider
+ * @param aComponent a (possibly indirect) child of aContainer, or
+ * aContainer itself
+ * @return the Component that should receive the focus before aComponent,
+ * or null if no suitable Component can be found
+ * @throws IllegalArgumentException if aContainer is not a focus cycle
+ * root of aComponent or focus traversal policy provider, or if either aContainer or
+ * aComponent is null
+ */
+ public Component getComponentBefore(Container aContainer, Component aComponent) {
+ if (aContainer == null || aComponent == null) {
+ throw new IllegalArgumentException("aContainer and aComponent cannot be null");
+ }
+ if (!aContainer.isFocusTraversalPolicyProvider() && !aContainer.isFocusCycleRoot()) {
+ throw new IllegalArgumentException("aContainer should be focus cycle root or focus traversal policy provider");
+
+ } else if (aContainer.isFocusCycleRoot() && !aComponent.isFocusCycleRoot(aContainer)) {
+ throw new IllegalArgumentException("aContainer is not a focus cycle root of aComponent");
+ }
+
+ synchronized(aContainer.getTreeLock()) {
+
+ if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
+ return null;
+ }
+
+ // See if the component is inside of policy provider.
+ Container provider = getTopmostProvider(aContainer, aComponent);
+ if (provider != null) {
+ if (log.isLoggable(Level.FINE)) {
+ log.fine("### Asking FTP " + provider + " for component after " + aComponent);
+ }
+
+ // FTP knows how to find component after the given. We don't.
+ FocusTraversalPolicy policy = provider.getFocusTraversalPolicy();
+ Component beforeComp = policy.getComponentBefore(provider, aComponent);
+
+ // Null result means that we overstepped the limit of the FTP's cycle.
+ // In that case we must quit the cycle, otherwise return the component found.
+ if (beforeComp != null) {
+ if (log.isLoggable(Level.FINE)) log.fine("### FTP returned " + beforeComp);
+ return beforeComp;
+ }
+ aComponent = provider;
+
+ // If the provider is traversable it's returned.
+ if (accept(aComponent)) {
+ return aComponent;
+ }
+ }
+
+ List<Component> cycle = getFocusTraversalCycle(aContainer);
+
+ if (log.isLoggable(Level.FINE)) log.fine("### Cycle is " + cycle + ", component is " + aComponent);
+
+ int index = getComponentIndex(cycle, aComponent);
+
+ if (index < 0) {
+ if (log.isLoggable(Level.FINE)) {
+ log.fine("### Didn't find component " + aComponent + " in a cycle " + aContainer);
+ }
+ return getLastComponent(aContainer);
+ }
+
+ Component comp = null;
+ Component tryComp = null;
+
+ for (index--; index>=0; index--) {
+ comp = cycle.get(index);
+ if (comp != aContainer && (tryComp = getComponentDownCycle(comp, BACKWARD_TRAVERSAL)) != null) {
+ return tryComp;
+ } else if (accept(comp)) {
+ return comp;
+ }
+ }
+
+ if (aContainer.isFocusCycleRoot()) {
+ this.cachedRoot = aContainer;
+ this.cachedCycle = cycle;
+
+ comp = getLastComponent(aContainer);
+
+ this.cachedRoot = null;
+ this.cachedCycle = null;
+
+ return comp;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns the first Component in the traversal cycle. This method is used
+ * to determine the next Component to focus when traversal wraps in the
+ * forward direction.
+ *
+ * @param aContainer the focus cycle root or focus traversal policy provider whose first
+ * Component is to be returned
+ * @return the first Component in the traversal cycle of aContainer,
+ * or null if no suitable Component can be found
+ * @throws IllegalArgumentException if aContainer is null
+ */
+ public Component getFirstComponent(Container aContainer) {
+ List<Component> cycle;
+
+ if (log.isLoggable(Level.FINE)) log.fine("### Getting first component in " + aContainer);
+ if (aContainer == null) {
+ throw new IllegalArgumentException("aContainer cannot be null");
+
+ }
+
+ synchronized(aContainer.getTreeLock()) {
+
+ if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
+ return null;
+ }
+
+ if (this.cachedRoot == aContainer) {
+ cycle = this.cachedCycle;
+ } else {
+ cycle = getFocusTraversalCycle(aContainer);
+ }
+
+ if (cycle.size() == 0) {
+ if (log.isLoggable(Level.FINE)) log.fine("### Cycle is empty");
+ return null;
+ }
+ if (log.isLoggable(Level.FINE)) log.fine("### Cycle is " + cycle);
+
+ for (int i = 0; i < cycle.size(); i++) {
+ Component comp = cycle.get(i);
+ if (accept(comp)) {
+ return comp;
+ } else if (comp instanceof Container && comp != aContainer) {
+ Container cont = (Container)comp;
+ if (cont.isFocusTraversalPolicyProvider()) {
+ return cont.getFocusTraversalPolicy().getDefaultComponent(cont);
+ }
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns the last Component in the traversal cycle. This method is used
+ * to determine the next Component to focus when traversal wraps in the
+ * reverse direction.
+ *
+ * @param aContainer the focus cycle root or focus traversal policy provider whose last
+ * Component is to be returned
+ * @return the last Component in the traversal cycle of aContainer,
+ * or null if no suitable Component can be found
+ * @throws IllegalArgumentException if aContainer is null
+ */
+ public Component getLastComponent(Container aContainer) {
+ List<Component> cycle;
+ if (log.isLoggable(Level.FINE)) log.fine("### Getting last component in " + aContainer);
+
+ if (aContainer == null) {
+ throw new IllegalArgumentException("aContainer cannot be null");
+ }
+
+ synchronized(aContainer.getTreeLock()) {
+
+ if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
+ return null;
+ }
+
+ if (this.cachedRoot == aContainer) {
+ cycle = this.cachedCycle;
+ } else {
+ cycle = getFocusTraversalCycle(aContainer);
+ }
+
+ if (cycle.size() == 0) {
+ if (log.isLoggable(Level.FINE)) log.fine("### Cycle is empty");
+ return null;
+ }
+ if (log.isLoggable(Level.FINE)) log.fine("### Cycle is " + cycle);
+
+ for (int i= cycle.size() - 1; i >= 0; i--) {
+ Component comp = cycle.get(i);
+ if (accept(comp)) {
+ return comp;
+ } else if (comp instanceof Container && comp != aContainer) {
+ Container cont = (Container)comp;
+ if (cont.isFocusTraversalPolicyProvider()) {
+ return cont.getFocusTraversalPolicy().getLastComponent(cont);
+ }
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Returns the default Component to focus. This Component will be the first
+ * to receive focus when traversing down into a new focus traversal cycle
+ * rooted at aContainer. The default implementation of this method
+ * returns the same Component as <code>getFirstComponent</code>.
+ *
+ * @param aContainer the focus cycle root or focus traversal policy provider whose default
+ * Component is to be returned
+ * @return the default Component in the traversal cycle of aContainer,
+ * or null if no suitable Component can be found
+ * @see #getFirstComponent
+ * @throws IllegalArgumentException if aContainer is null
+ */
+ public Component getDefaultComponent(Container aContainer) {
+ return getFirstComponent(aContainer);
+ }
+
+ /**
+ * Sets whether this ContainerOrderFocusTraversalPolicy transfers focus
+ * down-cycle implicitly. If <code>true</code>, during normal forward focus
+ * traversal, the Component traversed after a focus cycle root will be the
+ * focus-cycle-root's default Component to focus. If <code>false</code>,
+ * the next Component in the focus traversal cycle rooted at the specified
+ * focus cycle root will be traversed instead. The default value for this
+ * property is <code>true</code>.
+ *
+ * @param implicitDownCycleTraversal whether this
+ * ContainerOrderFocusTraversalPolicy transfers focus down-cycle
+ * implicitly
+ * @see #getImplicitDownCycleTraversal
+ * @see #getFirstComponent
+ */
+ public void setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal) {
+ this.implicitDownCycleTraversal = implicitDownCycleTraversal;
+ }
+
+ /**
+ * Returns whether this ContainerOrderFocusTraversalPolicy transfers focus
+ * down-cycle implicitly. If <code>true</code>, during normal forward focus
+ * traversal, the Component traversed after a focus cycle root will be the
+ * focus-cycle-root's default Component to focus. If <code>false</code>,
+ * the next Component in the focus traversal cycle rooted at the specified
+ * focus cycle root will be traversed instead.
+ *
+ * @return whether this ContainerOrderFocusTraversalPolicy transfers focus
+ * down-cycle implicitly
+ * @see #setImplicitDownCycleTraversal
+ * @see #getFirstComponent
+ */
+ public boolean getImplicitDownCycleTraversal() {
+ return implicitDownCycleTraversal;
+ }
+
+ /**
+ * Determines whether a Component is an acceptable choice as the new
+ * focus owner. By default, this method will accept a Component if and
+ * only if it is visible, displayable, enabled, and focusable.
+ *
+ * @param aComponent the Component whose fitness as a focus owner is to
+ * be tested
+ * @return <code>true</code> if aComponent is visible, displayable,
+ * enabled, and focusable; <code>false</code> otherwise
+ */
+ protected boolean accept(Component aComponent) {
+ if (!(aComponent.isVisible() && aComponent.isDisplayable() &&
+ aComponent.isFocusable() && aComponent.isEnabled())) {
+ return false;
+ }
+
+ // Verify that the Component is recursively enabled. Disabling a
+ // heavyweight Container disables its children, whereas disabling
+ // a lightweight Container does not.
+ if (!(aComponent instanceof Window)) {
+ for (Container enableTest = aComponent.getParent();
+ enableTest != null;
+ enableTest = enableTest.getParent())
+ {
+ if (!(enableTest.isEnabled() || enableTest.isLightweight())) {
+ return false;
+ }
+ if (enableTest instanceof Window) {
+ break;
+ }
+ }
+ }
+
+ return true;
+ }
+}