16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.awt;
26
27 import java.util.List;
28 import java.util.ArrayList;
29 import sun.util.logging.PlatformLogger;
30
31 /**
32 * A FocusTraversalPolicy that determines traversal order based on the order
33 * of child Components in a Container. From a particular focus cycle root, the
34 * policy makes a pre-order traversal of the Component hierarchy, and traverses
35 * a Container's children according to the ordering of the array returned by
36 * <code>Container.getComponents()</code>. Portions of the hierarchy that are
37 * not visible and displayable will not be searched.
38 * <p>
39 * By default, ContainerOrderFocusTraversalPolicy implicitly transfers focus
40 * down-cycle. That is, during normal forward focus traversal, the Component
41 * traversed after a focus cycle root will be the focus-cycle-root's default
42 * Component to focus. This behavior can be disabled using the
43 * <code>setImplicitDownCycleTraversal</code> method.
44 * <p>
45 * By default, methods of this class will return a Component only if it is
46 * visible, displayable, enabled, and focusable. Subclasses can modify this
47 * behavior by overriding the <code>accept</code> method.
48 * <p>
49 * This policy takes into account <a
50 * href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal
51 * policy providers</a>. When searching for first/last/next/previous Component,
52 * if a focus traversal policy provider is encountered, its focus traversal
53 * policy is used to perform the search operation.
54 *
55 * @author David Mendenhall
56 *
57 * @see Container#getComponents
58 * @since 1.4
59 */
60 public class ContainerOrderFocusTraversalPolicy extends FocusTraversalPolicy
61 implements java.io.Serializable
62 {
63 private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.ContainerOrderFocusTraversalPolicy");
64
65 private final int FORWARD_TRAVERSAL = 0;
66 private final int BACKWARD_TRAVERSAL = 1;
67
176 retComp = (traversalDirection == FORWARD_TRAVERSAL ?
177 cont.getFocusTraversalPolicy().getDefaultComponent(cont) :
178 cont.getFocusTraversalPolicy().getLastComponent(cont));
179
180 if (retComp != null && log.isLoggable(PlatformLogger.Level.FINE)) {
181 log.fine("### Transferred focus to " + retComp + " in the FTP provider " + cont);
182 }
183 }
184 }
185 return retComp;
186 }
187
188 /**
189 * Returns the Component that should receive the focus after aComponent.
190 * aContainer must be a focus cycle root of aComponent or a focus traversal policy provider.
191 * <p>
192 * By default, ContainerOrderFocusTraversalPolicy implicitly transfers
193 * focus down-cycle. That is, during normal forward focus traversal, the
194 * Component traversed after a focus cycle root will be the focus-cycle-
195 * root's default Component to focus. This behavior can be disabled using
196 * the <code>setImplicitDownCycleTraversal</code> method.
197 * <p>
198 * If aContainer is <a href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus
199 * traversal policy provider</a>, the focus is always transferred down-cycle.
200 *
201 * @param aContainer a focus cycle root of aComponent or a focus traversal policy provider
202 * @param aComponent a (possibly indirect) child of aContainer, or
203 * aContainer itself
204 * @return the Component that should receive the focus after aComponent, or
205 * null if no suitable Component can be found
206 * @throws IllegalArgumentException if aContainer is not a focus cycle
207 * root of aComponent or focus traversal policy provider, or if either aContainer or
208 * aComponent is null
209 */
210 public Component getComponentAfter(Container aContainer, Component aComponent) {
211 if (log.isLoggable(PlatformLogger.Level.FINE)) {
212 log.fine("### Searching in " + aContainer + " for component after " + aComponent);
213 }
214
215 if (aContainer == null || aComponent == null) {
216 throw new IllegalArgumentException("aContainer and aComponent cannot be null");
502 if (accept(comp)) {
503 return comp;
504 } else if (comp instanceof Container && comp != aContainer) {
505 Container cont = (Container)comp;
506 if (cont.isFocusTraversalPolicyProvider()) {
507 Component retComp = cont.getFocusTraversalPolicy().getLastComponent(cont);
508 if (retComp != null) {
509 return retComp;
510 }
511 }
512 }
513 }
514 }
515 return null;
516 }
517
518 /**
519 * Returns the default Component to focus. This Component will be the first
520 * to receive focus when traversing down into a new focus traversal cycle
521 * rooted at aContainer. The default implementation of this method
522 * returns the same Component as <code>getFirstComponent</code>.
523 *
524 * @param aContainer the focus cycle root or focus traversal policy provider whose default
525 * Component is to be returned
526 * @return the default Component in the traversal cycle of aContainer,
527 * or null if no suitable Component can be found
528 * @see #getFirstComponent
529 * @throws IllegalArgumentException if aContainer is null
530 */
531 public Component getDefaultComponent(Container aContainer) {
532 return getFirstComponent(aContainer);
533 }
534
535 /**
536 * Sets whether this ContainerOrderFocusTraversalPolicy transfers focus
537 * down-cycle implicitly. If <code>true</code>, during normal forward focus
538 * traversal, the Component traversed after a focus cycle root will be the
539 * focus-cycle-root's default Component to focus. If <code>false</code>,
540 * the next Component in the focus traversal cycle rooted at the specified
541 * focus cycle root will be traversed instead. The default value for this
542 * property is <code>true</code>.
543 *
544 * @param implicitDownCycleTraversal whether this
545 * ContainerOrderFocusTraversalPolicy transfers focus down-cycle
546 * implicitly
547 * @see #getImplicitDownCycleTraversal
548 * @see #getFirstComponent
549 */
550 public void setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal) {
551 this.implicitDownCycleTraversal = implicitDownCycleTraversal;
552 }
553
554 /**
555 * Returns whether this ContainerOrderFocusTraversalPolicy transfers focus
556 * down-cycle implicitly. If <code>true</code>, during normal forward focus
557 * traversal, the Component traversed after a focus cycle root will be the
558 * focus-cycle-root's default Component to focus. If <code>false</code>,
559 * the next Component in the focus traversal cycle rooted at the specified
560 * focus cycle root will be traversed instead.
561 *
562 * @return whether this ContainerOrderFocusTraversalPolicy transfers focus
563 * down-cycle implicitly
564 * @see #setImplicitDownCycleTraversal
565 * @see #getFirstComponent
566 */
567 public boolean getImplicitDownCycleTraversal() {
568 return implicitDownCycleTraversal;
569 }
570
571 /**
572 * Determines whether a Component is an acceptable choice as the new
573 * focus owner. By default, this method will accept a Component if and
574 * only if it is visible, displayable, enabled, and focusable.
575 *
576 * @param aComponent the Component whose fitness as a focus owner is to
577 * be tested
578 * @return <code>true</code> if aComponent is visible, displayable,
579 * enabled, and focusable; <code>false</code> otherwise
580 */
581 protected boolean accept(Component aComponent) {
582 if (!aComponent.canBeFocusOwner()) {
583 return false;
584 }
585
586 // Verify that the Component is recursively enabled. Disabling a
587 // heavyweight Container disables its children, whereas disabling
588 // a lightweight Container does not.
589 if (!(aComponent instanceof Window)) {
590 for (Container enableTest = aComponent.getParent();
591 enableTest != null;
592 enableTest = enableTest.getParent())
593 {
594 if (!(enableTest.isEnabled() || enableTest.isLightweight())) {
595 return false;
596 }
597 if (enableTest instanceof Window) {
598 break;
599 }
|
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.awt;
26
27 import java.util.List;
28 import java.util.ArrayList;
29 import sun.util.logging.PlatformLogger;
30
31 /**
32 * A FocusTraversalPolicy that determines traversal order based on the order
33 * of child Components in a Container. From a particular focus cycle root, the
34 * policy makes a pre-order traversal of the Component hierarchy, and traverses
35 * a Container's children according to the ordering of the array returned by
36 * {@code Container.getComponents()}. Portions of the hierarchy that are
37 * not visible and displayable will not be searched.
38 * <p>
39 * By default, ContainerOrderFocusTraversalPolicy implicitly transfers focus
40 * down-cycle. That is, during normal forward focus traversal, the Component
41 * traversed after a focus cycle root will be the focus-cycle-root's default
42 * Component to focus. This behavior can be disabled using the
43 * {@code setImplicitDownCycleTraversal} method.
44 * <p>
45 * By default, methods of this class will return a Component only if it is
46 * visible, displayable, enabled, and focusable. Subclasses can modify this
47 * behavior by overriding the {@code accept} method.
48 * <p>
49 * This policy takes into account <a
50 * href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal
51 * policy providers</a>. When searching for first/last/next/previous Component,
52 * if a focus traversal policy provider is encountered, its focus traversal
53 * policy is used to perform the search operation.
54 *
55 * @author David Mendenhall
56 *
57 * @see Container#getComponents
58 * @since 1.4
59 */
60 public class ContainerOrderFocusTraversalPolicy extends FocusTraversalPolicy
61 implements java.io.Serializable
62 {
63 private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.ContainerOrderFocusTraversalPolicy");
64
65 private final int FORWARD_TRAVERSAL = 0;
66 private final int BACKWARD_TRAVERSAL = 1;
67
176 retComp = (traversalDirection == FORWARD_TRAVERSAL ?
177 cont.getFocusTraversalPolicy().getDefaultComponent(cont) :
178 cont.getFocusTraversalPolicy().getLastComponent(cont));
179
180 if (retComp != null && log.isLoggable(PlatformLogger.Level.FINE)) {
181 log.fine("### Transferred focus to " + retComp + " in the FTP provider " + cont);
182 }
183 }
184 }
185 return retComp;
186 }
187
188 /**
189 * Returns the Component that should receive the focus after aComponent.
190 * aContainer must be a focus cycle root of aComponent or a focus traversal policy provider.
191 * <p>
192 * By default, ContainerOrderFocusTraversalPolicy implicitly transfers
193 * focus down-cycle. That is, during normal forward focus traversal, the
194 * Component traversed after a focus cycle root will be the focus-cycle-
195 * root's default Component to focus. This behavior can be disabled using
196 * the {@code setImplicitDownCycleTraversal} method.
197 * <p>
198 * If aContainer is <a href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus
199 * traversal policy provider</a>, the focus is always transferred down-cycle.
200 *
201 * @param aContainer a focus cycle root of aComponent or a focus traversal policy provider
202 * @param aComponent a (possibly indirect) child of aContainer, or
203 * aContainer itself
204 * @return the Component that should receive the focus after aComponent, or
205 * null if no suitable Component can be found
206 * @throws IllegalArgumentException if aContainer is not a focus cycle
207 * root of aComponent or focus traversal policy provider, or if either aContainer or
208 * aComponent is null
209 */
210 public Component getComponentAfter(Container aContainer, Component aComponent) {
211 if (log.isLoggable(PlatformLogger.Level.FINE)) {
212 log.fine("### Searching in " + aContainer + " for component after " + aComponent);
213 }
214
215 if (aContainer == null || aComponent == null) {
216 throw new IllegalArgumentException("aContainer and aComponent cannot be null");
502 if (accept(comp)) {
503 return comp;
504 } else if (comp instanceof Container && comp != aContainer) {
505 Container cont = (Container)comp;
506 if (cont.isFocusTraversalPolicyProvider()) {
507 Component retComp = cont.getFocusTraversalPolicy().getLastComponent(cont);
508 if (retComp != null) {
509 return retComp;
510 }
511 }
512 }
513 }
514 }
515 return null;
516 }
517
518 /**
519 * Returns the default Component to focus. This Component will be the first
520 * to receive focus when traversing down into a new focus traversal cycle
521 * rooted at aContainer. The default implementation of this method
522 * returns the same Component as {@code getFirstComponent}.
523 *
524 * @param aContainer the focus cycle root or focus traversal policy provider whose default
525 * Component is to be returned
526 * @return the default Component in the traversal cycle of aContainer,
527 * or null if no suitable Component can be found
528 * @see #getFirstComponent
529 * @throws IllegalArgumentException if aContainer is null
530 */
531 public Component getDefaultComponent(Container aContainer) {
532 return getFirstComponent(aContainer);
533 }
534
535 /**
536 * Sets whether this ContainerOrderFocusTraversalPolicy transfers focus
537 * down-cycle implicitly. If {@code true}, during normal forward focus
538 * traversal, the Component traversed after a focus cycle root will be the
539 * focus-cycle-root's default Component to focus. If {@code false},
540 * the next Component in the focus traversal cycle rooted at the specified
541 * focus cycle root will be traversed instead. The default value for this
542 * property is {@code true}.
543 *
544 * @param implicitDownCycleTraversal whether this
545 * ContainerOrderFocusTraversalPolicy transfers focus down-cycle
546 * implicitly
547 * @see #getImplicitDownCycleTraversal
548 * @see #getFirstComponent
549 */
550 public void setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal) {
551 this.implicitDownCycleTraversal = implicitDownCycleTraversal;
552 }
553
554 /**
555 * Returns whether this ContainerOrderFocusTraversalPolicy transfers focus
556 * down-cycle implicitly. If {@code true}, during normal forward focus
557 * traversal, the Component traversed after a focus cycle root will be the
558 * focus-cycle-root's default Component to focus. If {@code false},
559 * the next Component in the focus traversal cycle rooted at the specified
560 * focus cycle root will be traversed instead.
561 *
562 * @return whether this ContainerOrderFocusTraversalPolicy transfers focus
563 * down-cycle implicitly
564 * @see #setImplicitDownCycleTraversal
565 * @see #getFirstComponent
566 */
567 public boolean getImplicitDownCycleTraversal() {
568 return implicitDownCycleTraversal;
569 }
570
571 /**
572 * Determines whether a Component is an acceptable choice as the new
573 * focus owner. By default, this method will accept a Component if and
574 * only if it is visible, displayable, enabled, and focusable.
575 *
576 * @param aComponent the Component whose fitness as a focus owner is to
577 * be tested
578 * @return {@code true} if aComponent is visible, displayable,
579 * enabled, and focusable; {@code false} otherwise
580 */
581 protected boolean accept(Component aComponent) {
582 if (!aComponent.canBeFocusOwner()) {
583 return false;
584 }
585
586 // Verify that the Component is recursively enabled. Disabling a
587 // heavyweight Container disables its children, whereas disabling
588 // a lightweight Container does not.
589 if (!(aComponent instanceof Window)) {
590 for (Container enableTest = aComponent.getParent();
591 enableTest != null;
592 enableTest = enableTest.getParent())
593 {
594 if (!(enableTest.isEnabled() || enableTest.isLightweight())) {
595 return false;
596 }
597 if (enableTest instanceof Window) {
598 break;
599 }
|