DefaultFocusManager.java

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packagejavax.swing;

importjava.awt.Component;
importjava.awt.Container;
importjava.awt.FocusTraversalPolicy;
importjava.util.Comparator;


/**
 * This class has been obsoleted by the 1.4 focus APIs. While client code may
 * still use this class, developers are strongly encouraged to use
 * <code>java.awt.KeyboardFocusManager</code> and
 * <code>java.awt.DefaultKeyboardFocusManager</code> instead.
 * <p>
 * Please see
 * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
 * How to Use the Focus Subsystem</a>,
 * a section in <em>The Java Tutorial</em>, and the
 * <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
 * for more information.
 *
 * @author Arnaud Weber
 * @author David Mendenhall
 * @since 1.2
 */
publicclassDefaultFocusManagerextendsFocusManager {

finalFocusTraversalPolicygluePolicy =
newLegacyGlueFocusTraversalPolicy(this);
privatefinalFocusTraversalPolicylayoutPolicy =
newLegacyLayoutFocusTraversalPolicy(this);
privatefinalLayoutComparatorcomparator =
newLayoutComparator();

/**
 * Constructs a {@code DefaultFocusManager}.
 */
publicDefaultFocusManager() {
setDefaultFocusTraversalPolicy(gluePolicy);
 }

/**
 * Returns the component after.
 * @return the component after
 * @param aContainer a container
 * @param aComponent a component
 */
publicComponentgetComponentAfter(ContaineraContainer,
ComponentaComponent)
 {
Containerroot = (aContainer.isFocusCycleRoot())
 ? aContainer
 : aContainer.getFocusCycleRootAncestor();

// Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
// traversal policy is non-legacy, then honor it.
if (root != null) {
FocusTraversalPolicypolicy = root.getFocusTraversalPolicy();
if (policy != gluePolicy) {
returnpolicy.getComponentAfter(root, aComponent);
 }

comparator.setComponentOrientation(root.getComponentOrientation());
returnlayoutPolicy.getComponentAfter(root, aComponent);
 }

returnnull;
 }

/**
 * Returns the component before.
 * @return the component before
 * @param aContainer a container
 * @param aComponent a component
 */
publicComponentgetComponentBefore(ContaineraContainer,
ComponentaComponent)
 {
Containerroot = (aContainer.isFocusCycleRoot())
 ? aContainer
 : aContainer.getFocusCycleRootAncestor();

// Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
// traversal policy is non-legacy, then honor it.
if (root != null) {
FocusTraversalPolicypolicy = root.getFocusTraversalPolicy();
if (policy != gluePolicy) {
returnpolicy.getComponentBefore(root, aComponent);
 }

comparator.setComponentOrientation(root.getComponentOrientation());
returnlayoutPolicy.getComponentBefore(root, aComponent);
 }

returnnull;
 }

/**
 * Returns the first component.
 * @return the first component
 * @param aContainer a container
 */
publicComponentgetFirstComponent(ContaineraContainer) {
Containerroot = (aContainer.isFocusCycleRoot())
 ? aContainer
 : aContainer.getFocusCycleRootAncestor();

// Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
// traversal policy is non-legacy, then honor it.
if (root != null) {
FocusTraversalPolicypolicy = root.getFocusTraversalPolicy();
if (policy != gluePolicy) {
returnpolicy.getFirstComponent(root);
 }

comparator.setComponentOrientation(root.getComponentOrientation());
returnlayoutPolicy.getFirstComponent(root);
 }

returnnull;
 }

/**
 * Returns the last component.
 * @return the last component
 * @param aContainer a container
 */
publicComponentgetLastComponent(ContaineraContainer) {
Containerroot = (aContainer.isFocusCycleRoot())
 ? aContainer
 : aContainer.getFocusCycleRootAncestor();

// Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
// traversal policy is non-legacy, then honor it.
if (root != null) {
FocusTraversalPolicypolicy = root.getFocusTraversalPolicy();
if (policy != gluePolicy) {
returnpolicy.getLastComponent(root);
 }

comparator.setComponentOrientation(root.getComponentOrientation());
returnlayoutPolicy.getLastComponent(root);
 }

returnnull;
 }

/**
 * Compares the components by their focus traversal cycle order.
 * @param a the first component
 * @param b the second component
 * @return a comparison of the components by their focus traversal cycle order
 */
publicbooleancompareTabOrder(Componenta, Componentb) {
return (comparator.compare(a, b) < 0);
 }
}

@SuppressWarnings("serial") // JDK-implementation class
finalclassLegacyLayoutFocusTraversalPolicy
extendsLayoutFocusTraversalPolicy
{
LegacyLayoutFocusTraversalPolicy(DefaultFocusManagerdefaultFocusManager) {
super(newCompareTabOrderComparator(defaultFocusManager));
 }
}

finalclassCompareTabOrderComparatorimplementsComparator<Component> {
privatefinalDefaultFocusManagerdefaultFocusManager;

CompareTabOrderComparator(DefaultFocusManagerdefaultFocusManager) {
this.defaultFocusManager = defaultFocusManager;
 }

publicintcompare(Componento1, Componento2) {
if (o1 == o2) {
return0;
 }
return (defaultFocusManager.compareTabOrder(o1, o2)) ? -1 : 1;
 }
}