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 final private int FORWARD_TRAVERSAL = 0;
66 final private int BACKWARD_TRAVERSAL = 1;
67
68 /*
69 * JDK 1.4 serialVersionUID
70 */
71 private static final long serialVersionUID = 486933713763926351L;
72
73 private boolean implicitDownCycleTraversal = true;
74
75 /**
76 * Used by getComponentAfter and getComponentBefore for efficiency. In
77 * order to maintain compliance with the specification of
78 * FocusTraversalPolicy, if traversal wraps, we should invoke
79 * getFirstComponent or getLastComponent. These methods may be overriden in
80 * subclasses to behave in a non-generic way. However, in the generic case,
81 * these methods will simply return the first or last Components of the
82 * sorted list, respectively. Since getComponentAfter and
83 * getComponentBefore have already built the list before determining
84 * that they need to invoke getFirstComponent or getLastComponent, the
85 * list should be reused if possible.
86 */
87 transient private Container cachedRoot;
88 transient private List<Component> cachedCycle;
89
90 /*
91 * We suppose to use getFocusTraversalCycle & getComponentIndex methods in order
92 * to divide the policy into two parts:
93 * 1) Making the focus traversal cycle.
94 * 2) Traversing the cycle.
95 * The 1st point assumes producing a list of components representing the focus
96 * traversal cycle. The two methods mentioned above should implement this logic.
97 * The 2nd point assumes implementing the common concepts of operating on the
98 * cycle: traversing back and forth, retrieving the initial/default/first/last
99 * component. These concepts are described in the AWT Focus Spec and they are
100 * applied to the FocusTraversalPolicy in general.
101 * Thus, a descendant of this policy may wish to not reimplement the logic of
102 * the 2nd point but just override the implementation of the 1st one.
103 * A striking example of such a descendant is the javax.swing.SortingFocusTraversalPolicy.
104 */
105 /*protected*/ private List<Component> getFocusTraversalCycle(Container aContainer) {
106 List<Component> cycle = new ArrayList<Component>();
107 enumerateCycle(aContainer, cycle);
108 return cycle;
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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
68 /*
69 * JDK 1.4 serialVersionUID
70 */
71 private static final long serialVersionUID = 486933713763926351L;
72
73 private boolean implicitDownCycleTraversal = true;
74
75 /**
76 * Used by getComponentAfter and getComponentBefore for efficiency. In
77 * order to maintain compliance with the specification of
78 * FocusTraversalPolicy, if traversal wraps, we should invoke
79 * getFirstComponent or getLastComponent. These methods may be overriden in
80 * subclasses to behave in a non-generic way. However, in the generic case,
81 * these methods will simply return the first or last Components of the
82 * sorted list, respectively. Since getComponentAfter and
83 * getComponentBefore have already built the list before determining
84 * that they need to invoke getFirstComponent or getLastComponent, the
85 * list should be reused if possible.
86 */
87 private transient Container cachedRoot;
88 private transient List<Component> cachedCycle;
89
90 /*
91 * We suppose to use getFocusTraversalCycle & getComponentIndex methods in order
92 * to divide the policy into two parts:
93 * 1) Making the focus traversal cycle.
94 * 2) Traversing the cycle.
95 * The 1st point assumes producing a list of components representing the focus
96 * traversal cycle. The two methods mentioned above should implement this logic.
97 * The 2nd point assumes implementing the common concepts of operating on the
98 * cycle: traversing back and forth, retrieving the initial/default/first/last
99 * component. These concepts are described in the AWT Focus Spec and they are
100 * applied to the FocusTraversalPolicy in general.
101 * Thus, a descendant of this policy may wish to not reimplement the logic of
102 * the 2nd point but just override the implementation of the 1st one.
103 * A striking example of such a descendant is the javax.swing.SortingFocusTraversalPolicy.
104 */
105 /*protected*/ private List<Component> getFocusTraversalCycle(Container aContainer) {
106 List<Component> cycle = new ArrayList<Component>();
107 enumerateCycle(aContainer, cycle);
108 return cycle;
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