ContainerOrderFocusTraversalPolicypublic class ContainerOrderFocusTraversalPolicy extends FocusTraversalPolicy implements SerializableA 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
Container.getComponents(). Portions of the hierarchy that are
not visible and displayable will not be searched.
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
setImplicitDownCycleTraversal method.
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 accept method.
This policy takes into account focus traversal
policy providers. 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. |
| Fields Summary |
|---|
| private static final MutableBoolean | found | | private static final Logger | log | | private static final long | serialVersionUID | | private boolean | implicitDownCycleTraversal |
| Methods Summary |
|---|
| protected boolean | accept(java.awt.Component aComponent)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.
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;
| | public java.awt.Component | getComponentAfter(java.awt.Container aContainer, java.awt.Component aComponent)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.
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 setImplicitDownCycleTraversal method.
If aContainer is focus
traversal policy provider, the focus is always transferred down-cycle.
if (log.isLoggable(Level.FINE)) log.fine("Looking for next component in " + aContainer + " for " + 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()) {
found.value = false;
Component retval = getComponentAfter(aContainer, aComponent,
found);
if (retval != null) {
if (log.isLoggable(Level.FINE)) log.fine("After component is " + retval);
return retval;
} else if (found.value) {
if (log.isLoggable(Level.FINE)) log.fine("Didn't find next component in " + aContainer + " - falling back to the first ");
return getFirstComponent(aContainer);
} else {
if (log.isLoggable(Level.FINE)) log.fine("After component is null");
return null;
}
}
| | private java.awt.Component | getComponentAfter(java.awt.Container aContainer, java.awt.Component aComponent, java.awt.MutableBoolean found)
if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
return null;
}
if (found.value) {
if (accept(aContainer)) {
return aContainer;
}
} else if (aContainer == aComponent) {
found.value = true;
}
for (int i = 0; i < aContainer.ncomponents; i++) {
Component comp = aContainer.component[i];
if ((comp instanceof Container) &&
!((Container)comp).isFocusCycleRoot()) {
Component retval = null;
if (((Container)comp).isFocusTraversalPolicyProvider()) {
if (log.isLoggable(Level.FINE)) log.fine("Entering FTP " + comp);
Container cont = (Container) comp;
FocusTraversalPolicy policy = cont.getFocusTraversalPolicy();
if (log.isLoggable(Level.FINE)) log.fine("FTP contains " + aComponent + ": " + cont.isAncestorOf(aComponent));
if (found.value) {
retval = policy.getDefaultComponent(cont);
if (log.isLoggable(Level.FINE)) log.fine("Used FTP for getting default component: " + retval);
} else {
found.value = cont.isAncestorOf(aComponent);
if (found.value) {
if (aComponent == policy.getLastComponent(cont)) {
// Reached last component, going to wrap - should switch to next provider
retval = null;
} else {
retval = policy.getComponentAfter(cont, aComponent);
if (log.isLoggable(Level.FINE)) log.fine("FTP found next for the component : " + retval);
}
}
}
} else {
retval = getComponentAfter((Container)comp,
aComponent,
found);
}
if (retval != null) {
return retval;
}
} else if (found.value) {
if (accept(comp)) {
return comp;
}
} else if (comp == aComponent) {
found.value = true;
}
if (found.value &&
getImplicitDownCycleTraversal() &&
(comp instanceof Container) &&
((Container)comp).isFocusCycleRoot())
{
Container cont = (Container)comp;
Component retval = cont.getFocusTraversalPolicy().
getDefaultComponent(cont);
if (retval != null) {
return retval;
}
}
}
return null;
| | public java.awt.Component | getComponentBefore(java.awt.Container aContainer, java.awt.Component aComponent)Returns the Component that should receive the focus before aComponent.
aContainer must be a focus cycle root of aComponent or a focus traversal policy
provider.
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()) {
found.value = false;
Component retval = getComponentBefore(aContainer, aComponent,
found);
if (retval != null) {
if (log.isLoggable(Level.FINE)) log.fine("Before component is " + retval);
return retval;
} else if (found.value) {
if (log.isLoggable(Level.FINE)) log.fine("Didn't find before component in " + aContainer + " - falling back to the first ");
return getLastComponent(aContainer);
} else {
if (log.isLoggable(Level.FINE)) log.fine("Before component is null");
return null;
}
}
| | private java.awt.Component | getComponentBefore(java.awt.Container aContainer, java.awt.Component aComponent, java.awt.MutableBoolean found)
if (!(aContainer.isVisible() && aContainer.isDisplayable())) {
return null;
}
for (int i = aContainer.ncomponents - 1; i >= 0; i--) {
Component comp = aContainer.component[i];
if (comp == aComponent) {
found.value = true;
} else if ((comp instanceof Container) &&
!((Container)comp).isFocusCycleRoot()) {
Component retval = null;
if (((Container)comp).isFocusTraversalPolicyProvider()) {
if (log.isLoggable(Level.FINE)) log.fine("Entering FTP " + comp);
Container cont = (Container) comp;
FocusTraversalPolicy policy = cont.getFocusTraversalPolicy();
if (log.isLoggable(Level.FINE)) log.fine("FTP contains " + aComponent + ": " + cont.isAncestorOf(aComponent));
if (found.value) {
retval = policy.getLastComponent(cont);
if (log.isLoggable(Level.FINE)) log.fine("Used FTP for getting last component: " + retval);
} else {
found.value = cont.isAncestorOf(aComponent);
if (found.value) {
if (aComponent == policy.getFirstComponent(cont)) {
retval = null;
} else {
retval = policy.getComponentBefore(cont, aComponent);
if (log.isLoggable(Level.FINE)) log.fine("FTP found previous for the component : " + retval);
}
}
}
} else {
retval = getComponentBefore((Container)comp,
aComponent,
found);
}
if (retval != null) {
return retval;
}
} else if (found.value) {
if (accept(comp)) {
return comp;
}
}
}
if (found.value) {
if (accept(aContainer)) {
return aContainer;
}
} else if (aContainer == aComponent) {
found.value = true;
}
return null;
| | public java.awt.Component | getDefaultComponent(java.awt.Container aContainer)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 getFirstComponent.
return getFirstComponent(aContainer);
| | public java.awt.Component | getFirstComponent(java.awt.Container aContainer)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.
if (aContainer == null) {
throw new IllegalArgumentException("aContainer cannot be null");
}
synchronized(aContainer.getTreeLock()) {
if (!(aContainer.isVisible() &&
aContainer.isDisplayable()))
{
return null;
}
if (accept(aContainer)) {
return aContainer;
}
for (int i = 0; i < aContainer.ncomponents; i++) {
Component comp = aContainer.component[i];
if (comp instanceof Container &&
!((Container)comp).isFocusCycleRoot())
{
Component retval = null;
Container cont = (Container)comp;
if (cont.isFocusTraversalPolicyProvider()) {
FocusTraversalPolicy policy = cont.getFocusTraversalPolicy();
retval = policy.getDefaultComponent(cont);
} else {
retval = getFirstComponent((Container)comp);
}
if (retval != null) {
return retval;
}
} else if (accept(comp)) {
return comp;
}
}
}
return null;
| | public boolean | getImplicitDownCycleTraversal()Returns whether this ContainerOrderFocusTraversalPolicy transfers focus
down-cycle implicitly. If true, 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 false,
the next Component in the focus traversal cycle rooted at the specified
focus cycle root will be traversed instead.
return implicitDownCycleTraversal;
| | public java.awt.Component | getLastComponent(java.awt.Container aContainer)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.
if (aContainer == null) {
throw new IllegalArgumentException("aContainer cannot be null");
}
if (log.isLoggable(Level.FINE)) log.fine("Looking for the last component in " + aContainer);
synchronized(aContainer.getTreeLock()) {
if (!(aContainer.isVisible() &&
aContainer.isDisplayable()))
{
return null;
}
for (int i = aContainer.ncomponents - 1; i >= 0; i--) {
Component comp = aContainer.component[i];
if (comp instanceof Container &&
!((Container)comp).isFocusCycleRoot())
{
Component retval = null;
Container cont = (Container)comp;
if (cont.isFocusTraversalPolicyProvider()) {
if (log.isLoggable(Level.FINE)) log.fine("\tEntering FTP " + cont);
FocusTraversalPolicy policy = cont.getFocusTraversalPolicy();
retval = policy.getLastComponent(cont);
} else {
if (log.isLoggable(Level.FINE)) log.fine("\tEntering sub-container");
retval = getLastComponent((Container)comp);
}
if (retval != null) {
if (log.isLoggable(Level.FINE)) log.fine("\tFound last component : " + retval);
return retval;
}
} else if (accept(comp)) {
return comp;
}
}
if (accept(aContainer)) {
return aContainer;
}
}
return null;
| | public void | setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal)Sets whether this ContainerOrderFocusTraversalPolicy transfers focus
down-cycle implicitly. If true, 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 false,
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 true.
this.implicitDownCycleTraversal = implicitDownCycleTraversal;
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