SortingFocusTraversalPolicypublic class SortingFocusTraversalPolicy extends InternalFrameFocusTraversalPolicy | A FocusTraversalPolicy that determines traversal order by sorting the
Components of a focus traversal cycle based on a given Comparator. Portions
of the Component hierarchy that are not visible and displayable will not be
included.
By default, SortingFocusTraversalPolicy implicitly transfers focus down-
cycle. That is, during normal 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 Comparator | comparator | | private boolean | implicitDownCycleTraversal | | private Logger | log | | private Container | cachedRootUsed 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 sorted list before determining
that they need to invoke getFirstComponent or getLastComponent, the
sorted list should be reused if possible. | | private List | cachedCycle | | private static final SwingContainerOrderFocusTraversalPolicy | fitnessTestPolicy |
| Constructors Summary |
|---|
protected SortingFocusTraversalPolicy()Constructs a SortingFocusTraversalPolicy without a Comparator.
Subclasses must set the Comparator using setComparator
before installing this FocusTraversalPolicy on a focus cycle root or
KeyboardFocusManager.
| public SortingFocusTraversalPolicy(Comparator comparator)Constructs a SortingFocusTraversalPolicy with the specified Comparator.
this.comparator = comparator;
|
| 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.
return fitnessTestPolicy.accept(aComponent);
| | private void | enumerateAndSortCycle(java.awt.Container focusCycleRoot, java.util.List cycle, java.util.Map defaults)
List defaultRoots = null;
if (!focusCycleRoot.isShowing()) {
return;
}
enumerateCycle(focusCycleRoot, cycle);
boolean addDefaultComponents =
(defaults != null && getImplicitDownCycleTraversal());
if (log.isLoggable(Level.FINE)) log.fine("### Will add defaults: " + addDefaultComponents);
// Create a list of all default Components which should be added
// to the list
if (addDefaultComponents) {
defaultRoots = new ArrayList();
for (Iterator iter = cycle.iterator(); iter.hasNext(); ) {
Component comp = (Component)iter.next();
if ((comp instanceof Container) &&
((Container)comp).isFocusCycleRoot())
{
defaultRoots.add(comp);
}
}
Collections.sort(defaultRoots, comparator);
}
// Sort the Components in the cycle
Collections.sort(cycle, comparator);
// Find all of the roots in the cycle and place their default
// Components after them. Note that the roots may have been removed
// from the list because they were unfit. In that case, insert the
// default Components as though the roots were still in the list.
if (addDefaultComponents) {
for (ListIterator defaultRootsIter =
defaultRoots.listIterator(defaultRoots.size());
defaultRootsIter.hasPrevious(); )
{
Container root = (Container)defaultRootsIter.previous();
Component defComp =
root.getFocusTraversalPolicy().getDefaultComponent(root);
if (defComp != null && defComp.isShowing()) {
int index = Collections.binarySearch(cycle, root,
comparator);
if (index < 0) {
// If root is not in the list, then binarySearch
// returns (-(insertion point) - 1). defComp follows
// the index one less than the insertion point.
index = -index - 2;
}
defaults.put(new Integer(index), defComp);
}
}
}
| | private void | enumerateCycle(java.awt.Container container, java.util.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)comp).isFocusTraversalPolicyProvider()
&& !((Container)comp).isFocusCycleRoot()
&& !((comp instanceof JComponent)
&& ((JComponent)comp).isManagingFocus()))
{
enumerateCycle((Container)comp, cycle);
} else {
cycle.add(comp);
}
}
| | protected java.util.Comparator | getComparator()Returns the Comparator which will be used to sort the Components in a
focus traversal cycle.
return comparator;
| | 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, SortingFocusTraversalPolicy implicitly transfers focus down-
cycle. That is, during normal 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("### Searching in " + aContainer.getName() + " for component after " + aComponent.getName());
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");
}
// See if the component is inside of policy provider
Container ftp = getTopmostProvider(aContainer, aComponent);
if (ftp != null) {
if (log.isLoggable(Level.FINE)) log.fine("### Asking FTP " + ftp.getName() + " for component after " + aComponent.getName());
// FTP knows how to find component after the given. We don't.
FocusTraversalPolicy policy = ftp.getFocusTraversalPolicy();
Component retval = policy.getComponentAfter(ftp, aComponent);
if (retval == policy.getFirstComponent(ftp)) {
retval = null;
}
if (retval != null) {
if (log.isLoggable(Level.FINE)) log.fine("### FTP returned " + retval.getName());
return retval;
}
aComponent = ftp;
}
List cycle = new ArrayList();
Map defaults = new HashMap();
enumerateAndSortCycle(aContainer, cycle, defaults);
int index;
try {
index = Collections.binarySearch(cycle, aComponent, comparator);
} catch (ClassCastException e) {
if (log.isLoggable(Level.FINE)) log.fine("### Didn't find component " + aComponent.getName() + " in a cycle " + aContainer.getName());
return getFirstComponent(aContainer);
}
if (index < 0) {
// If we're not in the cycle, then binarySearch returns
// (-(insertion point) - 1). The next element is our insertion
// point.
index = -index - 2;
}
Component defComp = (Component)defaults.get(new Integer(index));
if (defComp != null) {
return defComp;
}
do {
index++;
if (index >= cycle.size()) {
if (aContainer.isFocusCycleRoot()) {
this.cachedRoot = aContainer;
this.cachedCycle = cycle;
Component retval = getFirstComponent(aContainer);
this.cachedRoot = null;
this.cachedCycle = null;
return retval;
} else {
return null;
}
} else {
Component comp = (Component)cycle.get(index);
if (accept(comp)) {
return comp;
} else if (comp instanceof Container && ((Container)comp).isFocusTraversalPolicyProvider()) {
return ((Container)comp).getFocusTraversalPolicy().getDefaultComponent((Container)comp);
}
}
} while (true);
| | 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.
By default, SortingFocusTraversalPolicy implicitly transfers focus down-
cycle. That is, during normal 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 (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");
}
// See if the component is inside of policy provider
Container ftp = getTopmostProvider(aContainer, aComponent);
if (ftp != null) {
if (log.isLoggable(Level.FINE)) log.fine("### Asking FTP " + ftp.getName() + " for component after " + aComponent.getName());
// FTP knows how to find component after the given. We don't.
FocusTraversalPolicy policy = ftp.getFocusTraversalPolicy();
Component retval = policy.getComponentBefore(ftp, aComponent);
if (retval == policy.getLastComponent(ftp)) {
retval = null;
}
if (retval != null) {
if (log.isLoggable(Level.FINE)) log.fine("### FTP returned " + retval.getName());
return retval;
}
aComponent = ftp;
}
List cycle = new ArrayList();
Map defaults = new HashMap();
enumerateAndSortCycle(aContainer, cycle, defaults);
if (log.isLoggable(Level.FINE)) log.fine("### Cycle is " + cycle + ", component is " + aComponent);
int index;
try {
index = Collections.binarySearch(cycle, aComponent, comparator);
} catch (ClassCastException e) {
return getLastComponent(aContainer);
}
if (index < 0) {
// If we're not in the cycle, then binarySearch returns
// (-(insertion point) - 1). The previous element is our insertion
// point - 1.
index = -index - 2;
} else {
index--;
}
if (log.isLoggable(Level.FINE)) log.fine("### Index is " + index);
if (index >= 0) {
Component defComp = (Component)defaults.get(new Integer(index));
if (defComp != null && cycle.get(index) != aContainer) {
if (log.isLoggable(Level.FINE)) log.fine("### Returning default " + defComp.getName() + " at " + index);
return defComp;
}
}
do {
if (index < 0) {
this.cachedRoot = aContainer;
this.cachedCycle = cycle;
Component retval = getLastComponent(aContainer);
this.cachedRoot = null;
this.cachedCycle = null;
return retval;
} else {
Component comp = (Component)cycle.get(index);
if (accept(comp)) {
return comp;
} else if (comp instanceof Container && ((Container)comp).isFocusTraversalPolicyProvider()) {
return ((Container)comp).getFocusTraversalPolicy().getLastComponent((Container)comp);
}
}
index--;
} while (true);
| | 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.
List cycle;
if (log.isLoggable(Level.FINE)) log.fine("### Getting first component in " + aContainer.getName());
if (aContainer == null) {
throw new IllegalArgumentException("aContainer cannot be null");
}
if (this.cachedRoot == aContainer) {
cycle = this.cachedCycle;
} else {
cycle = new ArrayList();
enumerateAndSortCycle(aContainer, cycle, null);
}
int size = cycle.size();
if (size == 0) {
return null;
}
for (int i= 0; i < cycle.size(); i++) {
Component comp = (Component)cycle.get(i);
if (accept(comp)) {
return comp;
} else if (comp instanceof Container && !(comp == aContainer) && ((Container)comp).isFocusTraversalPolicyProvider()) {
return ((Container)comp).getFocusTraversalPolicy().getDefaultComponent((Container)comp);
}
}
return null;
| | public boolean | getImplicitDownCycleTraversal()Returns whether this SortingFocusTraversalPolicy transfers focus down-
cycle implicitly. If true, during normal 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.
List cycle;
if (log.isLoggable(Level.FINE)) log.fine("### Getting last component in " + aContainer.getName());
if (aContainer == null) {
throw new IllegalArgumentException("aContainer cannot be null");
}
if (this.cachedRoot == aContainer) {
cycle = this.cachedCycle;
} else {
cycle = new ArrayList();
enumerateAndSortCycle(aContainer, cycle, null);
}
int size = cycle.size();
if (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 = (Component)cycle.get(i);
if (accept(comp)) {
return comp;
} else if (comp instanceof Container && !(comp == aContainer) && ((Container)comp).isFocusTraversalPolicyProvider()) {
return ((Container)comp).getFocusTraversalPolicy().getLastComponent((Container)comp);
}
}
return null;
| | java.awt.Container | getTopmostProvider(java.awt.Container focusCycleRoot, java.awt.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;
| | protected void | setComparator(java.util.Comparator comparator)Sets the Comparator which will be used to sort the Components in a
focus traversal cycle.
this.comparator = comparator;
| | public void | setImplicitDownCycleTraversal(boolean implicitDownCycleTraversal)Sets whether this SortingFocusTraversalPolicy transfers focus down-cycle
implicitly. If true, during normal 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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