/*
* @(#)SortingFocusTraversalPolicy.java 1.7 04/05/05
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.swing;
import java.awt.Component;
import java.awt.Container;
import java.awt.Window;
import java.util.*;
import java.awt.FocusTraversalPolicy;
import java.util.logging.*;
/**
* 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.
* <p>
* 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
* <code>setImplicitDownCycleTraversal</code> method.
* <p>
* 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 <code>accept</code> method.
* <p>
* This policy takes into account <a
* href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus traversal
* policy providers</a>. 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.
*
* @author David Mendenhall
* @version 1.7, 05/05/04
*
* @see java.util.Comparator
* @since 1.4
*/
public class SortingFocusTraversalPolicy
extends InternalFrameFocusTraversalPolicy
{
private Comparator<? super Component> comparator;
private boolean implicitDownCycleTraversal = true;
private Logger log = Logger.getLogger("javax.swing.SortingFocusTraversalPolicy");
/**
* Used 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 Container cachedRoot;
private List cachedCycle;
// Delegate our fitness test to ContainerOrder so that we only have to
// code the algorithm once.
private static final SwingContainerOrderFocusTraversalPolicy
fitnessTestPolicy = new SwingContainerOrderFocusTraversalPolicy();
/**
* Constructs a SortingFocusTraversalPolicy without a Comparator.
* Subclasses must set the Comparator using <code>setComparator</code>
* before installing this FocusTraversalPolicy on a focus cycle root or
* KeyboardFocusManager.
*/
protected SortingFocusTraversalPolicy() {
}
/**
* Constructs a SortingFocusTraversalPolicy with the specified Comparator.
*/
public SortingFocusTraversalPolicy(Comparator<? super Component> comparator) {
this.comparator = comparator;
}
private void enumerateAndSortCycle(Container focusCycleRoot,
List cycle, 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(Container container, 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);
}
}
}
Container getTopmostProvider(Container focusCycleRoot, 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;
}
/**
* 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.
* <p>
* 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
* <code>setImplicitDownCycleTraversal</code> method.
* <p>
* If aContainer is <a href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus
* traversal policy provider</a>, the focus is always transferred down-cycle.
*
* @param aContainer a focus cycle root of aComponent or a focus traversal policy provider
* @param aComponent a (possibly indirect) child of aContainer, or
* aContainer itself
* @return the Component that should receive the focus after aComponent, or
* null if no suitable Component can be found
* @throws IllegalArgumentException if aContainer is not a focus cycle
* root of aComponent or a focus traversal policy provider, or if either aContainer or
* aComponent is null
*/
public Component getComponentAfter(Container aContainer,
Component aComponent) {
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);
}
/**
* 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.
* <p>
* 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
* <code>setImplicitDownCycleTraversal</code> method.
* <p>
* If aContainer is <a href="doc-files/FocusSpec.html#FocusTraversalPolicyProviders">focus
* traversal policy provider</a>, the focus is always transferred down-cycle.
*
* @param aContainer a focus cycle root of aComponent or a focus traversal policy provider
* @param aComponent a (possibly indirect) child of aContainer, or
* aContainer itself
* @return the Component that should receive the focus before aComponent,
* or null if no suitable Component can be found
* @throws IllegalArgumentException if aContainer is not a focus cycle
* root of aComponent or a focus traversal policy provider, or if either aContainer or
* aComponent is null
*/
public Component getComponentBefore(Container aContainer,
Component 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");
}
// 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);
}
/**
* 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.
*
* @param aContainer a focus cycle root of aComponent or a focus traversal policy provider whose
* first Component is to be returned
* @return the first Component in the traversal cycle of aContainer,
* or null if no suitable Component can be found
* @throws IllegalArgumentException if aContainer is null
*/
public Component getFirstComponent(Container aContainer) {
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;
}
/**
* 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.
*
* @param aContainer a focus cycle root of aComponent or a focus traversal policy provider whose
* last Component is to be returned
* @return the last Component in the traversal cycle of aContainer,
* or null if no suitable Component can be found
* @throws IllegalArgumentException if aContainer is null
*/
public Component getLastComponent(Container aContainer) {
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;
}
/**
* 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 <code>getFirstComponent</code>.
*
* @param aContainer a focus cycle root of aComponent or a focus traversal policy provider whose
* default Component is to be returned
* @return the default Component in the traversal cycle of aContainer,
* or null if no suitable Component can be found
* @see #getFirstComponent
* @throws IllegalArgumentException if aContainer is null
*/
public Component getDefaultComponent(Container aContainer) {
return getFirstComponent(aContainer);
}
/**
* Sets whether this SortingFocusTraversalPolicy transfers focus down-cycle
* implicitly. If <code>true</code>, during normal focus traversal,
* the Component traversed after a focus cycle root will be the focus-
* cycle-root's default Component to focus. If <code>false</code>, 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 <code>true</code>.
*
* @param implicitDownCycleTraversal whether this
* SortingFocusTraversalPolicy transfers focus down-cycle implicitly
* @see #getImplicitDownCycleTraversal
* @see #getFirstComponent
*/
public void setImplicitDownCycleTraversal(boolean
implicitDownCycleTraversal) {
this.implicitDownCycleTraversal = implicitDownCycleTraversal;
}
/**
* Returns whether this SortingFocusTraversalPolicy transfers focus down-
* cycle implicitly. If <code>true</code>, during normal focus
* traversal, the Component traversed after a focus cycle root will be the
* focus-cycle-root's default Component to focus. If <code>false</code>,
* the next Component in the focus traversal cycle rooted at the specified
* focus cycle root will be traversed instead.
*
* @return whether this SortingFocusTraversalPolicy transfers focus down-
* cycle implicitly
* @see #setImplicitDownCycleTraversal
* @see #getFirstComponent
*/
public boolean getImplicitDownCycleTraversal() {
return implicitDownCycleTraversal;
}
/**
* Sets the Comparator which will be used to sort the Components in a
* focus traversal cycle.
*
* @param comparator the Comparator which will be used for sorting
*/
protected void setComparator(Comparator<? super Component> comparator) {
this.comparator = comparator;
}
/**
* Returns the Comparator which will be used to sort the Components in a
* focus traversal cycle.
*
* @return the Comparator which will be used for sorting
*/
protected Comparator<? super Component> getComparator() {
return comparator;
}
/**
* 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.
*
* @param aComponent the Component whose fitness as a focus owner is to
* be tested
* @return <code>true</code> if aComponent is visible, displayable,
* enabled, and focusable; <code>false</code> otherwise
*/
protected boolean accept(Component aComponent) {
return fitnessTestPolicy.accept(aComponent);
}
}
// Create our own subclass and change accept to public so that we can call
// accept.
class SwingContainerOrderFocusTraversalPolicy
extends java.awt.ContainerOrderFocusTraversalPolicy
{
public boolean accept(Component aComponent) {
return super.accept(aComponent);
}
}
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