File	Doc	Category	Size	Date	Package
LayoutFocusTraversalPolicy.java	API Doc	Java SE 5 API	10791	Fri Aug 26 14:57:58 BST 2005	javax.swing

LayoutFocusTraversalPolicy

• java.lang.Object
  • java.awt.FocusTraversalPolicy
    • javax.swing.InternalFrameFocusTraversalPolicy
      • javax.swing.SortingFocusTraversalPolicy

Fields Summary
private static final SwingDefaultFocusTraversalPolicy	fitnessTestPolicy

Constructors Summary
public LayoutFocusTraversalPolicy() Constructs a LayoutFocusTraversalPolicy. super(new LayoutComparator());
LayoutFocusTraversalPolicy(Comparator c) Constructs a LayoutFocusTraversalPolicy with the passed in Comparator. super(c);

Methods Summary
protected boolean	accept(java.awt.Component aComponent) Determines whether the specified Component is an acceptable choice as the new focus owner. This method performs the following sequence of operations: Checks whether aComponent is visible, displayable, enabled, and focusable. If any of these properties is false, this method returns false. If aComponent is an instance of JTable, returns true. If aComponent is an instance of JComboBox, then returns the value of aComponent.getUI().isFocusTraversable(aComponent). If aComponent is a JComponent with a JComponent.WHEN_FOCUSED InputMap that is neither null nor empty, returns true. Returns the value of DefaultFocusTraversalPolicy.accept(aComponent). param aComponent the Component whose fitness as a focus owner is to be tested see java.awt.Component#isVisible see java.awt.Component#isDisplayable see java.awt.Component#isEnabled see java.awt.Component#isFocusable see javax.swing.plaf.ComboBoxUI#isFocusTraversable see javax.swing.JComponent#getInputMap see java.awt.DefaultFocusTraversalPolicy#accept return true if aComponent is a valid choice for a focus owner; otherwise false if (!super.accept(aComponent)) { return false; } else if (aComponent instanceof JTable) { // JTable only has ancestor focus bindings, we thus force it // to be focusable by returning true here. return true; } else if (aComponent instanceof JComboBox) { JComboBox box = (JComboBox)aComponent; return box.getUI().isFocusTraversable(box); } else if (aComponent instanceof JComponent) { JComponent jComponent = (JComponent)aComponent; InputMap inputMap = jComponent.getInputMap(JComponent.WHEN_FOCUSED, false); while (inputMap != null && inputMap.size() == 0) { inputMap = inputMap.getParent(); } if (inputMap != null) { return true; } // Delegate to the fitnessTestPolicy, this will test for the // case where the developer has overriden isFocusTraversable to // return true. } return fitnessTestPolicy.accept(aComponent);
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. By default, LayoutFocusTraversalPolicy 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. 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 if (aContainer == null || aComponent == null) { throw new IllegalArgumentException("aContainer and aComponent cannot be null"); } Comparator comparator = getComparator(); if (comparator instanceof LayoutComparator) { ((LayoutComparator)comparator). setComponentOrientation(aContainer. getComponentOrientation()); } return super.getComponentAfter(aContainer, aComponent);
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. By default, LayoutFocusTraversalPolicy 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. 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 if (aContainer == null || aComponent == null) { throw new IllegalArgumentException("aContainer and aComponent cannot be null"); } Comparator comparator = getComparator(); if (comparator instanceof LayoutComparator) { ((LayoutComparator)comparator). setComponentOrientation(aContainer. getComponentOrientation()); } return super.getComponentBefore(aContainer, aComponent);
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. 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 if (aContainer == null) { throw new IllegalArgumentException("aContainer cannot be null"); } Comparator comparator = getComparator(); if (comparator instanceof LayoutComparator) { ((LayoutComparator)comparator). setComponentOrientation(aContainer. getComponentOrientation()); } return super.getFirstComponent(aContainer);
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. 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 if (aContainer == null) { throw new IllegalArgumentException("aContainer cannot be null"); } Comparator comparator = getComparator(); if (comparator instanceof LayoutComparator) { ((LayoutComparator)comparator). setComponentOrientation(aContainer. getComponentOrientation()); } return super.getLastComponent(aContainer);
private void	readObject(java.io.ObjectInputStream in) setComparator((Comparator)in.readObject()); setImplicitDownCycleTraversal(in.readBoolean());
private void	writeObject(java.io.ObjectOutputStream out) out.writeObject(getComparator()); out.writeBoolean(getImplicitDownCycleTraversal());