/**
* Requests focus for a component. If that's not possible it's {@link FocusTraversalPolicy}is
* checked. If that doesn't work all it's children is recursively checked with this method.
*
* @param component the component to request focus for
* @return the component which has focus or probably will obtain focus, null if no component will
* receive focus
*/
public static Component smartRequestFocus(Component component) {
Component componentTemp = component;
if (requestFocus(componentTemp)) return componentTemp;
if (componentTemp instanceof JComponent) {
FocusTraversalPolicy policy = ((JComponent) componentTemp).getFocusTraversalPolicy();
if (policy != null) {
Component focusComponent = policy.getDefaultComponent((Container) componentTemp);
if (focusComponent != null && requestFocus(focusComponent)) {
return focusComponent;
}
}
}
if (componentTemp instanceof Container) {
Component[] children = ((Container) componentTemp).getComponents();
for (int i = 0; i < children.length; i++) {
componentTemp = smartRequestFocus(children[i]);
if (componentTemp != null) return componentTemp;
}
}
return null;
}
public Component getDefaultComponent(Container focusCycleRoot) {
if (delegatePolicy != null) {
return delegatePolicy.getDefaultComponent(focusCycleRoot);
} else {
return getFirstComponent(focusCycleRoot);
}
}
public Component findNextFocus() {
// Find focus owner
Component c = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
Container root = c == null ? null : c.getFocusCycleRootAncestor();
if (root != null) {
FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
Component nextFocus = policy.getComponentAfter(root, c);
if (nextFocus == null) {
nextFocus = policy.getDefaultComponent(root);
}
return nextFocus;
}
return null;
}
/**
* Traverse to the next forward or backward component using the container's FocusTraversalPolicy.
*
* @param comp the assumed current focuse component
* @param forward if true, returns the next focus component, otherwise the previous one.
* @return
*/
public static Component getNextFocus(Component comp, boolean forward) {
Container focusContainer = comp.getFocusCycleRootAncestor();
while (focusContainer != null
&& (!focusContainer.isShowing()
|| !focusContainer.isFocusable()
|| !focusContainer.isEnabled())) {
comp = focusContainer;
focusContainer = comp.getFocusCycleRootAncestor();
}
Component next = null;
if (focusContainer != null) {
final FocusTraversalPolicy policy = focusContainer.getFocusTraversalPolicy();
next =
forward
? policy.getComponentAfter(focusContainer, comp)
: policy.getComponentBefore(focusContainer, comp);
if (next == null) {
next = policy.getDefaultComponent(focusContainer);
}
}
return next;
}
public Component getDefaultComponent(Container root) {
return defaultPolicy.getDefaultComponent(root);
}