public class JComponentHierarchyNavigator extends Object implements TreeNavigator<JComponent>
TreeNavigator for a Swing component hierarchy.
Note that getParent will return an (optional) JComponent. This is not possible
if the parent is not of a subtype (e.g. a JFrame) in which case an empty Optional
is returned. Similarly, children of JComponents might not be JComponents themselves. For this reason
getChild will return an empty Optional for a child which is no
JComponent. If this is undesired, consider using a ComponentHierarchyNavigator instead.
This implementation is thread-safe in the sense that individual method calls will not fail if the component hierarchy is changed concurrently. But it can not prevent return values from getting stale so chaining calls might lead to unexpected results, e.g.:
JComponent component = ...
if (getParent(component).isPresent()) {
// the component has a parent, so it should have a child index, too;
// but the component hierarchy may have changed, so 'indexPresent' may be false
boolean indexPresent = getChildIndex(component).isPresent();
}
Similarly:
JComponent parent = ... Optional<JComponent> child1 = getChild(parent, 0); Optional<JComponent> child2 = getChild(parent, 0); // if the component hierarchy changed between the two calls, this may be false boolean sameChildren = child1.equals(child2);
| Constructor and Description |
|---|
JComponentHierarchyNavigator() |
| Modifier and Type | Method and Description |
|---|---|
Optional<JComponent> |
getChild(JComponent parent,
int childIndex) |
OptionalInt |
getChildIndex(JComponent node) |
int |
getChildrenCount(JComponent parent) |
Optional<JComponent> |
getParent(JComponent child) |
public Optional<JComponent> getParent(JComponent child)
getParent in interface TreeNavigator<JComponent>child - an node in the treeempty is
returnedpublic OptionalInt getChildIndex(JComponent node)
getChildIndex in interface TreeNavigator<JComponent>node - a node in the treeempty is returnedpublic int getChildrenCount(JComponent parent)
getChildrenCount in interface TreeNavigator<JComponent>parent - a node in the treepublic Optional<JComponent> getChild(JComponent parent, int childIndex)
getChild in interface TreeNavigator<JComponent>parent - a node in the treechildIndex - a non-negative number specifying the index of the requested childempty is returnedThis documentation is licensed under CC-BY 4.0, attributed to Nicolai Parlog from CodeFX.