Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
// The MIT License (MIT)

import java.awt.Component;
import java.awt.Container;
import java.util.Optional;

import java.util.function.Predicate;

import javax.swing.JPopupMenu;

public class Main {
    /**
     * Find an ancestor of a component.
     * @param component the starting component
     * @param type the required type of the ancestor
     * @return the first ancestor of the specified type
     */
    public static <T> T findAncestor(Component component, Class<T> type) {
        return findAncestor(component, type, null);
    }

    /**
     * Find an ancestor of a component.
     * @param component the starting component
     * @param type the required type of the ancestor
     * @param defaultValue the value to use of no ancestor is found
     * @return the first ancestor of the specified type or {@code defaultValue}
     */
    public static <T> T findAncestor(Component component, Class<T> type, T defaultValue) {
        return findAncestor(component, type::isInstance).map(type::cast).orElse(defaultValue);
    }

    /**
     * Find an ancestor of a component that matches a condition.
     * @param component the starting component
     * @param condition the condition to match
     * @return the first ancestor for which {@code condition} is true
     */
    public static Optional<Component> findAncestor(Component component, Predicate<Component> condition) {
        while (component != null && !condition.test(component)) {
            component = getParent(component);
        }
        return Optional.ofNullable(component);
    }

    /**
     * Return the parent of a component. If the component is a popup menu and its parent is null then return its invoker.
     */
    public static Component getParent(Component component) {
        Container parent = component.getParent();
        if (parent == null && component instanceof JPopupMenu) {
            return ((JPopupMenu) component).getInvoker();
        }
        return parent;
    }
}