如何在 NetBeans 插件中创建动态菜单？

Question

我正在开发一个需要使用“动态”菜单的 NetBeans 插件，因为目前必须在一个专用于某个菜单项及其操作的类中进行硬编码。但是我希望允许用户通过插件提供的 UI 能够更改菜单项的值（它们的作用 - 这将在 main 方法中处理变量，我不允许用户编写主要方法本身的代码 - 它们被称为什么以及它们相关的键盘快捷键）以及添加和删除菜单项。我的插件可能会从文件中读取这些首选项，理想情况下只有一个类可以创建所有这些动态菜单项，其值在首选项文件中定义。

我知道有一种方法可以做到这一点，但我能找到的唯一真实信息是 this thread 和 the bugzilla page 它链接到的目前似乎已关闭，所以这对我没有帮助... 那么，究竟如何才能使用动态菜单项制作动态菜单呢？

我有 NetBeans 8.1 版和 JDK8。此外，当我说“动态菜单项”或类似内容时，我指的是从菜单中提供给您的实际选项（无论插件在那里做什么，在我的情况下，它会在何时将某些数据复制到剪贴板单击这些选项之一）。

Answer 1

我在我的 netbeans RCP 应用程序中使用动态菜单。以下是我用于将动态菜单项添加到右键菜单、工具栏、菜单栏的一般格式...

import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JComponent;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JSeparator;
import org.openide.awt.ActionID;
import org.openide.awt.ActionReference;
import org.openide.awt.ActionReferences;
import org.openide.awt.ActionRegistration;
import org.openide.awt.Actions;
import org.openide.awt.DynamicMenuContent;
import org.openide.util.actions.Presenter;

/* Register your dynamic action using annotations (perferred over layer.xml entries)
@ActionID(id = "ExampleDynamicMenu", category = "Edit")
@ActionRegistration(lazy = false, displayName = "ExampleDynamicMenu")
@ActionReferences({
    @ActionReference(path = "Loaders/folder/any/Actions", position = 666),
    @ActionReference(path = "Loaders/content/unknown/Actions", position = 666),
    @ActionReference(path = "Loaders/text/xml/Actions", position = 666),
    @ActionReference(path = "Projects/Actions", position = 666),
    @ActionReference(path = "Editors/TabActions", position = 666)
})
*/
public class ExampleDynamicMenu extends AbstractAction implements DynamicMenuContent, Presenter.Popup {

    @Override
    public JMenuItem getPopupPresenter() {
        JMenu menu = new JMenu(this);
        JComponent[] menuItems = createMenu();
        for (JComponent item : menuItems) {
            menu.add(item);
        }
        return menu;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        // does nothing, this is a popup menu
    }

    @Override
    public JComponent[] getMenuPresenters() {
        return createMenu();
    }

    @Override
    public JComponent[] synchMenuPresenters(JComponent[] items) {
        return createMenu();
    }

    private JComponent[] createMenu() {
        List<JComponent> items = new ArrayList<>(20);

        //TODO: Load the list of actions stored in the preferences, and for each action add a menu-item to the dynamic menu.
        // Note: You preferences can simply store the Action's category and id; then you can always get the action instances using
        //    Action action = Actions.forID(category_string, id_string);
        List<Action> actionsList = YOUR_PREFERENCES_GETTER.getActions(); //You have to figure out how to store and retrieve user's preferred actions list yourself :)
        for (Action action : actionsList) {
            if (action == null) { //Assume null means add a separator
                if (items.size() > 0 && !(items.get(items.size() - 1) instanceof JSeparator)) { //Only add separators after actions.
                    items.add(new JPopupMenu.Separator());
                }
            } else { //Convert action to menu item, and build your dynamic menu
                items.add(toMenuItem(action));
            }
        }
        return items.toArray(new JComponent[items.size()]);
    }

    /**
     * Creates a menu item from an action.
     *
     * @param action an action
     * @return JMenuItem
     */
    private static JMenuItem toMenuItem(Action action) {
        JMenuItem item;
        if (action instanceof Presenter.Menu) {
            item = ((Presenter.Menu) action).getMenuPresenter();
        } else if (action instanceof Presenter.Popup) {
            item = ((Presenter.Popup) action).getPopupPresenter();
        } else {
            item = new JMenuItem();
            Actions.connect(item, action, false);
        }
        return item;
    }
}