如果您查看模型并进行一般思考，所有类都具有一定程度的相似性，您可以将其分解为超类：
package model;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
public abstract class GameObject<T extends GameObject<?>> {
public GameObject(String name) {
setName(name);
}
private final StringProperty name = new SimpleStringProperty();
public final StringProperty nameProperty() {
return this.name;
}
public final String getName() {
return this.nameProperty().get();
}
public final void setName(final String name) {
this.nameProperty().set(name);
}
private final ObservableList<T> items = FXCollections.observableArrayList();
public ObservableList<T> getItems() {
return items ;
}
public abstract void createAndAddChild(String name);
}
类型参数T这里代表“子”对象的类型。所以你的Account类（其子类型是GameCharacter- 不要将类命名为与中的任何名称相同java.lang，顺便说一句...）看起来像
package model;
public class Account extends GameObject<GameCharacter> {
public Account(String name) {
super(name);
}
@Override
public void createAndAddChild(String name) {
getItems().add(new GameCharacter(name));
}
}
类似地，一直到层次结构。我会定义一个Information类（即使它只有一个名称）以使所有内容都符合结构，因此：
package model;
public class Item extends GameObject<Information> {
public Item(String name) {
super(name);
}
@Override
public void createAndAddChild(String name) {
getItems().add(new Information(name));
}
}
并且，自从Information没有孩子，它的孩子列表只是一个空列表：
package model;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
public class Information extends GameObject<GameObject<?>> {
public Information(String name) {
super(name);
}
@Override
public ObservableList<GameObject<?>> getItems() {
return FXCollections.emptyObservableList();
}
@Override
public void createAndAddChild(String name) {
throw new IllegalStateException("Information has no child items");
}
}
现在你的树中的每个项目都是GameObject<?>，所以你基本上可以构建一个TreeView<GameObject<?>>。棘手的部分是您的树项需要反映模型中已构建的结构。由于那里有可观察的列表，因此您可以使用列表上的侦听器来执行此操作。
您可以使用树上的单元工厂来自定义显示单元格的外观TreeItems。如果您希望每种类型的项目具有不同的外观，我建议在外部 CSS 类中定义样式，并设置CSS PseudoClass在与项目类型相对应的单元格上。如果您使用某种命名约定（我认为伪类名称是类名称的小写版本），则可以非常灵活地做到这一点。这是一个相当简单的例子：
package ui;
import static java.util.stream.Collectors.toList;
import java.util.Arrays;
import java.util.List;
import javafx.collections.ListChangeListener.Change;
import javafx.collections.ObservableList;
import javafx.css.PseudoClass;
import javafx.scene.control.TreeCell;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import model.Account;
import model.GameCharacter;
import model.GameObject;
import model.Information;
import model.Item;
public class Tree {
private final TreeView<GameObject<?>> treeView ;
private final List<Class<? extends GameObject<?>>> itemTypes = Arrays.asList(
Account.class, GameCharacter.class, Item.class, Information.class
);
public Tree(ObservableList<Account> accounts) {
treeView = new TreeView<>();
GameObject<?> root = new GameObject<Account>("") {
@Override
public ObservableList<Account> getItems() {
return accounts ;
}
@Override
public void createAndAddChild(String name) {
getItems().add(new Account(name));
}
};
TreeItem<GameObject<?>> treeRoot = createItem(root);
treeView.setRoot(treeRoot);
treeView.setShowRoot(false);
treeView.setCellFactory(tv -> {
TreeCell<GameObject<?>> cell = new TreeCell<GameObject<?>>() {
@Override
protected void updateItem(GameObject<?> item, boolean empty) {
super.updateItem(item, empty);
textProperty().unbind();
if (empty) {
setText(null);
itemTypes.stream().map(Tree.this::asPseudoClass)
.forEach(pc -> pseudoClassStateChanged(pc, false));
} else {
textProperty().bind(item.nameProperty());
PseudoClass itemPC = asPseudoClass(item.getClass());
itemTypes.stream().map(Tree.this::asPseudoClass)
.forEach(pc -> pseudoClassStateChanged(pc, itemPC.equals(pc)));
}
}
};
cell.hoverProperty().addListener((obs, wasHovered, isNowHovered) -> {
if (isNowHovered && (! cell.isEmpty())) {
System.out.println("Mouse hover on "+cell.getItem().getName());
}
});
return cell ;
}
}
public TreeView<GameObject<?>> getTreeView() {
return treeView ;
}
private TreeItem<GameObject<?>> createItem(GameObject<?> object) {
// create tree item with children from game object's list:
TreeItem<GameObject<?>> item = new TreeItem<>(object);
item.setExpanded(true);
item.getChildren().addAll(object.getItems().stream().map(this::createItem).collect(toList()));
// update tree item's children list if game object's list changes:
object.getItems().addListener((Change<? extends GameObject<?>> c) -> {
while (c.next()) {
if (c.wasAdded()) {
item.getChildren().addAll(c.getAddedSubList().stream().map(this::createItem).collect(toList()));
}
if (c.wasRemoved()) {
item.getChildren().removeIf(treeItem -> c.getRemoved().contains(treeItem.getValue()));
}
}
});
return item ;
}
private PseudoClass asPseudoClass(Class<?> clz) {
return PseudoClass.getPseudoClass(clz.getSimpleName().toLowerCase());
}
}
快速测试，可行，但请注意您可能需要测试更多功能：
package application;
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
import model.Account;
import model.GameCharacter;
import model.GameObject;
import model.Information;
import model.Item;
import ui.Tree;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception {
Tree tree = new Tree(createAccounts());
TreeView<GameObject<?>> treeView = tree.getTreeView();
TextField addField = new TextField();
Button addButton = new Button("Add");
EventHandler<ActionEvent> addHandler = e -> {
TreeItem<GameObject<?>> selected = treeView
.getSelectionModel()
.getSelectedItem();
if (selected != null) {
selected.getValue().createAndAddChild(addField.getText());
addField.clear();
}
};
addField.setOnAction(addHandler);
addButton.setOnAction(addHandler);
addButton.disableProperty().bind(Bindings.createBooleanBinding(() -> {
TreeItem<GameObject<?>> selected = treeView.getSelectionModel().getSelectedItem() ;
return selected == null || selected.getValue() instanceof Information ;
}, treeView.getSelectionModel().selectedItemProperty()));
Button deleteButton = new Button("Delete");
deleteButton.setOnAction(e -> {
TreeItem<GameObject<?>> selected = treeView.getSelectionModel().getSelectedItem() ;
TreeItem<GameObject<?>> parent = selected.getParent() ;
parent.getValue().getItems().remove(selected.getValue());
});
deleteButton.disableProperty().bind(treeView.getSelectionModel().selectedItemProperty().isNull());
HBox controls = new HBox(5, addField, addButton, deleteButton);
controls.setPadding(new Insets(5));
controls.setAlignment(Pos.CENTER);
BorderPane root = new BorderPane(treeView);
root.setBottom(controls);
Scene scene = new Scene(root, 600, 600);
scene.getStylesheets().add(getClass().getResource("/ui/style/style.css").toExternalForm());
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
private ObservableList<Account> createAccounts() {
Account jake = new Account("Jake");
Account mark = new Account("Mark");
Account freshAcc = new Account("Fresh Account");
Account marksAltAcc = new Account("Mark's alternative account");
Account jeffrey = new Account("Jeffrey");
GameCharacter jakesChar = new GameCharacter("Jakes character");
Item amazingSword = new Item("Amazing Sword");
Item brokenBow = new Item("Broken Bow");
Item junkMetal = new Item("Junk Metal");
GameCharacter myChar = new GameCharacter("Me");
Item godlyAxe = new Item("Godly Axe");
GameCharacter level = new GameCharacter("I'll level this I promise");
GameCharacter jeff = new GameCharacter("Jeff");
Item superGun = new Item("Super Gun");
Item superGunScope = new Item("Super Gun Scope");
jake.getItems().add(jakesChar);
mark.getItems().add(myChar);
marksAltAcc.getItems().add(level);
jeffrey.getItems().add(jeff);
jakesChar.getItems().addAll(amazingSword, brokenBow, junkMetal);
myChar.getItems().add(godlyAxe);
jeff.getItems().addAll(superGun, superGunScope);
return FXCollections.observableArrayList(jake, mark, freshAcc, marksAltAcc, jeffrey);
}
}
以 CSS 为例：
.tree-cell, .tree-cell:hover:empty {
-fx-background-color: -fx-background ;
-fx-background: -fx-control-inner-background ;
}
.tree-cell:hover {
-fx-background-color: crimson, -fx-background ;
-fx-background-insets: 0, 1;
}
.tree-cell:account {
-fx-background: lightsalmon ;
}
.tree-cell:gamecharacter {
-fx-background: bisque ;
}
.tree-cell:item {
-fx-background: antiquewhite ;
}
.tree-cell:selected {
-fx-background: crimson ;
}
