Javafx 学习笔记

javaFX应用程序的主类继承了javafx.application.Application,start()方法是所有javaFX 应用程序的主入口点.

JavaFX application 通过各种stage 和scene 定义了用户接口容器,JavaFxStage 类是最顶层的JavaFx容器,javaFx scene类是所有内容的容器.

public classWebViewSample extends Application {
 
   privateScenescene;
 
   @Override
   public void start(Stage stage) {
    
       //为用户界面设置标题
        stage.setTitle("Web View");
        //新建场景,设置场景节点,宽,高,颜色
        scene = new Scene(new Browser(), 750, 500, Color.web("#666970"));
        stage.setScene(scene);//将场景加入到stage
      
 //为场景添加css样式scene.getStylesheets().add("webviewsample/BrowserToolbar.css");
       //显示用户界面
        stage.show();
   }
 
   public static void main(String[] args) {
        //程序运行时,启动javaFx应用程序
	launch(args);
   }
}
class Browserextends Region {
    //新建水平盒子(Hbox)布局toolbar
	private HBox toolBar;
 
   private static String[] imageFiles= newString[]{
        "product.png",
        "blog.png",
        "documentation.png",
        "partners.png",
        "help.png"
   };
   private static String[] captions= newString[]{
        "Products",
        "Blogs",
        "Documentation",
        "Partners",
        "Help"
   };
   private static String[] urls= newString[]{
        "http://www.oracle.com/products/index.html",
        "http://blogs.oracle.com/",
        "http://docs.oracle.com/javase/index.html",
        "http://www.oracle.com/partners/index.html",
        WebViewSample.class.getResource("help.html").toExternalForm()
   };
	final ImageView selectedImage = new ImageView();
	//新建超链接数组
	final Hyperlink[] hpls = new Hyperlink[captions.length];
	//新建图片数组
	final Image[] images = new Image[imageFiles.length];
	//新建内嵌浏览器
  	 final WebView browser= new WebView();
	final WebEnginewebEngine = browser.getEngine();
	//新建showPrevDoc按钮
   	finalButtonshowPrevDoc= new Button("Toggle Previous Docs");
	final WebViewsmallView = new WebView();
	//新建下拉框
  	 final ComboBox comboBox= new ComboBox();
  	 private boolean needDocumentationButton =false;
 
   publicBrowser() {
        //apply the styles
        getStyleClass().add("browser");
 
        for (int i = 0; i () {
                @Override
                publicvoid handle(ActionEvent e) {
                    needDocumentationButton = addButton;
                    webEngine.load(url);
                }
            });
        }
 
        comboBox.setPrefWidth(60);
 
        // 新建水平盒子布局
        toolBar = new HBox();
       //设置对齐方式
       toolBar.setAlignment(Pos.CENTER);
       //添加css样式
        toolBar.getStyleClass().add("browser-toolbar");
       //添加下拉框到toolbar布局中
        toolBar.getChildren().add(comboBox);
       //添加超链接数组到布局中
        toolBar.getChildren().addAll(hpls);
       //设置控件之间的间隙
        toolBar.getChildren().add(createSpacer());
 
       //设置按钮的点击事件,按钮点击时,展开有下拉项的列表
        showPrevDoc.setOnAction(new EventHandler() {
            @Override
            public void handle(Event t) {
                  //为当前浏览器加载的文档,执行Javascript语句
                webEngine.executeScript("toggleDisplay('PrevRel')");
            }          
        });
       //设置webview的宽高
        smallView.setPrefSize(120, 80);
 
        //处理弹出窗口,有新窗口弹出时,设置新建的smallView的字体大小,将smallView加入到水平盒子布局中,在smallView中打开新窗口
        webEngine.setCreatePopupHandler(
            new Callback() {
                @Override public WebEngine call(PopupFeatures config) {
                    smallView.setFontScale(0.8);
                    if (!toolBar.getChildren().contains(smallView)) {
                        toolBar.getChildren().add(smallView);
                    }
                    returnsmallView.getEngine();
                }
             }
        );
 
        //处理历史记录,监听历史记录,当记录被删除,移除下拉框comoBox中url对应的选项,当增加记录时,向下拉框中添加URL选项
        final WebHistory history =webEngine.getHistory();
        history.getEntries().addListener(new
           ListChangeListener(){
                @Override
                public void onChanged(Change c) {
                    c.next();
                    for (Entry e : c.getRemoved()) {
                        comboBox.getItems().remove(e.getUrl());
                    }
                    for (Entry e : c.getAddedSubList()) {
                        comboBox.getItems().add(e.getUrl());
                    }
                }
        });
 
        //下拉框中的选中值改变时,相应改变browser中加载的url              
        comboBox.setOnAction(newEventHandler() {
            @Override
            public void handle(ActionEvent ev) {
                int offset =
                      comboBox.getSelectionModel().getSelectedIndex()
                        -history.getCurrentIndex();
                history.go(offset);
            }
        });
 
 
 
        // 处理页面加载,监听webEngine的状态,当页面切换成功时间添加applition方法到网页脚本,添加按钮showPreDoc到toolbar
        webEngine.getLoadWorker().stateProperty().addListener(
            new ChangeListener() {
                @Override
                public void changed(ObservableValue ov,
                    State oldState, State newState) {
                    toolBar.getChildren().remove(showPrevDoc);   
                    if (newState == State.SUCCEEDED) {
                         //获取js对象
                            JSObject win =
                                (JSObject) webEngine.executeScript("window");
                         //把应用程序对象设置为js对象
                            win.setMember("app",new JavaApp());
			//如果超链接名称为Documentation,添加节点到toolbar布局中
                            if (needDocumentationButton){
                                toolBar.getChildren().add(showPrevDoc);
                            }
                        }
                    }
                }
        );
 
        // load the home page       
        webEngine.load("http://www.oracle.com/products/index.html");
 
        //添加toolbar,browser节点到Browser
        getChildren().add(toolBar);
        getChildren().add(browser);
   }
 
 
 
   // JavaScript interface object
   public class JavaApp {
  
        public void exit() {
            Platform.exit();
        }
   }
 
 
// layoutChildren,computePrefWidth, computePrefHeight, createSpacer方法控制了webView对象browser和包含控制元素的toolbar在scene中的布局
 
   //控制Hbox节点之间的间隔
private Node createSpacer() {
        Region spacer = new Region();
        HBox.setHgrow(spacer, Priority.ALWAYS);
        return spacer;
   }
 
//控制toolbar 和browser的布局和显示
    @Override
   protected void layoutChildren() {
        double w = getWidth();
        double h = getHeight();
        double tbHeight =toolBar.prefHeight(w);
        layoutInArea(browser,0,0,w,h-tbHeight,0,HPos.CENTER,VPos.CENTER);
        layoutInArea(toolBar,0,h-tbHeight,w,tbHeight,0,HPos.CENTER,VPos.CENTER);
   }
 
   @Override
   protected double computePrefWidth(doubleheight) {
        return 750;
   }
 
   @Override
   protected double computePrefHeight(double width) {
        return 600;
   }
}
 

注解1:

Help.Html 调用WebViewSample Application 中的方法涉及代码: