JavaFX2.0-标题窗格TitledPane及手风琴控件Accordion.doc

标题窗格就是带有标题的面板，可以被打开和关闭，也可以被包进任何Node元素，诸如UI控件、图片、计入布局容器的元素组。
标题窗格可以用手风琴控件来形成组。手风琴控件能创建多个窗格而每次只显示一个。Figure 20-1 是带有3个标题窗格的手风琴控件。

Figure 20-1 Accordion with Three Titled Panes

Description of "Figure 20-1 Accordion with Three Titled Panes" 

JavaFX SDK API中的 Accordion 和 TitledPane 类用来实现这样的控件。
创建Titled Panes
创建TitledPane 控件要定义一个标题和一些内容。可以使用TitledPane 类的带有两个参数的构造方法，或者单独使用setText 和setContent 方法也行。两种方法都在Example 20-1 中 .
Example 20-1 Declaring a TitledPane Object
//using a two-parameter constructor TitledPane tp = new TitledPane("My Titled Pane", new Button("Button")); //applying methods TitledPane tp = new TitledPane(); tp.setText("My Titled Pane"); tp.setContent(new Button("Button"));
它们的效果系统，都是 Figure 20-2 .
Figure 20-2 Titled Pane with a Button

Description of "Figure 20-2 Titled Pane with a Button"

标题窗格可以改变大小来适应它的内容。可以添加多行文本，结果见Figure 20-3 .
Figure 20-3 Titled Pane with Some Text

Description of "Figure 20-3 Titled Pane with Some Text" 
不要明确指定标题窗格的最小、最大和优先的高度值，这样在打开关闭时可能导致难以预料的行为。
 Example 20-2 在的代码添加了几个控件到标题窗格，然后加入到了GridPane 布局容器。

Example 20-2 Titled Pane with the GridPane Layout Container
TitledPane gridTitlePane = new TitledPane(); GridPane grid = new GridPane(); grid.setVgap(4); grid.setPadding(new Insets(5, 5, 5, 5)); grid.add(new Label("First Name: "), 0, 0); grid.add(new TextField(), 1, 0); grid.add(new Label("Last Name: "), 0, 1); grid.add(new TextField(), 1, 1); grid.add(new Label("Email: "), 0, 2); grid.add(new TextField(), 1, 2);gridTitlePane.setText("Grid"); gridTitlePane.setContent(grid);

运行的结果是 Figure 20-4 。
Figure 20-4 Titled Pane that Contains Several Controls

Description of "Figure 20-4 Titled Pane that Contains Several Controls" 
可以定义标题窗格打开关闭的方式。默认地，标题窗格是可伸缩的，它们的移动也是动画。如果要阻止标题窗格关闭，将setCollapsible方法 设为false。 也可以将 setAnimated 方法设为false来关闭动画打开效果。Example 20-3 中的代码实现了该任务。

Example 20-3 Adjusting the Style of a Titled Pane
TitledPane tp = new TitledPane(); //prohibit closing tp.setCollapsible(false); //prohibit animating tp.setAnimated(false);

将Titled Panes加入到Accordion
在应用中，可以单独使用标题窗格，也可以使用Accordion 把控件编组。同样也不要指定手风琴控件的高度值。
将几个标题窗格加入到手风琴很类似把开关按钮加入到开关组：每次只能打开手风琴中的一个标题窗格。Example 20-4 创建了3个标题窗格并加入到了手风琴中。

Example 20-4 Accordion and Three Titled Panes
import javafx.application.Application; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.Accordion; import javafx.scene.control.TitledPane; import javafx.scene.image.Image; import javafx.scene.image.ImageView; import javafx.scene.paint.Color; import javafx.stage.Stage; public class TitledPaneSample extends Application { final String[] imageNames = new String[]{"Apples", "Flowers", "Leaves"}; final Image[] images = new Image[imageNames.length]; final ImageView[] pics = new ImageView[imageNames.length]; final TitledPane[] tps = new TitledPane[imageNames.length]; public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) { stage.setTitle("TitledPane"); Scene scene = new Scene(new Group(), 80, 180); scene.setFill(Color.GHOSTWHITE); final Accordion accordion = new Accordion (); for (int i = 0; i < imageNames.length; i++) { images[i] = newImage(getClass().getResourceAsStream(imageNames[i] + ".jpg")); pics[i] = new ImageView(images[i]);tps[i] = new TitledPane(imageNames[i],pics[i]); } accordion.getPanes().addAll(tps);accordion.setExpandedPane(tps[0]); Group root = (Group)scene.getRoot(); root.getChildren().add(accordion); stage.setScene(scene); stage.show(); } }

用循环创建了3个标题窗格，每个的内容都是ImageView 对象。把标题窗格加入到手风琴中要使用getPanes和addAll 方法。可以用add 方法代替addAll 方法来加入单个标题窗格。
默认地，应用启动后所有窗格都关着。setExpandedPane方法指定了带有苹果图片的窗格要打开。见 Figure 20-5 .
Figure 20-5 Accordion with Three Titled Panes

Description of "Figure 20-5 Accordion with Three Titled Panes" 
处理Accordion事件
可以使用标题窗格和手风琴程序不同的数据。Example 20-5 创建了一个单独的标题窗格放进GridPane 悲剧容器和三个标题窗格放进手风琴中。单独的窗格包含了一个email客户端元素，手风琴使得选择窗格会显示相应的图片。

Example 20-5 Implementing ChangeListener for an Accordion
import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.geometry.Insets; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.Accordion; import javafx.scene.control.Label; import javafx.scene.control.TextField; import javafx.scene.control.TitledPane; import javafx.scene.image.Image; import javafx.scene.image.ImageView; import javafx.scene.layout.GridPane; import javafx.scene.layout.HBox; import javafx.scene.paint.Color; import javafx.stage.Stage; public class TitledPaneSample extends Application { final String[] imageNames = new String[]{"Apples", "Flowers", "Leaves"}; final Image[] images = new Image[imageNames.length]; final ImageView[] pics = new ImageView[imageNames.length]; final TitledPane[] tps = new TitledPane[imageNames.length]; final Label label = new Label("N/A"); public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) { stage.setTitle("TitledPane"); Scene scene = new Scene(new Group(), 800, 250); scene.setFill(Color.GHOSTWHITE); // --- GridPane container TitledPane gridTitlePane = new TitledPane(); GridPane grid = new GridPane(); grid.setVgap(4); grid.setPadding(new Insets(5, 5, 5, 5)); grid.add(new Label("To: "), 0, 0); grid.add(new TextField(), 1, 0); grid.add(new Label("Cc: "), 0, 1); grid.add(new TextField(), 1, 1); grid.add(new Label("Subject: "), 0, 2); grid.add(new TextField(), 1, 2); grid.add(new Label("Attachment: "), 0, 3); grid.add(label,1, 3); gridTitlePane.setText("Grid"); gridTitlePane.setContent(grid); // --- Accordion final Accordion accordion = new Accordion (); for (int i = 0; i < imageNames.length; i++) { images[i] = new Image(getClass().getResourceAsStream(imageNames[i] + ".jpg")); pics[i] = new ImageView(images[i]); tps[i] = new TitledPane(imageNames[i],pics[i]); } accordion.getPanes().addAll(tps);accordion.expandedPaneProperty().addListener(new ChangeListener<TitledPane>() { public void changed(ObservableValue<? extends TitledPane> ov, TitledPane old_val, TitledPane new_val) { if (new_val != null) { label.setText(accordion.getExpandedPane().getText() + ".jpg"); } } }); HBox hbox = new HBox(10); hbox.setPadding(new Insets(20, 0, 0, 20)); hbox.getChildren().setAll(gridTitlePane, accordion); Group root = (Group)scene.getRoot(); root.getChildren().add(hbox); stage.setScene(scene); stage.show(); } }

当打开手风琴中的标题窗格时，手风琴的 expandedPaneProperty 属性就会改变。ChangeListener对象通报了该变化，而手风琴中打开的标题窗格就构建一个文件名，该文件名就作为相应Label对象的文本。
Figure 20-6 是应用启动后的样子，Attachment标签是"N/A,"因为没有窗格被选中。

Figure 20-6 Initial View of the TitledPaneSample Application

Description of "Figure 20-6 Initial View of the TitledPaneSample Application" 

如果打开的是Leaves标题窗格，Attachment标签就变成"Leaves.jpg,"见Figure 20-7 .
Figure 20-7 TitledPaneSample Application with the Leaves Titled Pane Expanded

Description of "Figure 20-7 TitledPaneSample Application with the Leaves Titled Pane Expanded"