想象一下有一个定义鼠标模式的枚举:
public enum MouseMode {
SELECTION,
EDITING,
DELETING }
想象一下,一个由3个按钮组成的切换组:
ToggleButton selection = new ToggleButton("Select");
ToggleButton editing = new ToggleButton("Edit");
ToggleButton deleting = new ToggleButton("Delete");
ToggleGroup mouseSelection = new ToggleGroup();
我希望字段MouseMode currentMode
是双向链接到切换组。无论何时设置切换,currentMode都会相应地切换,但如果某些外部进程更改了currentMode (可能是按键),则切换组将相应地进行调整。
我可以用两个侦听器来完成这个任务,但是我想知道是否有一种方法可以创建一个自定义的双向映射。
发布于 2014-04-26 22:50:15
我不认为有办法直接做到这一点。而一般的目的
Bindings.bindBidirectional(Property<S> property1, Property<T> property2, Function<S,T> mapping, Function<T,S> inverseMapping)
这可能是对API的一个很好的补充,即使在这种情况下也没有帮助,因为ToggleGroup
的selectedProperty
是只读的(因为每个Toggle
的setSelected(...)
方法调用时以及ToggleGroup
的selectedProperty
都需要处理选择)。
在这种情况下,使用几个侦听器是可行的。
与“自定义双向映射”最接近的是
Bindings.bindBiDirectional(StringProperty stringProperty, ObjectProperty<T> otherProperty, StringConverter<T> converter)
方法。在有(可写) ObjectProperty<S>
和(可写) ObjectProperty<T>
的情况下,理论上可以使用两个双向绑定和一个中间StringProperty
将它们绑定在一起。在实践中,这几乎总是比仅仅使用两个侦听器更多的代码,而且效率也较低。
发布于 2014-07-31 14:27:46
我已经成功地在ToggleGroupValue项目中使用了JFXtras类。
下面是一个示例:
import java.util.Arrays;
import java.util.List;
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.RadioButton;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
public class Main extends Application {
Child myChild = new Child();
@Override
public void start( Stage stage ) throws Exception {
stage.setTitle( "ToggleGroupValue Example" );
GridPane gridPane = new GridPane();
int rowIndex = 0;
gridPane.add( new Label("Nickname: "), 0, rowIndex );
ToggleGroupValue toggleGroupValue = new ToggleGroupValue();
rowIndex = createAddRadioButtons( gridPane, rowIndex, toggleGroupValue );
gridPane.add( new Label("Selected Nickname: "), 0, rowIndex );
Label selectedNickNameValueLabel = new Label();
gridPane.add( selectedNickNameValueLabel, 1, rowIndex );
myChild.nicknameProperty().bindBidirectional( toggleGroupValue.valueProperty() );
selectedNickNameValueLabel.textProperty().bind( toggleGroupValue.valueProperty() );
stage.setScene( new Scene( gridPane, 300, 100 ) );
stage.show();
}
private int createAddRadioButtons( GridPane gridPane, int rowIndex, ToggleGroupValue toggleGroupValue ) {
RadioButton radioButtonPunkin = new RadioButton();
radioButtonPunkin.setUserData( "Punkin" );
RadioButton radioButtonLittleBoy = new RadioButton();
radioButtonLittleBoy.setUserData( "Little Boy" );
RadioButton radioButtonBuddy = new RadioButton();
radioButtonBuddy.setUserData( "Buddy" );
List<RadioButton> radioButtons = Arrays.asList( radioButtonPunkin, radioButtonLittleBoy, radioButtonBuddy );
for ( RadioButton radioButton : radioButtons ) {
toggleGroupValue.add( radioButton, radioButton.getUserData() );
radioButton.setText( radioButton.getUserData().toString() );
gridPane.add( radioButton, 1, rowIndex++ );
}
return rowIndex;
}
private static class Child {
private StringProperty nickname = new SimpleStringProperty();
public StringProperty nicknameProperty() {
return nickname;
}
public String getNickname() {
return nickname.get();
}
public void setNickname( String notesProperty ) {
this.nickname.set( notesProperty );
}
}
public static void main(String[] args) {
launch(args);
}
}
发布于 2017-04-03 15:27:25
我正在使用Java属性适配器,但是您可以使用这段代码的最后一行并绑定它。
JavaBeanObjectProperty<fooEnum> property = null;
try {
property = new JavaBeanObjectPropertyBuilder<fooEnum>().bean(fooBean).name(fooField).build();
} catch (NoSuchMethodException e1) {
e1.printStackTrace();
}
property.addListener((obs, oldValue, newValue) -> {
System.out.println("Property value changed from " + oldValue + " to " + newValue);
});
BindingUtils.bindToggleGroupToProperty(fooToggleGroup, property);
您需要有一个用于BindingUtils的小型ToggleGroup类。
public final class BindingUtils {
private BindingUtils() {
}
public static <T> void bindToggleGroupToProperty(final ToggleGroup toggleGroup, final ObjectProperty<T> property) {
// Check all toggles for required user data
toggleGroup.getToggles().forEach(toggle -> {
if (toggle.getUserData() == null) {
throw new IllegalArgumentException("The ToggleGroup contains at least one Toggle without user data!");
}
});
// Select initial toggle for current property state
for (Toggle toggle : toggleGroup.getToggles()) {
if (property.getValue() != null && property.getValue().equals(toggle.getUserData())) {
toggleGroup.selectToggle(toggle);
break;
}
}
// Update property value on toggle selection changes
toggleGroup.selectedToggleProperty().addListener((observable, oldValue, newValue) -> {
property.setValue((T) newValue.getUserData());
});
}
https://stackoverflow.com/questions/23303087
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