JavaFX:窗格上的触发器不可见/已销毁
我想用可变内容填充窗格varPane。实现与此类似JavaFX:窗格上的触发器不可见/已销毁,javafx,eventtrigger,pane,Javafx,Eventtrigger,Pane,我想用可变内容填充窗格varPane。实现与此类似 Pane varPane = new Pane(); // .. someProperty.addListener(( obsv, oldV, newV) -> { varPane.getChildren().clear(); // Remove old Property Pane Content Pane propPane = getNewPane(newV); // Get new content
Pane varPane = new Pane();
// ..
someProperty.addListener(( obsv, oldV, newV) -> {
varPane.getChildren().clear(); // Remove old Property Pane Content
Pane propPane = getNewPane(newV); // Get new content
varPane.getChildren().add(propPane); // add Content
});
生成的窗格如下所示:
public Pane getNewPane(Object newV){
Pane myPane = new Pane();
// Add dummy Content
myPane.getChildren().add(new Label(newV.toString()))
// Here I need some listener
// somthing like [not working]:
myPane.setOnClosed( System.out.println("Pane closed: " + newV.toString() );
return myPane;
}
如上所述,我需要在不再使用窗格后执行一些清理。然而,我找不到正确的方法来实现这样一个侦听器
如果出现以下情况,则应触发侦听器:
varPane的内容已更改,旧窗格不再可见,或者
如果varPane被破坏,例如在平台上。退出
我可以要求在这些事件上调用一个函数进行清理。不过,我认为如果窗格自己检测到此类事件,会更安全。首先请注意,它不会按照您的想法进行操作。你需要
varPane.getChildren().clear();
您可以检查窗格的parentProperty是否更改为null:
myPane.parentProperty().addListener((obs, oldParent, newParent) -> {
if (newParent == null) {
System.out.println("Pane closed: " + newV);
}
});
检查包含窗格的窗口是否隐藏或关闭相当困难。您可以创建以下侦听器链,基本上侦听窗格的sceneProperty,以便侦听场景的windowProperty,以便侦听窗口的showingProperty:
ChangeListener<Boolean> showingListener = (obs, wasShowing, isNowShowing) -> {
if (! isNowShowing) {
System.out.println("Window containing "+newV+" hidden");
}
};
ChangeListener<Window> windowListener = (obs, oldWin, newWin) -> {
if (oldWin != null) {
oldWin.showingProperty().removeListener(showingListener);
}
if (newWin != null) {
newWin.showingProperty().addListener(showingListener);
}
};
ChangeListener<Scene> sceneListener = (obs, oldScene, newScene) -> {
if (oldScene != null) {
oldScene.windowProperty().removeListener(windowListener);
if (oldScene.getWindow() != null) {
oldScene.getWindow().showingProperty().removeListener(showingListener);
}
}
if (newScene != null) {
newScene.windowProperty().addListener(windowListener);
if (newScene.getWindow() != null) {
newScene.getWindow().showingProperty().addListener(showingListener);
}
}
};
myPane.sceneProperty().addListener(sceneListener);
EventStreams.changesOf(Val
.flatMap(myPane.sceneProperty(), Scene::windowProperty)
.flatMap(Window::showingProperty)
.orElseConst(false))
.filter(c -> ! c.getNewValue())
.observe(v -> System.out.println("Pane closed: "+newV));