Gluon mobile 5層不隱藏

Question

我創建了一個繁忙的層，在后台 IO 繁忙時顯示一個動畫進度指示器。 該層被添加到 Gluon mobile 4 的玻璃窗格中：

BusyLayer extends Layer { ...
    root = new FlowPane(new ProgressIndicator());
    MobileApplication.getInstance().getGlassPane().getLayers().add(this);

DH2FX extends MobileApplication { ...
    addLayerFactory("Busy", () -> new BusyLayer());
    ...
    showLayer("Busy");
    ...
    hideLayer("Busy");

在 Gluon 5 中 getLayers 已被刪除，根據遷移指南，可以直接顯示圖層：

BusyLayer extends Layer { ...
    root = new FlowPane(new ProgressIndicator());

DH2FX extends MobileApplication { ...
    BusyLayer busyLayer = new BusyLayer();
    ...
    busyLayer.show();
    ...
    busyLayer.hide();

但該層並未隱藏。

====

主要播放器是一個單例 Background 類，因此 BusyLayer 只顯示一次：

class BackgroundActivity {
    private final AtomicInteger busyAtomicInteger = new AtomicInteger(0);
    BusyLayer busyLayer = new BusyLayer();
    private long time;

    public BackgroundActivity() {
        busyLayer.setOnShowing(e -> {
            time = System.currentTimeMillis(); 
            System.out.println("Showing busyLayer");
        }); 
        busyLayer.setOnShown(e -> {
            System.out.println("busyLayer shown in: " + (System.currentTimeMillis() - time) + " ms");
        }); 
        busyLayer.setOnHiding(e -> System.out.println("hiding layer at " + (System.currentTimeMillis() - time) + " ms"));
    }

    void start() {
        if (busyAtomicInteger.getAndIncrement() == 0) {
             busyLayer.show();
        }
    }

    void done() {
        if (busyAtomicInteger.decrementAndGet() == 0) {
            busyLayer.hide();
        }
    }

    void failure(Throwable t) {
        t.printStackTrace();
        failure();
    }

    void failure() {
        done();
    }
}
protected final BackgroundActivity backgroundActivity = new BackgroundActivity();

使用 CompletableFutures 執行異步任務的代碼如下：

    // Hours
    backgroundActivity.start();
    CompletableFuture.supplyAsync( () -> entryService().getHours(calendarPickerForHessian))
    .exceptionally( e -> { backgroundActivity.failure(e); return null; } )
    .thenAcceptAsync( (Hour[] hours) -> {
        Platform.runLater( () -> {
            refreshHours(hours);
            backgroundActivity.done();
        });
    });

    // ProjectTotals
    backgroundActivity.start();
    CompletableFuture.supplyAsync( () -> entryService().getProjectTotals(calendarPickerForHessian) )
    .exceptionally( e -> { backgroundActivity.failure(e); return null; } )
    .thenAcceptAsync( (LinkedHashMap<Integer, Double> projectTotals) -> {
        Platform.runLater( () -> {
            refreshProjectTotals(projectTotals);
            backgroundActivity.done();
        });
    });

    // DayTotals
    backgroundActivity.start();
    CompletableFuture.supplyAsync( () -> entryService().getDayTotals(calendarPickerForHessian))
    .exceptionally( e -> { backgroundActivity.failure(e); return null; } )
    .thenAcceptAsync( (SortedMap<String, Double> dayTotals) -> {
        Platform.runLater( () -> {
            refreshDayTotals(dayTotals);
            backgroundActivity.done();
        });
    });

當然還有 BusyLayer 本身：

public class BusyLayer extends Layer {

public BusyLayer() {
    root = new StackPane(new ProgressIndicator());
    root.setAlignment(Pos.CENTER);
    root.getStyleClass().add("semitransparent7");
    getChildren().add(root);
}
private final StackPane root;

@Override
public void layoutChildren() {
    root.setVisible(isShowing());
    if (!isShowing()) {
        return;
    }

    GlassPane glassPane = MobileApplication.getInstance().getGlassPane();
    root.resize(glassPane.getWidth(), glassPane.getHeight());
    resizeRelocate(0, 0, glassPane.getWidth(), glassPane.getHeight());
}

}

Answer 1

當您嘗試過早隱藏圖層時，Charm 5.0 存在一個已知問題。

當您顯示一個圖層時，需要一些時間來進行渲染布局，即使沒有動畫過渡，您顯示圖層的時間和最終顯示的時間之間也有幾毫秒的差距。

如果在顯示Layer::hide之前調用Layer::hide ，該調用將退出，並且該圖層不會被隱藏。

一個簡單的測試如下：

private long time;

BusyLayer busyLayer = new BusyLayer();
busyLayer.setOnShowing(e -> {
    time = System.currentTimeMillis(); 
    System.out.println("Showing busyLayer");
}); 
busyLayer.setOnShown(e -> {
    System.out.println("busyLayer shown in: " + (System.currentTimeMillis() - time) + " ms");
}); 
busyLayer.setOnHiding(e -> System.out.println("hiding layer at " + (System.currentTimeMillis() - time) + " ms"));
busyLayer.show();

現在假設你有一個需要一秒鍾的長任務：

PauseTransition p = new PauseTransition(Duration.seconds(1));
p.setOnFinished(f -> busyLayer.hide());
p.play();

那么該層將按預期隱藏。

但是如果任務速度更快並且需要幾毫秒：

PauseTransition p = new PauseTransition(Duration.seconds(0.01));
p.setOnFinished(f -> busyLayer.hide());
p.play();

該層可能尚未顯示，且hide()調用將失敗。

解決方法

雖然這是正確修復的，但可能的解決方法是偵聽圖層的LifecycleEvent.SHOWN事件，並執行以下操作：

private BooleanProperty shown = new SimpleBooleanProperty();

BusyLayer busyLayer = new BusyLayer();
busyLayer.setOnShowing(e -> shown.set(false));
busyLayer.setOnShown(e -> shown.set(true));
busyLayer.show();

PauseTransition p = new PauseTransition(taskDuration);
p.setOnFinished(f -> {
    if (shown.get()) {
        // layer was shown, hide it
        busyLayer.hide();
    } else {
        // layer is not shown yet, wait until it does, and hide
        shown.addListener(new InvalidationListener() {
            @Override
            public void invalidated(Observable observable) {
                if (shown.get()) {
                    busyLayer.hide();
                    shown.removeListener(this);
                }
            }
        });
    }
});
p.play();

編輯

我正在添加一個可能的BusyLayer實現：

class BusyLayer extends Layer {

    private final GlassPane glassPane = MobileApplication.getInstance().getGlassPane();
    private final StackPane root;
    private final double size = 150;

    public BusyLayer() {
        root = new StackPane(new ProgressIndicator());
        root.setStyle("-fx-background-color: white;");
        getChildren().add(root);
        setBackgroundFade(0.5);
    }

    @Override
    public void layoutChildren() {
        super.layoutChildren();
        root.setVisible(isShowing());
        if (!isShowing()) {
            return;
        }
        root.resize(size, size);
        resizeRelocate((glassPane.getWidth() - size)/2, (glassPane.getHeight()- size)/2, size, size);
    }

}

編輯

主要問題與BusyLayer如何覆蓋Layer::layoutChildren方法有關。

正如您可以在此處閱讀Layer::layoutChildren ：

覆蓋此方法為您的圖層添加布局邏輯。 應注意在覆蓋方法中調用此方法以使層正常運行。

這意味着您必須調用super.layoutChildren()才能使圖層正常工作。

@Override
public void layoutChildren() {
    super.layoutChildren();
    // add your own implementation
}

這是擴展 JavaFX 內置控件時的常見模式。