JavaFX 对背景的影响

import javafx.animation.*;
import javafx.application.*;
import javafx.beans.property.*;
import javafx.embed.swing.SwingFXUtils;
import javafx.geometry.Insets;
import javafx.scene.*;
import javafx.scene.control.Label;
import javafx.scene.effect.*;
import javafx.scene.Cursor;
import javafx.scene.Node;
import javafx.scene.image.*;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
import javafx.util.Duration;

public class FrostyTech extends Application {

    private static final double BLUR_AMOUNT = 10;

    private static final Effect frostEffect =
        new BoxBlur(BLUR_AMOUNT, BLUR_AMOUNT, 3);

    private static final ImageView background = new ImageView();
    private static final StackPane layout = new StackPane();

    @Override public void start(Stage stage) {
        layout.getChildren().setAll(background, createContent());
        layout.setStyle("-fx-background-color: null");

        Scene scene = new Scene(
                layout,
                200, 300,
                Color.TRANSPARENT
        );

        Platform.setImplicitExit(false);

        scene.setOnMouseClicked(event -> {
                if (event.getClickCount() == 2) Platform.exit();
        });
        makeSmoke(stage);

        stage.initStyle(StageStyle.TRANSPARENT);
        stage.setScene(scene);
        stage.show();

        background.setImage(copyBackground(stage));
        background.setEffect(frostEffect);

        makeDraggable(stage, layout);
    }

    // copy a background node to be frozen over.
    private Image copyBackground(Stage stage) {
        final int X = (int) stage.getX();
        final int Y = (int) stage.getY();
        final int W = (int) stage.getWidth();
        final int H = (int) stage.getHeight();

        try {
            java.awt.Robot robot = new java.awt.Robot();
            java.awt.image.BufferedImage image = robot.createScreenCapture(new java.awt.Rectangle(X, Y, W, H));

            return SwingFXUtils.toFXImage(image, null);
        } catch (java.awt.AWTException e) {
            System.out.println("The robot of doom strikes!");
            e.printStackTrace();

            return null;
        }
    }

    // create some content to be displayed on top of the frozen glass panel.
    private Label createContent() {
        Label label = new Label("Create a new question for drop shadow effects.\n\nDrag to move\n\nDouble click to close");
        label.setPadding(new Insets(10));

        label.setStyle("-fx-font-size: 15px; -fx-text-fill: green;");
        label.setMaxWidth(250);
        label.setWrapText(true);

        return label;
    }

    // makes a stage draggable using a given node.
    public void makeDraggable(final Stage stage, final Node byNode) {
        final Delta dragDelta = new Delta();
        byNode.setOnMousePressed(mouseEvent -> {
            // record a delta distance for the drag and drop operation.
            dragDelta.x = stage.getX() - mouseEvent.getScreenX();
            dragDelta.y = stage.getY() - mouseEvent.getScreenY();
            byNode.setCursor(Cursor.MOVE);
        });
        final BooleanProperty inDrag = new SimpleBooleanProperty(false);

        byNode.setOnMouseReleased(mouseEvent -> {
            byNode.setCursor(Cursor.HAND);

            if (inDrag.get()) {
                stage.hide();

                Timeline pause = new Timeline(new KeyFrame(Duration.millis(50), event -> {
                    background.setImage(copyBackground(stage));
                    layout.getChildren().set(
                            0,
                            background
                    );
                    stage.show();
                }));
                pause.play();
            }

            inDrag.set(false);
        });
        byNode.setOnMouseDragged(mouseEvent -> {
            stage.setX(mouseEvent.getScreenX() + dragDelta.x);
            stage.setY(mouseEvent.getScreenY() + dragDelta.y);

            layout.getChildren().set(
                    0,
                    makeSmoke(stage)
            );

            inDrag.set(true);
        });
        byNode.setOnMouseEntered(mouseEvent -> {
            if (!mouseEvent.isPrimaryButtonDown()) {
                byNode.setCursor(Cursor.HAND);
            }
        });
        byNode.setOnMouseExited(mouseEvent -> {
            if (!mouseEvent.isPrimaryButtonDown()) {
                byNode.setCursor(Cursor.DEFAULT);
            }
        });
    }

    private javafx.scene.shape.Rectangle makeSmoke(Stage stage) {
        return new javafx.scene.shape.Rectangle(
                stage.getWidth(),
                stage.getHeight(),
                Color.WHITESMOKE.deriveColor(
                        0, 1, 1, 0.08
                )
        );
    }

    /** records relative x and y co-ordinates. */
    private static class Delta {
        double x, y;
    }

    public static void main(String[] args) {
        launch(args);
    }
}  

相关问题

• JavaFX中的磨砂玻璃效果？
• 如何创建仅在边框上有阴影的 JavaFX 透明舞台？

您希望用于依赖于操作系统的窗口装饰的视觉效果只能通过操作系统提供的 API 来实现。因此被以下淘汰。StageStyle.TRANSPARENT

对于 JavaFX 内容本身，您可以控制层次结构的视觉对象。舞台和场景不（也不旨在）支持高级样式，因此通过设置为下面的透明而被淘汰。stage > scene > root pane

@Override
public void start(Stage primaryStage) {
    StackPane root = new StackPane();
    root.setStyle("-fx-background-color: null;");
    root.setPadding(new Insets(10));

    DoubleProperty doubleProperty = new SimpleDoubleProperty(0);

    Region region = new Region();
    region.styleProperty().bind(Bindings
            .concat("-fx-background-radius:20; -fx-background-color: rgba(56, 176, 209, ")
            .concat(doubleProperty)
            .concat(");"));
    region.setEffect(new DropShadow(10, Color.GREY));

    Slider slider = new Slider(0, 1, .3);
    doubleProperty.bind(slider.valueProperty());

    root.getChildren().addAll(region, slider);

    primaryStage.initStyle(StageStyle.TRANSPARENT);
    Scene scene = new Scene(root, 300, 250);
    scene.setFill(Color.TRANSPARENT);

    primaryStage.setTitle("Hello World!");
    primaryStage.setScene(scene);
    primaryStage.show();
}

但是，投影效果不适用于背景色的 Alpha 值。您可以通过将阴影的颜色更改为另一个对比度的颜色来观察它。

输出：