鼠标滚动 Java FX

Mouse scrolling in Java FX

我想用mouse scroll把圆变大(mouse-scroll-up),把圆变小(mouse-scroll-down)。

我已有代码可以使用鼠标中键将圆半径变小,但我的问题是:

How can I use mouse-scroll-up and mouse-scroll-down to do the same thing?

我用谷歌搜索过,可以用 ScrollEvent 以某种方式完成,但我不太明白这一点。

回答您的问题

How can I use mouse-scroll-up and mouse-scroll-down to do the same thing?

  • 在圆上使用ScrollListener并使用ScrollEvent引用得到DeltaY
  • 创建一个zoomfactor来计算你想要的缩放系数。
  • 将此因素应用于节点的规模 属性。

完整示例

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.input.ScrollEvent;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;

public class ZoomInOutCircles extends Application {

    @Override
    public void start(Stage primaryStage) {
        Group root = new Group();
        Scene scene = new Scene(root, 350, 300);
        primaryStage.setTitle("Dots");
        primaryStage.setScene(scene);

        Circle circle = new Circle(175, 150, 10, Color.BLUE);
        addMouseScrolling(circle);
        root.getChildren().add(circle);

        primaryStage.show();
    }

    public void addMouseScrolling(Node node) {
        node.setOnScroll((ScrollEvent event) -> {
            // Adjust the zoom factor as per your requirement
            double zoomFactor = 1.05;
            double deltaY = event.getDeltaY();
            if (deltaY < 0){
                zoomFactor = 2.0 - zoomFactor;
            }
            node.setScaleX(node.getScaleX() * zoomFactor);
            node.setScaleY(node.getScaleY() * zoomFactor);
        });
    }
}