zooming - Javafx 2图表缩放

Question

当我选择图表区域时，我的缩放会得到一个“小开关”。在示例中，如果选择从刻度 3 到刻度 6，我将获得下限:3.67 和上限 6.74。

如何解决？

非常感谢任何帮助。

package testjavafxzoom;

import javafx.application.Application;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.event.EventHandler;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.LineTo;
import javafx.scene.shape.MoveTo;
import javafx.scene.shape.Path;
import javafx.scene.shape.Rectangle;

public class Zoom01 extends Application {

Path path;//Add path for freehand
BorderPane pane;
Rectangle rect;
SimpleDoubleProperty rectinitX = new SimpleDoubleProperty();
SimpleDoubleProperty rectinitY = new SimpleDoubleProperty();
SimpleDoubleProperty rectX = new SimpleDoubleProperty();
SimpleDoubleProperty rectY = new SimpleDoubleProperty();

@Override
public void start(Stage stage) {

    System.out.println("Java Version             : " + com.sun.javafx.runtime.VersionInfo.getVersion());
    System.out.println("Java getHudsonBuildNumber: " + com.sun.javafx.runtime.VersionInfo.getHudsonBuildNumber());
    System.out.println("Java getReleaseMilestone : " + com.sun.javafx.runtime.VersionInfo.getReleaseMilestone());
    System.out.println("Java getRuntimeVersion   : " + com.sun.javafx.runtime.VersionInfo.getRuntimeVersion());

    stage.setTitle("Lines plot");

    //final CategoryAxis xAxis = new CategoryAxis();
    final NumberAxis xAxis = new NumberAxis(1, 12, 1);
    final NumberAxis yAxis = new NumberAxis(0.53000, 0.53910, 0.0005);

    yAxis.setTickLabelFormatter(new NumberAxis.DefaultFormatter(yAxis) {

        @Override
        public String toString(Number object) {
            return String.format("%7.5f", object);
        }
    });


    //final LineChart<String, Number> lineChart = new LineChart<String, Number>(xAxis, yAxis);
    final LineChart<Number, Number> lineChart = new LineChart<Number, Number>(xAxis, yAxis);

    //lineChart.setTitle("Stock quotes");
    lineChart.setCreateSymbols(false);
    lineChart.setAlternativeRowFillVisible(false);
    lineChart.setAnimated(true);

    XYChart.Series series1 = new XYChart.Series();
    //series1.setName("Stock 1");
    series1.getData().add(new XYChart.Data(1, 0.53185));
    series1.getData().add(new XYChart.Data(2, 0.532235));
    series1.getData().add(new XYChart.Data(3, 0.53234));
    series1.getData().add(new XYChart.Data(4, 0.538765));
    series1.getData().add(new XYChart.Data(5, 0.53442));
    series1.getData().add(new XYChart.Data(6, 0.534658));
    series1.getData().add(new XYChart.Data(7, 0.53023));
    series1.getData().add(new XYChart.Data(8, 0.53001));
    series1.getData().add(new XYChart.Data(9, 0.53589));
    series1.getData().add(new XYChart.Data(10, 0.53476));
    series1.getData().add(new XYChart.Data(11, 0.530123));
    series1.getData().add(new XYChart.Data(12, 0.53035));


    pane = new BorderPane();
    pane.setCenter(lineChart);
    //Scene scene = new Scene(lineChart, 800, 600);
    Scene scene = new Scene(pane, 800, 600);
    lineChart.getData().addAll(series1);

    stage.setScene(scene);        

    path = new Path();
    path.setStrokeWidth(1);
    path.setStroke(Color.BLACK);

    scene.setOnMouseClicked(mouseHandler);
    scene.setOnMouseDragged(mouseHandler);
    scene.setOnMouseEntered(mouseHandler);
    scene.setOnMouseExited(mouseHandler);
    scene.setOnMouseMoved(mouseHandler);
    scene.setOnMousePressed(mouseHandler);
    scene.setOnMouseReleased(mouseHandler);

    //root.getChildren().add(lineChart);
    pane.getChildren().add(path);

    rect = new Rectangle();
    rect.setFill(Color.web("blue", 0.1));
    rect.setStroke(Color.BLUE);
    rect.setStrokeDashOffset(50);

    rect.widthProperty().bind(rectX.subtract(rectinitX));
    rect.heightProperty().bind(rectY.subtract(rectinitY));
    pane.getChildren().add(rect);

    stage.show();
}
EventHandler<MouseEvent> mouseHandler = new EventHandler<MouseEvent>() {

    @Override
    public void handle(MouseEvent mouseEvent) {

        if (mouseEvent.getEventType() == MouseEvent.MOUSE_PRESSED) {
            rect.setX(mouseEvent.getX());
            rect.setY(mouseEvent.getY());
            rectinitX.set(mouseEvent.getX());
            rectinitY.set(mouseEvent.getY());
        } else if (mouseEvent.getEventType() == MouseEvent.MOUSE_DRAGGED) {
            rectX.set(mouseEvent.getX());
            rectY.set(mouseEvent.getY());
        } else if (mouseEvent.getEventType() == MouseEvent.MOUSE_RELEASED) {

            System.out.println("Zoom bounds : [" + rectinitX.get()+", "+rectinitY.get()+"] ["+ rectX.get()+", "+rectY.get()+"]");                
            System.out.println("TODO: Determine bound ranges according these zoom coordinates.\n");

            // TODO: Determine bound ranges according this zoom coordinates.
            //LineChart<String, Number> lineChart = (LineChart<String, Number>) pane.getCenter();
            LineChart<Number, Number> lineChart = (LineChart<Number, Number>) pane.getCenter();

            // Zoom in Y-axis by changing bound range.
            NumberAxis yAxis = (NumberAxis) lineChart.getYAxis();
            yAxis.setLowerBound(0.532);
            yAxis.setUpperBound(0.538);

            // Zoom in X-axis by removing first and last data values.
            // Note: Maybe better if categoryaxis is replaced by numberaxis then setting the
            // LowerBound and UpperBound will be avaliable.
            /*
            XYChart.Series series1 = lineChart.getData().get(0);
            if (!series1.getData().isEmpty()) {
                series1.getData().remove(0);
                series1.getData().remove(series1.getData().size() - 1);
            }
            */

            NumberAxis xAxis = (NumberAxis) lineChart.getXAxis();
            System.out.println("(a) xAxis.getLowerBound() "+xAxis.getLowerBound()+" "+xAxis.getUpperBound());
            double Tgap = xAxis.getWidth()/(xAxis.getUpperBound() - xAxis.getLowerBound());
            double newXlower, newXupper;
            newXlower = (rectinitX.get()/Tgap)+xAxis.getLowerBound();

            newXupper = (rectX.get()/Tgap)+xAxis.getLowerBound();
            if (newXupper > xAxis.getUpperBound())
                newXupper = xAxis.getUpperBound();

            xAxis.setLowerBound( newXlower );
            xAxis.setUpperBound( newXupper );

            System.out.println("(b) xAxis.getLowerBound() "+xAxis.getLowerBound()+" "+xAxis.getUpperBound());

            // Hide the rectangle
            rectX.set(0);
            rectY.set(0);
        }
    }
   };

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

Answer 1

您将鼠标事件附加到场景。因此，mouseEvent.getX() 为您提供相对于场景的坐标。但是您的公式使用它们作为相对于 xAxis 节点的坐标。您需要考虑场景中的 xAxis 位置。

介绍下一个方法:

// summ layout shift against parent until we ascend to scene
private static double getSceneShift(Node node) {
    double shift = 0;
    do { 
        shift += node.getLayoutX(); 
        node = node.getParent();
    } while (node != null);
    return shift;
}

并相应地更改您的计算:

        double xAxisShift = getSceneShift(xAxis);
        newXlower = ((rectinitX.get() - xAxisShift) / Tgap) + xAxis.getLowerBound();
        newXupper = ((rectX.get() - xAxisShift) / Tgap) + xAxis.getLowerBound();