JavaFX 2.x:将鼠标单击坐标转换为XYChart轴值 [英] JavaFX 2.x: Translate mouse click coordinate into XYChart axis value
问题描述
在JavaFX 2.x中,我正在使用XYChart,并且希望在鼠标在图表上移动时显示图表的(X,Y)轴坐标值.我在图表上设置了一个事件处理程序来处理setOnMouseMoved事件.但是,我不确定如何将MouseEvent的getX()值转换为图表的坐标值?
In JavaFX 2.x, I am using an XYChart and I want to display the (X,Y) axis coordinate values of the chart as the mouse move across the chart. I setup an event handler on the chart to handle setOnMouseMoved events. However, I am not sure how to convert the MouseEvent's getX() value into the chart's coordinate value?
推荐答案
Use axis.getValueForDisplay(displayPosition) to determine the location of the mouse in axis value coordinates:
xAxis.getValueForDisplay(mouseEvent.getX()),
yAxis.getValueForDisplay(mouseEvent.getY())
这里是一个示例,该示例在折线图中报告鼠标悬停在其上的坐标.屏幕捕获不会捕获鼠标光标-您只需要在那里想象它;-)
Here is a sample which reports the co-ordinates over which the mouse is hovering in a line chart. The screen capture doesn't capture the mouse cursor - you'll just have to imagine it there ;-)
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.*;
import javafx.scene.chart.*;
import javafx.scene.control.Label;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class LineChartWithHoverCoords extends Application {
@Override public void start(Stage stage) {
stage.setTitle("Line Chart Sample");
final LineChart<Number, Number> lineChart = createChart();
Label cursorCoords = createCursorGraphCoordsMonitorLabel(lineChart);
stage.setScene(
new Scene(
layoutScene(
lineChart,
cursorCoords
)
)
);
stage.show();
}
private VBox layoutScene(LineChart<Number, Number> lineChart, Label cursorCoords) {
VBox layout = new VBox(10);
layout.setPadding(new Insets(10));
layout.setAlignment(Pos.CENTER);
layout.getChildren().setAll(
cursorCoords,
lineChart
);
return layout;
}
private LineChart<Number, Number> createChart() {
final NumberAxis xAxis = new NumberAxis();
final NumberAxis yAxis = new NumberAxis();
xAxis.setLabel("Number of Month");
final LineChart<Number,Number> lineChart =
new LineChart<>(xAxis,yAxis);
lineChart.setTitle("Stock Monitoring, 2010");
XYChart.Series<Number, Number> series = new XYChart.Series<>(
"My portfolio", FXCollections.<XYChart.Data<Number, Number>>observableArrayList(
new XYChart.Data<Number, Number>(1, 23),
new XYChart.Data<Number, Number>(2, 14),
new XYChart.Data<Number, Number>(3, 15),
new XYChart.Data<Number, Number>(4, 24),
new XYChart.Data<Number, Number>(5, 34),
new XYChart.Data<Number, Number>(6, 36),
new XYChart.Data<Number, Number>(7, 22),
new XYChart.Data<Number, Number>(8, 45),
new XYChart.Data<Number, Number>(9, 43),
new XYChart.Data<Number, Number>(10, 17),
new XYChart.Data<Number, Number>(11, 29),
new XYChart.Data<Number, Number>(12, 25)
)
);
lineChart.getData().add(series);
return lineChart;
}
private Label createCursorGraphCoordsMonitorLabel(LineChart<Number, Number> lineChart) {
final Axis<Number> xAxis = lineChart.getXAxis();
final Axis<Number> yAxis = lineChart.getYAxis();
final Label cursorCoords = new Label();
final Node chartBackground = lineChart.lookup(".chart-plot-background");
for (Node n: chartBackground.getParent().getChildrenUnmodifiable()) {
if (n != chartBackground && n != xAxis && n != yAxis) {
n.setMouseTransparent(true);
}
}
chartBackground.setOnMouseEntered(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setVisible(true);
}
});
chartBackground.setOnMouseMoved(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setText(
String.format(
"(%.2f, %.2f)",
xAxis.getValueForDisplay(mouseEvent.getX()),
yAxis.getValueForDisplay(mouseEvent.getY())
)
);
}
});
chartBackground.setOnMouseExited(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setVisible(false);
}
});
xAxis.setOnMouseEntered(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setVisible(true);
}
});
xAxis.setOnMouseMoved(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setText(
String.format(
"x = %.2f",
xAxis.getValueForDisplay(mouseEvent.getX())
)
);
}
});
xAxis.setOnMouseExited(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setVisible(false);
}
});
yAxis.setOnMouseEntered(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setVisible(true);
}
});
yAxis.setOnMouseMoved(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setText(
String.format(
"y = %.2f",
yAxis.getValueForDisplay(mouseEvent.getY())
)
);
}
});
yAxis.setOnMouseExited(new EventHandler<MouseEvent>() {
@Override public void handle(MouseEvent mouseEvent) {
cursorCoords.setVisible(false);
}
});
return cursorCoords;
}
public static void main(String[] args) {
launch(args);
}
}
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