问题
Starting from this question JavaFX LineChart Hover Values I modified the Gist in the first answer https://gist.github.com/jewelsea/4681797 into this
public class TestCharts extends Application
{
ObservableList<XYChart.Data<Integer, Integer>> _serie;
@SuppressWarnings("unchecked")
@Override
public void start(Stage stage) {
LineChart lineChart = new LineChart(new NumberAxis(), new NumberAxis());
XYChart.Series serie = new XYChart.Series(
"Test",
getTestValues()
);
lineChart.getData().add(serie);
lineChart.setCursor(Cursor.CROSSHAIR);
lineChart.setTitle("First Chart");
stage.setTitle("First Chart");
stage.setScene(new Scene(lineChart, 500, 400));
stage.show();
secondHandChart();
}
private void secondHandChart() {
LineChart lineChart = new LineChart(new NumberAxis(), new NumberAxis());
XYChart.Series serie = new XYChart.Series(
"Test",
getTestValues()
);
lineChart.getData().add(serie);
lineChart.setCursor(Cursor.CROSSHAIR);
lineChart.setTitle("Second Chart");
Stage stage = new Stage();
stage.setTitle("Second Chart");
stage.setScene(new Scene(lineChart, 500, 400));
stage.show();
}
private ObservableList<XYChart.Data<Integer, Integer>> getTestValues() {
return plot(23, 14, 15, 24, 34, 36, 22, 45, 43, 17, 29, 25);
}
public ObservableList<XYChart.Data<Integer, Integer>> plot(int... y) {
if (_serie == null) {
_serie = FXCollections.observableArrayList();
int i = 0;
while (i < y.length) {
XYChart.Data<Integer, Integer> data = new XYChart.Data<>(i + 1, y[i]);
data.setNode(
new HoveredThresholdNode(
(i == 0) ? 0 : y[i - 1],
y[i]
)
);
_serie.add(data);
i++;
}
return _serie;
}
else {
return FXCollections.observableArrayList(_serie);
}
}
/**
* a node which displays a value on hover, but is otherwise empty
*/
class HoveredThresholdNode extends StackPane
{
HoveredThresholdNode(int priorValue, int value) {
setPrefSize(8, 8);
final Label label = createDataThresholdLabel(priorValue, value);
setOnMouseEntered(new EventHandler<MouseEvent>()
{
@Override
public void handle(MouseEvent mouseEvent) {
getChildren().setAll(label);
setCursor(Cursor.NONE);
toFront();
}
});
setOnMouseExited(new EventHandler<MouseEvent>()
{
@Override
public void handle(MouseEvent mouseEvent) {
getChildren().clear();
setCursor(Cursor.CROSSHAIR);
}
});
}
private Label createDataThresholdLabel(int priorValue, int value) {
final Label label = new Label(value + "");
label.setStyle("-fx-font-size: 20; -fx-font-weight: bold;");
label.setMinSize(Label.USE_PREF_SIZE, Label.USE_PREF_SIZE);
return label;
}
}
public static void main(String[] args) { launch(args); }
}
This class has the only pourpose of showing my problem. I want to get two charts of the same serie, getTestValues(). The problem is: the second chart is perfect (2° Img) but the first one (1° Img) is missing the HoveredThresholdNode and when I resize the first chart, the HoveredThresholdNodes in the second chart are changing position (3° Image). How can I get a copy of the serie, containing also a copy of those nodes? I know that printing the same serie doesn't make sense, but in the reality I have a two lists of serie, and I have a chart for each and a chart with the two lists together for compairing pourposes. Anyway the problem can be semplified to just one serie in two charts.
回答1:
XYChart.Data cannot be shared across charts because it has-a Node that is added to the chart.
To share data between charts, you have to
- implement a custom data class that only contains the values
- keep a list of the shared data
- for each chart, create a XYChart.Data backed by the shared data
- manage the sync of the chart data with the backing data (note that the simple example below isn't complete in not updating the chart data on list modifications)
A quick example:
@SuppressWarnings({ "unchecked", "rawtypes" })
public class TestChart extends Application {
// the shared x/y data pairs
private ObservableList<XYData<Integer, Integer>> backingData;
/**
* Custom xy data class which exposes its values as properties and nothing
* else.
*/
public static class XYData<X, Y> {
private ObjectProperty<X> xValue;
private ObjectProperty<Y> yValue;
public XYData(X xValue, Y yValue) {
this.xValue = new SimpleObjectProperty<>(this, "xValue", xValue);
this.yValue = new SimpleObjectProperty<>(this, "yValue", yValue);
}
public ObjectProperty<X> xValueProperty() {
return xValue;
}
public void setXValue(X value) {
xValueProperty().set(value);
}
public X getXValue() {
return xValueProperty().get();
}
public ObjectProperty<Y> yValueProperty() {
return yValue;
}
public void setYValue(Y value) {
yValueProperty().set(value);
}
public Y getYValue() {
return yValueProperty().get();
}
}
@Override
public void start(Stage stage) {
if (backingData == null) {
backingData = createBackingData();
}
LineChart lineChart = new LineChart(new NumberAxis(), new NumberAxis());
XYChart.Series serie = new XYChart.Series("Test", createChartData());
lineChart.getData().add(serie);
lineChart.setCursor(Cursor.CROSSHAIR);
lineChart.setTitle("First Chart");
stage.setTitle("First Chart");
stage.setScene(new Scene(lineChart, 500, 400));
stage.show();
secondHandChart();
}
private void secondHandChart() {
LineChart lineChart = new LineChart(new NumberAxis(), new NumberAxis());
XYChart.Series serie = new XYChart.Series("Test", createChartData());
lineChart.getData().add(serie);
lineChart.setCursor(Cursor.CROSSHAIR);
lineChart.setTitle("Second Chart");
Stage stage = new Stage();
stage.setTitle("Second Chart");
stage.setScene(new Scene(lineChart, 500, 400));
stage.show();
}
private ObservableList<XYData<Integer, Integer>> createBackingData() {
ObservableList<XYData<Integer, Integer>> data = FXCollections
.observableArrayList();
Integer[] values = { 23, 14, 15, 24, 34, 36, 22, 45, 43, 17, 29, 25 };
for (int i = 0; i < values.length; i++) {
data.add(new XYData(i, values[i]));
}
return data;
}
private ObservableList<XYChart.Data<Integer, Integer>> createChartData() {
ObservableList<XYChart.Data<Integer, Integer>> chartData = FXCollections
.observableArrayList();
for (int i = 0; i < backingData.size(); i++) {
XYData<Integer, Integer> b = backingData.get(i);
XYChart.Data<Integer, Integer> cd = new XYChart.Data<>(
b.getXValue(), b.getYValue());
cd.XValueProperty().bind(b.xValueProperty());
cd.YValueProperty().bind(b.yValueProperty());
cd.setNode(new HoveredThresholdNode(
(i == 0) ? 0 : backingData.get(i - 1).getYValue(),
backingData.get(i).getYValue()));
chartData.add(cd);
}
return chartData;
}
/**
* a node which displays a value on hover, but is otherwise empty
*/
class HoveredThresholdNode extends StackPane {
HoveredThresholdNode(int priorValue, int value) {
setPrefSize(8, 8);
final Label label = createDataThresholdLabel(priorValue, value);
setOnMouseEntered(new EventHandler<MouseEvent>() {
@Override
public void handle(MouseEvent mouseEvent) {
getChildren().setAll(label);
setCursor(Cursor.NONE);
toFront();
}
});
setOnMouseExited(new EventHandler<MouseEvent>() {
@Override
public void handle(MouseEvent mouseEvent) {
getChildren().clear();
setCursor(Cursor.CROSSHAIR);
}
});
}
private Label createDataThresholdLabel(int priorValue, int value) {
final Label label = new Label(value + "");
label.setStyle("-fx-font-size: 20; -fx-font-weight: bold;");
label.setMinSize(Label.USE_PREF_SIZE, Label.USE_PREF_SIZE);
return label;
}
}
public static void main(String[] args) {
launch(args);
}
}
来源：https://stackoverflow.com/questions/49770442/javafx-print-the-same-xychart-series-in-two-charts