[英]JavaFX custom chart class - how to bind a node's layoutX and layoutY properties to the display positions of a NumberAxis?
我正在編寫一個基本的燭台圖表類,其中燭台被創建為Regions
,並通過將它們的layoutX
和layoutY
值設置為相關軸的getDisplayPosition()
來繪制。
例如,要在 X 軸上繪制值為 3 的燭台,我這樣做:
candlestick.setLayoutX(xAxis.getDisplayPosition(3));
當舞台調整大小或軸放大或縮小時,必須重置燭台的布局值,以便圖表正確呈現。 我目前正在通過ChangeListener
s 處理調整大小事件和Button.setOnAction()
s 進行縮放。
但是,我寧願將燭台的布局屬性綁定到軸的顯示位置,而不是設置/重置布局值,但找不到NumberAxis
的“displayPositionProperty”(或類似的)。
是否有可能做到這一點? 我將綁定到哪個NumberAxis
屬性? IE。
candlestick.layoutXProperty().bind(xAxis.WHICH_PROPERTY?);
另外,綁定屬性會比重置布局位置更有效嗎? 有些圖表可能有數千個燭台,但在我弄清楚如何對綁定進行編碼之前,我無法測試資源使用情況。
我已經嘗試將燭台縮放到軸的比例,但不能使用這種方法,因為縮放Region
會影響其邊框寬度。 對於某些類型的燭台,這可能會改變其含義。
我還使用了 Ensemble 燭台演示圖表。 它對我的開始很有用,但對於我的需求來說太簡單了。
這是一個 MVCE,它展示了我的方法。 任何重新綁定的指導將不勝感激。
我正在使用 OpenJFX 17。
package test023;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.Region;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Test023 extends Application {
@Override
public void start(Stage stage) {
NumberAxis xAxis = new NumberAxis(0D, 10D, 1D);
Pane pChart = new Pane();
Pane pAxis = new Pane();
VBox vb = new VBox();
BorderPane bp = new BorderPane();
pChart.setPrefHeight(100D);
pAxis.getChildren().add(xAxis);
xAxis.prefWidthProperty().bind(pAxis.widthProperty());
xAxis.setAnimated(false);
vb.setPadding(new Insets(10D));
vb.getChildren().addAll(pChart, pAxis);
Region point = new Region();
point.setPrefSize(5D, 5D);
point.setStyle("-fx-background-color: black;");
pChart.getChildren().add(point);
//Plot the point in its initial position (value 3 on the axis)
double pointXValue = 3D;
plotPoint(point, pointXValue, xAxis);
//*****************************************************************
//Can the listeners and button.setOnActions be replaced by binding
//the point's layout value to the axis display position?
//*****************************************************************
//Handle resize events
pChart.widthProperty().addListener((obs, oldVal, newVal) -> {
plotPoint(point, pointXValue, xAxis);
});
stage.maximizedProperty().addListener((obs, oldVal, newVal) -> {
plotPoint(point, pointXValue, xAxis);
});
//Handle zooming (hard-coded upper and lower bounds for the
//sake of simplicity)
Button btnZoomIn = new Button("Zoom in");
btnZoomIn.setOnAction((event) -> {
xAxis.setLowerBound(2D);
xAxis.setUpperBound(8D);
xAxis.layout();
plotPoint(point, pointXValue, xAxis);
});
Button btnZoomOut = new Button("Zoom out");
btnZoomOut.setOnAction((event) -> {
xAxis.setLowerBound(0D);
xAxis.setUpperBound(10D);
xAxis.layout();
plotPoint(point, pointXValue, xAxis);
});
bp.setCenter(vb);
bp.setTop(new HBox(btnZoomIn, btnZoomOut));
stage.setScene(new Scene(bp));
stage.setTitle("Test bind layoutX");
stage.setWidth(400D);
stage.setHeight(200D);
stage.show();
}
private void plotPoint(Region region, double axisPos, NumberAxis axis) {
Platform.runLater(() -> {
double posX = axis.getDisplayPosition(axisPos);
region.setLayoutX(posX);
region.setLayoutY(80D);
});
}
public static void main(String args[]){
launch(args);
}
}
像這樣的東西會起作用
@Override
public void start(Stage stage) {
NumberAxis xAxis = new NumberAxis(0D, 10D, 1D);
Pane pChart = new Pane();
Pane pAxis = new Pane();
VBox vb = new VBox();
BorderPane bp = new BorderPane();
pChart.setPrefHeight(100D);
pAxis.getChildren().add(xAxis);
xAxis.prefWidthProperty().bind(pAxis.widthProperty());
xAxis.setAnimated(false);
vb.setPadding(new Insets(10D));
vb.getChildren().addAll(pChart, pAxis);
Region point = new Region();
point.setPrefSize(5D, 5D);
point.setStyle("-fx-background-color: black;");
pChart.getChildren().add(point);
//Plot the point in its initial position (value 3 on the axis)
double pointXValue = 3D;
point.setLayoutY(80D);
point.layoutXProperty().bind(Bindings.createDoubleBinding(()-> {
return xAxis.getDisplayPosition(pointXValue);
}, xAxis.lowerBoundProperty(), xAxis.upperBoundProperty(), pChart.widthProperty()));
//Handle zooming (hard-coded upper and lower bounds for the
//sake of simplicity)
Button btnZoomIn = new Button("Zoom in");
btnZoomIn.setOnAction((event) -> {
xAxis.setLowerBound(2D);
xAxis.setUpperBound(8D);
xAxis.layout();
});
Button btnZoomOut = new Button("Zoom out");
btnZoomOut.setOnAction((event) -> {
xAxis.setLowerBound(0D);
xAxis.setUpperBound(10D);
xAxis.layout();
});
bp.setCenter(vb);
bp.setTop(new HBox(btnZoomIn, btnZoomOut));
stage.setScene(new Scene(bp));
stage.setTitle("Test bind layoutX");
stage.setWidth(400D);
stage.setHeight(200D);
stage.show();
}
這將創建一個定制的雙用計算的每一個依賴關系發生變化時綁定,請參閱值的函數結合createDoubleBinding獲取更多信息。
+1 @LukasOwen 答案實際上是您與綁定相關的實際問題。
但正如您所知,每個問題都有不止一種方法,我建議我考慮可擴展性(添加很多點)和太多綁定(對於每個點)。
這種方法的關鍵是:
以下是該方法的示例:
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.control.Button;
import javafx.scene.layout.*;
import javafx.stage.Stage;
import java.util.HashMap;
import java.util.Map;
public class Test023 extends Application {
Map<Double, Region> plotPoints = new HashMap<>();
double yOffset = 80D;
Pane pChart;
@Override
public void start(Stage stage) {
NumberAxis xAxis = new NumberAxis(0D, 10D, 1D);
xAxis.needsLayoutProperty().addListener((obs, old, needsLayout) -> {
if(!needsLayout) {
plotPoints.forEach((num, point) -> {
double posX = xAxis.getDisplayPosition(num);
point.setLayoutX(posX);
point.setLayoutY(yOffset);
});
}
});
pChart = new Pane();
Pane pAxis = new Pane();
VBox vb = new VBox();
BorderPane root = new BorderPane();
pChart.setPrefHeight(100D);
pAxis.getChildren().add(xAxis);
xAxis.prefWidthProperty().bind(pAxis.widthProperty());
xAxis.setAnimated(false);
vb.setPadding(new Insets(10D));
vb.getChildren().addAll(pChart, pAxis);
addPoint(3D, "black");
addPoint(4D, "red");
addPoint(5D, "blue");
//Handle zooming (hard-coded upper and lower bounds for the sake of simplicity)
Button btnZoomIn = new Button("Zoom in");
btnZoomIn.setOnAction((event) -> {
xAxis.setLowerBound(2D);
xAxis.setUpperBound(8D);
});
Button btnZoomOut = new Button("Zoom out");
btnZoomOut.setOnAction((event) -> {
xAxis.setLowerBound(0D);
xAxis.setUpperBound(10D);
});
root.setCenter(vb);
root.setTop(new HBox(btnZoomIn, btnZoomOut));
stage.setScene(new Scene(root));
stage.setTitle("Test bind layoutX");
stage.setWidth(400D);
stage.setHeight(200D);
stage.show();
}
private void addPoint(double num, String color) {
Region point = new Region();
point.setPrefSize(5D, 5D);
point.setStyle("-fx-background-color: " + color);
plotPoints.put(num, point);
pChart.getChildren().add(point);
}
public static void main(String args[]) {
launch(args);
}
}
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