JavaFX的錨沒有延伸到整個場景

Question

我有這樣的代碼：

package javafxapplication9; 

import javafx.application.Application; 
import javafx.beans.property.*; 
import javafx.beans.value.*; 
import javafx.collections.*; 
import javafx.event.EventHandler; 
import javafx.scene.*; 
import javafx.scene.input.MouseEvent; 
import javafx.scene.layout.StackPane; 
import javafx.scene.paint.Color; 
import javafx.scene.shape.*; 
import javafx.stage.Stage; 


public class JavaFXApplication9 extends Application { 
StackPane pane; 
public static void main(String[] args) throws Exception { launch(args); } 


@Override public void start(final Stage stage) throws Exception { 
Polygon triangle = createStartingTriangle(); 
pane=new StackPane(); 

Group root = new Group(); 
root.getChildren().add(triangle); 
root.getChildren().addAll(createControlAnchorsFor(triangle.getPoints())); 
pane.getChildren().add(root); 
pane.setPrefWidth(600); 
pane.setPrefHeight(600); 
stage.setTitle("Triangle Manipulation Sample"); 
stage.setScene(
    new Scene(
    pane, 
    400, 400, Color.ALICEBLUE 
) 
); 
stage.show(); 
} 

// creates a triangle. 
private Polygon createStartingTriangle() { 
Polygon triangle = new Polygon(); 

triangle.getPoints().setAll(
    100d, 100d, 
    150d, 50d, 
    250d, 150d 
); 

triangle.setStroke(Color.FORESTGREEN); 
triangle.setStrokeWidth(4); 
triangle.setStrokeLineCap(StrokeLineCap.ROUND); 
triangle.setFill(Color.CORNSILK.deriveColor(0, 1.2, 1, 0.6)); 

return triangle; 
} 


private ObservableList<Anchor> createControlAnchorsFor(final ObservableList<Double> points) { 
ObservableList<Anchor> anchors = FXCollections.observableArrayList(); 

for (int i = 0; i < points.size(); i+=2) { 
    final int idx = i; 

    DoubleProperty xProperty = new SimpleDoubleProperty(points.get(i)); 
    DoubleProperty yProperty = new SimpleDoubleProperty(points.get(i + 1)); 

    xProperty.addListener(new ChangeListener<Number>() { 
    @Override public void changed(ObservableValue<? extends Number> ov, Number oldX, Number x) { 
     points.set(idx, (double) x); 
    } 
    }); 

    yProperty.addListener(new ChangeListener<Number>() { 
    @Override public void changed(ObservableValue<? extends Number> ov, Number oldY, Number y) { 
     points.set(idx + 1, (double) y); 
    } 
    }); 
    Anchor an=new Anchor(Color.GOLD, xProperty, yProperty,pane); 
    anchors.add(an); 
} 

return anchors; 

}

class Anchor extends Circle { 
Anchor(Color color, DoubleProperty x, DoubleProperty y,StackPane pane) { 
    super(x.get(), y.get(), 10); 
    setFill(color.deriveColor(1, 1, 1, 0.5)); 
    setStroke(color); 
    setStrokeWidth(2); 
    setStrokeType(StrokeType.OUTSIDE); 

    x.bind(centerXProperty()); 
    y.bind(centerYProperty()); 
    enableDrag(); 
} 

// make a node movable by dragging it around with the mouse. 
private void enableDrag() { 
    final Delta dragDelta = new Delta(); 
    setOnMousePressed(new EventHandler<MouseEvent>() { 
    @Override public void handle(MouseEvent mouseEvent) { 
     // record a delta distance for the drag and drop operation. 
     dragDelta.x = getCenterX() - mouseEvent.getX(); 
     dragDelta.y = getCenterY() - mouseEvent.getY(); 
     pane.setCursor(Cursor.MOVE); 
    } 
    }); 
    setOnMouseReleased(new EventHandler<MouseEvent>() { 
    @Override public void handle(MouseEvent mouseEvent) { 
     pane.setCursor(Cursor.HAND); 
    } 
    }); 
    setOnMouseDragged(new EventHandler<MouseEvent>() { 
    @Override public void handle(MouseEvent mouseEvent) { 
     double newX = mouseEvent.getX() + dragDelta.x; 
     if (newX > 0 && newX < pane.getWidth()) { 
     setCenterX(newX); 
     } 
     double newY = mouseEvent.getY() + dragDelta.y; 
     if (newY > 0 && newY < pane.getHeight()) { 
     setCenterY(newY); 
     } 
    } 
    }); 
    setOnMouseEntered(new EventHandler<MouseEvent>() { 
    @Override public void handle(MouseEvent mouseEvent) { 
     if (!mouseEvent.isPrimaryButtonDown()) { 
     pane.setCursor(Cursor.HAND); 
     } 
    } 
    }); 
    setOnMouseExited(new EventHandler<MouseEvent>() { 
    @Override public void handle(MouseEvent mouseEvent) { 
     if (!mouseEvent.isPrimaryButtonDown()) { 
     pane.setCursor(Cursor.DEFAULT); 
     } 
    } 
    }); 
} 

// records relative x and y co-ordinates. 
private class Delta { double x, y; } 
} 
} 

的問題是，我不能動三角形的邊緣一路到場景的頂部。 如果我不使用stackPane，只有一個場景效果很好，但我需要Stack Pane，因爲接下來我要做的是將三角形保存爲圖像並將圖像用作背景。每次我都會保存一個新的三角形，它的形象將與其他人重疊。歡迎任何消化。謝謝。

Answer 1

首先，我不想說NICE PROGRAM ;-)
現在對您的問題，這個問題很容易解決。 ;-)
只需使用AnchorPane而不是組。

下面是代碼：

@Override 
public void start(final Stage stage) throws Exception { 
    Polygon triangle = createStartingTriangle(); 
    pane = new StackPane(); 

    //Use an AnchorPane instead of a Group ;) 
    AnchorPane ap = new AnchorPane(); 
    ap.getChildren().add(triangle); 
    ap.getChildren().addAll(createControlAnchorsFor(triangle.getPoints())); 
    pane.getChildren().add(ap); 
    pane.setPrefWidth(600); 
    pane.setPrefHeight(600); 
    stage.setTitle("Triangle Manipulation Sample"); 
    stage.setScene(
      new Scene(
      pane, 
      400, 400, Color.ALICEBLUE)); 
    stage.show(); 
}