JavaFX mouse event Throwing Exception - exception

Question

I Have this code, It uses JavaFX Controls, the Code "fi.setOnAction(e -> fi.setStyle("-fx-background-color: #00C275;"));" is supposed to Change the Color of the Button fi, But Doesn't work(Throws Exception), but Interestingly it works after All other Code except for button and the setOnAction is removed :
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleStringProperty;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Control;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.*;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.text.Text;
import javafx.stage.Stage;
import javafx.scene.control.*;
public class Medow extends Application {
public static void main(String arg[]) {
launch(arg);
}
public void start(Stage primarystage) {
primarystage.setTitle("Medow");
primarystage.setResizable(false);
// Label l = new Label("Hello");
// setXY( 0, 0, l);
Image image = new Image("/modified/user.jpg");
ImageView iv1 = new ImageView();
iv1.setImage(image);
iv1.setFitWidth(93.75);
iv1.setPreserveRatio(true);
//iv1.setX(75);
//iv1.setY(75);
Circle c = new Circle(46.875, 46.875, 46.875, Color.BLUE); // Previously it was 75, 75 - after adding image the Circle Moves Down, and changing it to 93.75/2 = 46.875 fixes this.
iv1.setClip(c);
VBox v1 = new VBox(iv1); // Upper Left VBox - inside vb
v1.setMinHeight(170);
v1.setPadding(new Insets(28.125, 0, 0, 28.125));
Label fa = new Label("Farming");
fa.setStyle("-fx-text-fill: #969696; -fx-font-weight: bold;");
fa.setPadding(new Insets(5, 0, 10, 10));
//fi.setStyle("-fx-background-color: #606365; -fx-text-fill: #ffffff; -fx-font-weight: bold;");
ImageView fiv = new ImageView(new Image("/modified/map.png"));
fiv.setFitHeight(20);
fiv.setPreserveRatio(true);
Button fi = new Button("Farm", fiv); // Farm Button
fi.setPadding(new Insets(7.5, 65, 7.5, 20)); // It would be more Efficient to use HBox inside Button
fi.setGraphicTextGap(10);
ImageView crv = new ImageView(new Image("/modified/crop.png"));
crv.setFitHeight(20);
crv.setPreserveRatio(true);
Button cr = new Button( "Crop", crv); // Crop Button
cr.setGraphicTextGap(10);
cr.setPadding(new Insets(7.5, 67, 7.5, 20));
ImageView rfv = new ImageView(new Image("/modified/rain.png"));
rfv.setFitHeight(20);
rfv.setPreserveRatio(true);
Button rf = new Button("Rainfall", rfv); // Rainfall Button
rf.setPadding(new Insets(7.5, 50, 7.5, 20));
rf.setGraphicTextGap(10);
ImageView mov = new ImageView(new Image("/modified/drop.png"));
mov.setFitHeight(20);
mov.setPreserveRatio(true);
Button mo = new Button("Moisture", mov); // Moisture
mo.setPadding(new Insets(7.5, 40, 7.5, 20));
mo.setGraphicTextGap(10);
ImageView evv = new ImageView(new Image("/modified/cal.png"));
evv.setFitHeight(20);
evv.setPreserveRatio(true);
Button ev = new Button("Events", evv); //Events
ev.setPadding(new Insets( 7.5, 55, 7.5, 20));
ev.setGraphicTextGap(10);
cr.setId("lp");
rf.setId("lp");
mo.setId("lp");
ev.setId("lp");
fi.setId("lp");
changeBackgroundOnHoverUsingBinding(cr);
changeBackgroundOnHoverUsingBinding(rf);
changeBackgroundOnHoverUsingBinding(mo);
changeBackgroundOnHoverUsingBinding(ev);
changeBackgroundOnHoverUsingBinding(fi);
/* fi.setOnMouseClicked(new EventHandler<MouseEvent>() {
fi.setStyle("")
}); */
fi.setOnAction(e -> fi.setStyle("-fx-background-color: #00C275;"));
/*
changeBackgroundOnClickUsingBinding(fi);
changeBackgroundOnClickUsingBinding(cr);
changeBackgroundOnClickUsingBinding(mo);
changeBackgroundOnClickUsingBinding(ev);
changeBackgroundOnClickUsingBinding(rf);
*/
VBox v2 = new VBox( fa, fi, cr, rf, mo, ev); // Lower Left VBox - inside vb
v2.setPadding(new Insets( 0, 0, 0, 0));
VBox vb = new VBox(v1, v2); // Left Outer Most VBox
vb.setMaxWidth(150);
vb.setMinWidth(150);
vb.setStyle("-fx-background-color: #454851;");
BorderPane bp = new BorderPane();
bp.setLeft(vb);
Scene sc = new Scene(bp, 800, 500);
sc.getStylesheets().add(Medow.class.getResource("all.css").toExternalForm()); // Adding all.css
primarystage.setScene(sc);
primarystage.show();
}
public void setXY(double x, double y, Control o){
o.setLayoutX(x);
o.setLayoutY(y);
}
/* public void butStyle(Control... b1){
for(Control b : b1){
//b.setStyle("-fx-background-color: :#606365;");
}
} */
private void changeBackgroundOnHoverUsingBinding(Node node) { // Function To Change Button Color on Hover
node.styleProperty().bind(
Bindings
.when(node.hoverProperty())
.then(
new SimpleStringProperty("-fx-background-color: #373940;")
)
.otherwise(
new SimpleStringProperty("-fx-background-color: #454851;")
)
);
}
}
Here is the Exception it is Throwing :
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: Button.style : A bound value cannot be set.
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:140)
at javafx.scene.Node$4.set(Node.java:1101)
at javafx.scene.Node$4.set(Node.java:1095)
at javafx.scene.Node.setStyle(Node.java:1073)
at Medow$1.handle(Medow.java:121)
at Medow$1.handle(Medow.java:116)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$355(GlassViewEventHandler.java:388)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: Button.style : A bound value cannot be set.
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:140)
at javafx.scene.Node$4.set(Node.java:1101)
at javafx.scene.Node$4.set(Node.java:1095)
at javafx.scene.Node.setStyle(Node.java:1073)
at Medow$1.handle(Medow.java:121)
at Medow$1.handle(Medow.java:116)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$355(GlassViewEventHandler.java:388)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
Process finished with exit code 0

Answer 1

The stack trace tells you the problem:
Button.style : A bound value cannot be set.
i.e. you have bound the style property with
node.styleProperty().bind(...
and then you try to call
fi.setStyle("-fx-background-color: #00C275;")
To fix this, you either need to unbind the style property before setting it in the handler (in which case it will no longer change color when the mouse hovers/unhovers over it), or your binding needs to accommodate the logic of having been pressed. Which approach you use depends on what functionality you want.