I'm building a JavaFX application with multiple Scenes. I have a problem with scope of variable when changing scenes within setOnAction event. This is my code:
Stage myStage;
public Scene logInScene(){
... all the buttons / textFields
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
**this.getStage().allScene(createAccountPane1);**
}
}
}
public Stage getStage(){
return this.myStage;
}
public void allScene(Pane p){
this.myStage.setScene(p);
}
I'm getting an error within the setOnAction function. "Cannot Find Symbol" getStage(). I know this must be a scope problem and it doesn't recognize any variables / functions outside of that scope. How do I make it so that I can change within? I've tried passing through the variable but that will just make my code messy and I wish there was a simpler way. Thanks guys!
Your code works as long as you keep consistency:
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Test extends Application{
private Stage stage;
#Override
public void start(Stage primaryStage) throws Exception {
stage = primaryStage;
Scene scene = logInScene();
primaryStage.setScene(scene);
primaryStage.show();
}
public Scene logInScene(){
Pane root = new Pane();
Button createAccountButton = new Button("create account");
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
stage.setScene(CreateAccountScene());
}
});
root.getChildren().add(createAccountButton);
return new Scene(root);
}
protected Scene CreateAccountScene() {
VBox root = new VBox();
Label userLabel = new Label("Insert the username:");
final TextField userField = new TextField();
Button createAccountButton = new Button("create account");
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
System.out.println("Account for user " + userField.getText() + " was created succesfully");
}
});
root.getChildren().addAll(userLabel,userField,createAccountButton);
return new Scene(root);
}
public static void main(String[] args) {
launch(args);
}
}
This question has already been solved, but I think it's worth clarifying that your line fails because the this keyword refers to the anonymous EventHandler you are implementing. In Java, you reference the outer class instance with OuterClass.this. So OuterClass.this.getStage().allScene(createAccountPane1); will work.
If you are looking for a prettier solution, some coders like to define a local variable that points to the outer class instance:
final OuterClass self = this;
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
self.getStage().allScene(createAccountPane1);
}
}
Related
I want to be able to always show the popup part of a combobox regardless of the fact it has been clicked or not, or even without the combo being focused. I tried to use the show() method of the combo, but in my case the popup part never shows.
My code is:
import javafx.application.Platform;
import javafx.collections.ObservableList;
import javafx.embed.swing.JFXPanel;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class ComBoBoxTest {
public static final void main(String[] args) {
ComBoBoxTest test = new ComBoBoxTest();
test.setup();
}
private void setup() {
new JFXPanel();
Platform.runLater(new Runnable() {
#Override
public void run() {
createUI();
}
});
}
private void createUI() {
Stage stage = new Stage();
Pane pane = new Pane();
ComboBox<String> combo = new ComboBox();
ObservableList<String> values = combo.getItems();
values.add("ONE");
values.add("TWO");
values.add("THREE");
combo.setVisibleRowCount(3);
combo.show();
pane.getChildren().add(combo);
Scene scene = new Scene(pane);
stage.setScene(scene);
stage.show(); // the important part
}
}
In that case, I thought that my show() method would force to open the popup, but the result is that the popup is never shown
Per the excellent comment of kleopatra, the solution is to call show() on the Combo after the Stage is shown. This example works:
import javafx.application.Platform;
import javafx.collections.ObservableList;
import javafx.embed.swing.JFXPanel;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class ComBoBoxTest {
public static final void main(String[] args) {
ComBoBoxTest test = new ComBoBoxTest();
test.setup();
}
private void setup() {
new JFXPanel();
Platform.runLater(new Runnable() {
#Override
public void run() {
createUI();
}
});
}
private void createUI() {
Stage stage = new Stage();
Pane pane = new Pane();
ComboBox<String> combo = new ComboBox();
ObservableList<String> values = combo.getItems();
values.add("ONE");
values.add("TWO");
values.add("THREE");
combo.setVisibleRowCount(3);
pane.getChildren().add(combo);
Scene scene = new Scene(pane);
stage.setScene(scene);
stage.show();
combo.show(); // call show() on the Combo after the stage is shown
}
}
According to this code, button("enlarge") will trigger an action which is calling the method enlarge(), which will do: circle.setRadius(circle.getRadius() + 2);
which is just merely changing the radius value. what I don't understand is that how merely changing the radius will somehow make the program redraw the entire circle.
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.BorderPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
public class ControlCircle extends Application {
private CirclePane1 circlePane = new CirclePane1();
#Override
public void start(Stage primaryStage) {
HBox hBox = new HBox();
hBox.setSpacing(10);
hBox.setAlignment(Pos.CENTER);
Button btEnlarge = new Button("Enlarge");
Button btShrink = new Button("Shrink");
hBox.getChildren().add(btEnlarge);
hBox.getChildren().add(btShrink);
btEnlarge.setOnAction(new EnlargeHandler());
btShrink.setOnAction(new ShrinkHandler());
BorderPane borderPane = new BorderPane();
borderPane.setCenter(circlePane);
borderPane.setBottom(hBox);
BorderPane.setAlignment(hBox, Pos.CENTER);
Scene scene = new Scene(borderPane, 200, 150);
primaryStage.setTitle("ControlCircle");
primaryStage.setScene(scene);
primaryStage.show();
}
class EnlargeHandler implements EventHandler<ActionEvent> {
#Override
public void handle(ActionEvent e) {
circlePane.enlarge();
}
}
class ShrinkHandler implements EventHandler<ActionEvent>{
#Override
public void handle(ActionEvent e) {
circlePane.shrink();
}
}
}
class CirclePane1 extends StackPane{
private Circle circle = new Circle(50);
public CirclePane1() {
getChildren().add(circle);
circle.setStroke(Color.BLACK);
circle.setFill(Color.WHITE);
}
public void enlarge() {
circle.setRadius(circle.getRadius() + 2);
}
public void shrink() {
circle.setRadius(circle.getRadius() > 2 ? circle.getRadius() - 2
: circle.getRadius());
}
}
Looking at the source code of Circle you can see how the radius property is defined:
private final DoubleProperty radius = new DoublePropertyBase() {
#Override
public void invalidated() {
NodeHelper.markDirty(Circle.this, DirtyBits.NODE_GEOMETRY);
NodeHelper.geomChanged(Circle.this);
}
#Override
public Object getBean() {
return Circle.this;
}
#Override
public String getName() {
return "radius";
}
};
When you change the value of the radius property its invalidated() method is called. And this is where the "magic" happens, it calls these two methods:
NodeHelper.markDirty(Circle.this, DirtyBits.NODE_GEOMETRY);
NodeHelper.geomChanged(Circle.this);
Now, I don't know what these methods do specifically - nor do I have the time/desire to study it - but they tell the JavaFX runtime that the Circle needs to be redrawn. This means that the next time a rendering pulse occurs, which may be triggered by these methods, the Circle will be drawn with its new radius.
This is all very optimized and will cause a redraw only when applicable (such as only when part of ascene-graph).
I have an internal jfxtra window. On clicking a button, I want to bring it forward.
The code that I have tried :
window w = new window("mdi win");
private Stage primaryStage;
private BorderPane rootLayout;
...
public void win() {
Parent bla = FXMLLoader.load(getClass().getResource("bla.fxml"));
w.getContentPane().getChildren().add(bla);
rootLayout.getChildren().add(w);
}
private void wfront(ActionEvent event) throws Exception {
w.isMoveToFront(); // is not?
}
How to make it possible?
So you made me curious and I went through the JFXtras docs. I came to know that Window in Jfxtras extends Control. So there is a method called toFront which can be fired on it. To show this I have created a sample for you.
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import jfxtras.scene.control.window.Window;
public class NewWindow extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
StackPane stackPane = new StackPane();
Button button = new Button("Click Me to show Window !");
Window window = new Window("Cick Me to bring me to front");
button.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
window.toFront();
window.setTitle("I am on the Front");
}
});
window.setPrefSize(200, 200);
stackPane.getChildren().addAll(window, button);
Scene scene = new Scene(stackPane, 500, 500);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Let me know, if you are looking for something else !
I'm building a JavaFX application with multiple Scenes. I have a problem with scope of variable when changing scenes within setOnAction event. This is my code:
Stage myStage;
public Scene logInScene(){
... all the buttons / textFields
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
**this.getStage().allScene(createAccountPane1);**
}
}
}
public Stage getStage(){
return this.myStage;
}
public void allScene(Pane p){
this.myStage.setScene(p);
}
I'm getting an error within the setOnAction function. "Cannot Find Symbol" getStage(). I know this must be a scope problem and it doesn't recognize any variables / functions outside of that scope. How do I make it so that I can change within? I've tried passing through the variable but that will just make my code messy and I wish there was a simpler way. Thanks guys!
Your code works as long as you keep consistency:
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Test extends Application{
private Stage stage;
#Override
public void start(Stage primaryStage) throws Exception {
stage = primaryStage;
Scene scene = logInScene();
primaryStage.setScene(scene);
primaryStage.show();
}
public Scene logInScene(){
Pane root = new Pane();
Button createAccountButton = new Button("create account");
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
stage.setScene(CreateAccountScene());
}
});
root.getChildren().add(createAccountButton);
return new Scene(root);
}
protected Scene CreateAccountScene() {
VBox root = new VBox();
Label userLabel = new Label("Insert the username:");
final TextField userField = new TextField();
Button createAccountButton = new Button("create account");
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
System.out.println("Account for user " + userField.getText() + " was created succesfully");
}
});
root.getChildren().addAll(userLabel,userField,createAccountButton);
return new Scene(root);
}
public static void main(String[] args) {
launch(args);
}
}
This question has already been solved, but I think it's worth clarifying that your line fails because the this keyword refers to the anonymous EventHandler you are implementing. In Java, you reference the outer class instance with OuterClass.this. So OuterClass.this.getStage().allScene(createAccountPane1); will work.
If you are looking for a prettier solution, some coders like to define a local variable that points to the outer class instance:
final OuterClass self = this;
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
public void handle(ActionEvent t){
self.getStage().allScene(createAccountPane1);
}
}
I am digging the documentation to see if there's a remove method, I just get this link whenever I google
http://www.coderanch.com/t/580998/JavaFX/java/remove-node
there's a simple remove option
Eg : .getChildren().remove(object)
It does not seem to work for me !
The code which you've provided works fine with me.
Add circle with ALT+Click, and remove them by simply clicking on them.
The reason I've used the ALT key for adding the circles is because in the below code, both the scene and the circles handle mouse clicks. Thus, the code has to know from where the event is coming from. This is just an example, of course.
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
public class ChangeListenerSample extends Application {
public static void main(final String[] args) {
launch(args);
}
#Override
public void start(final Stage primaryStage) throws Exception {
final Group root = new Group();
primaryStage.setResizable(false);
final Scene scene = new Scene(root, 400,80);
primaryStage.setScene(scene);
scene.addEventHandler(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
#Override public void handle(final MouseEvent event)
{
if (!event.isAltDown())
return;
final Circle circle = new Circle(event.getSceneX(), event.getSceneY(),30);
circle.setFill(Color.YELLOW);
root.getChildren().add(circle);
circle.addEventHandler(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
#Override public void handle(final MouseEvent arg0)
{
root.getChildren().remove(circle);
}
});
}
});
primaryStage.show();
}
}