Update JavaFX stage within method - java

I am writing a program that uses a lot of data to do several calculations and it takes quite a while to finish. This is why I want to update and inform the user on the current percentage of the program being done. However I don't know how I can update the stage within the calculation method.
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Text;
import javafx.stage.Stage;
public class Main extends Application {
public void calculate() {
//Here I want to change the "percentage text"
//and update the stage.
}
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Hello World!");
Text percentage = new Text();
Button btn = new Button();
btn.setText("Say 'Hello World'");
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
calculate();
}
});
final GridPane inputGridPane = new GridPane();
GridPane.setConstraints(btn, 0, 0);
GridPane.setConstraints(percentage, 1, 0);
inputGridPane.setHgap(6);
inputGridPane.setVgap(6);
inputGridPane.getChildren().addAll(btn, percentage);
final Pane rootGroup = new VBox(12);
rootGroup.setPrefWidth(400);
rootGroup.setPrefHeight(225);
rootGroup.getChildren().addAll(inputGridPane);
rootGroup.setPadding(new Insets(12,12,12,12));
primaryStage.setScene(new Scene(rootGroup));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
This is what my code roughly looks like. Thank you in advance.

JavaFx provides a class called "Task" which can be used for background calculations while keeping the progression syncronised!
I would suggest doing it that way:
Create a second class extending Task for doing the heavy calculation:
import javafx.concurrent.Task;
public class CalculationTask extends Task<String> {
#Override
protected String call() throws Exception {
for (int i = 0; i < 100000000;i++) {
updateProgress(i, 100000000);
}
succeeded();
return "This is the computed result... Datatype can be changed by generics if you are calculation numbers";
}
}
This is one way how you could use it in your application class:
import javafx.application.Application;
import javafx.concurrent.Task;
import javafx.concurrent.WorkerStateEvent;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.Dialog;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Text;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Hello World!");
Button btn = new Button();
btn.setText("Say 'Hello World'");
Task<String> calculationTask = new CalculationTask();
ProgressBar progressBar = new ProgressBar(); //ProgressIndicator could also be used
progressBar.progressProperty().bind(calculationTask.progressProperty());
progressBar.visibleProperty().bind(calculationTask.runningProperty());
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
calculationTask.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
#Override
public void handle(WorkerStateEvent workerStateEvent) {
new Alert(Alert.AlertType.CONFIRMATION, calculationTask.getValue()).show();
}
});
new Thread(calculationTask).start();
}
});
final GridPane inputGridPane = new GridPane();
GridPane.setConstraints(btn, 0, 0);
GridPane.setConstraints(progressBar, 1, 0);
inputGridPane.setHgap(6);
inputGridPane.setVgap(6);
inputGridPane.getChildren().addAll(btn, progressBar);
final Pane rootGroup = new VBox(12);
rootGroup.setPrefWidth(400);
rootGroup.setPrefHeight(225);
rootGroup.getChildren().addAll(inputGridPane);
rootGroup.setPadding(new Insets(12,12,12,12));
primaryStage.setScene(new Scene(rootGroup));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
I hope that helped, otherwise feel free to ask questions!

Related

Cannot change the width of a button below a certain minimum

I have this code:
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.ToggleButton;
import javafx.scene.image.Image;
import javafx.scene.layout.Background;
import javafx.scene.layout.BackgroundImage;
import javafx.scene.layout.BackgroundSize;
import javafx.scene.layout.TilePane;
import javafx.stage.Stage;
public class ToggleButtonSize extends Application {
#Override
public void start(Stage stage) throws Exception {
var toggleButton = new ToggleButton();
toggleButton.setMaxHeight(10);
toggleButton.setMaxWidth(10);
// tried also
toggleButton.setStyle("-fx-max-width: 10; -fx-pref-width: 10;");
var pane = new FlowPane(toggleButton);
var scene = new Scene(pane);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
This code works fine, but when I use MobileApplication instead the minimum width does not go to 10:
How can I shrink the size like when using Application?

JavaFX; Eclipse points error at main method

I was trying to learn JavaFX and used the code on this video: https://www.youtube.com/watch?v=FLkOX4Eez6o.
I have Google it but could not find a solution.
Then Eclipse IDE shows this error:
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;
public class Testes extends Application{
Button botao;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setTitle("Controle de processos");
botao = new Button();
botao.setText("+");
StackPane layout = new StackPane();
layout.getChildren().add(botao);
Scene cena = new Scene(layout, 300, 250);
primaryStage.setScene(cena);
primaryStage.show();
}
}

JavaFX - setOnAction not applicable

I am trying to learn JavaFX, and I've written the code shown down below, however I seem to be having trouble with this line of code:
btn.setOnAction(new EventHandler<ActionEvent>()
where it underlines setOnAction, and prints this Error:
The method setOnAction(EventHandler<ActionEvent>) in the type ButtonBase is not applicable for the arguments (new EventHandler<ActionEvent>(){})
import java.awt.event.ActionEvent;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
public class Test extends Application{
public static void main(String[] args){
launch(args);
}
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Hello World!");
Button btn = new Button();
btn.setText("Say 'Hello World' ");
btn.setOnAction(new EventHandler<ActionEvent>(){
#Override
public void handle(ActionEvent event) {
System.out.println("Button clicked");
}
});
StackPane root = new StackPane();
root.getChildren().add(btn);
primaryStage.setScene(new Scene(root, 300, 250));
primaryStage.show();
}
}
What am I doing wrong?
You have imported awt event listener just change this line of code
import java.awt.event.ActionEvent;
with this
import javafx.event.ActionEvent;
and you can also use lambda expression like this
btn.setOnAction((event) -> {
System.out.println("Button clicked");
});
You're mixing up Javafx with Swing. Replace
import java.awt.event.ActionEvent;
with
import javafx.event.ActionEvent;

ProgressIndicator (Node) as a mouse cursor?

Is it possible to use a Node as a mouse cursor? I'm thinking in a ProgressIndicator. For example a determinate one, letting the user know how much percentage of the current task is done.
Probably the most reliable way to do this is to set the cursor to Cursor.NONE, and have a label with the progress indicator as its graphic, which tracks the mouse coordinates.
I tried using an ImageCursor which updated, but nothing appeared: I am guessing the images couldn't be computed quickly enough.
Here's an SSCCE of the first technique:
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.concurrent.Service;
import javafx.concurrent.Task;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Cursor;
import javafx.scene.ImageCursor;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
public class ProgressIndicatorAsCursor extends Application {
#Override
public void start(Stage primaryStage) {
Button button = new Button("Start");
Service<Void> service = new Service<Void>() {
#Override
public Task<Void> createTask() {
return new Task<Void>() {
#Override
public Void call() throws Exception {
for (int i = 1 ; i <= 1000; i++) {
Thread.sleep(10);
updateProgress(i, 1000);
}
return null ;
}
};
}
};
button.disableProperty().bind(service.runningProperty());
button.setOnAction(e -> service.restart());
ProgressIndicator pi = new ProgressIndicator();
pi.progressProperty().bind(service.progressProperty());
Pane pane = new Pane();
// fill pane with rectangle as task progresses:
Rectangle rectangle = new Rectangle();
rectangle.setFill(Color.CORNFLOWERBLUE);
rectangle.setX(0);
rectangle.widthProperty().bind(pane.widthProperty());
rectangle.heightProperty().bind(pane.heightProperty().multiply(service.progressProperty()));
rectangle.yProperty().bind(pane.heightProperty().subtract(rectangle.heightProperty()));
pane.getChildren().add(rectangle);
Label label = new Label();
label.graphicProperty().bind(
Bindings.when(service.runningProperty())
.then(pi)
.otherwise((ProgressIndicator)null));
pane.setOnMouseEntered(e ->
pane.getChildren().add(label));
pane.setOnMouseExited(e ->
pane.getChildren().remove(label));
pane.setOnMouseMoved(e -> label.relocate(e.getX(), e.getY()));
pane.cursorProperty().bind(
Bindings.when(service.runningProperty())
.then(Cursor.NONE)
.otherwise(Cursor.DEFAULT));
BorderPane.setAlignment(button, Pos.CENTER);
BorderPane.setMargin(button, new Insets(10));
BorderPane root = new BorderPane(pane, new Rectangle(0,0,0,20), null, button, null);
primaryStage.setScene(new Scene(root, 400, 600));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Sees it's impossible, but you could obtain the cursor property and keep updating it with an image as your desire.

JavaFx removing from pane object when I am in this object's class

I don't know if anyone could understand my problem from the title, but here's more specific description. I have class, in which I created a FlowPane, where I added objects of another class(images packed inside VBoxes). Each VBox have ContextMenu, where is MenuItem "Remove File". My problem is, how to remove this object while beeing inside the VBox class. Here is a little part of my code:
//removed, entire code is below after edit
The code where I'm accessing my CustomPane (my class of FlowPane, with specified attributes) works, because I can remove object if I'm doing it by their indexes, but when I remove one of them, other's indexes changes, so I'm looking for another solution. I need to specifically remove the object of the class in the code.
Okay so here is so called sscce, which of I had no idea, since now:
package sscce;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.ContextMenu;
import javafx.scene.control.Label;
import javafx.scene.control.MenuItem;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
public class Sscce extends Application {
#Override
public void start(Stage primaryStage) {
CustomPane root = new CustomPane();
root.setPadding(new Insets(20));
root.setHgap(10);
root.setVgap(10);
for (int i = 0; i < 10; i++) {
RectangleBox recB = new RectangleBox();
root.getChildren().add(recB);
}
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
class RectangleBox extends VBox {
static int index = 0;
public RectangleBox() {
Rectangle rec = new Rectangle(150, 150);
rec.setFill(Color.GREEN);
StackPane sp = new StackPane();
sp.getChildren().add(rec);
Label label = new Label(Integer.toString(index));
index++;
sp.getChildren().add(label);
getChildren().add(sp);
final ContextMenu cm = new ContextMenu();
MenuItem removeRec = new MenuItem("Remove Rectangle");
removeRec.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent t) {
((CustomPane) getParent()).getPane().getChildren().remove(0); //here is the problem, I want this line to remove the rectangle I clicked on(now it's removing first element in the pane).
}
});
cm.getItems().add(removeRec);
createContextMenuEvent(cm, rec);
}
private void createContextMenuEvent(final ContextMenu cm, final Rectangle rec) {
addEventHandler(MouseEvent.MOUSE_CLICKED, new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent t) {
if (t.getButton() == MouseButton.SECONDARY) {
cm.show(rec, t.getScreenX(), t.getScreenY());
}
}
});
}
}
class CustomPane extends FlowPane {
public CustomPane() {
//setAlignment(Pos.CENTER);
setHgap(25);
setVgap(25);
setPadding(new Insets(20));
}
public CustomPane getPane() {
return this;
}
}
It should work after copy/paste this entire code to java project. So I removed everything that is not neccessary, and I have replaced images to rectangles, now this program looks kind of stupid;p
I added comment to a line I have problem with. I hope now it's a lot clearer than before.
try this:
((CustomPane) RectangleBox.this.getParent()).getChildren().remove(RectangleBox.this);
hope it helps.

Categories