How do I successfully call setPreferredSize in a method? I'm calling setPreferredSize twice. If I remove the call inside the constructor, the panel doesn't appear at all, whereas it had earlier appeared with the undesired size (500,300). This demonstrates that setPreferredSize is being executed in the constructor, but not in the method of the same class. Note that this is the only issue (as far as I have tested) with my code; there's no unexpected interference outside the code below.
...
public abstract class XYGrapher extends JPanel{
...
JFrame frame;
JPanel contentPane;
...
public XYGrapher() {
frame = new JFrame("Grapher");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane = new JPanel();
contentPane.setPreferredSize(new Dimension(500, 300));
contentPane.setLayout(new SpringLayout());
this.setPreferredSize(new Dimension(500, 300));
frame.setContentPane(contentPane);
frame.pack();
frame.setVisible(true);
contentPane.add(this);
}
//
public void drawGraph(int xPixelStart, int yPixelStart, int pixelsWide, int pixelsHigh) {
...
contentPane.setPreferredSize(new Dimension(pixelsWide, pixelsHigh));
this.setPreferredSize(new Dimension(pixelsWide, pixelsHigh));
...
}
//*/
}
For reference, this is how XYGrapher eventually gets used:
public class GrapherTester extends XYGrapher{
...
public static void main(String[] args) {
GrapherTester g = new GrapherTester();
g.drawGraph(0,0,100,100);
}
}
I have managed to fix the issue in the meantime. Simply add
frame.pack();
to the method.
Related
I read much about the JavaFX GUI Model, Plattform->RunLater and Threads, but I still do not figure out how to get this right. I had a JavaFX GUI which on a button click executed a process and updated a Progress Bar and Label. This was running well with Threading and Platform, but I had to Change this to an Observer Model.
I invoke a Progress Tracker in a Singleton Model, which gets updated by the class executing the process and is Observable. I implemented an Observer as well which should update the two UI Elements.
GUI Controller with Button Event
private void createKeyPressed(ActionEvent event) {
// Make Progressbar visible
pbKeyProgress.visibleProperty().set(true);
if (!Check.keyFileExistant() || cbKeyOverwrite.selectedProperty().get()) {
ProgressTracker.getTracker().addObserver(new ProgressObserver(pbKeyProgress, lblKeyProgress));
Creator.createKey(cbKeyLength.getValue());
} else {
}
}
Progress Observer
public class ProgressObserver implements Observer {
private final ProgressBar progressBar;
private final Label statusLabel;
public ProgressObserver(ProgressBar progressBar, Label statusLabel) {
this.progressBar = progressBar;
this.statusLabel = statusLabel;
}
#Override
public void update(Observable o, Object o1) {
Platform.runLater(() -> {
System.out.println("Tracker set to "+ProgressTracker.getProgress() + " " + ProgressTracker.getStatus());
progressBar.setProgress(ProgressTracker.getProgress());
statusLabel.setText(ProgressTracker.getStatus());
});
}
}
Progress Tracker
public synchronized void setTracker(int currentStep, String currentStatus) {
checkInstance();
instance.step = currentStep;
instance.status = currentStatus;
instance.notifyObservers();
System.out.println(instance.countObservers());
}
Creator
public static void createKey(String length) {
Task<Void> task;
task = new Task<Void>() {
#Override
public Void call() throws Exception {
initTracker(0,"Start");
doStuff();
ProgressTracker.getTracker().setTracker(1,"First");
doStuff();
ProgressTracker.getTracker().setTracker(2,"Second");
// and so on
return null;
}
};
new Thread(task)
.start();
}
The Print within the ProgressTracker gets executed. However, if I add a print within the update of the Observer nothing will be printed. If I check within the Progresstracker, the Observer Count is 1.
Why does the Observer not get notified or execute anything, even if the Notify is called? Did I get the Threading and Execution Modell wrong?
The Progress Bar and the Label will also stay on their initial values.
Don't reinvent the wheel. The JavaFX Properties Pattern is a ready-made implementation of the Observable pattern: there is no need to implement it yourself. Additionally, Task already defines methods for updating various properties, which can be called from any thread but will schedule the actual updates on the FX Application Thread. See updateProgress() and updateMessage(), for example.
So you can do, for example:
public static Task<Void> createKey(String length) {
Task<Void> task;
task = new Task<Void>() {
final int totalSteps = ... ;
#Override
public Void call() throws Exception {
updateProgress(0, totalSteps);
updateMessage("Start");
doStuff();
updateProgress(1, totalSteps);
updateMessage("First");
doStuff();
updateProgress(2, totalSteps);
updateMessage("Second");
// and so on
return null;
}
};
new Thread(task)
.start();
return task ;
}
and
private void createKeyPressed(ActionEvent event) {
// Make Progressbar visible
pbKeyProgress.visibleProperty().set(true);
if (!Check.keyFileExistant() || cbKeyOverwrite.selectedProperty().get()) {
Task<Void> task = Creator.createKey(cbKeyLength.getValue());
pbKeyProgress.progressProperty().bind(task.progressProperty());
lblKeyProgress.textProperty().bind(task.messageProperty());
} else {
}
}
I'm new guy here :)
I have a small problem which concerns binding in JavaFX. I have created Task which is working as a clock and returns value which has to be set in a special label (label_Time). This label presents how many seconds left for player's answer in quiz.
The problem is how to automatically change value in label using the timer task? I tried to link value from timer Task (seconds) to label_Time value in such a way...
label_Time.textProperty().bind(timer.getSeconds());
...but it doesn't work. Is it any way to do this thing?
Thanks in advance for your answer! :)
Initialize method in Controller class:
public void initialize(URL url, ResourceBundle rb) {
Timer2 timer = new Timer2();
label_Time.textProperty().bind(timer.getSeconds());
new Thread(timer).start();
}
Task class "Timer2":
public class Timer2 extends Task{
private static final int SLEEP_TIME = 1000;
private static int sec;
private StringProperty seconds;
public Timer2(){
Timer2.sec = 180;
this.seconds = new SimpleStringProperty("180");
}
#Override protected StringProperty call() throws Exception {
int iterations;
for (iterations = 0; iterations < 1000; iterations++) {
if (isCancelled()) {
updateMessage("Cancelled");
break;
}
System.out.println("TIK! " + sec);
seconds.setValue(String.valueOf(sec));
System.out.println("TAK! " + seconds.getValue());
// From the counter we subtract one second
sec--;
//Block the thread for a short time, but be sure
//to check the InterruptedException for cancellation
try {
Thread.sleep(10);
} catch (InterruptedException interrupted) {
if (isCancelled()) {
updateMessage("Cancelled");
break;
}
}
}
return seconds;
}
public StringProperty getSeconds(){
return this.seconds;
}
}
Why your app does not work
What is happening is that you run the task on it's own thread, set the seconds property in the task, then the binding triggers an immediate update of the label text while still on the task thread.
This violates a rule for JavaFX thread processing:
An application must attach nodes to a Scene, and modify nodes that are already attached to a Scene, on the JavaFX Application Thread.
This is the reason that your originally posted program does not work.
How to fix it
To modify your original program so that it will work, wrap the modification of the property in the task inside a Platform.runLater construct:
Platform.runLater(new Runnable() {
#Override public void run() {
System.out.println("TIK! " + sec);
seconds.setValue(String.valueOf(sec));
System.out.println("TAK! " + seconds.getValue());
}
});
This ensures that when you write out to the property, you are already on the JavaFX application thread, so that when the subsequent change fires for the bound label text, that change will also occur on the JavaFX application thread.
On Property Naming Conventions
It is true that the program does not correspond to JavaFX bean conventions as Matthew points out. Conforming to those conventions is both useful in making the program more readily understandable and also for making use of things like the PropertyValueFactory which reflect on property method names to allow table and list cells to automatically update their values as the underlying property is updated. However, for your example, not following JavaFX bean conventions does not explain why the program does not work.
Alternate Solution
Here is an alternate solution to your countdown binding problem which uses the JavaFX animation framework rather than the concurrency framework. I prefer this because it keeps everything on the JavaFX application thread and you don't need to worry about concurrency issues which are difficult to understand and debug.
import javafx.animation.*;
import javafx.application.Application;
import javafx.beans.*;
import javafx.beans.binding.Bindings;
import javafx.beans.property.*;
import javafx.event.*;
import javafx.geometry.Pos;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Duration;
public class CountdownTimer extends Application {
#Override public void start(final Stage stage) throws Exception {
final CountDown countdown = new CountDown(10);
final CountDownLabel countdownLabel = new CountDownLabel(countdown);
final Button countdownButton = new Button(" Start ");
countdownButton.setOnAction(new EventHandler<ActionEvent>() {
#Override public void handle(ActionEvent t) {
countdownButton.setText("Restart");
countdown.start();
}
});
VBox layout = new VBox(10);
layout.getChildren().addAll(countdownLabel, countdownButton);
layout.setAlignment(Pos.BASELINE_RIGHT);
layout.setStyle("-fx-background-color: cornsilk; -fx-padding: 20; -fx-font-size: 20;");
stage.setScene(new Scene(layout));
stage.show();
}
public static void main(String[] args) throws Exception {
launch(args);
}
}
class CountDownLabel extends Label {
public CountDownLabel(final CountDown countdown) {
textProperty().bind(Bindings.format("%3d", countdown.timeLeftProperty()));
}
}
class CountDown {
private final ReadOnlyIntegerWrapper timeLeft;
private final ReadOnlyDoubleWrapper timeLeftDouble;
private final Timeline timeline;
public ReadOnlyIntegerProperty timeLeftProperty() {
return timeLeft.getReadOnlyProperty();
}
public CountDown(final int time) {
timeLeft = new ReadOnlyIntegerWrapper(time);
timeLeftDouble = new ReadOnlyDoubleWrapper(time);
timeline = new Timeline(
new KeyFrame(
Duration.ZERO,
new KeyValue(timeLeftDouble, time)
),
new KeyFrame(
Duration.seconds(time),
new KeyValue(timeLeftDouble, 0)
)
);
timeLeftDouble.addListener(new InvalidationListener() {
#Override public void invalidated(Observable o) {
timeLeft.set((int) Math.ceil(timeLeftDouble.get()));
}
});
}
public void start() {
timeline.playFromStart();
}
}
Update for additional questions on Task execution strategy
Is it possible to run more than one Task which includes a Platform.runLater(new Runnable()) method ?
Yes, you can use multiple tasks. Each task can be of the same type or a different type.
You can create a single thread and run each task on the thread sequentially, or you can create multiple threads and run the tasks in parallel.
For managing multiple tasks, you can create an overseer Task. Sometimes it is appropriate to use a Service for managing the multiple tasks and the Executors framework for managing multiple threads.
There is an example of a Task, Service, Executors co-ordination approach: Creating multiple parallel tasks by a single service In each task.
In each task you can place no runlater call, a single runlater call or multiple runlater calls.
So there is a great deal of flexibility available.
Or maybe I should create one general task which will be only take data from other Tasks and updating a UI?
Yes you can use a co-ordinating task approach like this if complexity warrants it. There is an example of such an approach in in Render 300 charts off screen and save them to files.
Your "Timer2" class doesn't conform to the JavaFX bean conventions:
public String getSeconds();
public void setSeconds(String seconds);
public StringProperty secondsProperty();
For the life of me, I cannot figure out why this program does not work in Java 7. I've run it with no problems in using Java 6, but as soon as I run it with Java 7, it doesn't work.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class HelloWorld implements ActionListener {
JButton button;
boolean state;
public HelloWorld(){
init();
state = false;
System.out.println("state - "+state);
while (true){
if (state == true){
System.out.println("Success");
}
}
}
private void init(){
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
button = new JButton("Button");
button.addActionListener(this);
frame.add(button);
frame.pack();
frame.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
JButton source = (JButton)e.getSource();
if (source == button){
state = !state;
System.out.println("state - "+state);
}
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
new HelloWorld();
}
}
Using Java 6, if I press the button, it will print out the phrase "Success" until I hit the button again. Using Java 7 registers that the button was pressed and the value of state was changed to true, but the phrase "Success" is never printed. What's going on?
Add volatile to the field declaration.
Without volatile, changes in the field are not guaranteed to be visible on other threads.
In particular, the JITter is free to believe that the field never changes on the main thread, allowing it to remove the if entirely.
When you show the JFrame
frame.setVisible(true);
The Java Show the window and stop the execution on this line.
You configured the window to exit on close:
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
This program will terminate after you close the window.
So the code after the init() call will never be executed.
As I'm learning the new world of JavaFX2 I stumbled on another annoying problem. I'm developing a program with multiple scenes (~10 scenes). For that I created a small class like this:
public class SceneSelector {
...
public void setScene(Stage stage, String fxmlfilename, ObservableList ol) throws Exception{
String s = "../" + fxmlfilename;
Parent root = FXMLLoader.load(getClass().getResource(s));
root.setUserData(ol);
Scene scene = new Scene(root);
stage.setScene(scene);
//show the stage
stage.show();
}
}
This class works good enough for switching between the scenes.
Now the problem is that I sometimes need to pass data from Scene1 to Scene2. I'm trying to do this by setting the setUserData() for the new scene which basicly works exept for one thing. How can I get the userdata when the new Scene is beeing initialized? (because the Nodes are still null at that time)
Code at scene1:
//Code connected to a button that opens the new Scene
private void openLabID(ActionEvent event) throws Exception {
final Stage primaryStage = (Stage) btnNewScene.getScene().getWindow();
ObservableList<Koe> olAfTeWerkenKoeien = DA_Koe.getAfTeWerkenKoeien();
ss.setScene(primaryStage, "GUI/scenes/koe/Koe.fxml", olAfTeWerkenKoeien);
}
Code at scene2:
public void initialize(URL url, ResourceBundle rb) {
Scene s = lbl.getScene();
ObservableList<Koe> olAfTeWerkenKoeien = (ObservableList<Koe>) s.getRoot().getUserData();
System.out.println(olAfTeWerkenKoeien.size());
}
Of course Scene s gives a null value at this point (because lbl is null at this point), so I wonder, is there a method that is beeing fired right after initialize?
When I attach this code to a button on Scene2, it works like a charm, but it should be loaded automatically.
EDIT:
The setting of the data with the setMyData() method is not a problem, however retrieving it is:
public ObservableList<Koe> getMyData() {
return this.myData;
}
How can I get the CustomScene object when a controller initializes? Because doing this below will result in a NullPointerException (because btnSluiten is not initialized just yet):
#Override
public void initialize(URL url, ResourceBundle rb) {
...
Stage stage = (Stage) btnSluiten.getScene().getWindow();
CustomScene cs = (CustomScene) stage.getScene();
ObservableList<Koe> olKoe = cs.getMyData();
System.out.println(olKoe.size());
}
I believe you missed the point within the Scene object. From the Scene class documentation we can see that:
The JavaFX Scene class is the container for all content in a scene graph.
Which means that the Scene object is just a container and as such it's not supposed to hold any data.
With that in mind, you can make another static object with a field such as
private static Label lbl;
...
public static Label getLbl()
{
return MyStaticObject.Lbl;
}
...
and use it to store your lbl (or whatever object suits your information) and then statically retrieve it.
I'm doing that to set the owner of my other Stage objects from my application. I hope it helps. Cheers
If you really want your scene to be meaningful (aka store specific user data) you can extend it:
public class FooScene extends Scene {
private ObservableList myData;
public setMyData(ObservableList data) {
this.myData = data;
//handle data
}
}
The easiest way to make sure setup code is called after scene initialized it to call it by yourself:
public class SceneSelector {
...
public void setScene(Stage stage, String fxmlfilename, ObservableList ol) throws Exception{
String s = "../" + fxmlfilename;
Parent root = FXMLLoader.load(getClass().getResource(s));
// first: add root to scene
FooScene scene = new FooScene(root);
// second: apply data to scene (or root)
scene.setMyData(ol);
stage.setScene(scene);
//show the stage
stage.show();
}
}
You can use controller for scenes and pass the data through controller:
String filePath1 = "../" + fxmlfilename;
URL location1 = YourController1.class.getResource(filePath1);
FXMLLoader fxmlLoader = new FXMLLoader();
fxmlLoader.setLocation(location1);
fxmlLoader.setBuilderFactory(new JavaFXBuilderFactory());
Parent root = (Node) fxmlLoader.load(location1.openStream());
YourController1 ctrl1 = (YourController1) fxmlLoader.getController();
Then you can assign data to the controller:
ctrl1.setUserData();
Finally, just show the scene as you want:
Scene scene = new Scene(root);
stage.setScene(scene);
//show the stage
stage.show();
In the initialize() method in the controller, just get data from controller as usual data object.
Some Addition of #Sergey Grinev :
Create A custom Scene :
package sample;
import javafx.scene.Parent;
import javafx.scene.Scene;
public class DataPassingScene extends Scene {
public DataPassingScene(Parent parent) {
super(parent);
}
String tafsir;
public String getTafsir() {
return tafsir;
}
public void setTafsir(String tafsir) {
this.tafsir = tafsir;
}
}
Suppose your Main Class Name is App.java, Then Create a method to show new Stage :
public static void showLayout (Stage primaryStage, String fxmlFileName, String stringData) throws IOException {
Parent root = FXMLLoader.load(Objects.requireNonNull(App.class.getClassLoader().getResource(fxmlFileName)));
DataPassingScene scene = new DataPassingScene(root);
scene.setTafsir(stringData); // Here we pass the data
primaryStage.setScene(scene);
primaryStage.show();
}
Now When you want to pass the Data, Call the above method from any Where / any class in your app with some Data :
String tafsir = "This My Data" ;
try {
App.showLayout(new Stage(), "showTafsirFxml.fxml",tafsir);
} catch (IOException e) {
e.printStackTrace();
}
Then Get the data in your controller. To get the scene you have to get the stage, and to get the stage you have use one of your elements of FXML, suppose here your element is a button, called closeButton, So :
#FXML
private Button closeButton;
#Override
public void initialize(URL url, ResourceBundle rb) {
Platform.runLater(new Runnable() {
#Override public void run() {
Stage stage = (Stage) closeButton.getScene().getWindow();
DataPassingScene scene = (DataPassingScene) stage.getScene();
String s = scene.getTafsir(); // Here we get the Data
if(s!=null)
System.out.println("This is Tafsir From Highlight Table: "+s);
else
System.out.println("Data Passing Null");
}});
}
because, You have to wait some Times in above runLater, because for initializing scene take some time. Other wise scene will be null.
I know that the way the declaration of the graphics device is suppose to look in the main Game1() constructor is:
GraphicsDeviceManager graphics;
graphics = new GraphicsDeviceManager(this);
then you can use stuff like:
graphics.PreferredBackBufferWidth = 1366;
But if I declare the same inside a separate class, what do I fill in for "this"?
GraphicsDeviceManager graphics;
graphics = new GraphicsDeviceManager(?);
EDIT:
After modifying everything as you said, I now get a error that sends me to this line of code:
/// <summary>
/// Event handler for when the Play Game menu entry is selected.
/// </summary>
void PlayGameMenuEntrySelected(object sender, PlayerIndexEventArgs e, Game game)
{
LoadingScreen.Load(ScreenManager, true, e.PlayerIndex,
new GameplayScreen(game));
}
This program is the menu sample you can get from Microsoft, heavily modified of course, this is the code that executes when you hit enter on the main menu screen with "Play Game" highlighted. I guess the problem is passing the variable.
Edit 2:
I fixed the code I think but now it sent me to this line and I don't know how to edit it.
playGameMenuEntry.Selected += PlayGameMenuEntrySelected;
You need a reference to your Game instance. I'd just pass it to your new class constructor.
For example, if you want to move the GraphicsDeviceManager instance into a separate class, Foo,
/// <summary>
/// This is the main type for your game
/// </summary>
public class Game1 : Microsoft.Xna.Framework.Game
{
private Foo _foo;
public Game1()
{
_foo = new Foo(this);
}
protected override void Dispose(bool disposing)
{
if (_foo != null)
{
_foo.Dispose();
_foo = null;
}
base.Dispose(disposing);
}
}
public class Foo : IDisposable
{
private Game _game;
private GraphicsDeviceManager _graphics;
private SpriteBatch _spriteBatch;
public Foo(Game game)
{
_game = game;
_game.Content.RootDirectory = "Content";
_graphics = new GraphicsDeviceManager(_game);
_spriteBatch = new SpriteBatch(_game.GraphicsDevice);
}
public void Dispose()
{
if (!_spriteBatch.IsDisposed)
{
_spriteBatch.Dispose();
_spriteBatch = null;
}
}
}
Update
It's important to properly dispose of a lot of XNA objects (otherwise, you get memory leaks). See Foo.Dispose() and the Game1.Dispose() override above.