We Keep Coding

Wait for long-running operation and show popup

Is it possible to wait for a method (say METHOD1) to finish, but if it is running longer than X secs, call another method until METHOD1 returns?
Some pseudocode:
method1();
startCountdown(1000); // time in millis
while (method1() still running) {
method2(); // shows a popup with spinner (Swing/AWT)
}
I guess, it must be done with concurrency, but I am not used to concurrent programming. So, I have no idea how to start.
The UI framework used is Swing/AWT.

So, the basic idea would be to use a combination of a SwingWorker and a Swing Timer.
The idea is if the Timer triggers before the SwingWorker is DONE, you execute some other workflow, otherwise you stop the Timer, for example...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JLabel label;
private JButton startButton;
boolean hasCompleted = false;
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
label = new JLabel("Waiting for you");
startButton = new JButton("Start");
add(label, gbc);
add(startButton, gbc);
startButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
startButton.setEnabled(false);
startWork();
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
protected void startWork() {
label.setText("Something wicked this way comes");
// You could build an isoloated workflow, which allowed you to pass
// three targets, the thing to be executed, the thing to be
// executed if time run over and the thing to be executed when
// the task completed (all via a single interface),
// but, you get the idea
Timer timer = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (hasCompleted) {
return;
}
label.setText("Wickedness is a bit slow today");
}
});
timer.setRepeats(false);
SomeLongRunningOperation worker = new SomeLongRunningOperation();
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
switch (worker.getState()) {
case DONE:
hasCompleted = true;
timer.stop();
label.setText("All is done");
startButton.setEnabled(true);
break;
}
}
});
worker.execute();
timer.start();
}
}
public class SomeLongRunningOperation extends SwingWorker<Void, Void> {
#Override
protected Void doInBackground() throws Exception {
Thread.sleep(5000);
return null;
}
}
}
Play around with the timings to see what different effects you get.
Why use a SwingWorker? Because it has it's own state callbacks, which makes it easier to deal with
As I said in my comments, you could distill the workflow down into a re-usable concept, something like...
public class TimedTask<V> {
public static interface Task<V> {
public V execute() throws Exception;
}
public static interface TimedTaskListener<V> extends EventListener {
public void taskIsTakingLongThenExepected(TimedTask task);
public void taskDidComplete(TimedTask task, V value);
}
private Task<V> task;
private TimedTaskListener<V> listener;
private V value;
private int timeOut;
private Timer timer;
private SwingWorker<V, Void> worker;
private boolean hasCompleted = false;
public TimedTask(int timeOut, Task<V> task, TimedTaskListener<V> listener) {
this.task = task;
this.listener = listener;
this.timeOut = timeOut;
}
public V getValue() {
return value;
}
public int getTimeOut() {
return timeOut;
}
protected Task<V> getTask() {
return task;
}
protected TimedTaskListener<V> getListener() {
return listener;
}
public void execute() {
if (timer != null || worker != null) {
return;
}
hasCompleted = false;
worker = new SwingWorker<V, Void>() {
#Override
protected V doInBackground() throws Exception {
value = task.execute();
return value;
}
};
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
switch (worker.getState()) {
case DONE:
hasCompleted = true;
timer.stop();
getListener().taskDidComplete(TimedTask.this, value);
break;
}
}
});
timer = new Timer(getTimeOut(), new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (hasCompleted) {
return;
}
getListener().taskIsTakingLongThenExepected(TimedTask.this);
}
});
timer.setRepeats(false);
worker.execute();
timer.start();
}
}
And then you could replace the startWork method in the first example with something like...
protected void startWork() {
label.setText("Something wicked this way comes");
TimedTask.Task<Void> task = new TimedTask.Task<Void>() {
#Override
public Void execute() throws Exception {
Thread.sleep(5000);
return null;
}
};
TimedTask<Void> timedTask = new TimedTask(2000, task, new TimedTask.TimedTaskListener<Void>() {
#Override
public void taskIsTakingLongThenExepected(TimedTask task) {
label.setText("Wickedness is taking it's sweet time");
}
#Override
public void taskDidComplete(TimedTask task, Void value) {
label.setText("Wickedness has arrived");
startButton.setEnabled(true);
}
});
timedTask.execute();
}

While SwingWorker is the appropriate tool for the job, for simple tasks you can get away with a Thread for the off-edt long task and a swing Timer to update the GUI:
import java.awt.*;
import javax.swing.*;
import javax.swing.Timer;
public class Main{
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
frame.add(new TestPane());
frame.pack();
frame.setVisible(true);
}
}
class TestPane extends JPanel{
private static Dimension size = new Dimension(250, 100);
private final JLabel label;
private final JButton start;
private int counter;
private Timer timer;
public TestPane() {
setLayout(new BorderLayout(10, 10));
label = new JLabel("Click START to run long process", JLabel.CENTER);
add(label,BorderLayout.NORTH);
start = new JButton("START");
start.addActionListener(e-> start() );
add(start, BorderLayout.SOUTH);
}
private void start() {
start.setEnabled(false);
int processRunTime = 10;
int updateTime = 1; //if this value >= processRunTime update() is not invoked
counter = 1;
simulateLongProcessOf(processRunTime);
timer = new Timer(1000*updateTime, e->update(counter++));
label.setText("Long process started");
timer.start();
}
private void stop() {
label.setText("Long process ended");
timer.stop();
start.setEnabled(true);
}
#Override
public Dimension preferredSize() {
return size;
}
private void simulateLongProcessOf(int seconds){
Thread t1 = new Thread(()->{
try {
Thread.sleep(1000*seconds);
} catch (InterruptedException ex) {
ex.printStackTrace();
}finally {
SwingUtilities.invokeLater(()->stop());
}
});
t1.start();
}
private void update(int count){
label.setText("Update # "+ count+" : long process is running" );
}
}

I've struggled with this question before.
What I ended up doing was, creating a separate class that extends AsyncTask. Added an interface/listener to this class that returned my object. Right before I start my AsyncTask, I'll disable buttons and put up a loading spinner. Once the AsyncTask comes back, I'll do my processing and reenable the buttons and take down the loading spinner. Of coarse I'm doing a rest call in the example, but it can be applied to anything that takes awhile. The reason why this is a better option than a while loop is that it's won't be burning cycles checking conditions.
public class RestCall extends AsyncTask {
private Context mContext;
private static final String TAG = "RestCall";
private AsyncResponse mListener;
public RestCall(Context context, URL url, AsyncResponse listener) {
this.mListener = listener;
this.mContext = context;
this.url = url;
}
public interface AsyncResponse {
void processFinish(JSONArray results);
}
#Override
protected Object doInBackground(Object[] objects) {
Log.d(TAG, "doInBackground: Thread: " + Thread.currentThread().getName());
return getResultsInJSONArray(url);
}
private JSONArray getResultsInJSONArray(URL url) {
//Here is where you will be doing the bulk of the work
//Doing a rest call and
//Processing results to JSONArray
}
#Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
Log.d(TAG, "onPostExecute: Handing off Object");
mListener.processFinish((JSONArray) o);
}
Now in your original class you'll add the following to your class:
public class myClass
private restCall call;
Than create a listener from that interface you made. Then pass the results to a method.
restCall.AsyncResponse listener = results -> handleResults(results);
With the listener setup you can you can execute your AsyncTask.
//here is were you would throw up the loading bar.
call = new restCall(this, url, listener);
call.execute();
private void handleResults(JSONArray results){
//process what you need to
//take down loading bar
}

How can I fade out or fade in by command JPanel, its components and its color

I wanted to make a Glass Panel that contain a JPanel with white background, border and the msg "please wait".
Here is the code example:
JLabel glassLabel = new JLabel("Please wait");
FadingPanel msg = new FadingPanel();
glassLabel.setFont(new Font("Dialog", Font.BOLD, 26));
msg.setLayout(new BorderLayout());
msg.add(glassLabel,BorderLayout.NORTH);
msg.setBackground(Color.white);
msg.setFont(UIManager.getFont("Table.font").deriveFont(24f));
msg.setBorder(new CompoundBorder(new TitledBorder(""),
new EmptyBorder(20,20,20,20)));
It will fade in and out while waiting for the query.
the problem is that I am getting a bad result.
need help

the other is that none of them show it with glass panel
Animating the opacity state of a glassPane is no different from animating the state of any Swing component, after all, the glassPane is just another component.
one is that the Timer system doesn't know if the start function started and it keeps the panel hanging on because it closing it before fading the panel and then before it shows it and then it dont try to close it again
This is more about your own internal state management. The panel shouldn't care, it should just be responding to the request to change opacity level, forward or backwards
What you should have, is some kind of "engine" which can provide events when certain states are achieved, at which time, you make decisions about what should be done, removing the functionality from the "panel" itself.
Theory TL;DR
Okay, first, some theory.
Animation...
Animation is the illusion of change over time. In your case, you're moving from 0 to 1 and back again over a specified period of time. This is commonly known as "linear progression/animation". Most naive animation implementations will simple add a constant delta to a value and keep doing so until a desired state is reached. This is naive because not all systems are equal. Some will be able to achieve the desired state faster than others, making the animation uneven and providing a poor user experience.
Instead, you should be focused on perform a operation over a fixed period of time, calculating the required value as fast as the system will allow. This allows the animation to "drop" frames as required based on the system's capabilities. This is commonly known as "duration based animation".
This approach is much more powerful, as it allows you to play around with the speed of the animation in a very simply way. It also allows you do some very advanced operations, like easement, which wouldn't be easily achievable through a linear progression.
Swing and animation...
Swing is SINGLE threaded. This means you can't perform blocking or long running operations within the context of the Event Dispatching Thread.
Swing is also NOT thread safe. This means you shouldn't update the UI (or any state the UI depends on) from outside the context of the EDT.
For animation, what you need is some way to post, fast, repetitive, events onto the EDT, which will allow you to make changes to the UI safely. For this, the most common tool is a Swing Timer...
The Framework
So based on that, what we need is some kind of "engine", which given a "range" and a "duration" can notify us of "ticks" on a regular bases from which we can calculate the progression that the animation has played, and calculate the value we should use based on our inputs ... simple ...
I, personally, prefer to use an animation library, but the simple framework presented in the examples basically abstracts all these concepts into a re-usable framework.
Make it so...
nb: I ran out of room, so the underlying framework is included in the main example
Okay, that's all nice and fluffy, but how does this actually help us. Essentially, the idea of the above is to abstract common functionality out and make it re-usable (and yes, I actually do use it, a lot)
What we now need, is a component which can actually use it, something like...
public interface FaderListener {
public void fadeDidComplete(FadePane pane);
}
public class FadePane extends JPanel {
private double alpha = 1;
private boolean fadingIn = true;
private DoubleAnimatable animatable;
private Duration duration = Duration.ofSeconds(5);
private List<FaderListener> listeners = new ArrayList<>(5);
public FadePane() {
setOpaque(false);
}
public void addFadeListener(FaderListener listener) {
listeners.add(listener);
}
public void removeFadeListener(FaderListener listener) {
listeners.remove(listener);
}
public boolean isFadingIn() {
return fadingIn;
}
public double getAlpha() {
return alpha;
}
#Override
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.SrcOver.derive((float)getAlpha()));
g2d.setColor(getBackground());
g2d.fillRect(0, 0, getWidth(), getHeight());
super.paint(g2d);
g2d.dispose();
}
protected void fadeTo(double to) {
double currentAlpha = getAlpha();
if (animatable != null) {
animatable.stop();
animatable = null;
}
if (currentAlpha == to) {
fadeDidComplete();
return;
}
DoubleRange animationRange = new DoubleRange(currentAlpha, to);
double maxFrom = to == 1 ? 1 : 0;
double maxTo = to == 1 ? 0 : 1;
DoubleRange maxRange = new DoubleRange(maxFrom, maxTo);
animatable = new DoubleAnimatable(animationRange, maxRange, duration, new AnimatableListener<Double>() {
#Override
public void animationChanged(Animatable<Double> animatable) {
alpha = animatable.getValue();
repaint();
}
}, new AnimatableLifeCycleListenerAdapter<Double>() {
#Override
public void animationCompleted(Animatable<Double> animatable) {
fadeDidComplete();
}
});
Animator.INSTANCE.add(animatable);
}
public void fadeIn() {
fadingIn = true;
fadeTo(1);
}
public void fadeOut() {
fadingIn = false;
fadeTo(0);
}
protected void fadeDidComplete() {
for (FaderListener listener : listeners) {
listener.fadeDidComplete(this);
}
}
}
Okay, this is a pretty simple concept. It's a JPanel which has a alpha property which changes the opacity level of the component - basically, this is all faked, as Swing only support opaque and transparent components, not translucent components. So we set the component to be transparent and manually paint the background ourselves.
The component exposes two methods, fadeIn and fadeOut and supports a FaderListener which can be used to notify interested parties that the fade operation has been completed
Runnable example...
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setBackground(Color.RED);
setLayout(new BorderLayout());
FadePane pane = new FadePane();
pane.setLayout(new GridBagLayout());
pane.add(new JLabel("Look ma, no hands"));
add(pane);
JButton btn = new JButton("Switch");
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
btn.setEnabled(false);
if (pane.isFadingIn()) {
pane.fadeOut();
} else {
pane.fadeIn();
}
}
});
add(btn, BorderLayout.SOUTH);
pane.addFadeListener(new FaderListener() {
#Override
public void fadeDidComplete(FadePane pane) {
btn.setEnabled(true);
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public interface FaderListener {
public void fadeDidComplete(FadePane pane);
}
public class FadePane extends JPanel {
private double alpha = 1;
private boolean fadingIn = true;
private DoubleAnimatable animatable;
private Duration duration = Duration.ofSeconds(5);
private List<FaderListener> listeners = new ArrayList<>(5);
public FadePane() {
setOpaque(false);
}
public void addFadeListener(FaderListener listener) {
listeners.add(listener);
}
public void removeFadeListener(FaderListener listener) {
listeners.remove(listener);
}
public boolean isFadingIn() {
return fadingIn;
}
public double getAlpha() {
return alpha;
}
public void setFaddedOut() {
alpha = 0;
fadingIn = false;
}
public void setFaddedIn() {
alpha = 1;
fadingIn = true;
}
#Override
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.SrcOver.derive((float)getAlpha()));
g2d.setColor(getBackground());
g2d.fillRect(0, 0, getWidth(), getHeight());
super.paint(g2d);
g2d.dispose();
}
protected void fadeTo(double to) {
double currentAlpha = getAlpha();
if (animatable != null) {
animatable.stop();
animatable = null;
}
if (currentAlpha == to) {
fadeDidComplete();
return;
}
DoubleRange animationRange = new DoubleRange(currentAlpha, to);
double maxFrom = to == 1 ? 1 : 0;
double maxTo = to == 1 ? 0 : 1;
DoubleRange maxRange = new DoubleRange(maxFrom, maxTo);
animatable = new DoubleAnimatable(animationRange, maxRange, duration, new AnimatableListener<Double>() {
#Override
public void animationChanged(Animatable<Double> animatable) {
alpha = animatable.getValue();
repaint();
}
}, new AnimatableLifeCycleListenerAdapter<Double>() {
#Override
public void animationCompleted(Animatable<Double> animatable) {
fadeDidComplete();
}
});
Animator.INSTANCE.add(animatable);
}
public void fadeIn() {
fadingIn = true;
fadeTo(1);
}
public void fadeOut() {
fadingIn = false;
fadeTo(0);
}
protected void fadeDidComplete() {
for (FaderListener listener : listeners) {
listener.fadeDidComplete(this);
}
}
}
public class DoubleAnimatable extends AbstractAnimatable<Double> {
public DoubleAnimatable(DoubleRange animationRange, DoubleRange maxRange, Duration duration, AnimatableListener<Double> listener, AnimatableLifeCycleListener<Double> lifeCycleListener) {
super(animationRange, duration, listener, lifeCycleListener);
double maxDistance = maxRange.getDistance();
double aniDistance = animationRange.getDistance();
double progress = Math.min(100, Math.max(0, Math.abs(aniDistance / maxDistance)));
Duration remainingDuration = Duration.ofMillis((long) (duration.toMillis() * progress));
setDuration(remainingDuration);
}
}
public interface AnimatableListener<T> {
public void animationChanged(Animatable<T> animatable);
}
public interface AnimatableLifeCycleListener<T> {
public void animationStopped(Animatable<T> animatable);
public void animationCompleted(Animatable<T> animatable);
public void animationStarted(Animatable<T> animatable);
public void animationPaused(Animatable<T> animatable);
}
public class AnimatableLifeCycleListenerAdapter<T> implements AnimatableLifeCycleListener<T> {
#Override
public void animationStopped(Animatable<T> animatable) {
}
#Override
public void animationCompleted(Animatable<T> animatable) {
}
#Override
public void animationStarted(Animatable<T> animatable) {
}
#Override
public void animationPaused(Animatable<T> animatable) {
}
}
public abstract class AbstractAnimatable<T> implements Animatable<T> {
private Range<T> range;
private LocalDateTime startTime;
private Duration duration = Duration.ofSeconds(5);
private T value;
private AnimatableListener<T> animatableListener;
private AnimatableLifeCycleListener<T> lifeCycleListener;
// private Easement easement;
private double rawOffset;
public AbstractAnimatable(Range<T> range, Duration duration, AnimatableListener<T> listener) {
this.range = range;
this.value = range.getFrom();
this.animatableListener = listener;
}
public AbstractAnimatable(Range<T> range, Duration duration, AnimatableListener<T> listener, AnimatableLifeCycleListener<T> lifeCycleListener) {
this(range, duration, listener);
this.lifeCycleListener = lifeCycleListener;
}
// public AbstractAnimatable(Range<T> range, Duration duration, Easement easement, AnimatableListener<T> listener) {
// this(range, duration, listener);
// this.easement = easement;
// }
//
// public AbstractAnimatable(Range<T> range, Duration duration, Easement easement, AnimatableListener<T> listener, AnimatableLifeCycleListener<T> lifeCycleListener) {
// this(range, duration, easement, listener);
// this.lifeCycleListener = lifeCycleListener;
// }
//
// public void setEasement(Easement easement) {
// this.easement = easement;
// }
//
// #Override
// public Easement getEasement() {
// return easement;
// }
public Duration getDuration() {
return duration;
}
public Range<T> getRange() {
return range;
}
public void setRange(Range<T> range) {
this.range = range;
}
#Override
public T getValue() {
return value;
}
protected void setDuration(Duration duration) {
this.duration = duration;
}
public double getCurrentProgress(double rawProgress) {
double progress = Math.min(1.0, Math.max(0.0, getRawProgress()));
// Easement easement = getEasement();
// if (easement != null) {
// progress = easement.interpolate(progress);
// }
return Math.min(1.0, Math.max(0.0, progress));
}
public double getRawProgress() {
if (startTime == null) {
return 0.0;
}
Duration duration = getDuration();
Duration runningTime = Duration.between(startTime, LocalDateTime.now());
double progress = rawOffset + (runningTime.toMillis() / (double) duration.toMillis());
return Math.min(1.0, Math.max(0.0, progress));
}
#Override
public void tick() {
if (startTime == null) {
startTime = LocalDateTime.now();
fireAnimationStarted();
}
double rawProgress = getRawProgress();
double progress = getCurrentProgress(rawProgress);
if (rawProgress >= 1.0) {
progress = 1.0;
}
value = getRange().valueAt(progress);
fireAnimationChanged();
if (rawProgress >= 1.0) {
fireAnimationCompleted();
}
}
#Override
public void start() {
if (startTime != null) {
// Restart?
return;
}
Animator.INSTANCE.add(this);
}
#Override
public void stop() {
stopWithNotification(true);
}
#Override
public void pause() {
rawOffset += getRawProgress();
stopWithNotification(false);
double remainingProgress = 1.0 - rawOffset;
Duration remainingTime = getDuration().minusMillis((long) remainingProgress);
setDuration(remainingTime);
lifeCycleListener.animationStopped(this);
}
protected void fireAnimationChanged() {
if (animatableListener == null) {
return;
}
animatableListener.animationChanged(this);
}
protected void fireAnimationCompleted() {
stopWithNotification(false);
if (lifeCycleListener == null) {
return;
}
lifeCycleListener.animationCompleted(this);
}
protected void fireAnimationStarted() {
if (lifeCycleListener == null) {
return;
}
lifeCycleListener.animationStarted(this);
}
protected void fireAnimationPaused() {
if (lifeCycleListener == null) {
return;
}
lifeCycleListener.animationPaused(this);
}
protected void stopWithNotification(boolean notify) {
Animator.INSTANCE.remove(this);
startTime = null;
if (notify) {
if (lifeCycleListener == null) {
return;
}
lifeCycleListener.animationStopped(this);
}
}
}
public interface Animatable<T> {
public Range<T> getRange();
public T getValue();
public void tick();
public Duration getDuration();
//public Easement getEasement();
// Wondering if these should be part of a secondary interface
// Provide a "self managed" unit of work
public void start();
public void stop();
public void pause();
}
public abstract class Range<T> {
private T from;
private T to;
public Range(T from, T to) {
this.from = from;
this.to = to;
}
public T getFrom() {
return from;
}
public T getTo() {
return to;
}
#Override
public String toString() {
return "From " + getFrom() + " to " + getTo();
}
public abstract T valueAt(double progress);
}
public class DoubleRange extends Range<Double> {
public DoubleRange(Double from, Double to) {
super(from, to);
}
public Double getDistance() {
return getTo() - getFrom();
}
#Override
public Double valueAt(double progress) {
double distance = getDistance();
double value = distance * progress;
value += getFrom();
return value;
}
}
public enum Animator {
INSTANCE;
private Timer timer;
private List<Animatable> properies;
private Animator() {
properies = new ArrayList<>(5);
timer = new Timer(5, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
List<Animatable> copy = new ArrayList<>(properies);
Iterator<Animatable> it = copy.iterator();
while (it.hasNext()) {
Animatable ap = it.next();
ap.tick();
}
if (properies.isEmpty()) {
timer.stop();
}
}
});
}
public void add(Animatable ap) {
properies.add(ap);
timer.start();
}
protected void removeAll(List<Animatable> completed) {
properies.removeAll(completed);
}
public void remove(Animatable ap) {
properies.remove(ap);
if (properies.isEmpty()) {
timer.stop();
}
}
}
}
But it's not a glassPane
... ok, as I said, a glassPane is just another component
This is a simple example which makes use of the frame's glassPane and will, when the panel is faded out, reset the glassPane to a default component
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
JButton btn = new JButton("Switch");
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Window window = SwingUtilities.getWindowAncestor(TestPane.this);
if (!(window instanceof JFrame)) {
System.out.println("Not out frame");
return;
}
JFrame frame = (JFrame) window;
FadePane pane = new FadePane();
pane.setLayout(new BorderLayout());
pane.add(new JLabel("All your base are belong to us"));
pane.setFaddedOut();
pane.addFadeListener(new FaderListener() {
#Override
public void fadeDidComplete(FadePane pane) {
System.out.println("Completed");
if (pane.getAlpha() == 1) {
System.out.println("Fade out");
pane.fadeOut();
} else {
System.out.println("Remove glasspane");
frame.setGlassPane(new JPanel());
}
}
});
frame.setGlassPane(pane);
System.out.println("Fade in");
pane.setVisible(true);
pane.fadeIn();
}
});
add(btn);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}
nb: The required classes are in the previous example

Consider using JDialog container. When it is undecorated, you can change its opacity:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.WindowConstants;
public class FadeDialog extends JDialog {
private float alfa = 1;
private JLabel label;
private boolean isFadeIn = true;
private JButton fadeIn, fadeOut;
FadeDialog() {
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
setLocation(new Point(300, 300));
getContentPane().setLayout(new BorderLayout(5,0));
setUndecorated(true); //opacity supported for undecorated JDialogs
JButton close = new JButton("Close");
close.addActionListener(e -> dispose());
getContentPane().add(close, BorderLayout.PAGE_END);
getContentPane().add(new ContentPane(), BorderLayout.CENTER);
pack();
setVisible(true);
Timer timer = new Timer(2000, e -> fade());//endless fade-in-out loop
timer.setInitialDelay(100);
timer.start();
}
void fade() {
alfa = isFadeIn ? alfa + 0.1f : alfa -0.1f;
if(alfa <=0 ) {
alfa = 0; isFadeIn = true;
}else if(alfa >= 1) {
alfa = 1; isFadeIn = false;
}
fadeIn.setEnabled(! isFadeIn); fadeOut.setEnabled(isFadeIn);
label.setText("Alfa is " + alfa);
setOpacity(alfa); //set JDialog opacity
}
class ContentPane extends JPanel {
ContentPane() {
setPreferredSize(new Dimension(200, 100));
setLayout(new BorderLayout());
fadeIn = new JButton("Fade In");
fadeIn.addActionListener(e -> isFadeIn = true);
add(fadeIn, BorderLayout.PAGE_START);
label = new JLabel("Alfa is " + alfa);
add(label, BorderLayout.CENTER);
fadeOut = new JButton("Fade Out");
fadeOut.addActionListener(e -> isFadeIn = false);
add(fadeOut, BorderLayout.PAGE_END);
}
}
public static void main(String[] args) {
new FadeDialog();
}
}

Pause and Resume SwingWorker.doInBackground()

I have a basic Swing UI with a single button marked "Play." When the button is pressed the label changes to "Pause". When the button is pressed now it changes to say "Resume."
On "Play" I am instantiating and executing a SwingWorker. What I would like is to be able to pause this thread (NOT cancel it) and resume it according to the button presses described above. However, I'd prefer not to resort to Thread.sleep() in doInBackground(). That seems a bit hackish. Is there any way for the thread running doInBackground to block?

Pause and Resume SwingWorker.doInBackground()
First of all you have to be sure the background task being performed can be paused, otherwise the question doesn't make sense. So let's say the task can be paused, then you might extend SwingWorker class and make your own pausable worker using a simple flag variable to control the background thread status: paused or not paused.
public abstract class PausableSwingWorker<K, V> extends SwingWorker<K, V> {
private volatile boolean isPaused;
public final void pause() {
if (!isPaused() && !isDone()) {
isPaused = true;
firePropertyChange("paused", false, true);
}
}
public final void resume() {
if (isPaused() && !isDone()) {
isPaused = false;
firePropertyChange("paused", true, false);
}
}
public final boolean isPaused() {
return isPaused;
}
}
Subclasses might check isPaused() status in order to efectively proceed with the task or not. For example:
PausableSwingWorker<Void, String> worker = new PausableSwingWorker<Void, String>() {
#Override
protected Void doInBackground() throws Exception {
while (!isCancelled()) {
if (!isPaused()) {
// proceed with background task
} else {
Thread.sleep(200); // Optional sleep to avoid check status continuously
}
}
return null;
}
};
You can also add a PropertyChangeListener to the worker and listen for paused property changes:
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if ("paused".equals(evt.getPropertyName())) {
System.out.println("Old status: " + evt.getOldValue());
System.out.println("New status: " + evt.getNewValue());
}
}
});
Example (updated to make use of PropertyChangeListener)
Here is a complete example to play with. Please note that if worker is stopped then it cannot be paused nor resumed anymore.
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
public class Demo {
private void createAndShowGUI() {
final JTextArea textArea = new JTextArea(20, 50);
final PausableSwingWorker<Void, String> worker = new PausableSwingWorker<Void, String>() {
#Override
protected Void doInBackground() throws Exception {
while (!isCancelled()) {
if (!isPaused()) {
publish("Writing...");
} else {
Thread.sleep(200);
}
}
return null;
}
#Override
protected void process(List<String> chunks) {
String text = String.format("%s%n", chunks.get(chunks.size() - 1));
textArea.append(text);
}
};
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if ("paused".equals(evt.getPropertyName())) {
String text = (Boolean)evt.getNewValue() ? "Paused..." : "Resumed...";
textArea.append(String.format("%s%n", text));
}
}
});
Action pause = new AbstractAction("Pause") {
#Override
public void actionPerformed(ActionEvent e) {
worker.pause();
}
};
Action resume = new AbstractAction("Resume") {
#Override
public void actionPerformed(ActionEvent e) {
worker.resume();
}
};
Action stop = new AbstractAction("Stop") {
#Override
public void actionPerformed(ActionEvent e) {
worker.cancel(true);
}
};
JPanel buttonsPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
buttonsPanel.add(new JButton(pause));
buttonsPanel.add(new JButton(resume));
buttonsPanel.add(new JButton(stop));
JPanel content = new JPanel(new BorderLayout(8, 8));
content.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
content.add(new JScrollPane(textArea), BorderLayout.CENTER);
content.add(buttonsPanel, BorderLayout.SOUTH);
JFrame frame = new JFrame("Demo");
frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
frame.addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
if (!worker.isDone()) {
worker.cancel(true);
}
e.getWindow().dispose();
}
});
frame.add(content);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
worker.execute();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Demo().createAndShowGUI();
}
});
}
abstract class PausableSwingWorker<K, V> extends SwingWorker<K, V> {
private volatile boolean isPaused;
public final void pause() {
if (!isPaused() && !isDone()) {
isPaused = true;
firePropertyChange("paused", false, true);
}
}
public final void resume() {
if (isPaused() && !isDone()) {
isPaused = false;
firePropertyChange("paused", true, false);
}
}
public final boolean isPaused() {
return isPaused;
}
}
}

JProgressBar doesn't update , can't find a clue

nice job , now i just wanna know why if i add into while loop the instruction System.out.println below the progress is shown on both , cmd and Pgbar in the Gui ?? :
while(progress < 99){
System.out.println("into while of PBar Thread progress = "+progress);
if(progress != Path.operationProgress){
operationProgressBar.setValue(progress);
progress = Path.operationProgress;
operationProgressBar.repaint(); } }
need some help around , i can't get the JProgressBar to update, i
can't use SwingWorker, i have to solve this without it . the variable
Path.operationProgress is a static variable from a "Path" class
instance, and it's updated from another thread, so i think the PBar
and Path instances are both executed in user's Threads and not in the
EDT . here is the Code of the progress bar :
import javax.swing.*;
public class Pbar extends Thread {
JProgressBar operationProgressBar;
public Pbar(JProgressBar operationProgressBar) {
this.operationProgressBar = operationProgressBar;
}
#Override
public void run() {
int progress = Path.operationProgress;
while(progress < 99) {
if(progress != Path.operationProgress) {
operationProgressBar.setValue(progress);
progress = Path.operationProgress;
operationProgressBar.repaint();
}}}
}
this is the action that launches the threads :
private javax.swing.JProgressBar operationProgressBar;
private javax.swing.JLabel pathImage;
private javax.swing.JButton simulatedAnnelingButton;
public class TSPGUI extends javax.swing.JFrame {
TSPMG tspInstance;
Path p, result;
String filename = "";
int neighborHood_Type = 1, i = 0;
// ......Constructor Stuff and init()
private void simulatedAnnelingButtonActionPerformed(java.awt.event.ActionEvent evt)
{
Thread sa = new Thread(){
#Override
public void run(){
result = p.SimulatedAnnealing(neighborHood_Type);
String lastCostString = result.Cost() + "";
lastCostLabel.setText(lastCostString);
}};
sa.start();
Pbar pb = new Pbar(operationProgressBar);
pb.start();
}
//Some other Stuff ...
}

If you can't use SwingWorker then use SwingUtilities.invokeLater, e.g.:
if (progress != Path.operationProgress) {
final int progressCopy = progress; // Probably not final so copy is needed
SwingUtilities.invokeLater(new Runnable() {
#Override
void run() {
operationsProgressBar.setValue(progressCopy);
}
});
}
Note: When doing this, everything used in run has to be final or there have to be other measures to access the variables. This code is symbolic in that regard.
You need to do operations on Swing components outside the event dispatching thread, there is no way around this.

I would use a PropertyChangeListener to allow you to make the annealing progress value a "bound" property of the class. Than any observer can follow this property if desired. For example:
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
import javax.swing.event.SwingPropertyChangeSupport;
#SuppressWarnings("serial")
public class TspGui2 extends JPanel {
private static final String ANNEALING_PROGRESS = "Annealing Progress";
private JProgressBar progBar = new JProgressBar(0, 100);
private JLabel valueLabel = new JLabel();
private JButton beginAnnealingBtn = new JButton("Begin Annealing");
private MyAnnealing myAnnealing = new MyAnnealing(this);
public TspGui2() {
beginAnnealingBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
beginAnnealing();
}
});
myAnnealing.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equals(MyAnnealing.ANNEALING)) {
// be sure this is done on the EDT
SwingUtilities.invokeLater(new Runnable() {
public void run() {
int annealedValue = myAnnealing.getAnnealedValue();
setValue(annealedValue);
if (annealedValue >= MyAnnealing.MAX_ANNEALED_VALUE) {
beginAnnealingBtn.setEnabled(true);
}
}
});
}
}
});
progBar.setString(ANNEALING_PROGRESS);
progBar.setStringPainted(true);
JPanel northPanel = new JPanel(new GridLayout(1, 0));
northPanel.add(beginAnnealingBtn);
northPanel.add(valueLabel);
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(northPanel);
add(progBar);
}
public void setValue(int value) {
valueLabel.setText("Value:" + value);
progBar.setValue(value);
}
public void beginAnnealing() {
beginAnnealingBtn.setEnabled(false);
setValue(0);
myAnnealing.reset();
new Thread(new Runnable() {
public void run() {
myAnnealing.beginAnnealing();
}
}).start();
}
private static void createAndShowGui() {
TspGui2 mainPanel = new TspGui2();
JFrame frame = new JFrame("TspGui2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyAnnealing {
public static final String ANNEALING = "Annealing";
public static final int MAX_ANNEALED_VALUE = 100;
private SwingPropertyChangeSupport propChangeSupport =
new SwingPropertyChangeSupport(this);
private TspGui2 gui;
private int annealedValue;
public MyAnnealing(TspGui2 gui) {
this.gui = gui;
}
public void addPropertyChangeListener(
PropertyChangeListener listener) {
propChangeSupport.addPropertyChangeListener(listener);
}
public void removePropertyChangeListener(
PropertyChangeListener listener) {
propChangeSupport.removePropertyChangeListener(listener);
}
public void reset() {
setAnnealedValue(0);
}
// simulate some long process...
public void beginAnnealing() {
long sleepDelay = 100;
while (annealedValue < MAX_ANNEALED_VALUE) {
setAnnealedValue(annealedValue + 1);
try {
Thread.sleep(sleepDelay);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public int getAnnealedValue() {
return annealedValue;
}
private void setAnnealedValue(int value) {
final int oldValue = this.annealedValue;
this.annealedValue = value;
propChangeSupport.firePropertyChange(ANNEALING, oldValue, annealedValue);
}
}

MVC Progress Bar Threading

I am using an MVC pattern for my design, when a user presses the search button, I call a search in the model, but I also want to update a progress bar with information returned from that model.
I have tried using a swingworker, but the progress bar does not update. I suspect I am doing something wrong with my threading.
My button as defined in the controller is:
class SearchBtnListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
_view.displayProgress();
}
}
This calls the search in the model and has the following call in the view:
public void displayProgress() {
TwoWorker task = new TwoWorker();
task.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent e) {
if ("progress".equals(e.getPropertyName())) {
_progressBar.setValue((Integer) e.getNewValue());
}
}
});
task.execute();
}
private class TwoWorker extends SwingWorker<Void, Void> {
#Override
protected Void doInBackground() throws Exception {
_model.startSearch(getTerm()); // time intensive code
File file = new File("lock");
while (file.exists()){
setProgress(_model.getStatus());
System.out.println(_model.getStatus()); // never called
}
return null;
}
protected void done(){
updateMain();
}
}
Dummy function defined in Model for testing:
public int getStatus(){
Random r = new Random();
return r.nextInt();
}

Don't call
_progressBar.setValue(_model.getStatus());
from within your SwingWorker as this is calling Swing code from a background thread and is what the PropertyChangeListener is for anyway. Instead, just set the progress property, that's all.
Also, don't call done() from within the doInBackground method as this needs to be called from the EDT by the SwingWorker. So let the SwingWorker itself call this method when it is in fact done.
Also, Done() should be done() -- the first letter shouldn't be capitalized, and you should use #Override annotations in this code so you can be sure that you're overriding methods correctly.
Also, what does this do?
_model.startSearch(_view.getTerm());
Does it call code that takes a while to complete? Should this be initialized from within the SwingWorker doInBackground itself?
Edit:
Another option is to give the Model a bound int property, say called progress, and then add a PropertyChangeListener to it directly letting it update the JProgressBar. For example,
import java.awt.BorderLayout;
import java.awt.event.*;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import javax.swing.*;
public class MVC_ProgressBarThread {
private static void createAndShowUI() {
MVC_View view = new MVC_View();
MVC_Model model = new MVC_Model();
MVC_Control control = new MVC_Control(view, model);
view.setControl(control);
JFrame frame = new JFrame("MVC_ProgressBarThread");
frame.getContentPane().add(view);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
#SuppressWarnings("serial")
class MVC_View extends JPanel {
private MVC_Control control;
private JProgressBar progressBar = new JProgressBar();
private JButton startActionButton = new JButton("Start Action");
public MVC_View() {
startActionButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
buttonActionPerformed();
}
});
JPanel buttonPanel = new JPanel();
buttonPanel.add(startActionButton);
setLayout(new BorderLayout());
add(buttonPanel, BorderLayout.NORTH);
add(progressBar, BorderLayout.CENTER);
}
public void setControl(MVC_Control control) {
this.control = control;
}
private void buttonActionPerformed() {
if (control != null) {
control.doButtonAction();
}
}
public void setProgress(int progress) {
progressBar.setValue(progress);
}
public void start() {
startActionButton.setEnabled(false);
}
public void done() {
startActionButton.setEnabled(true);
setProgress(100);
}
}
class MVC_Control {
private MVC_View view;
private MVC_Model model;
public MVC_Control(final MVC_View view, final MVC_Model model) {
this.view = view;
this.model = model;
model.addPropertyChangeListener(new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent pce) {
if (MVC_Model.PROGRESS.equals(pce.getPropertyName())) {
view.setProgress((Integer)pce.getNewValue());
}
}
});
}
public void doButtonAction() {
view.start();
SwingWorker<Void, Void> swingworker = new SwingWorker<Void, Void>() {
#Override
protected Void doInBackground() throws Exception {
model.reset();
model.startSearch();
return null;
}
#Override
protected void done() {
view.done();
}
};
swingworker.execute();
}
}
class MVC_Model {
public static final String PROGRESS = "progress";
private static final int MAX = 100;
private static final long SLEEP_DELAY = 100;
private int progress = 0;
private PropertyChangeSupport pcs = new PropertyChangeSupport(this);
public void setProgress(int progress) {
int oldProgress = this.progress;
this.progress = progress;
PropertyChangeEvent evt = new PropertyChangeEvent(this, PROGRESS, oldProgress, progress);
pcs.firePropertyChange(evt);
}
public void reset() {
setProgress(0);
}
public void addPropertyChangeListener(PropertyChangeListener listener) {
pcs.addPropertyChangeListener(listener);
}
public void startSearch() {
for (int i = 0; i < MAX; i++) {
int newValue = (100 * i) / MAX;
setProgress(newValue);
try {
Thread.sleep(SLEEP_DELAY);
} catch (InterruptedException e) {}
}
}
}