I'm writing code for a 3D graph, and I want the scene graph to update when the user presses a JButton. I'm trying to use a Behavior class, but I can't find any information on using swing events to wake up the behavior. I would REALLY appreciate any help! Thank you!!
You can use a special behavior object which contains a queue of Runnables. You can then post runnables to the behaviour and wake it up. You will have to sort out proper synchronisation so the behaviour only goes to sleep when there are no more commands in the queue, but it should work.
Make the class into a singleton to be able to run Runnable's inside the BehaviorScheduler, analogous to the SwingUtilities.invokeLater() method.
public class ThreadTransferBehavior extends Behavior {
private final static int POST_ID = 9997;
private final WakeupOnBehaviorPost m_wakeupPost = new WakeupOnBehaviorPost(this, POST_ID);
private final Stack<Runnable> commands;
public synchronized void processStimulus(Enumeration i) {
while(!commands.isEmpty()) commands.pop().run();
wakeupOn(m_wakeupPost);
}
public synchronized void queueCommand(Runnable r) {
commands.push(r);
postId(POST_ID);
}
}
Related
I am making a program using the amazing libGDX+scene2d API and I structured it as follows:
I have a single MyGame instance, holding a single PolygonSpriteBatch instance.
There is an abstract MyScreen class, holding a MyStage class (see below)
Then there are lots of different screen classes that inherit from MyScreen, and instantiate each other at will.
(in all cases, removing the "My" gives you the name of the respective library class that it extends)
This model worked fine, until I encountered some problems to perform actions between screens using the Action system. I decided then that it would be a good idea to have a single OmnipresentActor belonging to MyGame that, as the name says, is present in every scene. So I modified MyStage to look more or less like this:
public class MyStage extends Stage {
public MyStage(MyGame g) {
super(new FitViewport(MyGame.WIDTH, MyGame.HEIGHT), g.batch);
addActor(game.omnipresentInvisibleActor);
}
#Override
public void clear() {
unfocusAll();
getRoot().clearActions();
getRoot().clearListeners();
removeActorsButNotListenersNorActions();
}
public void removeActorsButNotListenersNorActions() {
for (Actor a : getActors()) if (a.getClass()!= OmnipresentInvisibleActor.class) a.remove();
}
It followed a painful debugging phase, until I found out the following:
public PresentationScreen(MyGame g) {
// super() call and other irrelevant/already debugged code
System.out.println("PRINT_BEFORE: "+ stage.getActors().toString()); // OmnipresentActor is there
mainMenuScreen = new MainMenuScreen(game);
System.out.println("PRINT_AFTER: "+ stage.getActors().toString()); // OmnipresentActor is not there anymore, but was added to the mainMenuScreen
the "PRINT_BEFORE" statement shows that the stage holds the omnipresentActor. In "PRINT_AFTER" it isn't there anymore, whereas mainMenuScreen is indeed holding it. So my question, now more precise:
does scene2d prevent this to happen, or am I doing something wrong here?
Answers much appreciated! Cheers
An actor can only be a member of one stage: Thanks to #Tenfour04 for confirming that. The explanation is quite clear after doing a little research:
Stage.addActor() looks like this:
(here the github code of Stage.java)
/** Adds an actor to the root of the stage.
* #see Group#addActor(Actor) */
public void addActor (Actor actor) {
root.addActor(actor);
}
whereas root is simply initialized as a group in the Stage constructor: root = new Group();.
And Group.addActor() looks like this:
(here the github code of Group.java)
/** Adds an actor as a child of this group. The actor is first removed from its parent group, if any. */
public void addActor (Actor actor) {
if (actor.parent != null) actor.parent.removeActor(actor, false);
children.add(actor);
actor.setParent(this);
actor.setStage(getStage());
childrenChanged();
}
So in the tree first lines is the answer: when creating the new stage, if the actor to add already has a parent, it is removed from its current parent. So, There are two possible solutions to the problem I enounced:
SOLUTION 1: Override addActor removing the if statement, or any other alteration of the library, which I'm not sure if it would work. I rather think this could be very problematic, for instance it could prevent the stages from disposing correctly
SOLUTION 2: Change the design so you don't need an omnipresent actor, nor changing/reimplementing the libraries. For the moment this is what I've done based on this answer, it isn't very clean but it works so far:
1) In the MyScreen class added the following fields:
private boolean watchingTemp;
private Actor watchActorTemp;
private Action actionTemp;
2) Then added this method:
public void addActionOnStageAfterActorEndsHisActions(Actor actor, Action action) {
watchActorTemp = actor;
actionTemp = action;
watchingTemp = true;
}
3) then in the render method, I added the following:
if (watchingTemp && !watchActorTemp.hasActions()) {
watchingTemp = false;
stage.addAction(actionTemp);
}
4) finally, when wishing to perform an action at a screen transition (and eventually disposing the first one), you can do something like this: I use something similar when clicking on a door between screens
public void movePlayerTHENgotoNewScreen(float xPos, float yPos, whatever else...) {
game.player.walkToAnyPoint(xPos, yPos);
yourFavoriteScreen.addActionOnStageAfterActorEndsHisActions(game.player, gotoNewScreen(wathever else...));
}
Hope it helps!
I am new to automation and want to create an automation test which can do following:
Open one tab --- click and get some info from that tab
Switch to another tab --- click and get some info from this tab now.
Compare the infos.
We use Page Object Model to get info from one page. However the moment, I switch to another tab -- it switches the tab successfully but does not locate any element on it.
Any idea ?
Questions I would ask is,
Is the element locator correct?
Is this a unique element locator?
Is this a synchronization issue? Are you waiting enough for the page to load before finding the element?
Is this problem particular to a browser? Is it consistent across?
Also make sure you pass on the driver object from one page object to the other. Like,
public class PageOne {
public PageOne(WebDriver driver) {
//do something in constructor
}
public void someMethodInPage1() {
driver.findElement(By.id("button1")).click();
PageTwo pageTwo = new PageTwo(driver);
pageTwo.someMethodInPage2();
}
}
public class PageTwo {
private WebDriver driver;
public PageTwo(WebDriver driver) {
//do something in constructor
this.driver = driver;
}
public void someMethodInPage2() {
driver.findElement(By.id("button2")).click();
}
}
I am using axon 2.3.1 , I have one aggregate class
public class MyAggregate extends AbstractAnnotatedAggregateRoot<MBAggregate> {
#AggregateIdentifier
private MyId Id;
private Circle circle;
EventDispatcher a=new EventDispatcher();
public MyAggregate() {
}
#CommandHandler
public MyAggregate(NewCommand command ) {
apply(new SmallEvent(command.getId(), command.getCircle()));
}
#CommandHandler
public MyAggregate( StoreDestinationsCommand command ) {
apply(new BigEvent(command.getId(), command.getCircle()));
}
//And some event handlers like
#EventHandler
public void onSmallEvent(SmallEvent event)
{
//Some logic here
}
#EventHandler
public void onBigEvent(BigEvent event)
{
//Some logic here
}
Now i want these event handlers to be contained in some other class and be called when that event get triggered
public class EventContainer {
private static final long serialVersionUID = -6640657879730853388L;
#EventHandler
public void onSmallEvent(SmallEvent event)
{
//Some logic here
}
#EventHandler
public void onBigEvent(BigEvent event)
{
//Some logic here
}
I tried putting them in another class but those events are not triggered.
Any idea how can i achieve this in AXON.
Thanks,
Short Answer: You need to tell Axon that your EventContainer class can handle events published to an Event Bus.
AnnotationEventListenerAdapter.subscribe(new EventContainer(), eventBus);
Longer Answer:
To achieve what you want to do, taking a step back to understand the building blocks provided by Axon to build a CQRS application would be of help...
Axon Framework is a framework that provides you with the building blocks to build a CQRS application. And a CQRS application, in layman's term is just an architecture that allows you to separate the part of your application that executes actions (write) and the part that display your application state (read).
To do this Axon provide a couple of building blocks.
1) CommandBus
The Command Bus is the component within Axon Framework that provides the mechanism of having commands routed to their respective Command Handlers. For example from your code sample, the #CommandHandler annotation on MyAggregate means that when NewCommand is created, your MyAggregate method would be called. The Command Bus is the component that makes this possible.
2) CommandGateway
Command GateWay is a component that exposes a more friendly API to the CommnadBus. While you are not required to use a Gateway to dispatch Commands, it is generally the easiest option to do so.
3) EventBus
The EventBus handles the dispatching mechanism for events. Much like the Command Bus does for Commands. So when you have apply(new BigEvent(command.getId(), command.getCircle())); which fires a BigEvent it is the Event Bus that is responsibly for making sure the necessary event handler is called. And in your case, the question you are asking is how to have the Event handlers defined in a separate Class and still have Axon be able to route the events to them.
This is quite straight forward. I would assume you are not using Spring and that you are manually setting up the Axon components together by hand and creating the NewCommand that triggers the SmallEvent that you want to handle in EventContainer#onSmallEvent method. A way to get this done may look like this:
public class FireCommandAndCaptureEventInAnotherClass {
public static void main(String[] args) {
// We use the simple Command Bus.
// There are different implementation available. For example axon provides a distributed command bus that can be used to distribute commands over multiple nodes
CommandBus commandBus = new SimpleCommandBus();
// The friendlier API to send commands with
CommandGateway commandGateway = new DefaultCommandGateway(commandBus);
// You may skip this as it may not pertain to your question but since we are using event sourcing, we need a place to store the events. we'll store Events on the FileSystem, in the "events" folder
EventStore eventStore = new FileSystemEventStore(new SimpleEventFileResolver(new File("./events")));
// a Simple Event Bus will do
EventBus eventBus = new SimpleEventBus();
// You may skip this as it may not pertain to your question but since event sourcing is used in this example we need to configure the repository: an event sourcing repository.
EventSourcingRepository<MyAggregate> repository = new EventSourcingRepository<MyAggregate>(MyAggregate.class,
eventStore);
// Sets the event bus to which newly stored events should be published
repository.setEventBus(eventBus);
// Tells Axon that MyAggregate can handle commands
AggregateAnnotationCommandHandler.subscribe(MyAggregate.class, repository, commandBus);
// This is the part you need. With this We register an event listener to be able to handle events published on to an event bus. In this case EventContainer.
AnnotationEventListenerAdapter.subscribe(new EventContainer(), eventBus);
// and let's send some Commands on the CommandBus.
commandGateway.send(id, circle);
}
}
With this setup, the handlers in the EventContainer would be able to react to events triggered from MyAggregate
I am designing a game in Swing. Currently I am designing the maze for this game. The maze is generated by using Depth First Search algorithm. In my main JFrame, I have some JPanel. One JPanel, named mazePanel contains the maze. There are some other JPanel also, which contains the JButton for controlling. Following is the mazePanel code.
import java.awt.Graphics;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
public class MazePanel extends JPanel {
private MazeGenerator mazeGenerator;
private boolean startNewMaze = false;
public MazePanel() {
setBorder(BorderFactory.createTitledBorder("Maze"));
setToolTipText("This is the maze");
}
public void addNewMaze() {
startNewMaze = true;
mazeGenerator = new MazeGenerator();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (startNewMaze) {
mazeGenerator.generate(g);
startNewMaze = false;
}
}
}
There is one JButton, which calls the method mazePanel.addNewMaze() and set the Boolean startNewMaze to true. After setting the startNewMaze, maze should be generated. i.e. mazeGenerator.generate(g) is inside if() condition. Method mazeGenerator.generate(g) recursively draw the random maze. That is why I don’t want to run this method not more than once.
Up to this everything is looking fine. But while I am running the main JFrame and clicks on the JButton, maze is not rendered in the mazePanel. Sometimes when I minimize and maximize the JFrame, maze rendered (might be because of repaint() occur). Even if I comment mazeGenerator.generate(g) inside if() condition and put some g.drawString(). The string is not rendered while action performed (i.e.Pressing JButton).
Where is the problem? Please help.
Thank you.
So basically you have a JPanel which contains nothing, you call a method unknown to Swing and expects the paintComponent method is magically called when you change the state of a private field.
You already discovered that minimizing and maximizing again solves your problem due to a repaint. That should be sufficient information to know you have to trigger a repaint yourself when you press that button.
If you would have followed the suggestion from #kleopatra to, and I quote,
change the state and then trigger the revalidation/painting
you would already have solved your problem
I have a client-server application and i am using swing in the client side. My swing client has one main window (jframe) and lots of panels, toolbars and menubar in it.
I want to remove all client action/mouse events (or simply grab and do nothing) while client is waiting response from server by means of glasssPane.
Here is the code i wrote:
private final static MouseAdapter mouseAdapter = new MouseAdapter()
{
public void mouseClicked(MouseEvent e)
{
System.out.println("MouseClicked..!");
}
};
private static Cursor WAIT_CURSOR = Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR);
private static Cursor DEFAULT_CURSOR = Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
and
public static void startWaitCursor(JComponent comp)
{
MainWindow root = ((MainWindow) comp.getTopLevelAncestor());
root.getGlassPane().setCursor(WAIT_CURSOR);
root.getGlassPane().addMouseListener(mouseAdapter);
root.getGlassPane().setVisible(true);
}
public static void stopWaitCursor(JComponent comp)
{
MainWindow root = ((MainWindow) comp.getTopLevelAncestor());
root.getGlassPane().setCursor(DEFAULT_CURSOR);
root.getGlassPane().setVisible(false);
}
but i am not able to manage the grab mouse events. Changing cursors at the glassPane is working fine but either i am not able to add mouseAdapter or am not able to make glasssPane become to the top level component.
Any idea?
Thanks.
I realized that my code is working but my problem is threading related. My code was something like:
startWaitCursor();
work(); // server request that takes time
stopWaitCursor();
and changed it to:
startWaitCursor();
SwingUtilities.invokeLater(new Runnable() {
poblic void run() {
try
{
work(); // server request
}
finally
{
stopWaitCursor();
}
by doing this modification i could see the settings i made in the startWaitCursor() method while client is waiting response from the server.
But stil there is a small problem. In startWaitCursor() method i desabled key, mouse and focus events for the glass pane but events are still captured by main frame even glassPane is displayed.
addMouseListener(new MouseAdapter() {});
addMouseMotionListener(new MouseMotionAdapter() {});
addKeyListener(this);
setFocusTraversalKeysEnabled(false);
After server response reached to client and stopWaitCursor() method is invoked the events handled in the main frame.
If i disable the main frame of my application while client is waiting than cursor is not being changed to wait_cursor, if i am not disable the main frame then cursor is being changed but the events are queued.
cheers...
After digging swing threads issues couple of days, i finally found the real answer: SwingWorker
Now my final code is something like,
startWaitCursor();
SwingWorker worker = new SwingWorker() {
public Object doInBackground()
{
doWork(); // time consuming server request
return null;
}
public void done()
{
stopWaitCursor();
}
};
worker.execute();
In startWaitCursor() method i set the glasspane visible (with alpha valued background), display a message to warn the user time consuming job is doing, set the cursor to wait_cursor (hourglass) and consume all the key, mouse events. That is it.
And by using SwingWorker my client is actually responsive (it is working as if no server request is made) but since i display the glasspane and consume all key and mouse events it feels like irresponsive.
What a relief.. SwingWorker rocks...
cheers..