How can I force Eclipse to do a re-evaluation of the activeWhen-conditions of all handlers?
Situation:
I have defined a command on a TreeViewer. This command has more than one possible handlers. Handlers have defined some conditions to decide whether the handler shall be activated or not.
My problem is that there is no re-evaluation of the handler conditions until I de-seclect the item in the tree (e.g. select another item) and select it again.
If the selection does not change but the raise conditions do (e.g. due to an update of the element) the wrong handler will be executed.
Is there a way to manually force an Handler re-evaluation on the selection?
If your condition examines state in your treeviewer selection using property testers, then you need to notify the IEvaluationService that the property in question has changed. See org.eclipse.ui.services.IEvaluationService.requestEvaluation(String)
Related
I have a working JavaFX application. It has three main parts:
A list of signals visible globally to the entire application. Each signal has a String value property that is observable. This list is instantiated before the JavaFX scene is constructed, the signal list constructor is run in the Application FX thread.
A JavaFX table implemented as an Observable Array List so that as signal values change they are automatically updated on the GUI.
A simulation engine that runs a loop that changes signal values. This loop is run in a worker thread.
I am fully aware that GUI elements like selection lists, text in boxes, etc. can only be updated in the Application FX thread. I use Platform.runLater(someRunnableThing) to do that. However, what blindsided me was that even changing a signal value, which changes the value of the observable String property, must be done in the FX thread or not-in-Application-FX-thread exceptions will be thrown.
Curiously the application still works fine despite these exceptions, because eventually (instantaneously to a human observer) the changed value is picked up and displayed. I only noticed this when doing final checks of run-time behavior before release.
It is a very common thing for a worker thread to be changing variables in the background while a GUI is displaying information based on the changing variables. Platform.runLater() is expensive and somewhat non-deterministic. Since the worker thread is not touching the GUI and the application FX thread can choose to grab updates whenever it wants it seems draconian to me for Java to force this behavior.
Have I missed something about modifying observed properties? Any thoughts and ideas appreciated.
There are no rules about updating JavaFX properties from background threads. The only rule is that you cannot update nodes that are part of a scene graph from a background thread, and there are no plans (and likely never will be) to relax that rule.
You didn't post any code, so we can only make educated guesses as to what the actual problem is. What is likely happening is that you have a listener or a binding on one of the properties (or observable collections) that is being changed from your background thread, where the listener/binding is updating the UI. Listeners with observables (including listeners created and registered by bindings) are, of course, invoked on the same thread on which the observable is changed.
So if you have something like
someApplicationProperty.addListener((obs, oldValue, newValue) -> {
someUIElement.setSomeValue(...);
});
or perhaps
someUIElement.someProperty().bind(someApplicationProperty);
just replace it with
someApplicationProperty.addListener((obs, oldValue, newValue) -> {
Platform.runLater(() -> someUIElement.setSomeValue(...));
});
In other words, you can continue to update your application properties from the background thread, as long as your listener updates the UI from the FX Application Thread.
In the case where the listener is registered by the UI component itself, you must ensure that the observable with which the listener is registered is changed on the UI thread. This is the case in the example you allude to, for example updating the backing list for a ListView or TableView. You can do this either by directly invoking Platform.runLater(), or by placing a layer in between the model and the UI. For the latter approach, see Correct Way to update Observable List from background thread
Also maybe see http://www.oracle.com/technetwork/articles/java/javafxinteg-2062777.html
I'm trying to use RevertAllInCurrentGroup to undo the last operation but it doesn't seem to work. Actually what I really want to do is just remove the undo from the history; I don't care whether the undo is applied or not.
In some init code I have:
// 'component' is a MonoBehaviour-derived class. Here I create the default editor for the component
m_editor = Editor.CreateEditor(component);
And then in OnGUI in my EditorWindow:
m_editor.OnInspectorGUI();
// ..'hasChanged' is set to true if the user changed some property
if (hasChanged)
{
// ..do some stuff using the new values on the object, which includes sending a message to a server
Undo.RevertAllInCurrentGroup();
}
When I call RevertAllInCurrentGroup I get InvalidOperationException: Operation is not valid due to the current state of the object in some Stack object in GUILayoutUtility.EndLayoutGroup. I figured maybe I shouldn't be doing the revert in OnGUI, so I changed it to set a flag and do the revert in Update but that doesn't make any difference (except I obviously no longer get the exception).
Does anyone know how to use this function, or if there is some other way that I could undo the last operation that was applied by the Editor instance? I've tried using Undo.RegisterCompleteObjectUndo and Undo.ClearUndo but they don't seem to do anything either (the undo operation still appears in the undo stack).
For clarification, I'm dynamically creating GameObjects with components in the editor based on messages I receive from a server (which is a running Unity game, which could be inside or outside the editor - this is a live update system). Then I allow editing of those components, and send the changed components back to the server. I'm rendering my own inspector UI and I wanted to use the built-in Editor instances for components (e.g. so the built-in CameraEditor will be used if there is a Camera component).
The only problem is that using the built-in editors causes undo operations to be added to the stack, but I really don't care about these undo operations because the GameObject they apply to is just a temporary placeholder GameObject which is continually updated every coulpe of seconds, whenever I receive a new message from the server.
if what you want is the same as clicking on the Edit->Undo menu (or as you put, undo the last operation that was applied by the editor), use below code:
Undo.PerformUndo();
I need to add an Action to a Schedule object that is being created through the API. There are documented interfaces to set almost all the options except the Action. How are Actions attached to these Objects?
When I attempt to programmatically add a new event, read from a separate configuration file, to a Schedule object I get errors stating that the Schedule has already been initialized and that I must construct a new object and add its configuration manually. I can do most of that using the available Schedule API. I can set up everything about the Schedule except the Action code.
The Schedule is used in a Process Model. Looking at the model in the Java editor, I see the code I'm trying to replicate via the API in a function that looks like this:
#Override
#AnyLogicInternalCodegenAPI
public void executeActionOf( EventTimeout _e ) {
if ( _e == _fuelDeliverySchedule_Action_xjal ) {
Schedule<Integer> self = this.fuelDeliverySchedule;
Integer value = fuelDeliverySchedule.getValue();
logger.info("{} received {} pounds of fuel", this.getName(), this.fuelDeliverySchedule.getValue());
this.fuelAvailablePounds += fuelDeliverySchedule.getValue();
;
_fuelDeliverySchedule_Action_xjal.restartTo( fuelDeliverySchedule.getTimeOfNextValue() );
return;
}
super.executeActionOf( _e );
}
Maybe I can use something like this to create my own action function, but I'm not sure how to make the Scheduled event use it.
Thanks,
Thom
[Edited (expanded/rewrote) 03.11.2014 after more user detail on the context.]
You clarified the context with
When I attempt to programatically add "a thing that happens", read
from a separate configuration file, to a Schedule object I get errors
stating that the Schedule has already been initialized and that I must
construct a new object and add its configuration manually. I can do
most of that using the available Schedule API. I can set up everything
about the Schedule except the Action code.
(You might want to edit that into the question... In general, it's always good to explain the context for why you're trying to do the thing.)
I think I understand now. I presume that your config file contains scheduling details and, when you say you were trying to "add a thing that happens" (which errored), you meant that you were trying to change the scheduling 'pattern' in the Schedule. So your problem is that, since you couldn't adjust a pre-existing schedule, you had to instantiate (create) your own programmatically, but the Schedule API doesn't allow you to set the action code (as seen on the GUI schedule element).
This is a fairly involved solution so bear with me. I give a brief 'tl;dr'
summary before diving into the detail.
Summary
You can't programmatically code an AnyLogic action (for any element) because that would amount to
dynamically creating a Java class. Solving your problem requires recognising
that the schedule GUI element creates both a Schedule instance and a
timeout event (EventTimeout) instance to trigger the action. You can therefore create these two elements explicitly yourself (the former dynamically). The trick is to reset the timeout event when you replace the Schedule instance (to trigger at the next 'flip' point of the new Schedule).
[Actually, from your wording, I suspect that the action is always the same but, for generality, I show how you could handle it if your config file details might want to change the nature of the action as well as those of the scheduling pattern.]
Detail
The issue is that the GUI element (confusingly) isn't just a Schedule instance
in terms of the code it generates. There is one (with the same name as that of
the GUI element), which just contains the schedule 'pattern' and, as in the API,
has methods to determine when the next on/off period (for an on/off schedule) occurs. (So
it is kind of fancy calendar functionality.) But AnyLogic also generates a
timeout event to actually perform the action; if you look further in the code
generated, you'll see stuff similar to the below (assuming your GUI schedule is called
fuelSchedule, with Java comments added by
me):
// Definition of the timeout event
#AnyLogicInternalCodegenAPI
public EventTimeout _fuelSchedule_Action_xjal = new EventTimeout(this);
// First occurrence time of the event as the next schedule on/off change
// time
#Override
#AnyLogicInternalCodegenAPI
public double getFirstOccurrenceTime( EventTimeout _e ) {
if ( _e == _fuelSchedule_Action_xjal ) return fuelSchedule.getTimeOfValue() == time() ? time() : fuelSchedule.getTimeOfNextValue();
return super.getFirstOccurrenceTime( _e );
}
// After your user action code, the event is rescheduled for the next
// schedule on/off change time
_fuelSchedule_Action_xjal.restartTo( fuelSchedule.getTimeOfNextValue() );
i.e., this creates an event which triggers each time the schedule 'flips', and performs the action specified in the GUI schedule element.
So there is no action to change on the Schedule instance; it's actually related to the EventTimeout instance. However, you can't programmatically change it there (or create a new one dynamically) for the same reason that you can't change the action of any AnyLogic element:
this would effectively be programmatically
creating a Java class definition, which isn't possible without very specialised
Java code. (You can create Java source code in a string and
dynamically run a Java compiler on it to generate a class. However, this is very
'advanced' Java, has lots of potential pitfalls, and I would definitely not
recommend going that route. You would also have to be creating source for a user subclass
of EventTimeout, since you don't know the correct source code for AnyLogic's proprietary EventTimeout class, and this might change per release in any case.)
But you shouldn't need to: there should be a strict set of possible actions that your config file can contain. (They can't be arbitrary Java code snippets, since they have to 'fit in' with the simulation.) So you can do what you want by programmatically creating the Schedule but with a GUI-created timeout event that you adjust accordingly(assuming an off/on schedule here and that there is
only one schedule active at once; obviously tweak this skeleton to your needs
and I haven't completely tested this in AnyLogic):
1. Have an AnyLogic variable activeAction which specifies the current active
action. (I take this as an int here for simplicity, but it's better to use a
Java enum which is the same as an AnyLogic 7 Option List, and can just be
created in raw Java in AnyLogic 6.)
2. Create a variable in the GUI, say called fuelSchedule, of type Schedule but with initial value null. Create a separate timeout event, say called fuelScheduleTrigger, in User Control mode, with action as:
// Perform the appropriate action (dependent on activeAction)
doAppropriateScheduleAction();
// Set the event to retrigger at the next schedule on/off switch time
fuelScheduleTrigger.restartTo(fuelSchedule.getTimeOfNextValue());
(Being in User Control mode, this event isn't yet triggered to initially fire, which is what we want.)
3. Code a set of functions for each of the different action alternatives; let's say
there are only 2 (fuelAction1 and fuelAction2) here as an example. Code
doAppropriateScheduleAction as:
if (activeAction == 1) {
fuelAction1();
}
else if (activeAction == 2) {
fuelAction2();
}
4. In your code which reads the config file and gets updated schedule info.
(presumably run from a cyclic timeout event or similar), have this replace
fuelSchedule with a new instance with the revised schedule pattern (as you've
been doing), set activeAction appropriately, and then reset the timeout event to
the new fuelSchedule.getTimeOfValue() time:
[set up fuelSchedule and activeAction]
// Reset schedule action to match revised schedule
fuelScheduleTrigger.restartTo(fuelSchedule.getTimeOfNextValue());
I think this works OK in the edge case when the new Schedule had its next 'flip' at the time
you set it up. (If you restart an event to the current time, I think it schedules an event OK at the current time which will occur next if there are no other events also scheduled for the current time; actually, it will definitely occur next if you are using a LIFO simultaneous-time-scheduling regime---see my blog post.)
Alternative & AnyLogic Enhancement
An alternative is to create a 'full' schedule in the GUI with action as earlier. Your config file reading code can replace the underlying Schedule instance and then reset the internal AnyLogic-generated timeout event. However, this is less preferable because you are relying on an internally-named AnyLogic event (which might also change in future AnyLogic releases, breaking your code).
AnyLogic could help this situation by adding a method to the Schedule API that gets the related timeout event; e.g., getActionTriggeringEventTimeout(). Then you would be able to 'properly' restart it and the Schedule API would make much clearer that the Schedule was always associated with an EventTimeout that did the triggering for the action.
Of course, AnyLogic could also go further by changing Schedule to allow scheduling details to be changed dynamically (and internally handling the required updates to the timeout event if it continued to be designed like that), but that's a lot more work and there may be deeper technical reasons why they wanted the schedule pattern to be fixed once the Schedule is initialised.
Any AnyLogic support staff reading?
I have set the flag skipRowHoverCheck to true on the AbstractCellTable through the setter. By setting a debug point on the method onBrowseEvent2 inside AbstractCellTable I can confirm that the flag is set to true.
The code never executes the block where the skipRowHoverCheck is checked for being true, so no MouseOver browse events are added.
However, on debugging the project, the mouse over events are still caught and the row level hover events are picked up. This then makes the rows the mouse hovers over the selected row which is what we do not want.
Any advice on this would be great!
Thanks
The skipRowHoverCheck flag is used to avoid DOM restyling of the hovered row and firing of RowHoverEvents (handled by using addRowHoverHandler(RowHoverEvent.Handler handler)).
It is not used to avoid sinking the low-level BrowserEvents.MOUSEOVER and BrowserEvents.MOUSEOUT events. They are still fired, handled (with a no-op, if you have used setSkipRowHoverCheck(true)) and, if necessary, delegated to the underlying cell.
I don't know if I correctly understood your question, but this is the way the skipRowHoverCheck flag was meant to be.
I have two input fields which i would like to sync with each other.
Unfortunately, when I add a ChangeListener to each of the TextFields they will trigger each other,
and so create an andless loop.
Ofcourse I could unregister the Listeners, on every change and them put them back,
but is there any Java native approach?
Maybe something with bindings?
From general reasoning (i.e. not knowing swt or java): you can add a boolean flag (probably your class member) m_enteredChangeListener, temporary setting it to true in one of your handlers (not both), making the same handler do nothing if it's reentered recursively.