I am trying to design an activity diagram for an image editing application. Let's say that the application has one adjustment to edit an image. that's brightness. When the user opens the application he can change the brightness again and again. Then finally save it. That's really not a loop. but it's a repetitive process. How can I represent such a process. I have found stack answers for looping through documents and for loops. But didn't found a matching scenario for like this.
Thank you!
Oh, but why do you say it is not a loop? It is.
Sorry, no reasonable drawing tool at hand, so this will be textual
Let's look at a pseudocode:
open app (image as attribute)
while decide to continue to brighten the image do
brighten the image
loop
As you can see you do loop and your condition to loop or finish it depends on the decision to brighten or finish working with the app.
The brightening itself can be more complex (e.g. may have some selection of settings like level or method of brightening, it may even have the ability to break the brightenin or undoing) but it is still the loop.
Out of this solution to represent a loop you can use options 2 and 3 easily.
Related
I am new in doing an activity and currently, I am trying to draw one based on given description.
I enter into doubt on a particular section as I am unsure if it should be 'split'.
Under the "Employee", the given description is as follows:
Employee enter in details about physical damage and cleanliness on the
machine. For the cleanliness, there must be a statement to indicate
that the problem is no longer an issue.
As such, I use a foreach as a means to describe that there should be 2 checks - physical and cleanliness (see diagram in the link), before it moves on to the next activity under the System - for the system to record the checks.
Thus, am I on the right track? Thank you in advance for any replies.
Your example is no valid UML. In order to make it proper you need to enclose the fork/join in a expansion region like so:
A fork/join does not accept any sematic labels. They just split the control flow into several parallel ones which join at the end.
However, this still seems odd since you would probably have some control for the different inspections being entered. So I'd guess there's a decision which loops through multiple inspection entries. Personally I use regions only for handling interrupts. ADs are nice to a certain level. But sometimes a tabular text (like suggested by Cockburn) is just easier to write and read. Graphical programming is not the ultimate answer (unlike 42).
First, the 'NO' branch of the decision node must lead somewhere (at the end?).
After, It differs if you want to show the process for ONE or MULTIPLE inspections. But the most logical way is to represent the diagram for an inspection, because you wrote inspection without S ! If you want represent more than one inspection, you can use decision and merge node to represent loop that stop when there is no more inspection.
We're currently designing an application with an exit button, meaning the user can exit the application at any time. Now, we're not sure how to write this down.
Right now, we're thinking about doing it like shown in the picture below, because this is the only way we know how to do this. However, we feel like there must be an easier way. Also: if we do this for our whole application (which is quite big), we'd get a whole ton of decision and end nodes...
Your model looks ok. Instead of having multiple Final Flows you could lead all flows to a single one (just as an option).
Without knowing the exact requirements, here is another way:
The exit button is treated as exception. This could as well be written as
It is my first time doing a Petri net, and I want to model a washing machine. I have started and it looks like this so far:
Do you have any corrections or help? I obviously know its not correct, but I am a beginner and not aware of the mistakes you guys might see. Thanks in advance.
First comments on your net's way of working:
there is no arrow back to the off state. So once you switch on your washing machine, won't you never be able to switch it off again ?
drain and dry both conduct back to idle. But when idle has a token, it will either go to delicate or to T1. The conditions ("program" chosen by the operator) don't vanish, so they would be triggered again and again.
Considering the last point, I'd suggest to have a different idle for the end of the program to avoid this cycling. If you have to pass several times through the same state but take different actions depending on the progress, you have to work with more tokens.
Some remarks about the net's form:
you don't need to put the 1 on every arc. You could make this more readable by Leaving the 1 out and indicating a number on an arc, only when more than one tokens would be needed.
usually, the transitions are not aligned with the arcs (although nothing forbids is) but rather perpendicular to the flow (here, horizontal)
In principle, "places" (nodes) represent states or resources, and "transitions" (rectangles) represent an event that changes the state (or an action that consumes resources). Your naming convention should better reflect this
Apparently you're missing some condition to stop the process. Now once you start your washing will continue in an endless loop.
I think it would be nice to leave the transition graphics unshaded or unfilled if it is not enabled. Personally I fill it green if it is enabled.
If you want someone to check if you modeled a logic properly in your Petri Net then it would be nice if you include a description of your system logic in prose.
UI Control such as LISTVIEW or Tree or ... comes with model that is observable.
When one make a change to that model, I suppose JavaFX knows how to refresh it automatically in the display.
However my question here is as follows:
Is it the intent way, that someone who wants to update and not replace this model, do so in a background thread with a platform.runlater.
In other words, one has some serious computation to do, and needs to to update an ObservableList as a result. Is it the intended way, to do the heavy work in a background thread and at the end of it, run the update in a platform run later?
I'm asking this because this is what I have been doing so far without problem. But from my reading here and there, in particular in
http://docs.oracle.com/javase/8/javafx/api/javafx/concurrent/Task.html
It seems that some other mechanism shall be used. One should rather return a full list instead of updating the observable list.
But this works only if things comes from the GUI. In case the update is triggered from the back end, there is no way to do so.
The solution that I have used so far, was always to hold a reference to the observable list and updating it by means of platform.Runlater.
Is there any other way ?
The link you give has an example (the PartialResultsTask) that does as you describe: it updates an existing ObservableList as it progresses via a call to Platform.runLater(). So this is clearly a supported way of doing things.
For updating from the back end (i.e. from a class unaware that the data are being used in a UI), you'd really have to post some code for anyone to be able to help. But you might have a look at the techniques used in this article. While he doesn't actually update lists from the backend in the examples there, the same strategy could be used to do so.
I'm dealing with an old Motif application that needs to load and display a long list of entries (around 1500). It creates and manages an instance of xmFormWidgetClass via XtVaCreateManagedWidget() and then it stuffs it with a bunch of linear hierarchies xmFrameWidgetClass->xmFormWidgetClass->xmFormWidgetClass->xmPushButtonWidgetClass. Each PushButton contains a multi-line label. When this this thing is being populated, it takes a lot of CPU, which it spends doing some geometry calculations inside of X/Motif libraries. The pace at which new buttons are added, degrades very quickly. It looks like there is an O(N) algorithm being used inside of XtVaCreateManagedWidget().
The things get much much better if I do XtUnrealizeWidget() on the original instance of the xmFormWidgetClass. Entries are being added at almost constant speed but then I cannot find a way to display the whole thing that I built. XtRealizeWidget() for the original instance of the xmFormWidgetClass does not render it in the window.
What am I doing wrong? Is there a way to populate the hierarchy and then calculate the geometry and render it to the screen at once?
Redesigning the application is an option but it is a last resort type on an option.
Any advice that keeps me within Motif libraries will be highly appreciated!
Regards,
/Sergey
Try calling XtManageChild after XtRealizeWidget.
Try creating all widgets unmanaged and place them on a WidgetList, then call XtManageChildren(). Please see the following reference
http://www.s-and-b.su/syshlp/motif_guide/MotifProgGuide/Making_Widgets_Visible.html
Every time an individual widget is managed the parent changed_managed procedure is called.
XtManageChildren calls the changed_manage procedure only once. This may help.