Flex error when removing child - apache-flex

Have a rather bizarre issue with Flex throwing an error when teh application is running in the background. I use Selenium and SeleniumFlexApi to run various tests against my app. If the browser window is in the foreground or any part of it is visible to teh screen, the test pass as expected. However, if the window is in the background and not visible, I am getting the following error in 1 part of my app.
ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
I have a VBOX that creates a number of children and then upon creationComplete(or UpdateComplete, I've tried both) it then needs to remove any of the children that are not visible. Each child has a listener for CreationComplete which checks if the child is visible and if not, adds it to an array which is iterated over when the parent UpdateComplete is fired. I cant seem to find any reason for this behavior and am curious if its an issue with the Flex Component LifeCycle.

The most recent version of the Flash Player (10.1) will automatically "slow down" when minimized. I think it drops to a couple of frames a minute [as opposed to the standard 24 per second for Flex]. I don't know specific number.s This is for performance and 'battery life' reasons.
If there is anything in your app, or in your testing, that requires specific timing or uses a timer, then this will easily break unit tests.
I've heard from other folks that this have other folks that have had issues with this. The best solution I've heard proposed is "Add a flag to turn this off; even if it's only in the debug player." But, there is no solution right now other than "run your tests w/o the app minimized"

Related

Qt Activex MainWindow on TabWidget becomes unresponsive

I have a very strange problem. The application is based on Qt C++. There is a TabWidget whose tabs are created dynamically. The tab contains QtMainWindow in ActiveX widget. When multiple apps are started, the selected one works fine. But when another tab is selected, it becomes unresponsive.
When I minimize the Application and then maximize again then the tab starts working fine. I tried with setFocus, activateWindow, showNormal and setActiveWindow but nothing is working.
Can somebody help me in this issue?
The likeliest cause of the app becoming unresponsive is something that stalling the execution on the main thread. With running the project from/ or attaching to Visual Studio debugger (better debugger than the one used by Qt Creator) try to get your app in such unresponsive state. Now look at Main Thread in Threads view (select one), also look at Call Stack view. Where does the execution stall?
The log in Output View is also helping to recreate the context of how to get there. You can see Qt and your own debug output there.
While debugging I found that the App was not syncing because of missing WA_Mapped attribute. My problem was just opposite of the below issue. When I used to maximize after minimize, the App used to become responsive. Finally setting the attribute WA_Mapped at different places (trial n error) fixed the issue.
widgets freezing after minimise window
Thanks for #AlexanderVX response.

Flex Spark List item render with delayed refresh

I have a spark List in which I am adding custom components manually (without an item renderer). Everything is working fine except when I add hundreds of items in the list (based on several calculations), the render time increases to several seconds.
My questions are:
Does flex automatically delay the rendition of components that are added to a list?
If not then, how can I tell the spark list to only render the components once everything is added.
I hope what I am asking makes sense. I am pretty sure the render time is increasing because I have quite a few components inside the custom component. I just need a simple answer to my questions.
One more thing to know is that,
ActionScript 3 runs on flash player based on even-driven. It means that if you run a chunk of code in blocking, anything else, including rendering, will not be executed until the code ends.
This design sometimes causes issues: If a developer adds too much job in one blocking function, the player looks frozen and unresponsive momentarily. (If the code is an infinite loop, it stops until the player detects and throws ScriptTimeoutError, or possibly forever.)
However, for your question, yes, anything will be delayed until the adding job is done. Flex components doesn't basically split the job automatically.
Flex components are rendered in the list according to the Flex lifecycle: http://help.adobe.com/en_US/flex/using/WS460ee381960520ad-2811830c121e9107ecb-7fff.html
There are two reasons your List may be running slow, your components may not be following the Flex lifecycle correctly and the second because virtual layouts are not enabled on your List.
First the hard one:
Your first step should be to ensure you are following the correct phases in your custom components for commitProperties(), measure() and updateDisplayList(unscaledWidth:Number, unscaledHeight:Number).
So long as you are not calling any method named validateNow() on either your UIComponent subclasses or the LayoutManager then your components should follow this just fine.
The second may be that your list layout is not using virtual layout. This is enabled by default in a Spark List component but if you're overriding the layout you should ensure that useVirtualLayout is set to true on whatever layout you're using.
This is the property to enable it:
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/spark/components/List.html#useVirtualLayout
This is what it does to speed up rendering many items in a Spark DataGroup component (which a List is):
http://help.adobe.com/en_US/flex/using/WSc2368ca491e3ff92-1483ec4a12136246e76-8000.html#WS685c4ccbb85d340c6617851e121d4b8abae-8000

FlexMonkey Issue with TitleWindow Popups

We are currently testing parts of our application that open in popup windows. These windows are subclasses of TitleWindow. The issue we now run into is that the popups seems to be registered multiple times and that tests are sometimes executed on popups that have already been closed (or so it seems).
I thought this had to do with the way we closed and removed our popups, but I can't really spot any problems there. After looking into the FlexMonkey source code, I saw that there is an explicit check for "TitleWindow" in the ADDED_TO_STAGE handler, after which the popup is added as an application window. But the popup never seems to be removed from the "_windows" collection. As a result, when you open the tree view in FlexMonkey, there are several instances of the same popup window class. This probably also explains why our tests sometimes do not seem to run (visually), but execute and verify correctly, as they are ran on a hidden instance of a popup. I would expect the MonkeyAutomationManager to also listen to REMOVED_FROM_STAGE events and remove the popup when it is closed.
Am I missing something here or is this an (known) issue?
My guess is that it isn't an issue, it's simply that your code isn't properly cleaning the object and removing it from the display list. You also need to remember that garbage collection does not run right after you remove something from the stage. It could be possible that your window, even if it has been removed from the stage is in fact still listening and responding to events.

WebAii - problem facing while entering text in input box in web page

Steps performed
1. Open a web page where data needs to be entered programmatically
2. Retrieved Element instance by passing element Id.
3. Call SetText function in Actions instance in ArtOfTest.WebAii.TestTemplates.BaseTest class by passing element and textToSet
Expected solution
Text need to be entered in the text box always.
Actual Output
Text is not always entered in the text box. Some times entering correctly and sometimes skipping it without entering the value. When debugging, observed that, the element instance is retrieved properly and SetText function is called and no exceptions are thrown. When the value is not entered, setting the control again at the top of the function and running it again will set the value in the text box.
Can any one tell me the reason for this weird behaviour?
Please let me know if more details are required.
Your description sounds like a timing problem. Since test scripts usually run very quickly it is easy for them to outrun your web application. If your test runs while debugging it (i.e. running slowly or single stepping) but intermittently fails when run at full speed, you are almost certainly running into a timing problem. Your web application may not be ready to accept text input at the time your test script is trying to feed the data into it, which is a very common problem if your web application is doing an AJAX postback. The easiest method to overcome such a problem is to add a fixed delay just before the SetText call. A more advanced technique is to monitor some property or element contained within your web application to detect when it's ready for input and wait for that to be set. Once that property is correctly set then call the SetText function.
Cody
Telerik Technical Support Team

Flex Post Event Screen Updates

I came across this topic today while investigating something very strange. Doing certain things in our Flex app can cause the number of frames rendered to rocket, from 12fps to ~30fps: loaded animations start playing at high speed and the GUI starts to lock up.
Since everything I've read on Flex/Flash hammers home the point "the frame rate is capped at the fps set in the top level app", it seems the only way these extra renders can be happening is due to some events causing them (no programmatic changes to the stage's framerate are done anywhere). Since it only happens when I put my update logic in the ENTER_FRAME handler, I'm trying to figure out what might be happening which to apparently causing Flex to go render-crazy.
Hypothesis: something in my update function is triggering an immediate screen update, this raises another ENTER_FRAME immediately, which means my update loop gets called, which triggers another immediate screen update, ...
We have Flex components used in our GUI, if this is a factor. I don't really know where to go next on this.
Clarifications:
When I say things speed up, there
are two ways this manifests.
Firstly, my ENTER_FRAME handler gets
called far more often.
Secondly, a
loaded Flash SWF with a looping
animation built in suddenly speeds
up to te point it looks silly.
I am not using updateAfterEvent, I only
found this existed when researching
this problem. Apparently, some
events on Sprite subclasses
automatically call this and I wonder
if that's the root cause.
I am not doing any direct messsing about with rendering at all. Background animations play automatically as they have timelines built-in from CS3 authoring, all our update function does is change the position of DisPlayObjects or add/remove them etc
Update:
I added a label to my app to print out stage.frameRate, and discovered at certain times, it suddenly changes from 12 to 1000 (the maximum allowed value). While it was trivial to add a line to my ENTER_FRAME handler to reset it that's hardly a big help.
Also, even doing this, the rendering is all messed up. Certain actions (like raising an Alert popup) make it all spring back into life.
Unfortunately, I am not able to view the source of the Stage class to set a breakpoint on the setter property.
That's very interesting about the Flex loading 'set to 1000fps' thing. What we have are several Flex applications which all provide a common interface. A master app is in charge of loading these modules as required through the SWFLoader class. However, the loading process already takes into account the delayed loading... when the SWF loads we then wait for the APPLICATION_COMPLETE from the SystemManager. Once this is received, shouldn't the applications completion have occurred?
Flex sets the frame rate to 1000 during "phased instantiation" of Flex components, which occurs only during initial load of a flex swf. This allows it to build all components very quickly.
Are you waiting for the Flex app to be fully loaded and constructed? You should be waiting for FlexEvent.CREATION_COMPLETE before working with your Flex content.
If you would like a reference to where this occcurs, look in the Flex LayoutManager class, line 326 (using Flex SDK 3.0.194161), in the setter for the property usePhasedInstantiation.
Update:
APPLICATION_COMPLETE should have you covered for the initial load.
This actually happens any time components are created directly from MXML. So there are a few other cases to look for. Are you using any Repeaters? Do you use any navigation containers that are building their children on demand?
One thing I'm not clear on - are you seeing that the actual screen refreshes are occurring faster than the published framerate? Or is it that your animations are moving faster but the screen refreshes are unchanged? (i.e., it used to move 10 pixels per second, but now it moves faster than that, regardless of how often the screen is drawn.)
An easy way to check this would be to try publishing your content at 1 fps. It should be clear whether the screen is redrawing once per second, but animated elements are being moved more frequently than that, or whether the screen is actually updating more frequently.
If the latter, are you using any updateAfterEvent() methods in your code? This can cause actual screen refreshes to occur faster than the published framerate. It shouldn't affect ENTER_FRAME events though. You should still only get one of those per frame update.
Alternately, are the things you're animating just Sprites and so on, or are you implementing them as Flex components, and trying to redraw them with invalidate() methods and RENDER events and so on?
If you could clarify a few of these points in the question the answer might be clearer. Thanks...
Thanks for the clarifications. If a loaded clip with a animation (I assume you mean a frame animation) is speeding up, then that certainly sounds like something is changing your playback framerate, as opposed to other things that could be going on. With that said it's not a problem I've seen crop up before, but I do think there are some things you could try that ought to narrow down where the problem is:
You might as well try tracing out stage.frameRate during the speed-up. Presumably nothing ought to be changing your framerate, but since that would explain your issues you might as well rule it out.
Try removing as many GUI components as possible and seeing if the problem still occurs, if it's possible to trigger the problem without them.
One sanity check you could try, if it's feasible, is to copy some of the contents of your game into a fresh project and try it there. Sometimes mysterious issues like this happen because some class or SWC is being imported somewhere that everyone forgot about.
You could try driving your code from a different event. For example, as far as I know driving it from Event.EXIT_FRAME or Event.FRAME_CONSTRUCTED ought to look the same, but if it doesn't then that's a hint. Alternately, you could try driving it from something like a keyboard event or MouseEvent.MOUSE_MOVE. Then if updates occur even though you're not firing events, you'll know something else is driving things besides your event loop.
Those are the things I'd try, anyway. Hope you track it down...

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