Are webkit transitions slower after iOS 5 upgrade? - uiwebview

I'm experiencing slower webkit animations in UIWebView embedded apps after upgrading my iPad 2 to iOS 5. Two of my apps are noticeably jerky during multiple animations and transforms.
The simplest animation I have that demonstrates this is doing three things: scrolling a 2048x768 image to the left, moving a smaller image to the right and scaling it down, and playing an audio clip via AVAudioPlayer.
It's all jerky after the upgrade, even when I'm not running anything else. Memory isn't leaking or increasing in size. I did a CPU profile on the app before the upgrade, no problems there.
Is anyone else experiencing this?

Seems to be an intermittent problem - the app looks fine this morning. I suspect there's network operations occurring on the app. I have another I'm working on that has lots of transitions but doesn't require network access, so I might see if I can duplicate the problem over there.
For now, I'll just live with it and watch for it to reoccur.

Related

Node.js require becomes extremely slow after OS X has been running for a while

When I reboot my Mac, starting up Node.js apps is nice and fast. Later, after the Mac has been on for a few hours, it gets REALLY slow.
I've used process.hrtime() to time various things, and it seems that it's all the require calls that take time, ie loading dependencies. Once everything is loaded, my apps run reasonably fast.
The difference is extreme: just after I've rebooted, an app may take 300ms to get through the require calls, then it takes something like 30 seconds once it's been on for a few hours.
What could be causing this?
Since how fast executing require is perfectly related to a disk loading performance.
So I suppose It's highly possible that HDD/SSD or whatever your project belongs causing that.
it's working fine right after you rebooted so maybe some background software(such as virus scan or auto downloader) is making IO blocking
You'd better start by checking your CPU/RAM/HDD status while the issue is occurring and see what happens if you move your project into USB flash drive or external HDD

Mobile Website - How to keep process alive on client side in mobile browser in Android?

I am new to mobile website development, and facing this issue where I want to refresh data on the website in every 30 sec which is invoked from the client side and server provides the data in response. Problem is when I close the browser or when the browser goes in background it stops working. Is there any thing we can do to make this thing possible?
Have a look at the Android Developers - Processes and Threads guide. You'll get a deeper introduction to how process life-cycles work and what the difference is between the states for background- and foreground processes.
You could embed your web app in a WebView. This way you could deal with the closing browser case: you could provide a means to "exit" the app that involves closing only your container activity. That way the timers you have registered in javascript will still be running in the 'WebViewCoreThread'. This is an undesirable behavior and a source of problems, but you can take advantage of it if you want (just make sure you don't run UI-related code there). I've never tested this in Kit Kat (which uses a different WebView based on Chrome) but works for previous versions, as I described here.
Now the user can always close any app. Even without user interaction, the OS can kill your app on low memory. So just give up on long-running apps that never end, because the OS is designed in such a way this is simply not possible.
You could go native and schedule Alarms using the AlarmManager.
Just checked this out on the Android KitKat WebView and as per Mister Smith's comments the javascript will continue executing in the background until the Activity is killed off:
Just tested with this running in a WebView:
http://jsbin.com/EwEjIyaY/3/edit
My gut instinct is that if the user has moved your application into the background, there seems little value in performing updates every 30 seconds, it makes more sense to just start updating again once the user opens the device up and cache what information you currently have available to you.
As far as Chrome for Android goes the same is happening, as Chrome falls into the background the javascript is still running.
If you are experiencing different behaviour then what exactly are you seeing and can you give us an example?

Web uploader issue using Uploadify

I am working on a website that allows my clients to upload large amount of high resolution image files to my system. I have tried couple of uploaders but they don't seem to be as reliable as I was expecting - especially on Windows.
I have tried the following:
Uploadify 2 and 3
YUI Uploader (Yahoo Uploader)
The above uploaders all relies on Adobe Flash.
One of the most noticeable problem which is common to the mentioned uploaders is that the progress does not seem to work on Windows. It either stuck on 100% or 0% until the upload is actually finished. The files seems to be uploading fine but progress bar is totally out. This isn't a problem on a MAC though. I believe the problem is not within my code because even the uploaders' demo sites suffers the same problem.
On top of that I have heard clients complain about the uploaders being "self aborted" after say 33 files or so. They just don't seem to be that reliable.
My questions are:
Is there any way around this? To improve the visual at least (make the progress bar goes under windows)
Are there any other uploaders/methods that allows my clients to deliver large amount of files to my server reliably?
Running out of ideas and my clients are getting frustrated.

Is it possible to force termination of backgrounding apps on iOS?

I've written an app which is handling videos. As we know, video processing takes a huge amount of memory while dealing with HD resolution. My App always seemed to crash. But actually I am 100% sure, that there is no memory leak in my code. Instruments is showing no leak.
At the beginning I am startin up one OpenGLES view and the video engine. For a very short time the memory consumption is high, but falling down to normal level after the initializations are done. I am always getting memory warnings during this period. Normally this is no problem. But if I have a lot of apps in suspended mode running, the App seems to be crashing. Watching into the crash log and using the debugger shows up, that I am only running out of memory.
My customers are flooding my support mail with "app is crashing" mails. But I do know, that they have too much Apps running in the background, so there is no memory left to go. I think it's bad style programing saying the customer that he has to close Background tasks before running the app.
According to this post this is a common problem.
My question is: Is it possible to tell the OS that one needs a lot of memory so the OS should terminate some suspended Apps? This memory stuff makes me crazy, because it's no bug I could fix.
No. It is not possible to affect anything outside of your sandbox without API calls. None exist for affecting other processes in the public API.
Have you tried to minimize your memory usage? In my experience once a memory warning it thrown apps can be more likely to have problems once they are in the background, even when memory usages drops.
If you are using OpenGLES and textures, if you haven't already compress your textures. What is the specific cause of your memory allocation spike?

How to do zooming and paging in UIScrollView with big image size(1.5)MB and 100 images?

I am making an application using UIScrollView.In this we have to do zooming and paging of images.I have about 100 images and size of each image is 1.5 MB.Currently i am using scrollview for this ,but when i load more than 10 images the app crashes giving memory warnings.
Please somebody help me as i am stuck with this crashing of app.I have tried many other things also but it does not work.My app is just like photo library of iphone.Plese somebody suggest me what i have to do.
Thanks in advance.
This sounds like you are trying to load too much data into RAM. Are you aware of how little RAM your app has available on the iPhone, and how big an image gets once it is rendered? You should probably try and load images on demand, not pre-load them. Also release them once you're done with them, and release as many cached objects as you can when your app receives a memory warning.
But until you post more information, this is all just poking around in the dark.
Just try to debug your code and find where the app is crashing. So you can get the reason of crash.
xCode debuging is very strong and helpful.
put your crashing code here. so someone may tell you what you are doing wrong.

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