I want to read how much data from 3G every app uses. Is this is possible in iOS 5.x ? And in iOS 4.x? My goal is for example:
Maps consumed 3 MB from your data plan
Mail consumed 420 kB from your data plan
etc, etc. Is this possible?
EDIT:
I just found app doing that: Data Man Pro
EDIT 2:
I'm starting a bounty. Extra points goes to the answer that make this clear. I know it is possible (screen from Data Man Pro) and i'm sure the solution is limited. But what is the solution and how to implement this.
These are just hints not a solution. I thought about this many times, but never really started implementing the whole thing.
first of all, you can calculate transferred bytes querying network interfaces, take a look to this SO answer for code and a nice explanation about network interfaces on iOS;
use sysctl or similar system functions to detect which apps are currently running (and for running I mean the process state is set to RUNNING, like the ps or top commands do on OSX. Never tried I just suppose this to be possible on iOS, hoping there are no problems with app running as unprivileged user) so you can deduce which apps are running and save the traffic stats for those apps. Obviously, given the possibility to have applications runnning in background it is hard to determine which app is transferring data.
It also could be possible to retrieve informations about network activity per process/app like nettop does on OSX Lion, unfortunately nettop uses the private framework NetworkStatistics.framework so you can't dig something out it's implementation;
take into account time;
My 2 cents
No, all applications in iOS are sandboxed, meaning you cannot access anything outside of the application. I do not believe this is possible. Neither do I believe data-traffic is saved on this level on the device, hence apple would have implemented it in either the network page or the usage page in Settings.app.
Besides that, not everybody has a "data-plan". E.g. in Sweden its common that data-traffic is free of charge without limit in either size or speed.
Related
I'm new to Roku development (in R&D phase actually). I read that we can't test Roku app on simulator and need real device. If we develop an application, how will we test it?
I checked Roku developer site and different links on internet, but could not find anything that answers my questions
As per my info, Roku sells 5 devices so:
Can we do one app that supports all 5 devices?
Do we need assets in multiple resolutions?
Do I need to buy all devices?
Can we do one app that supports all 5 devices?
Yes. Roku is trying hard to keep their platform coherent, though there are performance issues between the OpenGL and non-OpenGL devices. The "legacy" models (<2222) are no more supported, the firmware is kept current for the others.
Do we need assets in multiple resolutions?
Theoretically yes, practically - not really. You can make-do with assets in only one resolution, if you RTFM and pre-plan carefully. You'll need 3 sizes of app icon, no sweat. For the real UI though, you can either do HD (720) or FHD (1080) and leave it scale accordingly - the thing is TV is very forgiving to scaling graphics because of 10ft watching distance (60" 1080p screen is "Retina" beyond 8ft). Can largely snub SD.
Do I need to buy all devices?
No. And there are much more than 5 devices that are in use - see https://forums.roku.com/viewtopic.php?f=34&t=86471&start=15#p536994 for some statistics (RokuCo does not publish statistics, so that's about the best info available). If you buy only 2 devices, i'll say get
a #42xx (Roku 3 or current Roku 2) as reference model with OpenGL
a #27xx (Roku 1 or SE) or #5xxx RokuTV as reference for "slower", non-OGLES
As 3rd model i'll say the "new HDMI stick" #3600. You can get that one as the only device, its performance is somewhere between (1) and (2) above... but i don't think developing with only 1 device is a good idea.
One thing you may not have noticed is that there are also these "Roku TV" things under Hisense/TCL/Sharp/Insignia brands, models #5xxx. These are proper TVs with proper Roku smarts - meaning can run your Roku app. And one can be had for as little as... (skimming BestBuy web) $130-150 for 24-32" screen.
And i haven't even mentioned the 4k/HDR craze here, nor the new 37xx/46xx models that will be out for the holiday season (i only expect minor, evolutionary changes there).
Disclosure: I am a Roku employee.
That's correct, you'll need an actual Roku device to test your application. You can buy them used on eBay for very cheap ($20-35), or you can buy a brand new unit from our website for $50. The latest Roku Streaming Stick (Model #3600X) is my personal favorite option, and a great value.
You don't need to buy all devices, although we do recommend having many models so that you can QA test across devices. However, one popular development approach is to build your channel on a lower-end model, which theoretically will assure it works on higher-end models as well. This will also mean you have to spend less on your purchase.
Download our Precertification Checklist and open the third sheet, which includes a list of all our model numbers and corresponding code names. I'd recommend building on a "Giga" or a "Paolo."
Think of this cost as an R&D expense. Plus you'll get to enjoy the device on your free time as well!
As for your other questions:
Yes, you will only build one app that will work on all different devices. We do recommend taking the time to make sure your app is optimized across all devices, including older devices with less processing power. Our Performance Guide is a great starting point for this.
The other option is to check if the first number of the device model is less than “3” (which indicates it's a lower-end device) and add conditionals off that, such as removing animations.
You can find two examples of this on our RokuDev GitHub page:
Hero-Grid-Channel —> Components —> LoadingIndicator —> LoadingIndicator.brs —> Line 244
Multi-Live-Channel —> Source —> Main.brs —> Line 21
Yes, you do need different assets based on resolutions. Take a look at this document: https://github.com/rokudev/docs/blob/master/design/channel-artwork.md
I have developed many apps on Android, and I have tried using Broadcast Receiver concept in many of them such as knowing when the battery is low or such.
I would like to use the same concept in developing on Windows phone, but I could not find Broadcast Receiver in it.
I want my application to know whenever the user took a new photo by camera. In addition, keep tracking of it.
What do you suggest?
There’s no broadcast receiver concept in Windows Phone.
IMO, this is by design.
I know two good reasons why I wouldn’t want that on my phone: privacy (almost no one reads list while installing apps) and battery life.
You can read those photos while your app is running (caching file list+modified times for faster updates).
And/or, you might want to create a lens extension, here’s a link for WP8.
I am looking for an API to monitor the tasks running on a plain iPhone (no jailbreak). Those are about:
look for CPU usage (my main concern).
look for memory usage.
look for disk usage (how many read/write)
look for network usage (how many bytes sent and received by network: 3G, Wifi, GSM).
is it possible to rely on the IOS simulator running on a Mac (or should I test my application directly on the device)?
I think I can look into the system C libraries (sigint, etc.) but I am not sure to be able to retrieve this information except for the current applications running. I know some monitor applications run on the global usage but I would like to be able to find the information process by process.
If someone can provide some links or something useful, I will start a deeper investigation then.
CPU usage can be found by looking at the code from this related question:
iOS - Get CPU usage from application
Memory usage:
Available memory for iPhone OS app
And here are a couple threads that talk about how to find out about the applications or tasks currently running:
Can we retrieve the applications currently running in iPhone and iPad
How to get information about free memory and running processes in an App Store approved app? (Yes, there is one!)
How to get the active processes running in iOS
The answers to these questions may point you in the direction you'd like to head towards.
Good luck!
The Activity Monitor should get you what you're looking for. You should be able to observe RAM, CPU, and VRAM usage for each iOS process. This is a default tool installed with xCode. Very handy.
Are there any "best practices" for writing a power-efficient background application in Symbian?
Specifically, is there any way (i.e. API) for a Symbian app to hint the OS regarding its current state in order to reduce battery consumption?
In Android, for instance, there is the notion of Wake Locks, which prevents the device from going into standby mode - Is there anything similar in Symbian?
EDIT:
Are there any implications when running code as a separate thread with the Open-C library, and not as "native" Symbian C++, using Active Objects etc.? (the Open-C code is blocking on IO most of the time).
You can check user (in-)activity with a RTimer::Inactivity() method. This way is described in Forum Nokia Wiki page. There it's also described how you can reset inactivity timer.
You can check whether device screen is turned on or off using HAL API. See classes HAL and HALData. You may use such a call:
TInt displayState;
HAL::Get(HALData::EDisplayState, displayState);
And the displayState will hold either 0 if display is turned off or 1 in other case.
With these APIs you will know whether user is active now, so you'll be able to change behavior of your background service to reduce its power consumption.
You can also use Nokia Energy Profiler application to record power consumption of handset, with different power saving options of your background service. Also please refer to Nokia's document describing best practices to save power of device. This document is quite straightforward, but useful nonetheless.
Hope this helps.
EDIT: About separate thread and Open C. As far as I know, Open C is just a plugin and deep down all the implementations are still "native Symbian". So, as far as you avoid periodic polling of some resource and just use usual blocking IO, your code is quite same economical on power as standard Symbian Active Objects techniques (which use Symbian-specific semaphores to block threads).
I have not come across anything special in Symbain to keep the device out of stand-by mode. Basically the "best practices" would be the same as all mobile devices:
Don't loop waiting for things, always use whatever signaling services avaialble on the platform, for Symbain ActiveObjects / User::WaitForXxx
Limit the number of background threads (currently all mobile devices are still only 1 CPU...)
Don't hang onto system services, close them ASAP (this is normally my main battery drain in my mobile applications, sometimes trying to find which system service causes the most battery drain can be a real pain, WinMo is very bad for this).
For me, I find that it mostly comes down to a tradeoff between battery life and performance / responsiveness for the application. Unfortunately power that be always seem to side with the performance / responsiveness side and damn the battery drain.....
Give your application low priority (see RProcess and RThread classes). Your approach will really depend on what your background application does. These things consume most battery: radio (GSM/3G/WIFI/BlueTooth), screen backlight, file accesses.
Symbian OS will always try to put your application to sleep, you don't need to tell it to do this. Just make sure your approach gives it the opportunity to put it to sleep.
Power management is an very most important issue while developing application.
In Symbian it depends on what you are using to run background activities .
Whether you are using Thread or ActiveX control.
For Eg. you are developing application browser that you want the browser to download something then that downloading activity should go in background and able activity starts and when to show progress and when it finishes it should again come to fore end.
It depends on how you are managing thread if you are using thread. You can do like which thread to pause when the long time taking activity starts and when to resume when background activity has finishes execution..
In fact this is the very good topic u have come across
There used to be an inactivity timer which could be reset by the application. This would prevent the screen from going into any screen saver mode.
If you use the various asynchronous function in Symbian, your app will run when appropriate.
One of these methods should work depending on your needs. If you describe what you want to achieve in more detail it would be easier to help you.
I want to write a program that monitors packets in and packets out, or in other words, network statistics. Is there any useful class in cocoa? I know there are some existed tools, but it will be a sub-routine of my program. So I must implement on my own.
Thanks a lot!
P.S. I only want to calculate one program / process 's statistics rather than the whole system.
You won't find much in Cocoa, you'll probably have to delve deeper into Core stuff. In the recently released pool of WWDC videos, they have a video on Core OS Networking that covers the Mac and iPhone platforms both, and gives a pretty good overview of some of the classes you might be needing to look at.
Might not hurt to give the Core Networking stuff a glance, since whatever you're monitoring is most likely using it:
http://developer.apple.com/mac/library/documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html