Develop Reference

Connecting phone to external display and launching app

Is it possible to create an app which launches on an external display when HDMI is connected to the phone?
Basically. I want to create an app that works like a mini OS, similar to Samsung Dex.
To start off, I'd just like to have the app launch automatically when HDMI is connected and adjust to the screen size, then show the user home screen app icons etc.
Is this possible?
I found some apps on the app store that do this:
Sentio desktop
Leena
How are they doing this?

Here's an open source project that can help you. right here

Is downloading files on Android possible when the app is in background without a charger?

I'm developing an app where I need to download a 200-300 mb file from the web. Today I noticed a strange behaviour.
I always have my phone plugged to the PC with a cable with Android Monitors running in IntelliJ. Everyhing was running nice, files were downloading even when I was clicking the 'home' button in the middle of the process and I always got a notification to the menu that the downloading has finished - and it was really, complately finished.
Today I unplugged my phone from the pc/cable and opened the app. The downloading process starts but when I click 'home' and the app goes to the background, it won't finish, it won't even continue. It freezes the networking thread or something connected with it.
I read some, and I remember that some popular apps like for example 'Hearthstone' game had the same problem. If you go to the menu, downloading stops.
I figured it out that this is caused by the charger. If the phone is charging when the files are being downloaded, everything is ok.
And my question is.
Is there any Android permission that will allow me to do this?
I heard that it can be changed on the device's settings, but this is a bad solution.
Is there any possibility to download files in background, without a charger and without user's interaction with the settings?
I'll also add that I'm using LibGDX engine but it doesn't matter, I can use all of the Android's features.

I found that there are two aspects that can limit the network:
Restrict background data - an option that you can set on each application in Data Usage settings
Power saving option which automatically makes a limit on the networking and more.
Extra: when device is connected to a charger, power saving is disabled by default - that's why it was working.

Android: Disable mandatory restart when changing SIM-cards

For an app that I am currently developing we want to read data from the SIM card of the user, which works fine. We want to make it possible that the user can switch the SIM card while the app is running. While doing this the OS request a device restart and we cannot seem to suppress this message.
Is there a way to make it able to insert a SIM card while the app is running without restarting the device. I'm open for all options (rooting, custom rom, etc...)

I don't think it's possible - I never saw any option in phone settings allowing to turn on or off this feature. What might interest you is that for some phones - for example Sony Xperia Z as far as I remember - phone allowed changing SIM card without restart.

I found a method but i don't know if it'll work with other devices.
Device:Sony E4g(2003)
Android:4.4.4
Root required :yes
Apps Needed :Romtoolbox pro
First open rom toolbox and go to app manager, then search for "Sim Detection" it is a system app, then click it and go to "advanced freeze option" then You Disable "SimDetectionReciever" and you're Done.
Hope this helps

How can I autorun Android Chrome homescreen app on startup

After adding a certain website to homescreen through Chrome for Android, I'm looking for a way to autorun that homescreen app as the device boots up. I found a few apps in the Google Play store that offer that behaviour but they don't list Chrome homescreen apps as possible to autorun on boot.
Any solution, anyone?

Unfortunately, there is no solution right now. Chrome homescreen apps work slightly differently from regular apps. Please read here for the full details: https://developer.chrome.com/multidevice/android/installtohomescreen
Specifically, Google developers have mentioned that Android can not detect Chrome homescreen apps as installed.
Do not prompt the user to add your app to the homescreen. There is no
way to detect if the app is running installed or not.
So by extension, you are not able to run them at startup.

Running homescreen apps on device boot up might be tricky since Android cannot detect them as installed, but here is a workaround you might be interested in:
Install AutoStart - No root on your Android device
In the app, Set "Auto startup" to ON
Add Chrome to the Applications list
In Chrome, add the page you wish to launch as the browser start page
Optional - Install a secondary browser and repeat the steps above in order to avoid interfering with the start screen of your regular browser
Optional - Install an app like Fulscrn Free or similar and add your browser to the list of apps that run in full screen mode.
This way, every time you boot up the device, a browser will launch with the page you designate, almost as if it is launching the homescreen app.

Here is what I did:
Installed Tasker and AutoInput . They are paid though.
In Tasker, add a profile for "On device boot" and an action from Plugins->AutoInput.
Follow the instructions in AutoInput to create an action that simulates a press on the web app's icon on the homescreen.
I placed my icon on the default home screen, otherwise you might need to add a swipe action first to get to the proper screen.

App Inventor app works in emulator, but not on my actual phone

I've got an app inventor app built and working pretty well in the emulator. When I put it on my phone none of the code runs. The app doesn't crash, but the code behind the objects doesn't do anything. I've got code which runs on screen load which doesn't fire, and my buttons don't do anything.
The drop downs show the menu item, but that's it.
Does anyone have any ideas?

Have you connected the phone with the Block Editor Open? Can u see live preview of the app being developed?
You need to install a small application "AppInventorPhoneApp" to the phone in-order to accomplishing this... Usually this will be installed when you connect the phone first time with your BlocksEditor...
Just connect the phone to the Blocks Editor. Blocks editor will automatically install this application. Then you can see the preview in Phone.
Click Download apk from app inventor. Then Click, Package for Phone--->Download To Connected Phone.
I hope this solves your issue.
Check if unknown Sources and Development options are turned on in the Application settings.... For an application to run without these, you have to sign it. (I am not sure about this)..