Develop Reference

Toggle GPS Programmatically Android 4.4

I know. Don't do this. I don't care. It's for a root app.
The app is installed to /system/app/ with 0777 permission
I was previously using:
ContentResolver cr = context.getContentResolver();
Settings.Secure.setLocationProviderEnabled(cr, LocationManager.GPS_PROVIDER, !isGpsOn);
This is how I'm trying it on 4.4 since that was deprecated:
int value;
if (isGpsOn)value = Settings.Secure.LOCATION_MODE_OFF;
else value = Settings.Secure.LOCATION_MODE_HIGH_ACCURACY;
Settings.Secure.putInt(cr, Settings.Secure.LOCATION_MODE, value);
And it is silently failing (according to some user reports). How can I properly toggle GPS with Android 4.4 from an app in System folder?

Don't do this. :)
Check the code for GPS TOGGLER
GPS toggle widget for Android rooted devices. It wrks well even for
those ROMs and kernels, other software failed.
With your code, just checking:
Hope you declared the following permissions in your manifest:
<uses-permission android:name="android.permission.WRITE_SETTINGS"/>
<uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS"/>
I had used this on rooted LG Optimus, android 4.0/4.1.
Reportedly this may no longer work but i am not sure about it for all devices and o.s.:
Switch it ON/OFF with a flag check and this code:
try {
Settings.Secure.putString (context.getContentResolver(),
Settings.Secure.LOCATION_PROVIDERS_ALLOWED, String.format ("%s,%s",
Settings.Secure.getString (context.getContentResolver(),
Settings.Secure.LOCATION_PROVIDERS_ALLOWED), LocationManager.GPS_PROVIDER));
} catch(Exception e) {}

Can I turn on WiFi-Direct from code? on API-16 (Android 4.2.2)

I am developing an application with NFC and wifi direct. I get the MAC address using NFC and the Wifi Direct to transfer data. I call discoverpeers() and could get success. But there is no callback WIFI_P2P_PEERS_CHANGED_ACTION, the callback comes only when I go to settings and the select wifidirect.
This was discussed in the other question
Can I turn on WiFi-Direct from code? on Android API-14 (ICS)
"I'd like to add that WiFi direct on JB and above (at least on AOSP) is not active all the time - it only appears to be. If you look at listeners for WiFi direct, it turns itself off after some time. It turns itself back on if you open the wifi direct menu, however. You might have to have the host do a peer search or initialize itself in order to be able to be found. Likely a battery saving trick. I have also found that it's blocking, since as it accepts a connection, the entire system will lock up and fail to connect sometimes. (The system invitation) – Mgamerz "
Can anyone suggest the solution for the problem WIFI_P2P_PEERS_CHANGED_ACTION callback is not got and can get only when manually go to settings->wifi->tap on wifidirect
I used two devices Samsung galaxy nexus and nexus 7 both running on 4.2.2

There is no available API to enable wifiP2P but you can invoke method "enableP2p" from android settings 4.0.1
WifiP2pManager manager = (WifiP2pManager) getActivity().getSystemService(Context.WIFI_P2P_SERVICE);
Channel channel = manager.initialize(getActivity(), getActivity().getMainLooper(), null);
try {
Method method1 = manager.getClass().getMethod("enableP2p", Channel.class);
method1.invoke(manager, channel);
//Toast.makeText(getActivity(), "method found",
// Toast.LENGTH_SHORT).show();
} catch (Exception e) {
//Toast.makeText(getActivity(), "method did not found",
// Toast.LENGTH_SHORT).show();
}
To disable wifiP2P use this method
Method method1 = manager.getClass().getMethod("disableP2p", Channel.class);

Not from code. The user has to. That's why the demo has the link to wifi settings in the action bar.
When you call manager.discoverPeers(channel, new WifiP2pManager.ActionListener()
define onFailure and look at the reasonCode. If it's 0, then either the Wifi or WiFi direct is off.
If you look at the WiFi Direct demo app, the WifiDirectBroadcast Reciever, this piece of code looks at whether p2p is enabled specifically
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
// UI update to indicate wifi p2p status.
int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
// Wifi Direct mode is enabled
activity.setIsWifiP2pEnabled(true);
} else {
activity.setIsWifiP2pEnabled(false);
activity.resetData();
}
Then when discover peers is called it looks at the variable set by setIsWifiP2pEnabled

thanks user3093354. to continue with your solution, in order to disable the p2p you have to invoke:
Method method1 = manager.getClass().getMethod("disableP2p", Channel.class);

//Try this it may be help you
WifiManager wifiManager = (WifiManager)this.getSystemService(this.WIFI_SERVICE);
wifiManager.setWifiEnabled(true); //True - to enable WIFI connectivity .
//False -disable WIFI connectivity.
//add this permissions in Manifest file :
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>

You can load the wifi driver from a command prompt with the desired concurrency level if you are rooted:
/system/bin/insmod /system/lib/modules/wlan.ko con_mode=3
These are the values:
typedef enum
{
VOS_STA_MODE=0,
VOS_STA_SAP_MODE=1,
VOS_P2P_CLIENT_MODE,
VOS_P2P_GO_MODE,
VOS_MONITOR_MODE,
VOS_FTM_MODE = 5,
VOS_IBSS_MODE,
VOS_P2P_DEVICE_MODE,
VOS_MAX_NO_OF_MODE
} tVOS_CON_MODE;
This is for an Atheros card.

How to disable GSM connection in Android programmatically

I want to enable/disable an Android phone's GSM connection. I need to disable/enable calls and SMS as required. How might I do this?

EDIT: This solution will also turn off wifi, bluetooth, etc...
If you want to turn off radio only, I think it's related to this issue: http://code.google.com/p/android/issues/detail?id=1065
I am really pessimistic about finding a good solution, but curious to see other answers.
See the blog article Android: Controlling Airplane Mode ,
// Toggle airplane mode.
Settings.System.putInt(
context.getContentResolver(),
Settings.System.AIRPLANE_MODE_ON, isEnabled ? 0 : 1);
// Post an intent to reload.
Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
intent.putExtra("state", !isEnabled);
sendBroadcast(intent);
where isEnabled is whether airplane mode is enabled or not.
Don't forget you need the WRITE_SETTINGS permission to do this, though.

/* Toggle airplane mode for 1 of the 4 allowed types
* type allowed values: cell, wifi, bluetooth, nfc
*/
private void changeRadioComponentEnabled(Context context, String type, boolean radio_component_enabled, boolean reset){
// now toggle airplane mode from on to off, or vice versa
Settings.System.putInt(context.getContentResolver(), Settings.System.AIRPLANE_MODE_ON, radio_component_enabled ? 0 : 1);
// now change system behavior so that only one component is turned off
// this also affects the future behavior of the system button for toggling air-plane mode.
// to reset it in order to maintain the system behavior, set reset to true, otherwise we lazily make sure mobile voice is always on
Settings.System.putString(context.getContentResolver(), Settings.System.AIRPLANE_MODE_RADIOS, type);
// post an intent to reload so the menu button switches to the new state we set
Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
intent.putExtra("state", radio_component_enabled ? false : true);
context.sendBroadcast(intent);
// revert to default system behavior or not
if (reset){ Settings.System.putString(context.getContentResolver(), Settings.System.AIRPLANE_MODE_RADIOS, "cell,bluetooth,wifi,nfc"); }
// if reset to default is not chosen, always enable mobile cell at least
// but only if NOT changing the mobile connection...
else if (type.indexOf("cell") == 0) { Settings.System.putString(context.getContentResolver(), Settings.System.AIRPLANE_MODE_RADIOS, "cell");}
}//end method
naturally this require the permission android.permission.WRITE_SETTINGS, and for bluetooth android.permission.BLUETOOTH_ADMIN. For NFC you might need android.permission.NFC.
EDITS: heavily modified since original, since I was actually using this in a different way in my own app

Setting airplane mode does not completely work

I've written the code below to set the phone into airplane mode to save power. The devices is being used as a WiFi-Hotspot to relay data from some sensors in a village in Indonesia. The sensors send their data at the same time so I just need to come out of airplane mode for five minutes at midnight and then reenter airplane mode.
The problem is the cellular radio is not shut off and the airplane icon does not appear. Though the the phone reports its status as airplane_mode on, it is still possible to call it. Other widgets in the marketplace seem to fare no better. I've tried "Airplane Mode Wi-Fi Tool". It too can not get the airplane icon to appear nor disable cell radio. When watching LogCat while using the device settings to go to Airplane mode, I can see that much more is happening than when trying from the program.
If I load my program on a Droid, this code works as expected. AIRPLANE_MODE_RADIOS is set to cell, bluetooth, wifi.
The offending device is a Samsung Galaxy 5, I5500 tested with:
-Froyo 2.2 build FROYO.UYJP2
-Froyo 2.2.1 build FROYO.UYJPE
One interesting side note: if I programmatically set airplane mode and then power cycle the device, it comes up in full airplane mode, rejects incoming calls etc.
Do others have similar stories with this or other devices? Is there a way to specifically turn off cell only?
public static void setAirplaneMode(Context context, boolean status) {
boolean isAM = Settings.System.getInt(context.getContentResolver(),
Settings.System.AIRPLANE_MODE_ON, 0) != 0;
String radios = Settings.System.getString(context.getContentResolver(),
Settings.System.AIRPLANE_MODE_RADIOS);
//This line is reporting all radios affected but annunciator does not seem to think so. Does not show airplane
Wake.logger("Airplane mode is: " + isAM + " changing to " + status + " For radios: " + radios, false);
// It appears Airplane mode should only be toggled. Don't reset to
// current state.
if (isAM && !status) {
Settings.System.putInt(context.getContentResolver(),
Settings.System.AIRPLANE_MODE_ON, 0);
Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
intent.putExtra("state", 0);
context.sendBroadcast(intent);
return;
}
if (!isAM && status) {
Settings.System.putInt(context.getContentResolver(),
Settings.System.AIRPLANE_MODE_ON, 1);
Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
intent.putExtra("state", 1);
context.sendBroadcast(intent);
return;
}
}

Classic bit twister error. The extra data argument in the broadcast intent needed to be true/false, not 1/0. Ugh!!!
intent.putExtra("state", true); //Not 1!!
One phone worked another didn't. Now both do.

USB_DEVICE_ATTACHED Intent not firing

Has anyone out there been able to get the android.hardware.usb.action.USB_DEVICE_ATTACHED" to work?
Ok so i'm trying to use the new usb host mode features to detect when a usb device is attached. For my purposes i want to be notified any time a device is attached. I was not able to see it happen. I'm using a broadcast reciever that i know works (when i have it listen for other things such as the home button being pressed. No matter what i try i can't seem to get the intent to fire.... So to make things simpler i decided to forget about my project and attempt to use google's own sample code and see if i could at least make that work. I don't have one of the missle launcher but i figured i could at least get it the USB_Device_Attached to fire. No go. I adapted the code to work for other devices. First i tried adjusting the device filter xml.
I added my device (a keyboard):
<usb-device vendor-id="1050" product-id="0010" />
I got the vendor and product from an lsusb command. When the device is attached the logcat shows that the device is found
D/EventHub( 144): No input device configuration file found for device 'Yubico Yubico Yubikey II'.
I/EventHub( 144): New device: id=43, fd=219, path='/dev/input/event8', name='Yubico Yubico Yubikey II', classes=0x80000003, configuration='', keyLayout='/system/usr/keylayout/Generic.kl', keyCharacterMap='/system/usr/keychars/Generic.kcm', builtinKeyboard=false
I/InputReader( 144): Device added: id=43, name='Yubico Yubico Yubikey II', sources=0x00000101
I/ActivityManager( 144): Config changed: { scale=1.0 imsi=0/0 loc=en_US touch=3 keys=2/1/1 nav=1/2 orien=L layout=0x10000014 uiMode=0x11 seq=47}
D/MissileLauncherActivity(16191): intent: android.intent.action.MAIN
I/EventHub( 144): Removed device: path=/dev/input/event8 name=Yubico Yubico Yubikey II id=43 fd=219 classes=0x80000003
I/InputReader( 144): Device removed: id=43, name='Yubico Yubico Yubikey II', sources=0x00000101
I/ActivityManager( 144): Config changed: { scale=1.0 imsi=0/0 loc=en_US touch=3 keys=1/1/2 nav=1/2 orien=L layout=0x10000014 uiMode=0x11 seq=48}
D/dalvikvm( 144): GC_EXPLICIT freed 78K, 26% free 14717K/19719K, paused 3ms+3ms
D/MissileLauncherActivity(16191): intent: android.intent.action.MAIN
The xoom does find the keyboard and it is usable from the device (i can use it in the browser to type letters). And the intent sort of fires (but it only fires the android.intent.action.MAIN) i don't ever get the DEVICE_ATTACHED Intent. The log entry comes from the sample code:
Log.d(TAG, "intent: " + intent.getAction().toString());
In the resume function. After more digging and removing any reference to usb i found that every app i make get's the resume called when a keyboard is attached/detached (hence the intent: android.intent.action.MAIN log entry).
Right now the only thing i can figure is that it's a bug in the android source.
By the way i'm using a wifi xoom with os 3.1.

I also had the same problem. I finally figured out that in the device filter xml we should add following line.
<usb-device vendor-id-"xxxxx" product-id="yyyyy">
the xxxxx and yyyyy should be decimal numbers. NOT HEX CODES. Then it all works as advertised!
I know it is late but I hope it helps.

So I found a solution to my problem and I've learned a lot hopefully it can help someone else.
So first off HID devices do not kick off any intent. Nor do they show up in the mUsbManager.getDeviceList() list. Other things however do. I gave a usb memory stick a go and what do you know the device is listed in the device list. I also found out that the device returned does not have the a class,subclass, or protocol. Debugging revealed that the parent interface did however have the proper class/subclass/and protocol.
Also if you must have a device filter. I ended up with a class=0008 (USB STORAGE) to work for my purposes. I'm guessing other classes would work as well.
So now on to figuring out intents. Turns out that the intent must be attached to a launcher activity. My attempts to attach it to a service or receiver will not bear any fruits. So now that I'm getting intents to fire I now see notifications popup when I attach my device (usb memory stick) it asks me to set my app as the default for that device. Perfect now my app gets run every time I attach that device. Note that you will be prompted for each unique device. But only once. It seems to be registered much like default programs.
Well, I think that about sums up what I found. too bad you can't get notified when an keyboard/mouse gets attached. Oh and one more thing. There are not any problems with the tiamat kernel, running it right now and no problems.

I recently discovered a solution to a similar issue.
As someone has already noted, HID devices do not kick off an intent, which I think was your issue.
However, a related issue is that, if your program is set to run when a USB device is connected, then even once your application is running, you can't capture the USB_DEVICE_ATTACHED action. Instead, the system sees that intent, and says "oh that means this application wants to run (as declared in your manifest) and then it sends you the android.intent.action.MAIN action instead of the USB_DEVICE_ATTACHED action, and it calls onResume(). Even if your app is running. So as far as I can tell, you CAN'T capture the USB_DEVICE_ATTACHED intent if your manifest declares that your app will run when USB devices are attached. You just have to put some code in onResume() to check to see if USB is connected. Even if your program is running, onResume will get called again when a USB device is attached.
I note my solution in more detail here: Android 3.1 USB-Host - BroadcastReceiver does not receive USB_DEVICE_ATTACHED

Enumerating devices
If your application is interested in inspecting all of the USB devices currently connected while your application is running, it can enumerate devices on the bus. Use the getDeviceList() method to get a hash map of all the USB devices that are connected. The hash map is keyed by the USB device's name if you want to obtain a device from the map.
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
If desired, you can also just obtain an iterator from the hash map and process each device one by one:
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
while(deviceIterator.hasNext()){
UsbDevice device = deviceIterator.next()
//your code
}

I had the same problem. My ultimate solution was to use the old fashioned polling technique. Here is a fairly minimal class which solves the problem to my satisfaction.
package com.YourCompancy.YourProduct;
import android.app.*;
import android.content.*;
import android.hardware.usb.*;
import java.util.*;
import android.util.*;
import android.os.*;
public class UsbDeviceWatcher extends BroadcastReceiver
{
public void onReceive(Context context, Intent intent)
{
if (intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_DETACHED))
{
UsbDevice d = (UsbDevice)
intent.getExtras().get(UsbManager.EXTRA_DEVICE);
DeviceConnect(d, false);
}
}
public void DeviceConnect(UsbDevice device, boolean Attached)
{
if (Attached)
{
// Some suggestions ...
// play sound effect
// notify consumer software
// determine if interested in device
// etc
Log.i("usb", "device attached");
} else
{
Log.i("usb", "device detached");
}
}
public UsbManager manager;
public Handler handler;
public UsbDeviceWatcher(Context context, Handler handle)
{
this.handler = handle;
manager = (UsbManager)
context.getSystemService(Context.USB_SERVICE);
IntentFilter dev = new IntentFilter();
dev.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
context.registerReceiver(this, dev);
final UsbDeviceWatcher _this = this;
Thread thread = new Thread(new Runnable()
{
public void run()
{
LinkedList<UsbDevice> seen = new LinkedList<UsbDevice>();
LinkedList<UsbDevice> attached = new LinkedList<UsbDevice>();
//there is a need for multithread support here
// so the thread can watch for an exit condition
while (true)
{
HashMap<String, UsbDevice>
D = manager.getDeviceList();
for (UsbDevice d : D.values())
{
if (!seen.contains(d))
{
if (!attached.contains(d))
{
final UsbDevice dev = d;
handler.post(new Runnable(){
public void run()
{
DeviceConnect(dev, true);
}
});
}
seen.add(d);
}
}
for (UsbDevice d : seen)
{
if (!D.values().contains(d)) seen.remove(d);
}
try
{
Thread.sleep(500);
} catch (InterruptedException exception)
{
return;
}
}
}
});
thread.start();
}
}

Another workaround is to use
new FileObserver("/dev/input") {
#Override public void onEvent(int event, String path) {
//gets called on input device insert / remove
}
};
which will work for some usb devices (keyboard, mouse)

I have my app set as launchMode="singleTop" and in that mode it seems like the getIntent().getAction() is always equal to the action that first started the app.
So if you start the app manually and then plug in a device (even after switching away from that app), you will receive android.intent.action.MAIN.
If you kill the app and then plug in the device, you will always get android.hardware.usb.action.USB_DEVICE_ATTACHED, even from switching away and back to your app, or even for rotating the device.
I actually weirdly receive intents when unplugging the USB device, which I don't think is documented - but of course I receive USB_DEVICE_ATTACHED when my device is detached.
Without singleTop, it does kind of work as expected, but then you get another stupid extra activity if your app is already open and you plug in the device.
Once again Android's API is buggy, overly complicated and difficult to use.

OK more work, more failure, but some progress.
I found out more from the sdk documentation. it appears that you have to have the device filter in order to use the intents. so I decided to try using a class filter instead of the vendor/product ids. I figure that it would be more general and hopefully catch the hid device. I used 03h as the class id , I tried various formats, I tried the subclasses, I even used lsusb to discover, class, subclass, and protocol of my device. these didn't seem to help at all. so I went further in to the sdk documentation and decided to try enumerating all of the devices to see what the os saw the class/subclass/protocol integers. I copied the code pasted it into the click listener and adding log.v statements. nothing shows in the logcat .
it looks, like the us system isn't seeing any device (even though the device actually works.) now this is very indicitive of the USB device connected intent not firing. now I must say that I am using a custom kernel in my xoom (tiamat). I thought this might have something to do with the problem a while ago, so I reverted to stock 3.1. and still now progress. now this was a while ago, before I tried enumerating, so now I will revert agaian and keep working with stock until I am sure the kernel is not the issue. I'll check back In when I found out more. success or failure. ofcourse if anyone else unterstands this better than me please chime in.
one last note I'm a big worried about the whole otg host mode when I saw this in the documentation.. notice that the coe is identical even thought it references two methods of enumeration. probably just a copy writers mistake, but still worry some in light of all this failure.

This is what I did to detect USB/Media Connect.
Manifest file
<receiver
android:name=".UsbReceiver"
android:enabled="true" >
<intent-filter>
<action android:name="android.intent.action.MEDIA_MOUNTED"/>
<action android:name="android.intent.action.MEDIA_UNMOUNTED"/>
<data android:scheme="file"/>
</intent-filter>
</receiver>
I didn't do anything in the activity nor my receiver.
looks like this line is doing the stuff.
<data android:scheme="file"/>

Connect Usb Keyboard WONT fire USB_DEVICE_ATTACHED.
Instead, the System will fire Intent.ACTION_CONFIGURATION_CHANGED. However, as there is a configuration change, system will restart the Activity. You wont catch the action with the Activity restarted. In this case, you need to add android:configChanges="keyboard|keyboardHidden" in your Android Manifest so that the Activity wont be restarted once a external keyboard is connected.

From my testing, Android can fire an intent when an HID device is connected. (The MissileLauncher sample application does just that. See the sample source code for more info.)
The Missile Launcher (Dream Cheeky USB Missle Launcher) HID Device has its subclass and protocol set to 0x00. For more info see: http://www.mattcutts.com/blog/playing-with-a-usb-missile-launcher/
The caveat is that Android does not throw an intent for mouse and keyboard devices specifically (maybe more). I can however detect HID devices that have their InterfaceClass = 0x03, InterfaceSubClass = 0x00, InterfaceProtocol = 0x00. For my application, my HID device is an embedded controller so setting the subclass and protocol is not an issue.