Develop Reference

How to open a settings page specific to devices using activity name or package name?

I have a system settings activity called .settings.AppLockSettingsActivity and I want to launch that settings page when my app launches. App is a simple launcher doesn't show other pages except the settings.

Add to this intent filters in your AndroidManifest.xml
<activity
android:name=".settings.AppLockSettingsActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
and if somewhere intent filters is written, delete them as well

How to start specific activity by saying OK Google?

I would like to have two activities. FirstActivity should be started from
launcher (by tapping on icon) and SecondActivity should be started by voice
command (by saying "OK Google, start play example").
The problem is that for my current configuration only FirstActivity is
started. Also method isVoiceInteraction returns false. I also don't see any values in flags that indicates that activity was started by voice.
Here's part of AndroidManifest.xml:
<application android:label="play example">
<activity android:name="com.example.FirstActivity" android:label="play example">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="com.example.EXAMPLE_ACTION" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity android:name="com.example.SecondActivity" android:label="play example">
<intent-filter>
<action android:name="com.example.EXAMPLE_ACTION" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.VOICE" />
</intent-filter>
</activity>
</application>
Here it states:
To specify the text to say after "Start", specify a label attribute for the activtiy that you want to start.
But when I change label for SecondActivity it does not help.
I'm using API version 26.
How to setup configuration to handle described behavior?

AFAIK isVoiceInteraction will always return false when the application is opened using "open" voice command. However, the scenario which you described, having another activity to respond to voice commands, should've worked.
The only thing that you might have missed is to put the action android.intent.action.MAIN in the second activity.

Android App name is not displayed in the multitasking screen

I've developed a simple NFC application that reads and displays the data(NDEF Records) present in the NFC tag. I modified the Manifest file so that whenever a tag gets tapped, my app gets opened.
Now the problem is when I manually open the app and check the multitasking screen, it displays my app name i.e NFCReader but when the app gets opened itself when a tag comes in contact with the device, my app gets opened but when I check the multitasking screen, it doesn't display my app name. Instead it displays NFC Service. What should I do to overcome this issue?

I assume that you have set your activity declaration, in your manifest, to something like this:
<activity
android:name=".packagename.MainActivity"
android:alwaysRetainTaskState="true"
android:launchMode="singleTask"
android:theme="#style/AppTheme.Main">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.nfc.action.NDEF_DISCOVERED" />
<category android:name="android.intent.category.DEFAULT" />
<data
android:host="domain.com"
android:scheme="http" />
</intent-filter>
</activity>
I think the answer to your question is the following line of code that you forgot to add:
android:launchMode="singleTask"
I invite you to read about launch modes here and here.
Please note: This answer is based on the use of Reader mode API, otherwise check this answer.
Hope this helps!

Android hidden application

I'm writing a (legal) spy program. I want to make this program hidden on the launcher (so that no icon is shown). I tried to remove <category android:name="android.intent.category.LAUNCHER" /> line from AndroidManifest.xml, but then the user can't launch the application in first start mode (configuration). Who have any ideas ?
How can I do it?

You need to make your app into a service. Here is Androids take on creating services components:
http://developer.android.com/guide/components/services.html
Found this as well on MobiWare:
When you want to track the usage of the mobile or gather some data without user knowledge,this might help you.
Step1: Create an application with No icon.
Normally,an activity is declared as follows in manifest.
<activity
android:label="#string/app_name"
android:name="org.security.tracker.Tracker-activity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
Remove the Category TAG ,you wont get app icon anymore.
Now,you don't need activity anymore. so remove this segment.
BUt you might think,how the app will run without any trigger or what is the starting point of the application.
This is the solution.
<!-- Start the Service if applicable on boot -->
<receiver android:name="org.security.tracker.ServiceStarter" >
<intent-filter >
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
This triggers your code that written in Receiver there by you can run service to implement your thoughts.
<service android:name="org.security.tracker.serviceCode" />
You need to add this permission,
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
Your code runs when the phone reboots only.
Step 2. Write your code
On Reboot,the recevier will fire ,there you can start your service.
class ServiceStarter extends BroadcastReceiver {
#Override
public void onReceive(Context _context, Intent _intent) {
Intent i = new Intent("com.prac.test.MyPersistingService");
i.setClass(_context, ServiceCode.class);
_context.startService(i);
}
}

You can remove the <category android:name="android.intent.category.LAUNCHER"/> from the AndroidManifest.xml file.
But remember to add <category android:name="android.intent.category.LEANBACK_LAUNCHER"/> so that Android studio will be able to compile your app (yet hidden from launcher) :) :D

remove
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
from the manifest file

The app can be hidden programmatically, Below is the code which will hide the app from the Launcher menu. this works fine android 10 as well
// App will be hidden when this method will be called from menu
private fun hideApp() {
val packageManager =packageManager
val name =ComponentName(this,MainActivity::class.java)
packageManager.setComponentEnabledSetting(name,PackageManager.COMPONENT_ENABLED_STATE_DISABLED,PackageManager.DONT_KILL_APP)
Log.d("TAG", "hideApp: success")
}
For more information, you can check this link https://developer.android.com/reference/android/content/pm/PackageManager#setComponentEnabledSetting(android.content.ComponentName,%20int,%20int)

adding custom action won't start the activity when running it in the emulator

I have the following code in my Manifest:
<activity android:name="com.fletech.android.apparent.CategoriesGrid"
android:configChanges="keyboardHidden|orientation">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
When I run the app in Eclipse it starts this activity in the emulator, as expected.
But when I also add:
<action android:name="com.fletech.android.apparent.action.APPARENT_MAIN" />
right below the other action, and run the app, it only installs it to the emulator but doesn't run it. Why?
What I wanted to achieve is this: I would like to be able to show a dialog to the user (from another apps) to chose between all my apps that have "com.fletech.android.apparent.action.APPARENT_MAIN" as an action.

If you want to specify another launch scenario, you should just add another whole intent-filter block rather than putting all of the action clauses in the same one.