Develop Reference

Android: Can explicit intents work without adding QUERY_ALL_PACKAGES (or package under queries tag) to my manifest?

I have small code which makes sure a url is always opened in browser. It is working so far.
Recently, I got message from Google Play Console stating:
If your app requires the QUERY_ALL_PACKAGES permission, you need to
submit the declaration form in Play Console by July 12
I have checked and verified, we don't use QUERY_ALL_PACKAGES in my app. However, we use Explicit Intents and resolveActivity in few places. One of the code (I took it from this place) is:
override fun openInBrowser(url: String) {
val dummyIntent = Intent(Intent.ACTION_VIEW, Uri.parse("http://"))
val resolveInfo = context.packageManager.resolveActivity(dummyIntent, PackageManager.MATCH_DEFAULT_ONLY)
val browserPackageName = resolveInfo?.activityInfo?.packageName
val realIntent = Intent(Intent.ACTION_VIEW, Uri.parse(url))
if (browserPackageName != null && browserPackageName.isNotBlank() && browserPackageName != "android") {
realIntent.setPackage(browserPackageName)
}
startActivity(context, realIntent, null)
}
I am not sure if it falls under the category of querying a package. I have gone through this link and as per my understanding I don't need to add either package under queries tag or QUERY_ALL_PACKAGES. I just want to validate my understanding.
The limited app visibility affects the return results of methods that give information about other apps, such as queryIntentActivities(), getPackageInfo(), and getInstalledApplications(). The limited visibility also affects explicit interactions with other apps, such as starting another app's service.
Some packages are still visible automatically. Your app can always see these packages in its queries for other installed apps. To view other packages, declare your app's need for increased package visibility using the element. The use cases page provides examples for common app interaction scenarios.

NFC-tag password protection with ST25 android SDK

I'm working with ST25 tags, more specifically type5 tags ST25DV64K. The ST25 SDK for android has some interesting examples and tutorials in it. I'm still struggling to use the code example provided at the end of the doc here concerning password-protected data, which consist in those lines:
byte[] password;
int passwordNumber = type5Tag.getPasswordNumber(area);
tag.presentPassword(passwordNumber, password);
NDEFMsg ndefMsg = myTag.readNdefMessage(area);
first problem, when I instanciate a type5 tag i don't see those methods for Type5Tag class:
import com.st.st25sdk.type5.*;
Type5Tag tag5;
tag5.??
Then, it is not clear how we are supposed to set up a password in the first place. I can't find any examples of setting up a password for a specific area, and removing it, and what is the format of the password that we can use? Is it possible to do this from android or do we have to use the ST25 app? Examples welcome! Thanks.

In the ST25 SDK Zip file, you will find an example of a basic Android App using the ST25 SDK Library (it is in \integration\android\examples\ST25AndroidDemoApp).
This example uses a class called “TagDiscovery” which is able to identify any ST25 Tag and to instantiate the right object. In your case, if you are only using ST25DV64K Tags, you will probably want to do something simple.
Here is what I suggest you:
In your android activity, I expect that you have subscribed to receive a notification every time an NFC tag is taped (in “ST25AndroidDemoApp” example, look at enableForegroundDispatch() in onResume() function).
To identify if the Intent corresponds to an “NFC Intent”, we check if the Intent’s Action is ACTION_NDEF_DISCOVERED, or ACTION_TECH_DISCOVERED or ACTION_TAG_DISCOVERED.
When this is the case, we know that it is an NFC Intent. We can then call this to get the instance of androidTag:
Tag androidTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
This object represents the current NFC tag in Android.
We’re now going to instantiate a ST25DVTag object.
import com.st.st25sdk.type5.st25dv.ST25DVTag;
…
AndroidReaderInterface readerInterface = AndroidReaderInterface.newInstance(androidTag);
byte[] uid = androidTag.getId();
uid = Helper.reverseByteArray(uid);
ST25DVTag myST25DVTag = new ST25DVTag(readerInterface, uid);
You now have an object called myST25DVTag that can be used to communicate with the tag!
For example, if you want to use the passwords:
byte[] password = new byte[]; // TODO: Fill the password
int passwordNumber = myST25DVTag.getPasswordNumber(area);
myST25DVTag.presentPassword(passwordNumber, password);
NDEFMsg ndefMsg = myST25DVTag.readNdefMessage(area);
Before doing that, you need to check which password is associated to this area. The tag has 3 passwords that can be freely assigned to any area. By default no password is set so you should set one. Here is an example where I use the password 2 for Area1:
int AREA1 = 1;
int passwordChosen = 2;
myST25DVTag.setPasswordNumber(AREA1, passwordChosen);
I suggest that you install the ”ST25 NFC Tap” Android App from Google Play: https://play.google.com/store/apps/details?id=com.st.st25nfc&hl=fr&gl=US
If you tap you ST25DV and go to the “Areas Security Status” menu, you will be able to see: the number of areas, which ones are protected by password for read and/or write, which password is used…etc
If you are interested, the source code of this application is available here: https://www.st.com/en/embedded-software/stsw-st25001.html
Tell me if something is unclear.
Disclaimer: I am on of the development team for the ST25 SDK.

How to enable Android Open Application voice interaction

According to the system voice command docs, you can open an application with a voice command. e.g. OK Google - open foobar. Also according to the docs, this Works by default; no specific intent.
In my sample development app, this isn't working. I've tried adding a few combinations of action and category permutations to the intent-filter, but no luck so far.
I'm targeting a minimum SDK of 23, testing on a device with 6.0.1.
Should this work, and if so, what are the changes to a new empty activity project I need to enable it?

As far as I am aware, Google simply iterates over a list of installed applications and opens the corresponding application if it finds an exact match.
To test this, use the following Intent
final String PACKAGE_NAME_GOOGLE_NOW = "com.google.android.googlequicksearchbox";
final String GOOGLE_NOW_SEARCH_ACTIVITY = ".SearchActivity";
final String APP_NAME = "Open " +getString(R.string.app_name);
final Intent startMyAppIntent = new Intent(Intent.ACTION_WEB_SEARCH);
startMyAppIntent.setComponent(new ComponentName(PACKAGE_NAME_GOOGLE_NOW,
PACKAGE_NAME_GOOGLE_NOW + GOOGLE_NOW_SEARCH_ACTIVITY));
startMyAppIntent.putExtra(SearchManager.QUERY, APP_NAME);
startMyAppIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
try {
startActivity(startMyAppIntent);
} catch (final ActivityNotFoundException e) {
e.printStackTrace();
}
If this opens your application, then it is simply a case of the phonetics of your application name, or how Google interprets your pronunciation of it.
I do think that there should be an option to add a 'phonetic app label' to the application's manifest (or some other globally available configuration file), so Google could open your application if the unique name is not common enough to generate a voice search result.
If this doesn't open your application, check that you are correctly defining your application name in the manifest as follows:
<application
android:label="#string/app_name"

How to detect if an android app is a game?

In an app I am developing I need to iterate through the installed apps and detect which ones are games. Is there any way to do this?
I was thinking to a Play Store API that can search for package name and returns its category even if it's only limited to apps on the store. Does something similar exist? Would it be possible?
Is there any alternative way to do it?

This answer is deprecated!
Correct and backwards compatible way to do this is here!
Since Android API version 21, there's finally a way to check if an application is a game.
PackageManager pm = mContext.getPackageManager();
ApplicationInfo ai = pm.getApplicationInfo(mPackageName,0);
if((ai.flags & ApplicationInfo.FLAG_IS_GAME) == ApplicationInfo.FLAG_IS_GAME)
return true;
return false;

There is no automatical way to detect if an app is a game. You just could compaire the package name of the common part of the package name. My solution was to index the google store pages and hash the package names.
I could optimize my hashes by building common prefixes. I handled the package name as a domain and grep the public suffix. I use the list from http://publicsuffix.org/.
A "public suffix" is one under which Internet users can directly register names. Some examples of public suffixes are .com, .co.uk and pvt.k12.ma.us. The Public Suffix List is a list of all known public suffixes.
The Public Suffix List is an initiative of Mozilla, but is maintained as a community resource. It is available for use in any software, but was originally created to meet the needs of browser manufacturers.
With this list you can detect part of a packagename is a common prefix.

For me the above answer didn't work, the ApplicationInfo.FLAG_IS_GAME is now deprecated, with API 28+ (in my case), you can do something like this:
_pm = _context.PackageManager;
List<string> packageList = new List<string>();
Intent intent = new Intent(Intent.ActionMain);
intent.AddCategory(Intent.CategoryLeanbackLauncher); // or add any category you want
var list = _pm.QueryIntentActivities(intent, PackageInfoFlags.MetaData);
foreach (var app in list)
{
ApplicationInfo ai = _pm.GetApplicationInfo(app.ActivityInfo.PackageName, 0);
var allFlags = ai.Flags;
if (allFlags.HasFlag(ApplicationInfoFlags.IsGame))
{
packageList.Add(app.ActivityInfo.PackageName);
}
}

How can I do an Amazon App Store search using an Intent and filter it by developer name?

Is there a way to start an Intent on the Kindle Fire that will cause the AppStore app to open and display all the apps for a certain developer? For instance, on a phone/tablet with the Android Market installed, I can do this:
Intent otherApps = new Intent(Intent.ACTION_VIEW,Uri.parse("market://search?q=pub:\"" + developerName + "\""));
activity.startActivity(otherApps);
And show all my apps in the Android Market. Can I do that with the Amazon App Store? If so, how? I've tried that Intent with other seemingly valid names (such as "ZeptoLab") and I don't get any filtering. It just drops me in the full unfiltered App Store. Looking up a specific app with "market://details?id=package.name" does seem to work.

From https://developer.amazon.com/help/faq.html#Marketing:
To point to your app for marketing purposes use the URL http://www.amazon.com/gp/mas/dl/android?p=packagename (where packagename is your app package name).
If you want to link to the list of all your applications on the Amazon Appstore use the URL http://www.amazon.com/gp/mas/dl/android?p=packagename&showAll=1.
e.g. http://www.amazon.com/gp/mas/dl/android?p=com.rovio.angrybirds&showAll=1
All this can be seen here: https://developer.amazon.com/sdk/in-app-purchasing/sample-code/deeplink.html
Update(deep linking):
amzn://apps/android?p=

Best way is to look at their website (or here), which currently states this :
search: amzn://apps/android?s=amazon%20mp3 or http://www.amazon.com/gp/mas/dl/android?s=amazon%20mp3
detail page using package name: amzn://apps/android?p=com.amazon.mp3 or http://www.amazon.com/gp/mas/dl/android?p=com.amazon.mp3
detail page using unique ID ("asin") : amzn://apps/android?asin=B004FRX0MY or http://www.amazon.com/gp/mas/dl/android?asin=B004FRX0MY
show all apps of the developer who made the app: amzn://apps/android?p=com.amazon.mp3&showAll=1 or http://www.amazon.com/gp/mas/dl/android?p=com.amazon.mp3&showAll=1

Amazon supports their own deep links now: https://developer.amazon.com/appsandservices/apis/earn/in-app-purchasing/docs/deeplink
E.g. you can start an intent with uri amzn://apps/android?p=my.package.name.

From - https://developer.amazon.com/help/tuabg.html
For in-app advertising or mobile browser based linking, please:
Use this link structure: http:// www.amazon.com/gp/mas/dl/android?p=com.example.package/ref=mas_pm_app_name
For a link that directs to a list of all of your apps within our U.S. store, please:
Use this link structure: http://www.amazon.com/gp/mas/dl/android?p=com.example.package&showAll=1
Now, you think amazon would have this correct on their own website, but the first part that I put in bold is wrong. This is what it should actually be:
http://www.amazon.com/gp/mas/dl/android?p=com.example.package&ref=mas_pm_app_name
Notice the & instead of the / between the package name and ref. Hopefully this helps some other people since this little detail wasted some of my time...

Here's the solution I came up with using the advice below from chiuki:
I added a boolean to one of my resource files that indicates whether or not the app is published in the Amazon AppStore or Android Market. Yeah, you have to change it whenever you publish your app, but think of it sort of like remembering to set debuggable to "false" when you publish. Put it on a check list. It goes like this:
In resource file:
<bool name="app_is_in_amazon_app_store">true< /bool>
In code:
public class SomeUtil
{
private static Boolean isInAmazonAppStore;
public static boolean isInAmazonAppStore(Activity activity)
{
if (isInAmazonAppStore == null)
{
isInAmazonAppStore = activity.getResources().getBoolean(R.bool.app_is_in_amazon_app_store) ;
}
return isInAmazonAppStore;
}
public static void startOtherMarketAppsActivity(Activity activity)
{
try
{
Intent otherApps = null;
if (isInAmazonAppStore(activity))
{
otherApps = new Intent(Intent.ACTION_VIEW,Uri.parse("http://www.amazon.com/gp/mas/dl/android?p=" + getPackageNameInAmazonAppStore(activity) + "&showAll=1"));
}
else
{
otherApps = new Intent(Intent.ACTION_VIEW,Uri.parse("market://search?q=pub:\"" + getAndroidDeveloperName(activity) + "\""));
}
activity.startActivity(otherApps);
}
catch(Exception ex){ /* error handling */}
}