Twitter login button Android.

There is no proper tutorial on twitter-kit-android Github.

After some search on google I finally found the way.
If you encountered an error, check at the end of the post for some solutions

Create app in developer console: developer.twitter.com/apps

Make sure you selected Sign in with Twitter.

To make android app to work, you need to add the scheme: 

twittersdk://

as callback url

Import the library :

If you just need login with twitter button, just use core

implementation("com.twitter.sdk.android:twitter-core:3.3.0@aar") {     transitive = true }

otherwise include entire libraby

implementation("com.twitter.sdk.android:twitter:3.3.0@aar") {     transitive = true }

Adding the TwitterLoginButton in layout:

<com.twitter.sdk.android.core.identity.TwitterLoginButton     android:id="@+id/twitterLoginButton"     android:layout_width="wrap_content"     android:layout_height="match_parent" />

The rendering error:

If you are targeting SDK version 28, you may get error in the design file.

The error might be 

java.lang.IllegalArgumentException: Invalid Region.Op - only INTERSECT and DIFFERENCE are allowed

The error is because of corners of twitter button background.

So you have to manually fix the error by creating a manual class that extend TwitterLoginButton.

If you want you can use the files in the below link.

https://www.dropbox.com/sh/l1xou6unkc0sxkk/AACMBW9OcvEpIxAnTPnggsYBa?dl=0

Setup the button:

Add the following code in onCreate(Bundle savedInstanceState) method of your activity.  If you are adding the button in fragment, then add the code in the enclosing activity. I mean in the activity the fragment/fragment adapter is getting used.

This code needs to be before setContentView(int/view) method call.

TwitterAuthConfig authConfig = new TwitterAuthConfig(ConsumerToken, ConsumerSecret); //find these in Keys and tokens tab of twitter app details TwitterConfig config = new TwitterConfig.Builder(this)         .logger(new DefaultLogger(Log.DEBUG))         .twitterAuthConfig(authConfig)         .debug(Logger.getCanLog())         .build(); Twitter.initialize(config);

Initialise the button and set callback in activity/fragment:

twitterLoginButton = findViewById(R.id.twitterLoginButton); twitterLoginButton.setCallback(new Callback<TwitterSession>() {             @Override             public void success(final Result<TwitterSession> data) {                 //Todo your code to run after login is success             }             @Override             public void failure(TwitterException exception) {                 //Todo your code to run after login is failed             }         });

Send the activity result to TwitterLoginButton

In onActivityResult method of activity or fragment, 

@Override protected/public void onActivityResult(int requestCode, int resultCode, Intent data) {     super.onActivityResult(requestCode, resultCode, data);         twitterLoginButton.onActivityResult(requestCode, resultCode, data); }

if you are using the button inside fragment, then send the activity result back to fragment,

@Override protected/public void onActivityResult(int requestCode, int resultCode, Intent data) {     super.onActivityResult(requestCode, resultCode, data);         Fragment fragment = getSupportFragmentManager().findFragmentByTag("YOUR_TAG");     if (fragment != null && fragment.isVisible()         fragment.onActivityResult(requestCode, resultCode, data); }

Possible errors while running or at runtime:

If you get an error saying some thing like this,

Caused by: com.android.builder.dexing.DexArchiveBuilderException: Failed to process .gradle/caches/transforms-1/files-1.1/tweet-composer-3.3.0.aar classes.jar

add the following in your module level build.gradle file scope android ( means inside android{})

compileOptions {     sourceCompatibility JavaVersion.VERSION_1_8     targetCompatibility JavaVersion.VERSION_1_8 }

If you get message saying "Failed to get request token", make sure you added twittersdk:// in callback urls or schemes.

If you get message like "Authorise token error", make sure you copied the consumer kay and secret correctly.