LoginActivity.java

package com.zedeff.twittererer.ui.activities;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;

import com.zedeff.twittererer.R;
import com.twitter.sdk.android.core.Callback;
import com.twitter.sdk.android.core.Result;
import com.twitter.sdk.android.core.TwitterException;
import com.twitter.sdk.android.core.TwitterSession;
import com.twitter.sdk.android.core.identity.TwitterLoginButton;

public class LoginActivity extends AppCompatActivity {

    private TwitterLoginButton loginButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        loginButton = (TwitterLoginButton) findViewById(R.id.twitter_login_button);
        loginButton.setCallback(new Callback<TwitterSession>() {
            @Override
            public void success(Result<TwitterSession> result) {
                startActivity(new Intent(LoginActivity.this, TimelineActivity.class));
                finish();
            }

            @Override
            public void failure(TwitterException exception) {
                Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
    }

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