/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.vinidsl.googleioextended.ui;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

import com.vinidsl.googleioextended.R;
import com.vinidsl.googleioextended.helper.PreferencesHelper;

public class WelcomeActivity extends AppCompatActivity implements View.OnClickListener {

    private Button buttonReject;
    private Button buttonAccept;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);
        buttonReject = (Button) findViewById(R.id.buttonReject);
        buttonAccept = (Button) findViewById(R.id.buttonAccept);
        buttonAccept.setOnClickListener(this);
        buttonReject.setOnClickListener(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.buttonReject:
                finish();
                break;
            case R.id.buttonAccept:
                PreferencesHelper.putBoolean(PreferencesHelper.ACCEPT_CONDITIONS,true,this);
                Intent intent = new Intent(this,MainActivity.class);
                startActivity(intent);
                finish();
                break;
        }
    }
}

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.vinidsl.googleioextended.ui;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

import com.vinidsl.googleioextended.R;
import com.vinidsl.googleioextended.helper.PreferencesHelper;

public class WelcomeActivity extends AppCompatActivity implements View.OnClickListener {

    private Button buttonReject;
    private Button buttonAccept;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);
        buttonReject = (Button) findViewById(R.id.buttonReject);
        buttonAccept = (Button) findViewById(R.id.buttonAccept);
        buttonAccept.setOnClickListener(this);
        buttonReject.setOnClickListener(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.buttonReject:
                finish();
                break;
            case R.id.buttonAccept:
                PreferencesHelper.putBoolean(PreferencesHelper.ACCEPT_CONDITIONS,true,this);
                Intent intent = new Intent(this,MainActivity.class);
                startActivity(intent);
                finish();
                break;
        }
    }
}

Update WelcomeActivity.java