package com.example.inctest;

import android.os.Bundle;
import android.app.Activity;
import android.view.Gravity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
        ((Button)findViewById(R.id.button1)).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast toast = Toast.makeText(getApplicationContext(),
                                "button!",
                                Toast.LENGTH_SHORT);
                toast.setGravity(Gravity.CENTER, 0, 0);
                toast.show();
            }
        });
        
	}

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

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >
    
    <include
        android:id="@+id/butt1"
        layout="@layout/inc_button" />
    
    <include
        android:id="@+id/butt2"
        layout="@layout/inc_button" />
    
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />

</merge>

<style name="myButton">
        <item name="android:textAppearance">?android:attr/textAppearanceListItemSmall</item>
        <item name="android:gravity">center_vertical</item>
        <item name="android:paddingLeft">?android:attr/listPreferredItemPaddingLeft</item>
        <item name="android:paddingRight">?android:attr/listPreferredItemPaddingRight</item>
        <item name="android:minHeight">?android:attr/listPreferredItemHeight</item>
        <item name="android:onClick">OnButtonClick</item>
    </style>


<Button style="style/mybutton"/>

<style name="myButton">
        <item name="android:onClick">OnButtonClick</item>
</style>