Android - Event callback

```java package exam.Input; import android.app.*; import android.content.*; import android.os.*; import android.view.*; import android.widget.*; //* 1.핸들러 메소드 재정의 - 상속을 받아야만 재정의 가능하다. public class HandleEvent extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); View vw = new MyView(this); setContentView(vw); } protected class MyView extends View { public MyView(Context context) { super(context); } public boolean onTouchEvent(MotionEvent event) { super.onTouchEvent(event); if (event.getAction() == MotionEvent.ACTION_DOWN) { Toast.makeText(HandleEvent.this,"Touch Event Received", Toast.LENGTH_SHORT).show(); return true; } return false; } } } //*/ /* 2.인터페이스 구현 객체 생성 - 별도의 클래스가 필요함 public class HandleEvent extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); View vw = new View(this); // 3.리스너 등록 vw.setOnTouchListener(TouchListener); setContentView(vw); } // 1.리스너 구현 클래스 선언 class TouchListenerClass implements View.OnTouchListener { public boolean onTouch(View v, MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) { Toast.makeText(HandleEvent.this,"Touch Event Received", Toast.LENGTH_SHORT).show(); return true; } return false; } } // 2.리스너 객체 생성 TouchListenerClass TouchListener = new TouchListenerClass(); } //*/ /* 3.액티비티가 리스너 구현 public class HandleEvent extends Activity implements View.OnTouchListener { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); View vw = new View(this); vw.setOnTouchListener(this); setContentView(vw); } public boolean onTouch(View v, MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) { Toast.makeText(this,"Touch Event Received", Toast.LENGTH_SHORT).show(); return true; } return false; } } //*/ /* 4.뷰에서 리스너 구현 public class HandleEvent extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); MyView vw = new MyView(this); vw.setOnTouchListener(vw); setContentView(vw); } protected class MyView extends View implements View.OnTouchListener { public MyView(Context context) { super(context); } public boolean onTouch(View v, MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) { Toast.makeText(HandleEvent.this,"Touch Event Received", Toast.LENGTH_SHORT).show(); return true; } return false; } } } //*/ /* 5.익명 이너 클래스 사용 public class HandleEvent extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); View vw = new View(this); vw.setOnTouchListener(TouchListener); setContentView(vw); } private View.OnTouchListener TouchListener = new View.OnTouchListener() { public boolean onTouch(View v, MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) { Toast.makeText(HandleEvent.this,"Touch Event Received", Toast.LENGTH_SHORT).show(); return true; } return false; } }; } //*/ /* 6.익명 이너 클래스의 임시 객체 생성 public class HandleEvent extends Activity { public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); View vw = new View(this); vw.setOnTouchListener(new View.OnTouchListener() { public boolean onTouch(View v, MotionEvent event) { if (event.getAction() == MotionEvent.ACTION_DOWN) { Toast.makeText(HandleEvent.this,"Touch Event Received", Toast.LENGTH_SHORT).show(); return true; } return false; } }); setContentView(vw); } } //*/ ```