BAB 5 Android Event Handling Mahardeka Tri Ananta

BAB 5 Android Event Handling Mahardeka Tri Ananta [email protected]

Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

Konten • Event pada Widget • Event Handler • Event Listener


Event • Event adalah suatu cara untuk mengumpulkan data tentang interaksi pengguna dengan komponen interaktif dari Aplikasi. • Contoh: Aksi (action) yang terjadi ketika user berinteraksi dengan widget (clicks, typing, scrolling)


Setting an Event Listener (SoftCoding) 1. Interacting with widgets /views

• in Layout, give that view a unique ID property value • in Java code, call findViewById to access its View object • pass it a parameter of R.id.your_unique_ID • cast the returned value to the appropriate type (Button, TextView, etc.) • In Layout XML file:

• In Activity onCreate() method: TextView nameView = (TextView)findViewById(R.id.textViewName);


Setting an Event Listener (SoftCoding) 2. Modify onClick property in layout file. • Scroll down its Properties until you find onClick. or edit .XML file manually via text. • Type the name of a method you'll write to handle the click event


Setting an Event Listener (SoftCoding) 3. Add method in onclick Event in JavaCode • In your Activity, create method that have been registered in layout. • Add View object in method parameter.


activity_main.xml <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="call 0888111222" android:id="@+id/button" android:layout_gravity="center" android:onClick="button1" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Button 2" android:id="@+id/button2" android:layout_gravity="center" android:onClick="button2" /> Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

MainActivity.java public class MainActivity extends AppCompatActivity { private Button button1, button2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button1=(Button)findViewById(R.id.button); button2=(Button)findViewById(R.id.button2); } public void button1(View view){ Intent dial = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:0888111222")); startActivity(dial); }

public void button2 (View view){ Toast.makeText(this,"you have pressed: " +button2.getText(), Toast.LENGTH_LONG).show(); } } Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

Setting an Event Listener (Hard Coding) • An event is handled by an event listener object. • Define an object that implements event listener interface and register it with the designated View. • • • •

View.OnClickListener (for handling "clicks" on a View), View.OnTouchListener (for handling screen touch events), View.OnKeyListener (for handling device key presses). etc..


Setting an Event Listener (Hard Coding) Illustration 

User Click Event

View Widget Button setOnClickListener()

onClick()

Event Handler Object

View.OnClickListener Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

Setting an Event Listener (Hard Coding) • Step 1: Add button to Activity

• Activity.findViewById( buttonViewID )

• Step 2: Implement Event Handler… • for a Button click event means the handler object should implements the View.OnClickListener interface consists of TWO OPTIONS in the following: 1. using a separate (specific) object to handle event(s) that implements the interface, OR 2. have the Activity containing the button do the event handling and letting the Activity implements the interface

• Step 3: Register Event Handler to the button

• button.setOnClickListener( clickEventHandlerObject ) Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

Setting an Event Listener (Hard Coding) – Option 1 • EVENT HANDLING CODE in separate object named mCorkyListener // Create an anonymous implementation of OnClickListener STEP 2 private OnClickListener mCorkyListener = new OnClickListener() { public void onClick(View v) { // do something when the button is clicked } }; //Now inside your Activity class onCreate event method protected void onCreate(Bundle savedValues) { ... // STEP 1: Capture our button from layout Button button = (Button)findViewById(R.id.corky);

// STEP 3: Register the onClick listener // with the implementation above button.setOnClickListener(mCorkyListener); }

...


Setting an Event Listener (Hard Coding) - Option 2  Here's the code to handle Button's click event using the Activity itself

public class ExampleActivity extends Activity implements OnClickListener { protected void onCreate(Bundle savedValues) { ... Button button = (Button)findViewById(R.id.corky); // STEP 1 button.setOnClickListener(this); //STEP 2 – registration }

// Implement the OnClickListener callback method // STEP 3 – event handler public void onClick(View v) { // do something when the button is clicked

}

} ...


activity_main.xml


activity_main.xml

<EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/editText" android:hint="masukkan angka ke-1"/>

<EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/editText2" android:hint="masukkan angka ke-2"/> <EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/editText3" android:layout_gravity="center" android:text="hasil: " android:editable="false"/> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="hitung" android:id="@+id/button" android:layout_gravity="center"/>


MainActivity.java

public class MainActivity extends AppCompatActivity { private EditText txtAngka1, txtAngka2, txtHasil; private Button buttonHitung; private View.OnClickListener click; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); txtAngka1= (EditText)findViewById(R.id.editText); txtAngka2= (EditText)findViewById(R.id.editText2); txtHasil = (EditText)findViewById(R.id.editText3); buttonHitung = (Button)findViewById(R.id.button);

STEP 1

// Create an anonymous implementation of OnClickListener STEP 2

click = new View.OnClickListener() { @Override public void onClick(View v) { try { int angka1 = Integer.parseInt(txtAngka1.getText().toString()); int angka2 = Integer.parseInt(txtAngka2.getText().toString()); int jumlah = angka1 + angka2; txtHasil.setText(String.valueOf(jumlah)); } catch (Exception e){ e.printStackTrace(); } } };// STEP 3: Register the onClick listener buttonHitung.setOnClickListener(click); }

}


TUGAS KELOMPOK • Buat sebuah aplikasi Android pada platform Google Android yang teridiri dari hanya 1 Activity, dengan menggunakan 4 event handler yang ada di bawah ini: 1. 2. 3. 4. 5. 6.

onClick() onLongClick() onFocusChange() onKey() onTouch() onCreateContextMenu()

• Jalankan aplikasi, kemudian amati perbedaan dari 4 event handler yang digunakan • Buat dokumentasi (.pdf) yang berisi: 1. 2.

Langkah2 implementasi Event Handling pada aplikasi yang Anda buat (dilengkapi dengan screenshot) Jelaskan perbedaan dari 6 event handler yang ada di atas, dan berikan contoh kasus penggunaannya Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

TUGAS KELOMPOK • Nama File: PAPB-G-T3-Kelompok99 • Deadline: 6 OKTOBER 2015 • Dikumpulkan secara kolektif di koordinator kelas. KUIS 1 PAPB 13 OKTOBER 2016 closed book (Tulis tangan [Teori & Code Completion]) Materi: 1. Perkembangan Aplikasi Mobile 2. Android Activities 3. User Interface 4. Event Handling Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

TERIMA KASIH SEMOGA BERMANFAAT


BAB 5 Android Event Handling Mahardeka Tri Ananta

Recommend Documents