BAB 5 Android Event Handling · PDF file05/10/2016 · Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB BAB 5 Android Event Handling Mahardeka Tri Ananta [email protected]

Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

BAB 5Android Event Handling

Mahardeka Tri Ananta

[email protected]

Konten

• Event pada Widget

• Event Handler

• Event Listener


Event

• Event adalah suatu cara untuk mengumpulkan data tentang interaksipengguna dengan komponen interaktif dari Aplikasi.

• Contoh: Aksi (action) yang terjadi ketika user berinteraksi denganwidget (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:

<TextView android:id="@+id/textViewName"/>

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



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



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.


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

android:gravity="center">

<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:text="Button 2"

android:id="@+id/button2"


android:onClick="button2" />

</LinearLayout>

activity_main.xml


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();

}

}

MainActivity.java


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..



Illustration

View Widget

Button

Event Handler Object

setOnClickListener() onClick()

User Click

Event

View.OnClickListener



• 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 )


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 methodprotected void onCreate(Bundle savedValues) {

...

// STEP 1: Capture our button from layoutButton button = (Button)findViewById(R.id.corky);

}

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

... Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB

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 1button.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


<LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

android:paddingBottom="@dimen/activity_vertical_margin"

tools:context=".MainActivity"

android:orientation="vertical">

<TextView



android:textAppearance="?android:attr/textAppearanceLarge"

android:text="Penjumlahan 2 bilangan"

android:id="@+id/textView" />

<EditText



android:id="@+id/editText"

android:hint="masukkan angka ke-1"/>

<EditText



android:id="@+id/editText2"

android:hint="masukkan angka ke-2"/>

<EditText



android:id="@+id/editText3"


android:text="hasil: "

android:editable="false"/>

<Button



android:text="hitung"

android:id="@+id/button"

android:layout_gravity="center"/>

</LinearLayout>

activity_main.xml


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);

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();

}

}

};

buttonHitung.setOnClickListener(click);

}

}

MainActivity.java

STEP 1

// Create an anonymous implementation of OnClickListener STEP 2

// STEP 3: Register the onClick listener


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. onClick()2. onLongClick()3. onFocusChange()4. onKey()5. onTouch()6. onCreateContextMenu()

• Jalankan aplikasi, kemudian amati perbedaan dari 4 event handler yang digunakan

• Buat dokumentasi (.pdf) yang berisi:1. Langkah2 implementasi Event Handling pada aplikasi yang Anda buat (dilengkapi dengan

screenshot)2. Jelaskan perbedaan dari 6 event handler yang ada di atas, dan berikan contoh kasus

penggunaannya


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 Mobile2. Android Activities3. User Interface4. Event Handling

TERIMA KASIH SEMOGA BERMANFAAT


Documents

BAB 5 Android Event Handling · PDF file05/10/2016 · Lab. Pemrograman Aplikasi Perangkat Bergerak FILKOM UB BAB 5 Android Event Handling Mahardeka Tri Ananta [email protected]