Platform For Learning Programming Language: December 2014

Wednesday, 3 December 2014

Sending data from one activity to another in Android

Step1: Using Intent Object for sending data from one activity:

public class MainActivity extends Activity implements OnClickListener {
  
  EditText etFName;
  EditText etLName;
  
  Button btnSubmit;
  
  
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        etFName = (EditText) findViewById(R.id.etFName);
        etLName = (EditText) findViewById(R.id.etLName);
        
        btnSubmit = (Button) findViewById(R.id.btnSubmit);
        btnSubmit.setOnClickListener(this);
        
    }


  @Override
  public void onClick(View v) {
    Intent intent = new Intent(this, ViewActivity.class); 
    
 intent.putExtra("fname", etFName.getText().toString());
    intent.putExtra("lname", etLName.getText().toString());
 
     OR
     
 Bundle b = new Bundle();
    //Inserts a String value into the mapping of this Bundle
    b.putString("fname", etFName.getText().toString());
 b.putString("lname", etLName.getText().toString());
 intent.putExtras(b);
    
 startActivity(intent);
  } 
}

Step2: Using Intent Object for receiving data in another activity

public class AnotherActivity extends Activity {
  
  TextView tvView;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view);
    
    tvView = (TextView) findViewById(R.id.tvView);
    
    Intent intent = getIntent();
    String fName = intent.getStringExtra("fname");
    String lName = intent.getStringExtra("lname");
 
     OR
 Bundle b = getIntent().getExtras();
 String fName = b.getCharSequence("fname");
    String lName = b.getCharSequence("lname");
    
    tvView.setText("Your name is: " + fName + " " + lName);
  }
}

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Providing UP Navigation in Android

Step1: specifying parentActivityName attibute in an activity

Declare which activity is the appropriate parent for each activity. You can do it by specifying parentActivityName attibute in an activity.

<activity
 android:name="com.example.test.MainActivity2"
 android:label="@string/title_activity_main_activity2"
 android:parentActivityName="com.example.test.MainActivity" >
</activity>

Step2: Call setDisplayHomeAsUpEnabled() method of getActionBar() in the onCreate()

Call setDisplayHomeAsUpEnabled() method of getActionBar() in the onCreate method of the activity to enable the back button in the top action bar

@Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main_activity2);
      getActionBar().setDisplayHomeAsUpEnabled(true);
   }

Step3: Override onOptionsItemSelected()

When the user presses it, your activity receives a call to onOptionsItemSelected(). The ID for the action is android.R.id.home.

public boolean onOptionsItemSelected(MenuItem item) {
 switch (item.getItemId()) {
  case android.R.id.home:
  NavUtils.navigateUpFromSameTask(this);
  return true;
 } 
}

Step4: Handling device back button

Overrid onBackPressed() and then calling moveTaskToBack() and finish() method.

@Override
public void onBackPressed() {
   moveTaskToBack(true); 
   MainActivity2.this.finish();
}

Complete Code:

<application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" >
      <activity
         android:name="com.example.test.MainActivity"
         android:label="@string/app_name" >
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
      <activity
         android:name="com.example.test.MainActivity2"
         android:label="@string/title_activity_main_activity2"
         android:parentActivityName="com.example.test.MainActivity" >
      </activity>
   </application>

public class MainActivity2 extends Activity {

   @SuppressLint("NewApi")
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main_activity2);
      getActionBar().setDisplayHomeAsUpEnabled(true);
   }
   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.main_activity2, menu);
      return true;
   }  
   @Override
   public boolean onOptionsItemSelected(MenuItem item) {
      switch (item.getItemId()) {
         // Respond to the action bar's Up/Home button
         case android.R.id.home:
         NavUtils.navigateUpFromSameTask(this);
         return true;
      }
      return super.onOptionsItemSelected(item);
   }
   @Override
   public void onBackPressed() {
      moveTaskToBack(true); 
      MainActivity2.this.finish();
   }

}

Next Article: Android - Sending data from one activity to another

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Adding EditBox in LisView Header in Android

Create a separate layout header.xml and add below code:

<TableLayout   
    android:layout_weight="0"   
    android:layout_width="fill_parent"   
    android:layout_height="wrap_content">  

    <TableRow>  
        <EditText android:id="@+id/newmessagecontent"  
            android:layout_height="wrap_content"   
            android:singleLine="false"  
            android:gravity="top"  
            android:layout_width="250dp"  
            android:layout_alignParentTop="true"  
              />  

        <Button android:layout_height="wrap_content"   
            android:id="@+id/sendmessage"   
            android:text="Send"   
            android:layout_width="wrap_content"  
            />  
    </Table> 
      </TableLayout>

Update the main activity java code with below code

ListView lv = getListView(); 
LayoutInflater inflater = getLayoutInflater(); 
ViewGroup header = (ViewGroup)inflater.inflate(R.layout.header, lv, false); //header is above XML code
lv.addHeaderView(header, null, false);

Next Article: Android - Providing UP Navigation

For any questions, suggestions and feedback, Please write to us. Thanks for Reading :)

Tuesday, 2 December 2014

Different ways to create Android View Separator

Example:1 Using View control to create View Separator

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:adjustViewBounds="true"
    android:orientation="horizontal">
    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        style="?android:attr/buttonBarButtonStyle"
        android:text="Yes"
        android:layout_weight="1"
        android:id="@+id/button1"
        android:textColor="#00b0e4" />
    <View android:layout_height="fill_parent"
        android:layout_width="1px"
        android:background="#90909090"
        android:layout_marginBottom="5dp"
        android:layout_marginTop="5dp"
        android:id="@+id/separator1" />
  
    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        style="?android:attr/buttonBarButtonStyle"
        android:text="No"
        android:layout_weight="1"
        android:id="@+id/button2"
        android:textColor="#00b0e4" />
    
</LinearLayout>

Example:2 Using android:divider attribute in LinearLayout

Create a new file called separator.xml in the drawable folder:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
 <size android:width="1dp" />
 <solid android:color="#90909090" />
</shape>


<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:adjustViewBounds="true"
    android:divider="@drawable/separator"
    android:showDividers="middle"
    android:orientation="horizontal">
    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        style="?android:attr/buttonBarButtonStyle"
        android:text="Yes"
        android:layout_weight="1"
        android:id="@+id/button1"
        android:textColor="#00b0e4" />
    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        style="?android:attr/buttonBarButtonStyle"
        android:text="No"
        android:layout_weight="1"
        android:id="@+id/button2"
        android:textColor="#00b0e4" />
  
</LinearLayout>

Example:3 Using ButtonBarStyle attribute in LinearLayout style attribute

<LinearLayout
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    style="?android:buttonBarStyle"
    android:dividerPadding="15dp"
    >
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button1"
        android:id="@+id/button1"
        android:layout_gravity="center_vertical" />
    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Button2"
        android:id="@+id/button2"
android:layout_gravity="center_vertical"/>
     
</LinearLayout>

Next Article: Android - Adding EditBox in LisView Header

For any questions, suggestions and feedback, Please write to us. Thanks for Reading :)