why display black background between two layouts

Question

I have radio app stream, and when open this app, first its open splash layout like this :

splash.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<ImageView
    android:id="@+id/imageView1"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:src="@drawable/loading" />

<ProgressBar
    android:id="@+id/progressBar1"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1.67" />

</LinearLayout>

and class for it like :

StartPoint.java

public class StartPoint extends Activity{

ProgressBar progressBar;
private int progressBarStatus = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.splash);

    progressBar = (ProgressBar)findViewById(R.id.progressBar1);


    Thread timer = new Thread(){
        public void run(){
            try{
                sleep(5000);
                while(progressBarStatus < 5000){
                    StartPoint.this.runOnUiThread(new Runnable(){
                        public void run()
                        {
                            progressBar.setProgress(progressBarStatus);
                            progressBarStatus += 1000;
                        }
                    });

                }
            }catch(InterruptedException e){
                e.printStackTrace();
            }finally{
                Intent openMainList = new Intent(StartPoint.this, 
                                           com.example.kam.MainActivity.class);
                startActivity(openMainList);
            }
        }
    };
    timer.start();
}

@Override
protected void onStop(){
   super.onStop();
   finish();
}

}

this class when finished, its call MainActivity.java class, and its show :

MainActivity.java

public class MainActivity extends Activity implements OnClickListener {
    // Define ..............................................................
    private static ProgressDialog progressDialog;
    public MediaPlayer mp;
    boolean isPrepared = false;
    Button PlayBtn, ExitBtn, PauseBtn, RefreshBtn;
    String MEDIA_PATH;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        progressDialog = ProgressDialog.show(MainActivity.this, "", 
                                                  "Buffering Radio...", true);
        progressDialog.setCancelable(false);
        // Declare
        // ..............................................................
        mp = new MediaPlayer();
        PlayBtn = (Button) findViewById(R.id.btnPlay);
        PlayBtn.setOnClickListener(this);
        PauseBtn = (Button) findViewById(R.id.btnPause);
        PauseBtn.setOnClickListener(this);
        RefreshBtn = (Button) findViewById(R.id.btnRefresh);
        RefreshBtn.setOnClickListener(this);
        ExitBtn = (Button) findViewById(R.id.btnExit);
        ExitBtn.setOnClickListener(this);
        MEDIA_PATH = "http://radio.arabhosters.com:8015/";

        // Volume Control
        // ..............................................................
        final AudioManager leftAm = (AudioManager)
                                      getSystemService(Context.AUDIO_SERVICE);
        int maxVolume = leftAm.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        int curVolume = leftAm.getStreamVolume(AudioManager.STREAM_MUSIC);
        SeekBar volControl = (SeekBar) findViewById(R.id.volumebar);
        volControl.setMax(maxVolume);
        volControl.setProgress(curVolume);
        volControl.setOnSeekBarChangeListener
                                      (new SeekBar.OnSeekBarChangeListener() {

            @Override
            public void onStopTrackingTouch(SeekBar arg0) {
                // TODO Auto-generated method stub
            }

            @Override
            public void onStartTrackingTouch(SeekBar arg0) {
                // TODO Auto-generated method stub
            }

            @Override
            public void onProgressChanged
                                (SeekBar arg0, int arg1, boolean arg2) {
                // TODO Auto-generated method stub
            leftAm.setStreamVolume(AudioManager.STREAM_MUSIC, arg1, 0);
             }
        });
    }

    @Override
    public void onClick(View v) {
        if (v == PlayBtn) {
            startradio();
        }
        else if (v == PauseBtn) {
            pauseradio();
        }
        else if (v == ExitBtn) {
            exitradio();
        }
        else if (v == RefreshBtn) {
            try {
                refreshradio();
            }
            catch (IllegalArgumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            catch (SecurityException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    public void onCompletion(MediaPlayer mediaPlayer) {
        synchronized (this) {
            isPrepared = false;
        }
    }

    protected void onResume() {
        super.onResume();

        try {
            mp.setDataSource(MEDIA_PATH);
        }
        catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (SecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
        try {
            mp.prepare();
        }
        catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } // also consider mp.prepareAsync().
            // defult start stream when start App.
        mp.start();
        mp.setVolume(100, 100);
        progressDialog.dismiss();
    }

    // method for play stream after stop it.
    public void startradio() {
        try {
            if (mp.isPlaying()) {
                return;
            }
            mp.start();
            progressDialog.dismiss();
        }
        catch (IllegalStateException ex) {
            ex.printStackTrace();
        }
    }

    // method for Refresh stream.
    public void refreshradio() throws IllegalArgumentException, 
                                       SecurityException, IOException {
        try {
            if (mp.isPlaying()) {
                return;
            }
            mp.reset();
            mp.setDataSource(MEDIA_PATH);
            mp.prepare();
            mp.start();
            progressDialog.dismiss();
        }
        catch (IllegalStateException ex) {
            ex.printStackTrace();
        }
    }

    // method for pause stream.
    public void pauseradio() {
        mp.pause();
    }

    // method for check is radio paly or not stream
    public boolean isPlaying() {
        return mp.isPlaying();
    }

    // method for Looping audio if your record it - Soon :)
    public boolean isLooping() {
        return mp.isLooping();
    }

    // method for Looping audio if your record it - Soon :)
    public void setLooping(boolean isLooping) {
        mp.setLooping(isLooping);
    }

    // method for volume
    public void setVolume(float volumeLeft, float volumeRight) {
        mp.setVolume(volumeLeft, volumeRight);
    }

    // method for stop stream.
    public void stopradio() {
        if (mp.isPlaying()) {
            mp.stop();
        }
        mp.release();
    }

    // method for exit.
    public void exitradio() {
        finish();
        System.exit(0);
    }

    // method for back to main menu "Home".
    public void backtomenu() {
        finish();
    }

    @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, menu);
        return true;
    }

}

and layout for it like :

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/screen" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:background="@drawable/bg">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:orientation="vertical"
         >

        <LinearLayout
            android:layout_weight="6" 
            android:orientation="vertical" 
            android:layout_alignParentTop="true" 
            android:layout_alignParentLeft="true" 
            android:layout_width="fill_parent" 
            android:layout_height="0dip" >

        </LinearLayout>

        <LinearLayout
            android:id="@+id/buttons"
            android:layout_width="match_parent"
            android:layout_height="0dip"
            android:layout_alignParentLeft="true"
            android:layout_weight="0.62"
            android:background="@drawable/iconbgrepate"
            android:gravity="center"
            android:orientation="horizontal"
            android:tileMode="repeat"
            android:weightSum="5" 
            android:alpha=".75">

        <SeekBar
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:id="@+id/volumebar"
            android:max="100"
            android:paddingBottom="10dip"/>

        </LinearLayout>

        <LinearLayout
            android:id="@+id/buttons"
            android:layout_width="match_parent"
            android:layout_height="0dip"
            android:layout_alignParentLeft="true"
            android:layout_weight="0.62"
            android:background="@drawable/iconbgrepate"
            android:gravity="center"
            android:orientation="horizontal"
            android:tileMode="repeat"
            android:weightSum="5" >

           <Button
               android:id="@+id/btnRefresh"
               android:layout_width="32dp"
               android:layout_height="match_parent"
               android:layout_margin="5dp"
               android:layout_weight="0.10"
               android:background="@drawable/refreshbutton" />

           <View android:layout_weight="1" 
               android:layout_width="0dip" 
               android:layout_height="0dip" />

            <Button
                android:id="@+id/btnPause"
                android:layout_width="32dp"
                android:layout_height="match_parent"
                android:layout_margin="5dp"
                android:layout_weight="0.05"
                android:background="@drawable/pausebutton" />

            <View android:layout_weight="1" 
                android:layout_width="0dip" 
                android:layout_height="0dip" />

            <Button
                android:id="@+id/btnPlay"
                android:layout_width="32dp"
                android:layout_height="match_parent"
                android:layout_margin="5dp"
                android:layout_weight="0.05"
                android:background="@drawable/playbutton" />

            <View android:layout_weight="1" 
                android:layout_width="0dip" 
                android:layout_height="0dip" />

            <Button
                android:id="@+id/btnExit"
                android:layout_width="32dp"
                android:layout_height="match_parent"
                android:layout_margin="5dp"
                android:layout_weight="0.12"
                android:background="@drawable/exitbutton" />

        </LinearLayout>
    </LinearLayout>
</RelativeLayout>

why when trans from splash.xml to activity_main.xml display black background few min and display app.

Answer 1

Since you are changing activity, its gonna show some animation or black screen like you said. Its the default behavior. You can use a custom dialog with your splash layout on top of main activity. you can trigger the dialog to close on progress complete. Using two activities can have other effects. for instance when the user hits the back button, its gonna go back to splash screen instead of exiting the app.

Answer 2

try it

 Thread timer = new Thread(){
    public void run(){
        try{

            while(progressBarStatus < 5000){
                StartPoint.this.runOnUiThread(new Runnable(){
                    public void run()
                    {
                        progressBar.setProgress(progressBarStatus);
                        progressBarStatus += 1000;
                    }
                });
                    sleep(5000);
            }