Camera Preview in android

Hello developers, again i am come up with new sample example about camera preview in your XML layout instead of  camera activity.

To see camera preview we require  SurfaceView and SurfaceHolder.

I have create simple XML Layout file in which i have set two buttons and to show real camera preview we need SurfaceView .

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01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29	<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" >   <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Hello" />   <Button android:id="@+id/startcamerapreview" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="- Start Camera Preview -" />   <Button android:id="@+id/stopcamerapreview" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="- Stop Camera Preview -" />   <SurfaceView android:id="@+id/surfaceview" android:layout_width="fill_parent" android:layout_height="wrap_content" />   </LinearLayout>

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

<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Hello" />

<Button
android:id="@+id/startcamerapreview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="- Start Camera Preview -" />

<Button
android:id="@+id/stopcamerapreview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="- Stop Camera Preview -" />

<SurfaceView
android:id="@+id/surfaceview"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />

</LinearLayout>

How to mange SurfaceView in java file ?

We will initialize Camera, SurfaceView & SurfaceHolder as global to mange the view. Here is the whole java file which help you easily.

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01 02 03 04 05 06 07 08 09 10 11 12 13 14	@Override public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.main);     buttonStartCameraPreview = (Button) findViewById(R.id.startcamerapreview);     buttonStopCameraPreview = (Button) findViewById(R.id.stopcamerapreview);     surfaceView = (SurfaceView) findViewById(R.id.surfaceview);     surfaceHolder = surfaceView.getHolder();     surfaceHolder.addCallback(this);     // write below code inside this block     surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);     buttonStartCameraPreview.setOnClickListener();     // write below code inside this block     buttonStopCameraPreview.setOnClickListener(); }

@Override public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    buttonStartCameraPreview = (Button) findViewById(R.id.startcamerapreview);
    buttonStopCameraPreview = (Button) findViewById(R.id.stopcamerapreview);
    surfaceView = (SurfaceView) findViewById(R.id.surfaceview);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    // write below code inside this block 
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    buttonStartCameraPreview.setOnClickListener();
    // write below code inside this block 
    buttonStopCameraPreview.setOnClickListener();
}

Implement SurfaceHolder.Callback

This will @Override method surfaceChanged , surfaceCreated , surfaceDestroyed You can write your optional code here as per your requirement.

Task of Show_Preview &  Stop_Preview ?

This is not two different function but i have just filter it so easy to understand.

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01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36	Show_Preview() {     if (!previewing) {         camera = Camera.open();         if (camera != null) {             try {                 camera.setPreviewDisplay(surfaceHolder);                 camera.startPreview();                 previewing = true;             } catch (IOException e) {                 // TODO Auto-generated catch block                 e.printStackTrace();             }         }     } }   Stop_Preview() {     if (camera != null && previewing) {         camera.stopPreview();         camera.release();         camera = null;         previewing = false;     } }   @Override public void onClick(View v) {     // TODO Auto-generated method stub     if (v.getId() == R.id.startcamerapreview) {         Show_Preview();     }     if (v.getId() == R.id.stopcamerapreview) {         Stop_Preview();     }   }

Show_Preview() {
    if (!previewing) {
        camera = Camera.open();
        if (camera != null) {
            try {
                camera.setPreviewDisplay(surfaceHolder);
                camera.startPreview();
                previewing = true;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

Stop_Preview() {
    if (camera != null && previewing) {
        camera.stopPreview();
        camera.release();
        camera = null;
        previewing = false;
    }
}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    if (v.getId() == R.id.startcamerapreview) {
        Show_Preview();
    }
    if (v.getId() == R.id.stopcamerapreview) {
        Stop_Preview();
    }

}

And don't forget to add android:name="android.permission.CAMERA" in Manifest file.

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