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Introduction

A simple guide for integrating the Camera Hardware inside your Android App.

Step 1: Create a class that extends SurfaceView and implements SurfaceHolder.Callback

Before you can integrate the Camera hardware with your Activity, you must provide a Preview screen. The camera's Preview output is supplied to this screen. The SurfaceView instance with a SurfaceHolder.Callback implementation provides such a View

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback
{
	private SurfaceHolder holder;
	private Camera camera;
	
	public CameraSurfaceView(Context context) 
	{
		super(context);
		
		//Initiate the Surface Holder properly
		this.holder = this.getHolder();
		this.holder.addCallback(this);
		this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
	}

Step 2: In the surfaceCreated method, get an instance of the Camera

        @Override
	public void surfaceCreated(SurfaceHolder holder) 
	{
		try
		{
			//Open the Camera in preview mode
			this.camera = Camera.open();
			this.camera.setPreviewDisplay(this.holder);
		}
		catch(IOException ioe)
		{
			ioe.printStackTrace(System.out);
		}
	}

Step 3: In the surfaceChanged callback

        @Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) 
	{
		// Now that the size is known, set up the camera parameters and begin
		// the preview.
		Camera.Parameters parameters = camera.getParameters();
		parameters.setPreviewSize(width, height);
		camera.setParameters(parameters);
		camera.startPreview();
	}

During this callback, you get an idea of how big your preview screen is going to be. Based on that, assign the proper size to the Camera.

Step 4: Implement surfaceDestroyed to cleanup

        @Override
	public void surfaceDestroyed(SurfaceHolder holder) 
	{
		// Surface will be destroyed when replaced with a new screen
		//Always make sure to release the Camera instance
		camera.stopPreview();
		camera.release();
		camera = null;
	}

When the preview screen is removed from view, this callback is used to perform cleanup. In this phase, make sure the preview is stopped and the Camera hardware is released

Step 5: Add the SurfaceView to your layout

                //Setup the FrameLayout with the Camera Preview Screen
		final CameraSurfaceView cameraSurfaceView = new CameraSurfaceView(this);
		FrameLayout preview = (FrameLayout)ViewHelper.findViewById(this, "preview"); 
		preview.addView(cameraSurfaceView);

Step 6: Add a Button for Taking the Picture

//Setup the 'Take Picture' button to take a picture
		Button takeAPicture = (Button)ViewHelper.findViewById(this, "buttonClick");
		takeAPicture.setOnClickListener(new OnClickListener() 
		{
			public void onClick(View v) 
			{
				Camera camera = cameraSurfaceView.getCamera();
				camera.takePicture(null, null, new HandlePictureStorage());
			}
		});

You must supply a Callback to process the information that the camera sends back to your App

        private class HandlePictureStorage implements PictureCallback
	{

		@Override
		public void onPictureTaken(byte[] picture, Camera camera) 
		{
			//The picture can be stored or do something else with the data
			//in this callback such sharing with friends, upload to a Cloud component etc
			
			//This is invoked when picture is taken and the data needs to be processed
			System.out.println("Picture successfully taken: "+picture);
			
			String fileName = "shareme.jpg";
			String mime = "image/jpeg";
			
			MainActivity.this.shareme = new CloudPhoto();
			MainActivity.this.shareme.setFullName(fileName);
			MainActivity.this.shareme.setMimeType(mime);
			MainActivity.this.shareme.setPhoto(picture);
		}
	}

Inside this callback, you can do whatever you need with the picture. You can store it on your local file system, in a sqlite database, or in this case, send it to a remote service located in the cloud.

Step 7: Acquire permission for using the Camera hardware

   <uses-permission android:name="android.permission.CAMERA" />

You can do this in the AndroidManifest.xml by adding the above mentioned line

Full Source for CameraSurfaceView.java

package org.openmobster.app;

import java.io.IOException;

import android.content.Context;
import android.view.SurfaceView;
import android.view.SurfaceHolder;
import android.hardware.Camera;

/**
 * 
 * @author openmobster@gmail.com
 */
public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback
{
	private SurfaceHolder holder;
	private Camera camera;
	
	public CameraSurfaceView(Context context) 
	{
		super(context);
		
		//Initiate the Surface Holder properly
		this.holder = this.getHolder();
		this.holder.addCallback(this);
		this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
	}
	
	@Override
	public void surfaceCreated(SurfaceHolder holder) 
	{
		try
		{
			//Open the Camera in preview mode
			this.camera = Camera.open();
			this.camera.setPreviewDisplay(this.holder);
		}
		catch(IOException ioe)
		{
			ioe.printStackTrace(System.out);
		}
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) 
	{
		// Now that the size is known, set up the camera parameters and begin
		// the preview.
		Camera.Parameters parameters = camera.getParameters();
		parameters.setPreviewSize(width, height);
		camera.setParameters(parameters);
		camera.startPreview();
	}


	@Override
	public void surfaceDestroyed(SurfaceHolder holder) 
	{
		// Surface will be destroyed when replaced with a new screen
		//Always make sure to release the Camera instance
		camera.stopPreview();
		camera.release();
		camera = null;
	}
	
	public Camera getCamera()
	{
		return this.camera;
	}
}

Download this tutorial

• Download

• Go to the cloud directory: mvn -PrunCloud integration-test

• Go the the app-android directory: mvn -Phot-deploy install

• Go to the DevCloud app and activate the device with the Cloud

• Run the CloudCamera app

Related Links: Beginner Area