1. camera

2. Make button called TakePicture Make button called ShowLastPic
Make new project
Give permission to use camera
Make button called TakePicture
Make button called ShowLastPic
Add SurfaceView to layout
Surface view is something we can draw on
This will show the picture preview
Set layout height = fill_parent (or try 10dip)
Set layout width = fill_parent
Set layout weight = 1 Id
SurfaceView changes when the phone’s orientation changes.

3. Our MyCamera class needs some objects
To handle the surface and changes in the surface, we need our activity to implement SurfaceHolder.Callback.
public class MyCamera extends Activity implements SurfaceHolder.Callback {
Our MyCamera class needs some objects
Camera mCamera; // to hold the camera object
private SurfaceView mSurfaceView; // to hold the surface view
private SurfaceHolder mSurfaceHolder; // to hold the interface for the surfacevieww
We’ll add some more later
After super.onCreate
setContentView(R.layout.main);
mSurfaceView = (SurfaceView) findViewById(R.id.surface_camera); // get surface object
mSurfaceHolder = mSurfaceView.getHolder(); // get surface holder
mSurfaceHolder.addCallback(this); // this activity is the callback
// note, instead this, we could make a new classss that implements SurfcaeHolder.Callback
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // says ?
Implementing SurfaceHolder.CallBack requires three functions to be implemented
surfaceCreated
surfaceChanged
Called when orientation is changed and after surfaceCreated
surfaceDestroyed

4. public void surfaceCreated(SurfaceHolder holder) {
Log.e("My camera app", "surfaceCreated");
mCamera = Camera.open();}

5. public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
Log.d("My camera app", "surfaceChanged");
mCamera.stopPreview();
…. Set up preview ….
mCamera.startPreview();
But
mCamera.stopPreview() requires that startPreview was called

6. boolean previewRunning = false;
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
Log.d(“My camera app”, "surfaceChanged");
If (previewRunning)
mCamera.stopPreview();
…. Set up preview ….
mCamera.startPreview();
previewRunning = true;

7. public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
Log.d(“My camera app”, "surfaceChanged");
if (previewRunning) {
mCamera.stopPreview(); }
Log.e("My camera app","view width"+w+" height"+h);
Camera.Parameters p = mCamera.getParameters(); // set the preview size
p.setPreviewSize(w, h);
mCamera.setParameters(p);
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
mCamera.startPreview();
mPreviewRunning = true;

8. public void surfaceDestroyed(SurfaceHolder holder) {
Log.e("My camera app", "surfaceDestroyed");
mCamera.stopPreview();
mCamera.release();
previewRunning = false;}

9. run It crashes on nexus 1 Check log
Note that error when setting preview size
Note that preview size is odd.
Check web for more info on Camera.Parameters and Camera.Parameters.setPreviewSize
see getSupportedPreviewSizes

10. Before setParameters, do the following
Log.e("My camera app","width"+w+" h"+h);
List<Camera.Size> sizes = mCamera.getParameters().getSupportedPreviewSizes();
Camera.Size sizeToSet = null;
for (Camera.Size t: sizes) {
String str = "view";
str += t.width;
str += "by" + t.height;
Log.e("My camera app”, str); }
Log.e("My camera app“,"w="+sizeToSet.width+" h="+sizeToSet.height);
add
Boolean found = new Boolean(false);
Inside loop, add
if (t.width<=w && t.height<=h && found==false) {
sizeToSet = t;
found = true; }

11. Change parameter setting to:
Camera.Parameters p = mCamera.getParameters();
p.setPreviewSize(sizeToSet.width, sizeToSet.height);
mCamera.setParameters(p);

12. Rotation/orientation
Note that the orientation is messed up
Perhaps the image is correct in only one orientation.
Two fixes
Fix the orientation to be in portrait or landscape and set display orientation accordingly
In onCreate, add
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
In surfaceChanged, add
mCamera.setDisplayOrientation(180); // or whatever value works
Get the rotation and then set camera orientation accordingly
Display display = getWindowManager().getDefaultDisplay();
switch (display.getRotation()) {
case Surface.ROTATION_0:
Log.e("DEBUG INFO","rotation = 0");
mCamera.setDisplayOrientation(180); // whatever value works
break;
case Surface.ROTATION_90:
Etc. etc.

13. Take picture In onCreate add button click listener When clicked call
previewRunning = false;
mCamera.stopPreview ();
mCamera.takePicture(null, null, pictureCallback);
The first null could be set to play a sound. But we will just use the default
pictureCallback is a Camera.PictureCallback object that we must make

14. Where to save files? Private directories External Storage Directory
Only accessible by this app (cannot share files)
Deleted when app is uninstalled
Can be on internal memory or external (e.g., sdcard)
External Storage Directory
Might be on sdcard or internal memory
Can be mounted on another machine
when attaching phone to laptop via usb, the external memory is accessible by the laptop and might not be accessible by the phone apps
No standard directories, so files can get messy. Hence not recommended unless you are careful to clean up after yourself
External Storage Public Directory
Like External Storage Directory, but uses specific directories e.g., pictures, music, video

15. External storage
Before external storage is used, the app must check that the storage is accessible
If the phone is attached to a computer via usb, the storage might not be accessible because the computer is controlling the storage device
boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
// We can read and write the media
mExternalStorageAvailable = mExternalStorageWriteable = true;
Log.e("DEBUG INFO","storage is readble and writable");
} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
// We can only read the media
mExternalStorageAvailable = true;
mExternalStorageWriteable = false;
Log.e("DEBUG INFO","storage is readable only");
} else {
// Something else is wrong. It may be one of many other states, but all we need
// to know is we can neither read nor write
mExternalStorageAvailable = mExternalStorageWriteable = false;
Log.e("DEBUG INFO","storage is not accessible"); }

16. External Storage Public Directory
If external storage is available, we can get the directory
if (mExternalStorageWriteable) {
File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
// arg must not be null, can be
DIRECTORY_MUSIC, DIRECTORY_PODCASTS, DIRECTORY_RINGTONES, DIRECTORY_ALARMS, DIRECTORY_NOTIFICATIONS, DIRECTORY_PICTURES, DIRECTORY_MOVIES, DIRECTORY_DOWNLOADS, or
DIRECTORY_DCIM
Pcitures and videos from camera
// this is a small set of directories
path.mkdirs();
File file = new File(path, "my_pic.jpeg");

17. External Storage Directory
if (mExternalStorageWriteable) {
File path = Environment. getExternalStorageDirectory();
File file = new File(path, "my_pic.jpeg");

18. Application Storage
Internal storage: only accessible by the applications. Security is enforced
File path = getFilesDir();
File file = new File(path, "my_pic.jpeg");
External storage.
Typically not visible to user media applications (e.g., if you store a movie here, your movie player will not find it)
No security enforcement. So other applications could overwrite
File path = getExternalFilesDir (type);
// type is DIRECTORY_MUSIC, DIRECTORY_PODCASTS, DIRECTORY_RINGTONES, DIRECTORY_ALARMS, DIRECTORY_NOTIFICATIONS, DIRECTORY_PICTURES, or DIRECTORY_MOVIES.
Or null

19. public void onPictureTaken(byte[] imageData, Camera c) {
Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
public void onPictureTaken(byte[] imageData, Camera c) {
if (imageData == null) {
Log.e("DEBUG INFO","image is null");
} else {
// get file as just explained
We will use Bitmap, which has lots of bitmap related functions
To create a Bitmap we use BitmapFactory. decodeByteArray(byte[] data, int offset, int length)
Where data is imageData (the function argument,; offset = 0; and length = imageData.length
add
Bitmap bitmap = BitmapFactory.decodeByteArray(imageData,0,imageData.length);
To write to a jpeg file, we use
Bitmap.compress(file format, quality, outputStream);
add
FileOutputStream fos = new FileOutputStream(file);
bitmap.compress(CompressFormat.JPEG, 50, fos); // quality is 50, but could be between 0 and 100
fos.close();
Finally, start the preview again:
previewRunning = false;
mCamera.startPreview();

20. Show picture
Make new activity (see previous tutorial on making another activity)
In layout add
Add ImageView
In onCreate
Get file name
String pathForAppFiles = getFilesDir().getAbsolutePath();
pathForAppFiles = pathForAppFiles + "/" + "myPic.jpeg";
Log.d("Still image source filename:", pathForAppFiles);
Get bitmap from file
Bitmap bm = BitmapFactory.decodeFile(pathForAppFiles);
Show bitmap in ImageView
ImageView imageView = (ImageView)this.findViewById(R.id.ImageView);
imageView.setImageBitmap(bm);

21. Record video Add button for stopping the record
We’ll use the button for taking a picture to start recording
In the start recording button, replace
previewRunning = false;
mCamera.stopPreview ();
mCamera.takePicture(null, null, pictureCallback);
With
mCamera.unlock();
mediaRecorder = new MediaRecorder();
mediaRecorder.setCamera(mCamera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
mediaRecorder.setMaxDuration(-1);
mediaRecorder.setOutputFile(file.getPath()); // your file
mediaRecorder.setVideoFrameRate(10);//videoFramesPerSecond);
mediaRecorder.setVideoSize(320, 240); // or some other size
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);
mediaRecorder.setPreviewDisplay(mSurfaceHolder.getSurface());
mediaRecorder.setMaxFileSize( ); // size in bytes
mediaRecorder.prepare();
mediaRecorder.start();

22. In stop video button
mediaRecorder.stop();
mCamera.lock();