I'm creating a custom camera application (which'll be contained within a larger, main application) that loads up a view with the camera -preview and a picture gallery preview - so the user can either take a picture or select a preexisting one. If the user does take a photo, I just wanna display a confirmation dialog and, if confirmed, pass control back to the main activity. I can't store the photo: need to quickly use it as an attachment, and once sent via the main activity, dispose of it.
The problem comes up when I take a picture and onPictureTaken() is called: it either doesn't work, or takes an absurdly long time for it to save a photo. Also, I can't seem to figure out how to extract the photo right on the spot, without saving it to a directory; I planned on immediately deleting the directory, but there's got to be a cleaner way (essentially, I just wanna access that raw byte array, without having to save it).
I want it to be modular (gonna use the camera a lot in my upcoming projects), and I think that's what's adding to the overall lag.
I followed Google's Developer Android Guide on Cameras, and most of my code is derived from the examples presented there.
I'm also using ActionBarSherlock.
I currently have three classes:
CameraManager
public class CameraManager {
private static Camera CAMERA;
/** Check if this device has a camera */
public static boolean doesDeviceHaveCamera(Context context) {
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
return true;
}
else {
return false;
}
}
public static Camera getCameraInstance(){
CAMERA = null;
try {
CAMERA = Camera.open();
}
catch (Exception e){
// Camera is not available (in use or does not exist)
}
return CAMERA;
}
}
CameraPreview
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
private SurfaceHolder surfaceHolder;
private Camera camera;
public CameraPreview(Context context, Camera camera) {
super(context);
this.camera = camera;
surfaceHolder = getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // deprecated setting, but required on Android versions prior to 3.0
}
public void surfaceCreated(SurfaceHolder holder) {
try {
camera.setPreviewDisplay(holder);
camera.startPreview();
}
catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
camera.stopPreview();
camera.release();
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (surfaceHolder.getSurface() == null){
return;
}
try {
camera.stopPreview();
}
catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
camera.setDisplayOrientation(90);
// start preview with new settings
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
}
catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
CameraActivity
public class CameraActivity extends SherlockActivity {
private static final String TAG = "CameraActivity";
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
private Camera camera;
private CameraPreview preview;
private PictureCallback picture = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
Log.d(TAG, "Error creating media file, check storage permissions: media file is null.");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
}
catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
}
catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().hide();
setContentView(R.layout.camera_view);
/**Get a camera instance**/
if(CameraManager.doesDeviceHaveCamera(this)){
camera = CameraManager.getCameraInstance();
}
else{
return;
}
/**Create a SurfaceView preview (holds the camera feed) and set it to the corresponding XML layout**/
preview = new CameraPreview(this, camera);
FrameLayout previewContainer = (FrameLayout) findViewById(R.id.camera_preview);
previewContainer.addView(preview);
/**Set up a capture button, which takes the picture**/
Button captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
camera.takePicture(null, null, picture);
}
});
}
/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type){
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyDirectory");
// This location works best if you want the created images to be shared
// between applications and persist after your app has been uninstalled.
// Create the storage directory if it does not exist
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyDirectory", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US).format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE){
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
}
else if(type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4");
}
else {
return null;
}
return mediaFile;
}
}
I'm calling CameraActivity from a button on my main activity screen.
