Develop Reference

How to implement AutoFocus in Camerapagerenderer in Android xamarin forms

I've used CameraPageRenderer where there is no implementation of AutoFocus. I don't know how to implement it in Xamarin Android.
public async void OnSurfaceTextureAvailable(SurfaceTexture surface, int width, int height)
{
camera = global::Android.Hardware.Camera.Open((int)cameraType);
textureView.LayoutParameters = new FrameLayout.LayoutParams(width, height);
surfaceTexture = surface;
camera.SetPreviewTexture(surface);
PrepareAndStartCamera();
}

From CameraPageRenderer, setup the "Focus Mode" in the Camera properties by implementing IAutoFocusCallback in CameraPageRenderer.
public class CameraPageRenderer : PageRenderer, TextureView.ISurfaceTextureListener, IAutoFocusCallback
{
Then implementing OnAutoFocus method, setting AutoFocus.
public void OnAutoFocus(bool success, Camera camera)
{
var parameters = camera.GetParameters();
if (parameters.FocusMode != Android.Hardware.Camera.Parameters.FocusModeContinuousPicture)
{
parameters.FocusMode = Android.Hardware.Camera.Parameters.FocusModeContinuousPicture;
if (parameters.MaxNumFocusAreas > 0)
{
parameters.FocusAreas = null;
}
camera.SetParameters(parameters);
camera.StartPreview();
}
}
Update:
I following this thread(How to implement visual indicator when camera is focused), to add AutoFocus for CameraPageRenderer.
private void TextureView_Touch(object sender, TouchEventArgs e)
{
if (camera != null)
{
var parameters = camera.GetParameters();
camera.CancelAutoFocus();
Rect focusRect = CalculateTapArea(e.Event.GetX(), e.Event.GetY(), 1f);
if (parameters.FocusMode != Android.Hardware.Camera.Parameters.FocusModeAuto)
{
parameters.FocusMode = Android.Hardware.Camera.Parameters.FocusModeAuto;
}
if (parameters.MaxNumFocusAreas > 0)
{
List<Area> mylist = new List<Area>();
mylist.Add(new Android.Hardware.Camera.Area(focusRect, 1000));
parameters.FocusAreas = mylist;
}
try
{
camera.CancelAutoFocus();
camera.SetParameters(parameters);
camera.StartPreview();
camera.AutoFocus(this);
MarginLayoutParams margin = new MarginLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WrapContent,
ViewGroup.LayoutParams.WrapContent));
margin.SetMargins(focusRect.Left, focusRect.Top,
focusRect.Right, focusRect.Bottom);
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(margin);
layoutParams.Height = 200;
layoutParams.Width = 200;
takePhotoButton.LayoutParameters = layoutParams;
takePhotoButton.Visibility = ViewStates.Visible;
}
catch (System.Exception ex)
{
Console.WriteLine(ex.ToString());
Console.Write(ex.StackTrace);
}
//return true;
}
else
{
//return false;
}
}
private Rect CalculateTapArea(object x, object y, float coefficient)
{
var focusAreaSize = Math.Max(textureView.Width, textureView.Height) / 8; //Recommended focus area size from the manufacture is 1/8 of the image
int areaSize = focusAreaSize * (int)coefficient;
int left = clamp(Convert.ToInt32(x) - areaSize / 2, 0, textureView.Width - areaSize);
int top = clamp(Convert.ToInt32(y) - areaSize / 2, 0, textureView.Height - areaSize);
RectF rectF = new RectF(left, top, left + areaSize, top + areaSize);
Matrix.MapRect(rectF);
return new Rect((int)System.Math.Round(rectF.Left), (int)System.Math.Round(rectF.Top), (int)System.Math.Round(rectF.Right), (int)System.Math.Round(rectF.Bottom));
}
private int clamp(int x, int min, int max)
{
if (x > max)
{
return max;
}
if (x < min)
{
return min;
}
return x;
}
public void OnAutoFocus(bool success, Camera camera)
{
var parameters = camera.GetParameters();
if (parameters.FocusMode != Android.Hardware.Camera.Parameters.FocusModeContinuousPicture)
{
parameters.FocusMode = Android.Hardware.Camera.Parameters.FocusModeContinuousPicture;
if (parameters.MaxNumFocusAreas > 0)
{
parameters.FocusAreas = null;
}
camera.SetParameters(parameters);
camera.StartPreview();
}
if(success)
{
Task.Delay(1000);
this.takePhotoButton.Visibility = ViewStates.Invisible;
}
}
Update:

If you're using the Camera API 1 (the old one) you can set the focus mode to continuous like this:
public void OnSurfaceTextureAvailable(SurfaceTexture surface, int width, int height)
{
try
{
var camera = Camera.Open((int)cameraType);
var parameters = camera.GetParameters();
//SET FOCUS MODE HERE
parameters.FocusMode = Camera.Parameters.FocusModeContinuousPicture;
camera.SetParameters(parameters);
}
catch (Exception ex)
{
//log error
return;
}
//other code related to the camera
textureView.LayoutParameters = new FrameLayout.LayoutParams(width, height);
surfaceTexture = surface;
camera.SetPreviewTexture(surface);
PrepareAndStartCamera();
}

Camera live preview freezes on camera switch

I am creating a custom camera app. The problem I am facing is that the camera preview freezes when I switch between the front and the back camera. When starting the activity with either the front or back camera by calling
boolean opened = safeCameraOpenInView(view, Camera.CameraInfo.CAMERA_FACING_BACK)
in the OnCreateView method of the fragment, both cameras will display on startup as expected. As soon as I call the same method in the on click listener of my switch button, the camera freezes immediately.
This is a new implementation which I tried where all the code is within the same fragment instead of a custom class based on the question here: Custom class camera live preview freezes on camera switch yet the result is exactly the same. I am pretty sure I need to do something with the surface view to bind it to the new camera but I am at a loss of how to do this. Anybody have some pointers?
My activity:
public class Camera2ActivityFragment extends Fragment {
// Native camera.
private Camera mCamera;
// View to display the camera output.
private CameraPreview mPreview;
// Reference to the containing view.
private View mCameraView;
/**
* Default empty constructor.
*/
public Camera2ActivityFragment(){
super();
}
/**
* Static factory method
* #param sectionNumber
* #return
*/
public static Camera2ActivityFragment newInstance(int sectionNumber) {
Camera2ActivityFragment fragment = new Camera2ActivityFragment();
//Bundle args = new Bundle();
//args.putInt(ARG_SECTION_NUMBER, sectionNumber);
//fragment.setArguments(args);
return fragment;
}
/**
* OnCreateView fragment override
* #param inflater
* #param container
* #param savedInstanceState
* #return
*/
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_camera2, container, false);
boolean opened = safeCameraOpenInView(view, Camera.CameraInfo.CAMERA_FACING_BACK);
if(opened == false){
Log.d("CameraGuide","Error, Camera failed to open");
return view;
}
// Trap the capture button.
Button captureButton = (Button) view.findViewById(R.id.btnCameraStart);
captureButton.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
// get an image from the camera
mCamera.takePicture(null, null, mPicture);
}
}
);
Button switchCameraButton = (Button) view.findViewById(R.id.btnSwitchCamera);
switchCameraButton.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
safeCameraOpenInView(getView(), Camera.CameraInfo.CAMERA_FACING_FRONT); //ISSUE OCCURS HERE!
}
}
);
return view;
}
/**
* Recommended "safe" way to open the camera.
* #param view
* #return
*/
private boolean safeCameraOpenInView(View view, int camID) {
boolean qOpened = false;
releaseCameraAndPreview();
//mCamera = getCameraInstance(Camera.CameraInfo.CAMERA_FACING_BACK);
mCamera = getCameraInstance(camID);
mCameraView = view;
qOpened = (mCamera != null);
if(qOpened == true){
mPreview = new CameraPreview(getActivity().getBaseContext(), mCamera,view);
FrameLayout preview = (FrameLayout) view.findViewById(R.id.camera_view);
preview.addView(mPreview);
mPreview.startCameraPreview();
}
return qOpened;
}
/**
* Safe method for getting a camera instance.
* #return
*/
public static Camera getCameraInstance(int camID){
Camera c = null;
try {
c = Camera.open(camID); // attempt to get a Camera instance
}
catch (Exception e){
e.printStackTrace();
}
return c; // returns null if camera is unavailable
}
#Override
public void onPause() {
super.onPause();
}
#Override
public void onDestroy() {
super.onDestroy();
releaseCameraAndPreview();
}
/**
* Clear any existing preview / camera.
*/
private void releaseCameraAndPreview() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
if(mPreview != null){
mPreview.destroyDrawingCache();
mPreview.mCamera = null;
}
}
/**
* Surface on which the camera projects it's capture results. This is derived both from Google's docs and the
* excellent StackOverflow answer provided below.
*
* Reference / Credit: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
*/
class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
// SurfaceHolder
private SurfaceHolder mHolder;
// Our Camera.
private Camera mCamera;
// Parent Context.
private Context mContext;
// Camera Sizing (For rotation, orientation changes)
private Camera.Size mPreviewSize;
// List of supported preview sizes
private List<Camera.Size> mSupportedPreviewSizes;
// Flash modes supported by this camera
private List<String> mSupportedFlashModes;
// View holding this camera.
private View mCameraView;
public CameraPreview(Context context, Camera camera, View cameraView) {
super(context);
// Capture the context
mCameraView = cameraView;
mContext = context;
setCamera(camera);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setKeepScreenOn(true);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
/**
* Begin the preview of the camera input.
*/
public void startCameraPreview()
{
try{
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
}
catch(Exception e){
e.printStackTrace();
}
}
/**
* Extract supported preview and flash modes from the camera.
* #param camera
*/
private void setCamera(Camera camera)
{
// Source: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
mCamera = camera;
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
mSupportedFlashModes = mCamera.getParameters().getSupportedFlashModes();
// Set the camera to Auto Flash mode.
if (mSupportedFlashModes != null && mSupportedFlashModes.contains(Camera.Parameters.FLASH_MODE_AUTO)){
Camera.Parameters parameters = mCamera.getParameters();
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
parameters.setRotation(90);
//parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
}
requestLayout();
}
/**
* The Surface has been created, now tell the camera where to draw the preview.
* #param holder
*/
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(holder);
//mCam = Camera.open();
//mCam.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Dispose of the camera preview.
* #param holder
*/
public void surfaceDestroyed(SurfaceHolder holder) {
if (mCamera != null){
mCamera.stopPreview();
}
}
/**
* React to surface changed events
* #param holder
* #param format
* #param w
* #param h
*/
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
//Log.e(TAG, "surfaceChanged => w=" + w + ", h=" + 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 (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
//mCamera.release();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or reformatting changes here
// start preview with new settings
try {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
parameters.setRotation(90);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mHolder);
mCamera.enableShutterSound(true);
mCamera.startPreview();
} catch (Exception e){
//Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
/**
* Calculate the measurements of the layout
* #param widthMeasureSpec
* #param heightMeasureSpec
*/
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
/*
// Source: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null){
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
*/
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
float ratio;
if(mPreviewSize.height >= mPreviewSize.width)
ratio = (float) mPreviewSize.height / (float) mPreviewSize.width;
else
ratio = (float) mPreviewSize.width / (float) mPreviewSize.height;
// One of these methods should be used, second method squishes preview slightly
setMeasuredDimension(width, (int) (width * ratio));
// setMeasuredDimension((int) (width * ratio), height);
}
/**
* Update the layout based on rotation and orientation changes.
* #param changed
* #param left
* #param top
* #param right
* #param bottom
*/
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom)
{
// Source: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
if (changed) {
final int width = right - left;
final int height = bottom - top;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null){
Display display = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
switch (display.getRotation())
{
case Surface.ROTATION_0:
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
mCamera.setDisplayOrientation(90);
break;
case Surface.ROTATION_90:
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
break;
case Surface.ROTATION_180:
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
break;
case Surface.ROTATION_270:
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
mCamera.setDisplayOrientation(180);
break;
}
}
final int scaledChildHeight = previewHeight * width / previewWidth;
mCameraView.layout(0, height - scaledChildHeight, width, height);
}
}
/**
*
* #param sizes
* #param width
* #param height
* #return
*/
private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int width, int height)
{
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) height / width;
if (sizes == null)
return null;
Camera.Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = height;
for (Camera.Size size : sizes) {
double ratio = (double) size.height / size.width;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Camera.Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
}
/**
* Picture Callback for handling a picture capture and saving it out to a file.
*/
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null){
Toast.makeText(getActivity(), "Image retrieval failed.", Toast.LENGTH_SHORT)
.show();
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
};
/**
* Used to return the camera File output.
* #return
*/
private File getOutputMediaFile(){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "Pocket Booth");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("Camera Guide", "Required media storage does not exist");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
//DialogHelper.showDialog( "Success!","Your picture has been saved!",getActivity());
return mediaFile;
}
}

Well, Here I'm going to write a tutorial for you about capturing an
image using Camera by enabling some common features of camera.
Step 1 : Create a preview class
/**
* A basic Camera preview class
*/
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
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 (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
startPreview();
}
public void resetCamera(Camera camera) {
mCamera = camera;
}
public void startPreview() {
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
Step 2 : Use FrameLayout to hold the preview.
<FrameLayout
android:id="#+id/cameraPreview"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
Step 3 : Get the camera and send to the preview class. you may need to set the parameters that you need prior passing the camera.
/**
* Create our Preview view and set it as the content of UI.
*/
private void initCameraPreview(final int cameraId, final boolean createPreview) {
mCamera = getCameraInstance(cameraId);
setupCameraParameters(cameraId);
if (createPreview) {
mPreview = new CameraPreview(this, mCamera);
mPreviewHolder.addView(mPreview);
}
mReadyToCapture = true;
}
/**
* A safe way to get an instance of the Camera object.
*/
private Camera getCameraInstance(int cameraId) {
Camera c = null;
try {
c = Camera.open(cameraId); // attempt to get a Camera instance
} catch (Exception e) {
e.printStackTrace();
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
/**
* Measure and Setup the camera parameters.
*/
private void setupCameraParameters(int cameraId) {
boolean hasFlash;
Camera.Parameters parameters = mCamera.getParameters();
mPreviewSize = determineBestPreviewSize(parameters);
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
Camera.Size bestPictureSize = determineBestPictureSize(parameters);
parameters.setPictureSize(bestPictureSize.width, bestPictureSize.height);
hasFlash = Util.hasSystemFeature(this, PackageManager.FEATURE_CAMERA_FLASH);
if (mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
hasFlash = Util.hasFrontCameraFlash(parameters);
} else {
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
}
if (hasFlash)
parameters.setFlashMode(mFlashMode);
int[] orientations = Util.getCameraDisplayOrientation(this, cameraId);
mDisplayOrientation = orientations[0];
mLayoutOrientation = orientations[1];
mCamera.setDisplayOrientation(mDisplayOrientation);
mCamera.setParameters(parameters);
}
private Camera.Size determineBestPreviewSize(Camera.Parameters parameters) {
List<Camera.Size> sizes = parameters.getSupportedPreviewSizes();
return determineBestSize(sizes);
}
private Camera.Size determineBestPictureSize(Camera.Parameters parameters) {
List<Camera.Size> sizes = parameters.getSupportedPictureSizes();
return determineBestSize(sizes);
}
private Camera.Size determineBestSize(List<Camera.Size> sizes) {
Camera.Size bestSize = null;
for (Camera.Size currentSize : sizes) {
boolean isDesiredRatio = (currentSize.width / 4) == (currentSize.height / 3);
boolean isBetterSize = (bestSize == null || currentSize.width > bestSize.width);
boolean isInBounds = currentSize.width <= PICTURE_SIZE_MAX_WIDTH;
if (isDesiredRatio && isInBounds && isBetterSize) {
bestSize = currentSize;
}
}
if (bestSize == null) {
return sizes.get(0);
}
return bestSize;
}
Step 4 : Writing method for swapping camera
/**
* Swapping between system cameras
*/
private void swapCamera() {
if (!(Camera.getNumberOfCameras() > 1)) {
/* No front facing camera to switch.*/
return;
}
mReadyToCapture = false;
mCamera.stopPreview();
releaseCamera(false);
if (mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK)
mCurrentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
else
mCurrentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
initCameraPreview(mCurrentCameraId, false);
mPreview.resetCamera(mCamera);
mPreview.startPreview();
}
Step 5 : Method for toggling flash
/**
* Toggling camera flash to ON/OFF
*/
private void toggleFlash() {
if (Util.hasSystemFeature(this, PackageManager.FEATURE_CAMERA_FLASH)) {
Camera.Parameters parameters = mCamera.getParameters();
if (mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
if (!Util.hasFrontCameraFlash(parameters)) {
/* Front facing camera doesn\'t supported flash. */
return;
}
}
mReadyToCapture = false;
if (Camera.Parameters.FLASH_MODE_ON.equals(parameters.getFlashMode())) {
mFlashMode = Camera.Parameters.FLASH_MODE_OFF;
} else {
mFlashMode = Camera.Parameters.FLASH_MODE_ON;
}
mCameraHandler.post(new Runnable() {
#Override
public void run() {
mCamera.stopPreview();
releaseCamera(false);
initCameraPreview(mCurrentCameraId, false);
mPreview.resetCamera(mCamera);
mPreview.startPreview();
}
});
} else {
/* warning_no_flash */
}
}
Step 6: Methods for handling camera during the states changes of a screen
/**
* Release the camera for other applications
*/
private void releaseCamera(boolean remove) {
if (mCamera != null) {
if (remove)
mPreview.getHolder().removeCallback(mPreview);
mCamera.release();
mCamera = null;
}
}
Step 7: Utility classes.
/**
* Check whether the given feature available in s/m
*
* #return Returns true if the devices supports the feature, else
* false.
*/
public static boolean hasSystemFeature(Context context, String feature) {
return context.getPackageManager().hasSystemFeature(feature);
}
/**
* Check whether front camera flash feature available in s/m
*/
public static boolean hasFrontCameraFlash(Camera.Parameters cameraParameters) {
boolean result = true;
if (cameraParameters.getFlashMode() == null) {
result = false;
}
List<String> supportedFlashModes = cameraParameters.getSupportedFlashModes();
if (supportedFlashModes == null || supportedFlashModes.isEmpty()
|| supportedFlashModes.size() == 1 &&
supportedFlashModes.get(0).equals(Camera.Parameters.FLASH_MODE_OFF)) {
result = false;
}
return result;
}
/**
* Showing camera in the same orientation as the display
*/
public static int[] getCameraDisplayOrientation(Activity activity,
int cameraId) {
Camera.CameraInfo info =
new Camera.CameraInfo();
Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay()
.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
return new int[]{result, degrees};
}
Step 8: Capturing
// Get an image from the camera
if (null != mCamera && mReadyToCapture) {
mCameraOrientationListener.rememberOrientation();
mCamera.takePicture(mShutter, null, mPicture)
}
/**
* Camera shutter sound callback,
* used to enable sound while capture
*/
private Camera.ShutterCallback mShutter = new Camera.ShutterCallback() {
#Override
public void onShutter() {
}
};
/**
* Camera picture callback
*/
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
mReadyToCapture = false;
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
int rotation = ((mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK ? mDisplayOrientation :
((360 - mDisplayOrientation) % 360)) + mCameraOrientationListener.getRememberedOrientation()
+ mLayoutOrientation) % 360;
if (rotation != 0) {
Matrix matrix = new Matrix();
matrix.postRotate(rotation);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, false);
}
}
};
Step 9: Camera orientation listener for handling image rotation
/**
* Orientation listener to remember the device's orientation when the user presses
* the shutter button.
* <p/>
* The orientation will be normalized to return it in steps of 90 degrees
* (0, 90, 180, 270).
*/
public class CameraOrientationListener extends OrientationEventListener {
private int currentNormalizedOrientation;
private int rememberedNormalizedOrientation;
public CameraOrientationListener(Context context) {
super(context, SensorManager.SENSOR_DELAY_NORMAL);
}
#Override
public void onOrientationChanged(int orientation) {
if (orientation != ORIENTATION_UNKNOWN) {
currentNormalizedOrientation = normalize(orientation);
}
}
private int normalize(int degrees) {
if (degrees > 315 || degrees <= 45) {
return 0;
}
if (degrees > 45 && degrees <= 135) {
return 90;
}
if (degrees > 135 && degrees <= 225) {
return 180;
}
if (degrees > 225 && degrees <= 315) {
return 270;
}
throw new RuntimeException("The physics as we know them are no more. Watch out for anomalies.");
}
public void rememberOrientation() {
rememberedNormalizedOrientation = currentNormalizedOrientation;
}
public int getRememberedOrientation() {
return rememberedNormalizedOrientation;
}
}
Step 10: States handling
#Override
public void onPause() {
super.onPause();
mReadyToCapture = false;
releaseCamera(true);
}
#Override
public void onResume() {
super.onResume();
removePreview();
mReadyToCapture = false;
smoothCameraLoading();
}
private void removePreview() {
mPreviewHolder.removeAllViews();
}
private void smoothCameraLoading() {
mCameraHandler.post(new Runnable() {
#Override
public void run() {
initCameraPreview(mCurrentCameraId, true);
}
});
}
Step 11: Instance variable used
private String mFlashMode = Camera.Parameters.FLASH_MODE_OFF;
private int mCurrentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
private int mDisplayOrientation;
private int mLayoutOrientation;
private boolean mReadyToCapture = false;
private Camera.Size mPreviewSize;
private FrameLayout mPreviewHolder;
private Camera mCamera;
private CameraPreview mPreview;
private Handler mCameraHandler;
private CameraOrientationListener mCameraOrientationListener;
private FrameLayout mRootView;

In my camera app, it works with somethings different from yours:
1. Open camera when surfaceCreated.
2. StartPreview and no stopPreview in surfaceChanged.
3. Release camera in surfaceDestoryed.
To change the camera, simply set the surfaceView to INVISIBLE, then set your camera parameters, then set the surfaceView to VISIBLE again. In my app, I only do it like this:
mbtCamera.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(cameraMax > 1){
mSurfaceView.setVisibility(View.INVISIBLE);
if(mCameraParam.isZoomSupported()) cameraZoomRatios.clear();
if(cameraUsing == 0) cameraUsing = 1; else cameraUsing = 0;
mCameraOverlayView.setScaleFactor(1.0f);
mSurfaceView.setVisibility(View.VISIBLE);
}
}
});
Hope this will help!
The complete callback:
class CameraSurfaceHolderCallback implements SurfaceHolder.Callback {
#Override
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open(cameraUsing);
mCameraParam = mCamera.getParameters();
supportFlashMode = mCameraParam.getSupportedFlashModes();
if(supportFlashMode == null) mbtFlash.setVisibility(View.INVISIBLE);
android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(cameraUsing, info);
int rotation = 0;
if (info.facing == CameraInfo.CAMERA_FACING_FRONT){
rotation = (info.orientation - rt + 360) % 360;
if(mCameraParam.getSupportedFlashModes() == null) mbtFlash.setVisibility(View.INVISIBLE);
}
else{ // back-facing camera
rotation = (info.orientation + rt) % 360;
mbtFlash.setVisibility(View.VISIBLE);
if(flashMode.equals(Camera.Parameters.FLASH_MODE_AUTO)) icons[0] = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_flash_automatic);
else if(flashMode.equals(Camera.Parameters.FLASH_MODE_OFF)) icons[0] = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_flash_off);
else if(flashMode.equals(Camera.Parameters.FLASH_MODE_ON)) icons[0] = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_flash_on);
Matrix rot = new Matrix();
rot.setRotate(360-rt, icons[0].getWidth()/2, icons[0].getHeight()/2);
icons[0] = Bitmap.createBitmap(icons[0], 0, 0, icons[0].getWidth(), icons[0].getHeight(), rot, true);
mbtFlash.setImageBitmap(icons[0]);
mCameraParam.setFlashMode(flashMode);
}
if(mCameraParam.isZoomSupported()){
cameraZoomRatios = mCameraParam.getZoomRatios();
mCameraOverlayView.setMaxScaleFactor(cameraZoomRatios.get(mCameraParam.getMaxZoom())/100f);
}else mCameraOverlayView.setMaxScaleFactor(1.0f);
List<Size> ss = mCameraParam.getSupportedPictureSizes();
Size maxResolution = ss.get(0);
long pixel1, pixel2;
pixel1 = maxResolution.width * maxResolution.height;
for(int i=0; i<ss.size(); i++){
pixel2 = ss.get(i).width * ss.get(i).height;
if(pixel2 > pixel1){
maxResolution = ss.get(i);
pixel1 = pixel2;
}
}
mCameraParam.setPictureSize(maxResolution.width, maxResolution.height);
mCameraParam.setJpegQuality(100);
LayoutParams rlParams = (LayoutParams) mSurfaceView.getLayoutParams();
WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
Display dp = wm.getDefaultDisplay();
DisplayMetrics dm = new DisplayMetrics();
dp.getMetrics(dm);
float dpiScale = dm.density;
float wScaleFactor = (dm.widthPixels-10*dpiScale)/maxResolution.height;
float hScaleFactor = (dm.heightPixels-mllTopButtons.getHeight()-mllBotButtons.getHeight()-10*dpiScale)/maxResolution.width;
if(wScaleFactor < hScaleFactor){
rlParams.width = (int) (dm.widthPixels - 10*dpiScale);
rlParams.height = (int) (maxResolution.width * wScaleFactor);
}else{
rlParams.width = (int) (maxResolution.height * hScaleFactor);
rlParams.height = (int) (dm.heightPixels-mllTopButtons.getHeight()-mllBotButtons.getHeight()-10*dpiScale);
}
mSurfaceView.setLayoutParams(rlParams);
mCameraOverlayView.setLayoutParams(rlParams);
ss = mCameraParam.getSupportedJpegThumbnailSizes();
float photoAspectRatio, thumbAspectRatio;
photoAspectRatio = (float)maxResolution.width / maxResolution.height;
thumbAspectRatio = 0;
pixel1 = 0;
for(int i=0; i<ss.size(); i++){
if(ss.get(i).height != 0) thumbAspectRatio = (float)ss.get(i).width / ss.get(i).height;
if(thumbAspectRatio == photoAspectRatio){
if(pixel1 == 0)
{
maxResolution = ss.get(i);
pixel1 = ss.get(i).width * ss.get(i).height;
}else{
pixel2 = ss.get(i).width * ss.get(i).height;
if((pixel2 < pixel1)&&(pixel2 != 0)){
maxResolution = ss.get(i);
pixel1 = pixel2;
}
}
}
}
if(pixel1 != 0){
mCameraParam.setJpegThumbnailSize(maxResolution.width, maxResolution.height);
mCameraParam.setJpegThumbnailQuality(100);
}
List<String> focusModes = mCameraParam.getSupportedFocusModes();
if(focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)){
mCameraParam.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
focusingColor = Color.YELLOW;
}
int minEv = mCameraParam.getMinExposureCompensation();
int maxEv = mCameraParam.getMaxExposureCompensation();
if((minEv == 0)&&(maxEv == 0)) mCameraOverlayView.setEVCompensate(false);
else mCameraOverlayView.setEVCompensate(minEv, maxEv);
mCameraParam.setRotation(rotation);
mCamera.setParameters(mCameraParam);
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
try {
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mSurfaceView.getHolder());
List<Size> ss = mCameraParam.getSupportedPreviewSizes();
Size maxResolution = ss.get(0);
long pixel1, pixel2;
float photoAspectRatio, previewAspectRatio;
photoAspectRatio = (float)mCameraParam.getPictureSize().width / mCameraParam.getPictureSize().height;
previewAspectRatio = 0;
pixel1 = 0;
for(int i=0; i<ss.size(); i++){
if(ss.get(i).height != 0) previewAspectRatio = (float)ss.get(i).width / ss.get(i).height;
if(previewAspectRatio == photoAspectRatio){
if(pixel1 == 0)
{
maxResolution = ss.get(i);
pixel1 = ss.get(i).width * ss.get(i).height;
}else{
pixel2 = ss.get(i).width * ss.get(i).height;
if(pixel2 > pixel1){
maxResolution = ss.get(i);
pixel1 = pixel2;
}
}
}
}
if(pixel1 != 0) mCameraParam.setPreviewSize(maxResolution.width, maxResolution.height);
mCamera.setParameters(mCameraParam);
mCamera.startPreview();
}
catch(Exception e){}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
}
}
I used it in activity and no fragment. I am not sure this will make something different.

I think that there is a little problem in the safeCameraOpenInView method and that is:
Your new camera view is made under the frozen picture.
So you should edit this line: preview.addView(mPreview);
as this: preview.addView(mPreview, preview.getChildCount());
Or you can first delete the previous camera view and then add new one :
preview.removeAllViews();
preview.addView(mPreview);
Hope that this will work.

camera2 preview with SurfaceTexture works perfectly in SDK v21, but stays black in v23

I test SDK v21 on a Samsung Galaxy A3 (2014), v23 on a Nexus 5X. I tested the Camera2Basic example, too, and it works on both devices. I wonder how my little code restructuring (I use an Activity instead of a Fragment) causes this error on only one of both devices:
// ...
protected void onCreate() {
// setContentView ...
viewfinder = (AutoFitTextureView)findViewById(R.id.viewfinder);
// Choose back camera device, choose maxPictureSize (for JPEG), find out whether dimensions must be swapped
if (!swappedDimensions)
viewfinder.setAspectRatio(maxPictureSize.getWidth(), maxPictureSize.getHeight());
else
viewfinder.setAspectRatio(maxPictureSize.getHeight(), maxPictureSize.getWidth());
// initialize image reader
}
protected void onResume() {
if (viewfinder.isAvailable()) {
// Alternative to call in onSurfaceTextureAvailable()
init();
}
else {
viewfinder.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
public void onSurfaceTextureAvailable(SurfaceTexture texture, int width, int height) {
Log.d(tag(), "surfaceTexture available: " + width + " x " + height);
configureSurface(width, height);
init();
}
public void onSurfaceTextureSizeChanged(SurfaceTexture texture, int width, int height) {
Log.d(tag(), "surfaceTexture size changed: " + width + " x " + height);
// Currently, don't react to changes. In opposite to the surface change listener, this method is not called after onSurfaceTextureAvailable and only needs to be implemented if the texture view size will change during the app is running
}
public boolean onSurfaceTextureDestroyed(SurfaceTexture texture) {
Log.d(tag(), "surfaceTexture destroyed");
return true;
}
public void onSurfaceTextureUpdated(SurfaceTexture texture) {
Log.d(tag(), "surfaceTexture updated");
}
});
}
try {
if (!openCloseLock.tryAcquire(2500, TimeUnit.MILLISECONDS)) {
throw new RuntimeException("Time out waiting to lock camera opening.");
}
cameraManager.openCamera(deviceId, new CameraDevice.StateCallback() {
#Override
public void onOpened(CameraDevice camera) {
openCloseLock.release();
device = camera;
init();
}
// ...
}, null);
}
catch(InterruptedException e) {
// ...
}
}
protected void configureSurface(int view_width, int view_height) {
SurfaceTexture surfaceTexture = viewfinder.getSurfaceTexture();
if (surfaceTexture == null)
return;
// Can this be changed after the session has been started?:
Size rotatedSurfaceSize = swappedDimensions
? new Size(view_height, view_width)
: new Size(view_width, view_height);
Size previewSize = bestOutputSize(SurfaceTexture.class, rotatedSurfaceSize, Sizes.aspectRatio(maxPictureSize));
Log.i(tag(), "Preview size for " + rotatedSurfaceSize + " (" + Sizes.aspectRatio(maxPictureSize) + ":1): "+previewSize);
surfaceTexture.setDefaultBufferSize(previewSize.getWidth(), previewSize.getHeight());
//
// Copied from Camera2Basic, just changed var names:
int rotation = getWindowManager().getDefaultDisplay().getRotation();
Matrix matrix = new Matrix();
RectF viewRect = new RectF(0, 0, view_width, view_height);
RectF bufferRect = new RectF(0, 0, previewSize.getHeight(), previewSize.getWidth());
float centerX = viewRect.centerX();
float centerY = viewRect.centerY();
if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
float scale = Math.max(
(float) view_height / previewSize.getHeight(),
(float) view_width / previewSize.getWidth());
matrix.postScale(scale, scale, centerX, centerY);
matrix.postRotate(90 * (rotation - 2), centerX, centerY);
} else if (Surface.ROTATION_180 == rotation) {
matrix.postRotate(180, centerX, centerY);
}
viewfinder.setTransform(matrix);
//
}
/**
* Prerequisites:
* - The device must be opened.
* - The surface texture must be available.
*/
protected void init() {
// Executed only after second call, loadingState makes sure both prerequisites are true
if (++loadingState != 2)
return;
final CameraDevice d = device;
final Surface surface = new Surface(viewfinder.getSurfaceTexture());
try {
previewRequestBuilder = d.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
previewRequestBuilder.addTarget(surface);
} catch (CameraAccessException e) {
e.printStackTrace();
}
CameraCaptureSession.StateCallback cb = new CameraCaptureSession.StateCallback() {
#Override
public void onConfigured(CameraCaptureSession cameraCaptureSession) {
// The camera is already closed
if (d == null) {
return;
}
Log.d(tag(), "Configured!");
// When the session is ready, we start displaying the preview.
captureSession = cameraCaptureSession;
try {
Log.d(tag(), "Surface: " + surface);
previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_OFF);
previewRequest = previewRequestBuilder.build();
captureSession.setRepeatingRequest(previewRequest, previewCallback, null);
Log.d(tag(), "Preview started!");
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
#Override
public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) {
Log.e(tag(), "Configure failed!");
}
};
try {
d.createCaptureSession(Arrays.asList(surface, imageReader.getSurface()), cb, null);
Log.d(tag(), "Session started");
}
catch (CameraAccessException e) {
}
}
// ...
My own log output is the same on both devices without errors or exceptions thrown, both CameraCaptureSession.CaptureCallback.onCaptureCompleted and TextureView.SurfaceTextureListener.onSurfaceTextureUpdated are regularly called. (Probably there are entries from the camera service that will tell another story, but then those errors should be reflected by explicit errors thrown in the activity.)
The preview is only live on my Samsung device, on my Nexus it has the right size but stays black.

I had a same issue ever.
I used same code you coded.
As you know, viewfinder.isavailable() returns false.
Finally I found out AutoTextureView class is not available in API level 23.
So you should create new TextureView class which is available in API level 23.

Android custom camera setFocusAreas and setMeteringAreas not work on Samsung Devices

Maybe this question duplicate another question, but others i have not found a solution. I'm trying to write a custom android camera and the camera works fine on my device(HTC One).I tried some different devices, and works in one of them. but I'm having problems on Samsung devices. Do not turn off the autofocus feature on the device. Therefore, the device can not change the focus area. That is my touch event.
#Override
public boolean onTouchEvent(final MotionEvent event){
Camera.Parameters cameraParameters = camera.getParameters();
if (event.getAction() == MotionEvent.ACTION_UP){
focusAreas.clear();
meteringAreas.clear();
Rect focusRect = calculateTapArea(event.getX(), event.getY(), 1f);
Rect meteringRect = calculateTapArea(event.getX(), event.getY(), 1.5f);
focusAreas.add(new Camera.Area(focusRect, 800));
meteringAreas.add(new Camera.Area(meteringRect, 800));
cameraParameters.setFocusAreas(focusAreas);
cameraParameters.setMeteringAreas(meteringAreas);
cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_MACRO);
try{
camera.setParameters(cameraParameters);
} catch(Exception e){
Log.e("Focus problem", e.toString());
return false;
}
camera.autoFocus(new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
camera.cancelAutoFocus();
Camera.Parameters params = camera.getParameters();
if(params.getFocusMode() != Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE){
params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
camera.setParameters(params);
}
}
});
focusSound = new MediaPlayer();
showSquareFocus();
try {
AssetFileDescriptor descriptor = this.getApplicationContext().getAssets()
.openFd("focus.wav");
focusSound.setDataSource(descriptor.getFileDescriptor(),
descriptor.getStartOffset(), descriptor.getLength());
descriptor.close();
focusSound.prepare();
focusSound.setLooping(false);
focusSound.start();
focusSound.setVolume(10,10);
focusSound.setOnCompletionListener(new OnCompletionListener(){
public void onCompletion(MediaPlayer mp){
mp.release();
}
});
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return true;
}
Maybe need this code...
private Rect calculateTapArea(float x, float y, float coefficient) {
int areaSize = Float.valueOf(FOCUS_AREA_SIZE * coefficient).intValue();
int left = clamp((int) x - areaSize / 2, 0, width - areaSize);
int top = clamp((int) y - areaSize / 2, 0, height - areaSize);
RectF rectF = new RectF(left, top, left + areaSize, top + areaSize);
matrix.mapRect(rectF);
return new Rect(Math.round(rectF.left), Math.round(rectF.top), Math.round(rectF.right), Math.round(rectF.bottom));
}
private int clamp(int x, int min, int max) {
if (x > max) {
return max;
}
if (x < min) {
return min;
}
return x;
}

I've experienced the same problem in a Samsung Galaxy S3.
The solution I've found (even if its dirty) is to set an alternative focus mode before the desired one.
private void setFocusMode(final Camera camera, final String newFocusMode)
{
// Apply an alternative focus mode
Camera.Parameters parameters = camera.getParameters();
final List<String> focusModes = parameters.getSupportedFocusModes();
if (focusModes.contains(Parameters.FOCUS_MODE_FIXED) && newFocusMode.compareToIgnoreCase(Parameters.FOCUS_MODE_FIXED) == false)
{
parameters.setFocusMode(Parameters.FOCUS_MODE_FIXED);
}
else if (focusModes.contains(Parameters.FOCUS_MODE_INFINITY) && newFocusMode.compareToIgnoreCase(Parameters.FOCUS_MODE_INFINITY) == false)
{
parameters.setFocusMode(Parameters.FOCUS_MODE_INFINITY);
}
else if (focusModes.contains(Parameters.FOCUS_MODE_MACRO) && newFocusMode.compareToIgnoreCase(Parameters.FOCUS_MODE_MACRO) == false)
{
parameters.setFocusMode(Parameters.FOCUS_MODE_MACRO);
}
else if (focusModes.contains(Parameters.FOCUS_MODE_AUTO) && newFocusMode.compareToIgnoreCase(Parameters.FOCUS_MODE_AUTO) == false)
{
parameters.setFocusMode(Parameters.FOCUS_MODE_AUTO);
}
camera.setParameters(parameters);
// Now apply the desired focus mode
parameters = camera.getParameters();
parameters.setFocusMode(newFocusMode);
camera.setParameters(parameters);
}

Android Camera Focus Mode

I am trying to make a custom camera application
I want to let the users can choose the focus mode in this application.
The focus mode is auto and touch-to-focus
If we want to use touch-to-focus in the camera , how can be start with?

The feature is software/hardware/manufacture dependent, my suggestion is that you first find a phone like Galaxy Nexus flashed with Android 4.x, then try the android.hardware.Camera.Parameters.getMaxNumFocusAreas() on it, if the return value is greater than zero then you are lucky, and can then use the setFocusAreas() to implement your "touch to focus" feature.
Why:
In old Android versions there is no public API to set the focus areas. Although many manufacturers managed to create their own API and implementation, they won't share.
Android introduced the focus areas API in API level 14, however the phone manufacturers may choose not to implement it (i.e. choose to stick to their own solutions). To check if the API is supported you can call getMaxNumFocusAreasa() first, if it returns a positive integer that means the phone does implement the API and you can go on enabling the "touch focus" feature in your camera app. (The API is also one of the enablers of the "face detection" feature, when faces are recognized the camera app uses the API to let the camera do auto focus on the them.)
You may refer to the vanilla Android Camera app source code for how to use the API properly.
References:
Android Camera API
getMaxNumFocusAreas()
setFocusAreas()
Android 4.0 Camera app source code
mInitialParams.getMaxNumFocusAreas()
mParameters.setFocusAreas()
Regards
Ziteng Chen

Try this:
public void takePhoto(File photoFile, String workerName, int width, int height, int quality) {
if (getAutoFocusStatus()){
camera.autoFocus(new AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
});
}else{
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
However, I've also seen this to work, possibly more accurately:
if (getAutoFocusStatus()){
camera.autoFocus(new AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
if(success) camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
});
}else{
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
The last one takes the picture at the moment the focussing is successfully completed. It works very well for using with QR scanning codes. I believe the same applies to cases like this.

It is already implemented buthow to modify this if I want to add touch to focus?
public void takePhoto(File photoFile, String workerName, int width, int height, int quality) {
if (getAutoFocusStatus()){
camera.autoFocus(new AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
});
}else{
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
this.photoFile = photoFile;
this.workerName = workerName;
this.imageOutputWidth = width;
this.imageOutputHeight = height;
}
public void takePhoto(File photoFile, int width, int height, int quality) {
takePhoto(photoFile, null, width, height, quality);
}

I was trying to implement focus functionality in my app and achieved this functionality in the way i wanted. To implement Touch to Focus please refer the code below.
CameraPreview.java
public class CameraPreview extends SurfaceView implements
SurfaceHolder.Callback {
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
private OnFocusListener onFocusListener;
private boolean needToTakePic = false;
private Camera.AutoFocusCallback myAutoFocusCallback = new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean arg0, Camera arg1) {
if (arg0) {
mCamera.cancelAutoFocus();
}
}
};
// Constructor that obtains context and camera
#SuppressWarnings("deprecation")
public CameraPreview(Context context, Camera camera) {
super(context);
this.mCamera = camera;
this.mSurfaceHolder = this.getHolder();
this.mSurfaceHolder.addCallback(this);
this.mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
this.onFocusListener = (OnFocusListener) context;
}
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
try {
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.getParameters().setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
mCamera.setDisplayOrientation(90);
mCamera.startPreview();
} catch (IOException e) {
// left blank for now
e.printStackTrace();
}
}
#Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
mCamera.stopPreview();
this.mSurfaceHolder.removeCallback(this);
mCamera.release();
}
#Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int format,
int width, int height) {
// start preview with new settings
try {
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
} catch (Exception e) {
// intentionally left blank for a test
e.printStackTrace();
}
}
/**
* Called from PreviewSurfaceView to set touch focus.
*
* #param - Rect - new area for auto focus
*/
public void doTouchFocus(final Rect tfocusRect) {
try {
List<Camera.Area> focusList = new ArrayList<Camera.Area>();
Camera.Area focusArea = new Camera.Area(tfocusRect, 1000);
focusList.add(focusArea);
Camera.Parameters param = mCamera.getParameters();
param.setFocusAreas(focusList);
param.setMeteringAreas(focusList);
mCamera.setParameters(param);
mCamera.autoFocus(myAutoFocusCallback);
} catch (Exception e) {
e.printStackTrace();
}
if (isNeedToTakePic()) {
onFocusListener.onFocused();
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
float x = event.getX();
float y = event.getY();
Rect touchRect = new Rect(
(int) (x - 100),
(int) (y - 100),
(int) (x + 100),
(int) (y + 100));
final Rect targetFocusRect = new Rect(
touchRect.left * 2000 / this.getWidth() - 1000,
touchRect.top * 2000 / this.getHeight() - 1000,
touchRect.right * 2000 / this.getWidth() - 1000,
touchRect.bottom * 2000 / this.getHeight() - 1000);
doTouchFocus(targetFocusRect);
}
return false;
}
public boolean isNeedToTakePic() {
return needToTakePic;
}
public void setNeedToTakePic(boolean needToTakePic) {
this.needToTakePic = needToTakePic;
}
}
MainActivity.java
public class MainActivity extends Activity
implements OnFocusListener {
private Button captureButton, switchCameraButton;
private Camera mCamera;
private CameraPreview mCameraPreview;
private int currentCameraId;
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (getIntent().hasExtra("camera_id")) {
currentCameraId = getIntent().getIntExtra("camera_id", Camera.CameraInfo.CAMERA_FACING_BACK);
} else {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
}
captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(final View v) {
// Obtain MotionEvent object
v.setEnabled(false);
mCameraPreview.setNeedToTakePic(true);
long downTime = SystemClock.uptimeMillis();
long eventTime = SystemClock.uptimeMillis() + 100;
float x = mCameraPreview.getWidth() / 2;
float y = mCameraPreview.getHeight() / 2;
// List of meta states found here: developer.android.com/reference/android/view/KeyEvent.html#getMetaState()
int metaState = 0;
MotionEvent motionEvent = MotionEvent.obtain(
downTime,
eventTime,
MotionEvent.ACTION_DOWN,
x,
y,
metaState
);
// Dispatch touch event to view
mCameraPreview.dispatchTouchEvent(motionEvent);
}
});
switchCameraButton = (Button) findViewById(R.id.button_switch_camera);
switchCameraButton.setVisibility(
Camera.getNumberOfCameras() > 1 ? View.VISIBLE : View.GONE);
switchCameraButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mCamera.stopPreview();
//NB: if you don't release the current camera before switching, you app will crash
mCameraPreview.getHolder().removeCallback(mCameraPreview);
mCamera.release();
//swap the id of the camera to be used
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK) {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
} else {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
}
mCamera = getCameraInstance(currentCameraId);
mCameraPreview = new CameraPreview(MainActivity.this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.removeAllViews();
preview.addView(mCameraPreview);
}
});
}
#Override
protected void onResume() {
super.onResume();
mCamera = getCameraInstance(currentCameraId);
mCameraPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mCameraPreview);
}
/**
* Helper method to access the camera returns null if it cannot get the
* camera or does not exist
*
* #return
*/
private Camera getCameraInstance(int currentCameraId) {
Camera camera = null;
try {
camera = Camera.open(currentCameraId);
} catch (Exception e) {
// cannot get camera or does not exist
}
return camera;
}
Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
};
private static File getOutputMediaFile() {
File mediaStorageDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
"MyCameraApp");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
// String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
// .format(new Date());
File mediaFile;
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + "DEMO_" + ".jpg");
if (mediaFile.exists()) mediaFile.delete();
return mediaFile;
}
#Override
public void onFocused() {
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
mCamera.takePicture(null, null, mPicture);
mCameraPreview.setNeedToTakePic(false);
captureButton.setEnabled(true);
}
}, 1500);
}
}
activity_main.xml
<?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">
<FrameLayout
android:id="#+id/camera_preview"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<Button
android:id="#+id/button_switch_camera"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Switch Camera" />
<Button
android:id="#+id/button_capture"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Capture" />
</LinearLayout>
You can find sample app on Github - Custom Camera App

Call this to enable Touch-To-Focus mode:
private void setTouchToFocusMode(Camera.Parameters parameters){
String focusMode;
if (parameters.getSupportedFocusModes().contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
focusMode = Camera.Parameters.FOCUS_MODE_AUTO;
}
if (focusMode != null && focusMode.length() > 0){
parameters.setFocusMode(focusMode);
}
}
When user taps on screen, call this below to set focus area:
private static final int FOCUS_WIDTH = 80;
private static final int FOCUS_HEIGHT = 80;
public static String setFocalPoint(Camera.Parameters params, int x, int y){
String focusMode = "";
if (params != null && params.getMaxNumFocusAreas() > 0) {
List<Camera.Area> focusArea = new ArrayList<Camera.Area>();
focusArea.add(new Camera.Area(new Rect(x, y, x + FOCUS_WIDTH, y + FOCUS_HEIGHT), 1000));
params.setFocusAreas(focusArea);
if(params.getMaxNumMeteringAreas() > 0) {
params.setMeteringAreas(focusArea);
}
if(params.getSupportedFocusModes().contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
focusMode = Camera.Parameters.FOCUS_MODE_AUTO;
}
}
return focusMode;
}
Call autoFocus/cancelAutoFocus for action:
mCamera.cancelAutoFocus();
mCamera.autoFocus(mAutoFocusCallback);