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Make things safer
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1. Fallback for requested camera
2. Not crashing when taking pictures at the wrong time
3. Callback for state changes - to be able to take actions only when actually ready
4. Query for modes, like is flash available?
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@danielgindi
danielgindi committed May 1, 2017
1 parent a558930 commit c118ad0
Showing 1 changed file with 115 additions and 17 deletions.
132 changes: 115 additions & 17 deletions ...main/java/com/google/android/gms/samples/vision/barcodereader/ui/camera/CameraSource.java
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Original file line number Diff line number Diff line change
Expand Up @@ -91,6 +91,14 @@ public class CameraSource {
*/
private static final float ASPECT_RATIO_TOLERANCE = 0.01f;

public CameraSourceStateListener getStateListener() {
return mStateListener;
}

public void setStateListener(CameraSourceStateListener stateListener) {
this.mStateListener = stateListener;
}

@StringDef({
Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE,
Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO,
Expand Down Expand Up @@ -122,11 +130,16 @@ public class CameraSource {

private int mFacing = CAMERA_FACING_BACK;

private boolean mCameraFallbackAllowed = true;

private CameraSourceStateListener mStateListener = null;

/**
* Rotation of the device, and thus the associated preview images captured from the device.
* See {@link Frame.Metadata#getRotation()}.
*/
private int mRotation;
private int mRequestedCameraId;

private Size mPreviewSize;

Expand All @@ -143,7 +156,9 @@ public class CameraSource {
// These instances need to be held onto to avoid GC of their underlying resources. Even though
// these aren't used outside of the method that creates them, they still must have hard
// references maintained to them.
@SuppressWarnings("FieldCanBeLocal")
private SurfaceView mDummySurfaceView;
@SuppressWarnings("FieldCanBeLocal")
private SurfaceTexture mDummySurfaceTexture;

/**
Expand All @@ -153,6 +168,8 @@ public class CameraSource {
private Thread mProcessingThread;
private FrameProcessingRunnable mFrameProcessor;

private boolean mCanTakePicture = false;

/**
* Map to convert between a byte array, received from the camera, and its associated byte
* buffer. We use byte buffers internally because this is a more efficient way to call into
Expand Down Expand Up @@ -240,6 +257,16 @@ public Builder setFacing(int facing) {
return this;
}

/**
* Sets whether fallback from front to back or vice versa is allowed.
* Used in case the requested camera was not available.
* Default: true.
*/
public Builder setCameraFallbackAllowed(boolean allowed) {
mCameraSource.mCameraFallbackAllowed = allowed;
return this;
}

/**
* Creates an instance of the camera source.
*/
Expand Down Expand Up @@ -356,6 +383,11 @@ public CameraSource start() throws IOException {
mFrameProcessor.setActive(true);
mProcessingThread.start();
}

if (mStateListener != null) {
mStateListener.onCameraSourceStarted();
}

return this;
}

Expand All @@ -377,10 +409,17 @@ public CameraSource start(SurfaceHolder surfaceHolder) throws IOException {
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();

mCanTakePicture = true;

mProcessingThread = new Thread(mFrameProcessor);
mFrameProcessor.setActive(true);
mProcessingThread.start();
}

if (mStateListener != null) {
mStateListener.onCameraSourceStarted();
}

return this;
}

Expand Down Expand Up @@ -411,6 +450,8 @@ public void stop() {
// clear the buffer to prevent oom exceptions
mBytesToByteBuffer.clear();

mCanTakePicture = false;

if (mCamera != null) {
mCamera.stopPreview();
mCamera.setPreviewCallbackWithBuffer(null);
Expand All @@ -433,6 +474,10 @@ public void stop() {
mCamera = null;
}
}

if (mStateListener != null) {
mStateListener.onCameraSourceStopped();
}
}

/**
Expand All @@ -450,6 +495,22 @@ public int getCameraFacing() {
return mFacing;
}

/**
* Sets whether fallback from front to back or vice versa is allowed.
* Used in case the requested camera was not available.
*/
public boolean isCameraFallbackAllowed() {
return mCameraFallbackAllowed;
}

public boolean isCameraFacingBackAvailable() {
return getIdForRequestedCamera(CAMERA_FACING_BACK) != -1;
}

public boolean isCameraFacingFrontAvailable() {
return getIdForRequestedCamera(CAMERA_FACING_FRONT) != -1;
}

public int doZoom(float scale) {
synchronized (mCameraLock) {
if (mCamera == null) {
Expand Down Expand Up @@ -494,7 +555,10 @@ public int doZoom(float scale) {
*/
public void takePicture(ShutterCallback shutter, PictureCallback jpeg) {
synchronized (mCameraLock) {
if (mCamera != null) {
if (mCamera != null && mCanTakePicture) {

mCanTakePicture = false; // Preview is suspended until we're done

PictureStartCallback startCallback = new PictureStartCallback();
startCallback.mDelegate = shutter;
PictureDoneCallback doneCallback = new PictureDoneCallback();
Expand Down Expand Up @@ -535,7 +599,8 @@ public boolean setFocusMode(@FocusMode String mode) {
synchronized (mCameraLock) {
if (mCamera != null && mode != null) {
Camera.Parameters parameters = mCamera.getParameters();
if (parameters.getSupportedFocusModes().contains(mode)) {
final List<String> supportedFocusModes = parameters.getSupportedFlashModes();
if (supportedFocusModes != null && supportedFocusModes.contains(mode)) {
parameters.setFocusMode(mode);
mCamera.setParameters(parameters);
mFocusMode = mode;
Expand Down Expand Up @@ -575,7 +640,8 @@ public boolean setFlashMode(@FlashMode String mode) {
synchronized (mCameraLock) {
if (mCamera != null && mode != null) {
Camera.Parameters parameters = mCamera.getParameters();
if (parameters.getSupportedFlashModes().contains(mode)) {
final List<String> supportedFlashModes = parameters.getSupportedFlashModes();
if (supportedFlashModes != null && supportedFlashModes.contains(mode)) {
parameters.setFlashMode(mode);
mCamera.setParameters(parameters);
mFlashMode = mode;
Expand All @@ -587,6 +653,15 @@ public boolean setFlashMode(@FlashMode String mode) {
}
}

public boolean isModeSupported(String mode) {
if (mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
final List<String> supportedModes = parameters.getSupportedFlashModes();
return supportedModes != null && supportedModes.contains(mode);
}
return false;
}

/**
* Starts camera auto-focus and registers a callback function to run when
* the camera is focused. This method is only valid when preview is active
Expand All @@ -600,7 +675,7 @@ public boolean setFlashMode(@FlashMode String mode) {
* <p/>
* <p>If the current flash mode is not
* {@link Camera.Parameters#FLASH_MODE_OFF}, flash may be
* fired during auto-focus, depending on the driver and camera hardware.<p>
* fired during auto-focus, depending on the driver and camera hardware.</p>
*
* @param cb the callback to run
* @see #cancelAutoFocus()
Expand Down Expand Up @@ -699,6 +774,7 @@ public void onPictureTaken(byte[] data, Camera camera) {
synchronized (mCameraLock) {
if (mCamera != null) {
mCamera.startPreview();
mCanTakePicture = true;
}
}
}
Expand Down Expand Up @@ -740,11 +816,23 @@ public void onAutoFocusMoving(boolean start, Camera camera) {
*/
@SuppressLint("InlinedApi")
private Camera createCamera() {
int requestedCameraId = getIdForRequestedCamera(mFacing);
if (requestedCameraId == -1) {
mRequestedCameraId = getIdForRequestedCamera(mFacing);

if (mRequestedCameraId == -1 && mCameraFallbackAllowed) {
if (mFacing == CAMERA_FACING_BACK) {
mFacing = CAMERA_FACING_FRONT;
} else {
mFacing = CAMERA_FACING_BACK;
}

mRequestedCameraId = getIdForRequestedCamera(mFacing);
}

if (mRequestedCameraId == -1) {
throw new RuntimeException("Could not find requested camera.");
}
Camera camera = Camera.open(requestedCameraId);

Camera camera = Camera.open(mRequestedCameraId);

SizePair sizePair = selectSizePair(camera, mRequestedPreviewWidth, mRequestedPreviewHeight);
if (sizePair == null) {
Expand All @@ -770,11 +858,11 @@ private Camera createCamera() {
previewFpsRange[Camera.Parameters.PREVIEW_FPS_MAX_INDEX]);
parameters.setPreviewFormat(ImageFormat.NV21);

setRotation(camera, parameters, requestedCameraId);
setRotation(camera, parameters, mRequestedCameraId);

if (mFocusMode != null) {
if (parameters.getSupportedFocusModes().contains(
mFocusMode)) {
final List<String> supportedFocusModes = parameters.getSupportedFlashModes();
if (supportedFocusModes != null && supportedFocusModes.contains(mFocusMode)) {
parameters.setFocusMode(mFocusMode);
} else {
Log.i(TAG, "Camera focus mode: " + mFocusMode + " is not supported on this device.");
Expand All @@ -785,13 +873,11 @@ private Camera createCamera() {
mFocusMode = parameters.getFocusMode();

if (mFlashMode != null) {
if (parameters.getSupportedFlashModes() != null) {
if (parameters.getSupportedFlashModes().contains(
mFlashMode)) {
parameters.setFlashMode(mFlashMode);
} else {
Log.i(TAG, "Camera flash mode: " + mFlashMode + " is not supported on this device.");
}
final List<String> supportedFlashModes = parameters.getSupportedFlashModes();
if (supportedFlashModes != null && supportedFlashModes.contains(mFlashMode)) {
parameters.setFlashMode(mFlashMode);
} else {
Log.i(TAG, "Camera flash mode: " + mFlashMode + " is not supported on this device.");
}
}

Expand Down Expand Up @@ -972,6 +1058,12 @@ private int[] selectPreviewFpsRange(Camera camera, float desiredPreviewFps) {
return selectedFpsRange;
}

public void updateRotation() {
if (mCamera != null) {
setRotation(mCamera, mCamera.getParameters(), mRequestedCameraId);
}
}

/**
* Calculates the correct rotation for the given camera id and sets the rotation in the
* parameters. It also sets the camera's display orientation and rotation.
Expand Down Expand Up @@ -1211,4 +1303,10 @@ public void run() {
}
}
}

public interface CameraSourceStateListener
{
void onCameraSourceStarted();
void onCameraSourceStopped();
}
}

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