File	Doc	Category	Size	Date	Package
CameraTooActivity.java	API Doc	Android 5.1 API	18591	Thu Mar 12 22:22:42 GMT 2015	com.example.android.camera2.cameratoo

CameraTooActivity

• java.lang.Object
  • android.app.Activity

Fields Summary
static final String	CAPTURE_FILENAME_PREFIX Output files will be saved as /sdcard/Pictures/cameratoo*.jpg
static final String	TAG Tag to distinguish log prints.
android.os.HandlerThread	mBackgroundThread An additional thread for running tasks that shouldn't block the UI.
android.os.Handler	mBackgroundHandler Handler for running tasks in the background.
android.os.Handler	mForegroundHandler Handler for running tasks on the UI thread.
android.view.SurfaceView	mSurfaceView View for displaying the camera preview.
android.media.ImageReader	mCaptureBuffer Used to retrieve the captured image when the user takes a snapshot.
android.hardware.camera2.CameraManager	mCameraManager Handle to the Android camera services.
android.hardware.camera2.CameraDevice	mCamera The specific camera device that we're using.
android.hardware.camera2.CameraCaptureSession	mCaptureSession Our image capture session.
final SurfaceHolder.Callback	mSurfaceHolderCallback Callbacks invoked upon state changes in our {@code SurfaceView}.
final CameraDevice.StateCallback	mCameraStateCallback Calledbacks invoked upon state changes in our {@code CameraDevice}. These are run on {@code mBackgroundThread}.
final CameraCaptureSession.StateCallback	mCaptureSessionListener Callbacks invoked upon state changes in our {@code CameraCaptureSession}. These are run on {@code mBackgroundThread}.
final ImageReader.OnImageAvailableListener	mImageCaptureListener Callback invoked when we've received a JPEG image from the camera.

Constructors Summary

Methods Summary
static android.util.Size	chooseBigEnoughSize(android.util.Size[] choices, int width, int height) Given {@code choices} of {@code Size}s supported by a camera, chooses the smallest one whose width and height are at least as large as the respective requested values. param choices The list of sizes that the camera supports for the intended output class param width The minimum desired width param height The minimum desired height return The optimal {@code Size}, or an arbitrary one if none were big enough // Collect the supported resolutions that are at least as big as the preview Surface List<Size> bigEnough = new ArrayList<Size>(); for (Size option : choices) { if (option.getWidth() >= width && option.getHeight() >= height) { bigEnough.add(option); } } // Pick the smallest of those, assuming we found any if (bigEnough.size() > 0) { return Collections.min(bigEnough, new CompareSizesByArea()); } else { Log.e(TAG, "Couldn't find any suitable preview size"); return choices[0]; }
public void	onClickOnSurfaceView(android.view.View v) Called when the user clicks on our {@code SurfaceView}, which has ID {@code mainSurfaceView} as defined in the {@code mainactivity.xml} layout file. Captures a full-resolution image and saves it to permanent storage. if (mCaptureSession != null) { try { CaptureRequest.Builder requester = mCamera.createCaptureRequest(mCamera.TEMPLATE_STILL_CAPTURE); requester.addTarget(mCaptureBuffer.getSurface()); try { // This handler can be null because we aren't actually attaching any callback mCaptureSession.capture(requester.build(), /*listener*/null, /*handler*/null); } catch (CameraAccessException ex) { Log.e(TAG, "Failed to file actual capture request", ex); } } catch (CameraAccessException ex) { Log.e(TAG, "Failed to build actual capture request", ex); } } else { Log.e(TAG, "User attempted to perform a capture outside our session"); } // Control flow continues in mImageCaptureListener.onImageAvailable()
protected void	onPause() Called when our {@code Activity} loses focus. Tears everything back down. super.onPause(); try { // Ensure SurfaceHolderCallback#surfaceChanged() will run again if the user returns mSurfaceView.getHolder().setFixedSize(/*width*/0, /*height*/0); // Cancel any stale preview jobs if (mCaptureSession != null) { mCaptureSession.close(); mCaptureSession = null; } } finally { if (mCamera != null) { mCamera.close(); mCamera = null; } } // Finish processing posted messages, then join on the handling thread mBackgroundThread.quitSafely(); try { mBackgroundThread.join(); } catch (InterruptedException ex) { Log.e(TAG, "Background worker thread was interrupted while joined", ex); } // Close the ImageReader now that the background thread has stopped if (mCaptureBuffer != null) mCaptureBuffer.close();
protected void	onResume() Called when our {@code Activity} gains focus. Starts initializing the camera. super.onResume(); // Start a background thread to manage camera requests mBackgroundThread = new HandlerThread("background"); mBackgroundThread.start(); mBackgroundHandler = new Handler(mBackgroundThread.getLooper()); mForegroundHandler = new Handler(getMainLooper()); mCameraManager = (CameraManager) getSystemService(CAMERA_SERVICE); // Inflate the SurfaceView, set it as the main layout, and attach a listener View layout = getLayoutInflater().inflate(R.layout.mainactivity, null); mSurfaceView = (SurfaceView) layout.findViewById(R.id.mainSurfaceView); mSurfaceView.getHolder().addCallback(mSurfaceHolderCallback); setContentView(mSurfaceView); // Control flow continues in mSurfaceHolderCallback.surfaceChanged()