Add nullable and nonnull annotations everywhere

MIGRATION.md

@@ -124,13 +124,16 @@ The listener interface brings two breaking signature changes:
 - `onVideoTaken()` now returns a `VideoResult`. Use `result.getFile()` to access the video file.
   The result class includes rich information about the video (or video snapshot) that was taken.
   
+## Experimental mode
+The v2 version introduces a `cameraExperimental` XML flag that you can use to enable experimental features.
+Might be used in the future to speed up development.
+
 ## Other improvements
+- Added `@Nullable` and `@NonNull` annotations pretty much everywhere. This might **break** your Kotlin build.
 - Added `setGridColor()` and `cameraGridColor` to control the grid color
 - Default `Facing` value is not `BACK` anymore but rather a value that guarantees that you have cameras (if possible).
   If device has no `BACK` cameras, defaults to `FRONT`.  
   
-  
-TODO: max size for video snapshot is naive
 TODO: document cameraGridColor
 TODO: document setVideoBitRate
 TODO: document setAudioBitRate

cameraview/src/androidTest/java/com/otaliastudios/cameraview/CameraViewTest.java

@@ -642,9 +642,9 @@ public class CameraViewTest extends BaseTest {
         assertTrue(cameraView.mFrameProcessors.isEmpty());
 
         // Ensure this does not throw a ConcurrentModificationException
-        cameraView.addFrameProcessor(new FrameProcessor() { public void process(Frame f) {} });
-        cameraView.addFrameProcessor(new FrameProcessor() { public void process(Frame f) {} });
-        cameraView.addFrameProcessor(new FrameProcessor() { public void process(Frame f) {} });
+        cameraView.addFrameProcessor(new FrameProcessor() { public void process(@NonNull Frame f) {} });
+        cameraView.addFrameProcessor(new FrameProcessor() { public void process(@NonNull Frame f) {} });
+        cameraView.addFrameProcessor(new FrameProcessor() { public void process(@NonNull Frame f) {} });
         for (FrameProcessor test : cameraView.mFrameProcessors) {
             cameraView.mFrameProcessors.remove(test);
         }

cameraview/src/androidTest/java/com/otaliastudios/cameraview/MockCameraController.java

@@ -40,49 +40,49 @@ public class MockCameraController extends CameraController {
     }
 
     @Override
-    void setZoom(float zoom, PointF[] points, boolean notify) {
+    void setZoom(float zoom, @Nullable PointF[] points, boolean notify) {
         mZoomValue = zoom;
         mZoomChanged = true;
     }
 
     @Override
-    void setExposureCorrection(float EVvalue, float[] bounds, PointF[] points, boolean notify) {
+    void setExposureCorrection(float EVvalue, @NonNull float[] bounds, @Nullable PointF[] points, boolean notify) {
         mExposureCorrectionValue = EVvalue;
         mExposureCorrectionChanged = true;
     }
 
     @Override
-    void setFacing(Facing facing) {
+    void setFacing(@NonNull Facing facing) {
         mFacing = facing;
     }
 
     @Override
-    void setFlash(Flash flash) {
+    void setFlash(@NonNull Flash flash) {
         mFlash = flash;
     }
 
     @Override
-    void setWhiteBalance(WhiteBalance whiteBalance) {
+    void setWhiteBalance(@NonNull WhiteBalance whiteBalance) {
         mWhiteBalance = whiteBalance;
     }
 
     @Override
-    void setMode(Mode mode) {
+    void setMode(@NonNull Mode mode) {
         mMode = mode;
     }
 
     @Override
-    void setHdr(Hdr hdr) {
+    void setHdr(@NonNull Hdr hdr) {
         mHdr = hdr;
     }
 
     @Override
-    void setAudio(Audio audio) {
+    void setAudio(@NonNull Audio audio) {
         mAudio = audio;
     }
 
     @Override
-    void setLocation(Location location) {
+    void setLocation(@Nullable Location location) {
         mLocation = location;
     }
 
@@ -92,7 +92,7 @@ public class MockCameraController extends CameraController {
     }
 
     @Override
-    void takePictureSnapshot(AspectRatio viewAspectRatio) {
+    void takePictureSnapshot(@NonNull AspectRatio viewAspectRatio) {
     }
 
     @Override
@@ -127,7 +127,7 @@ public class MockCameraController extends CameraController {
     }
 
     @Override
-    public void onBufferAvailable(byte[] buffer) {
+    public void onBufferAvailable(@NonNull byte[] buffer) {
     }
 
     @Override

cameraview/src/androidTest/java/com/otaliastudios/cameraview/MockCameraPreview.java

@@ -30,11 +30,13 @@ public class MockCameraPreview extends CameraPreview<View, Void> {
         return new View(context);
     }
 
+    @NonNull
     @Override
     Class<Void> getOutputClass() {
         return null;
     }
 
+    @NonNull
     @Override
     Void getOutput() {
         return null;

cameraview/src/main/gles/com/otaliastudios/cameraview/AudioMediaEncoder.java

@@ -9,6 +9,7 @@ import android.media.MediaMuxer;
 import android.media.MediaRecorder;
 import android.os.Build;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.annotation.RequiresApi;
 
 import java.io.IOException;
@@ -40,7 +41,7 @@ class AudioMediaEncoder extends MediaEncoder {
 
     @EncoderThread
     @Override
-    void prepare(MediaEncoderEngine.Controller controller, long maxLengthMillis) {
+    void prepare(@NonNull MediaEncoderEngine.Controller controller, long maxLengthMillis) {
         super.prepare(controller, maxLengthMillis);
         final MediaFormat audioFormat = MediaFormat.createAudioFormat(MIME_TYPE, SAMPLE_RATE, 1);
         audioFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
@@ -65,7 +66,7 @@ class AudioMediaEncoder extends MediaEncoder {
 
     @EncoderThread
     @Override
-    void notify(String event, Object data) { }
+    void notify(@NonNull String event, @Nullable Object data) { }
 
     @EncoderThread
     @Override
@@ -74,7 +75,9 @@ class AudioMediaEncoder extends MediaEncoder {
         synchronized (mLock) {
             try {
                 mLock.wait();
-            } catch (InterruptedException e) {}
+            } catch (InterruptedException e) {
+                // do nothing
+            }
         }
     }
 

cameraview/src/main/gles/com/otaliastudios/cameraview/MediaEncoder.java

@@ -3,6 +3,8 @@ package com.otaliastudios.cameraview;
 import android.media.MediaCodec;
 import android.media.MediaFormat;
 import android.os.Build;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.annotation.RequiresApi;
 import android.util.Log;
 
@@ -14,6 +16,7 @@ abstract class MediaEncoder {
 
     private final static int TIMEOUT_USEC = 10000; // 10 msec
 
+    @SuppressWarnings("WeakerAccess")
     protected MediaCodec mMediaCodec;
 
     private MediaCodec.BufferInfo mBufferInfo;
@@ -32,7 +35,7 @@ abstract class MediaEncoder {
      * @param controller the muxer controller
      */
     @EncoderThread
-    void prepare(MediaEncoderEngine.Controller controller, long maxLengthMillis) {
+    void prepare(@NonNull MediaEncoderEngine.Controller controller, long maxLengthMillis) {
         mController = controller;
         mBufferInfo = new MediaCodec.BufferInfo();
         mMaxLengthMillis = maxLengthMillis;
@@ -53,7 +56,7 @@ abstract class MediaEncoder {
      * @param data object
      */
     @EncoderThread
-    abstract void notify(String event, Object data);
+    abstract void notify(@NonNull String event, @Nullable Object data);
 
     /**
      * Stop recording.
@@ -77,7 +80,8 @@ abstract class MediaEncoder {
     /**
      * Encode data into the {@link #mMediaCodec}.
      */
-    protected void encode(final ByteBuffer buffer, final int length, final long presentationTimeUs) {
+    @SuppressWarnings("WeakerAccess")
+    protected void encode(@Nullable final ByteBuffer buffer, final int length, final long presentationTimeUs) {
         final ByteBuffer[] inputBuffers = mMediaCodec.getInputBuffers();
         while (true) {
             final int inputBufferIndex = mMediaCodec.dequeueInputBuffer(TIMEOUT_USEC);
@@ -111,6 +115,7 @@ abstract class MediaEncoder {
      * is set, we send EOS to the encoder, and then iterate until we see EOS on the output.
      * Calling this with endOfStream set should be done once, right before stopping the muxer.
      */
+    @SuppressWarnings("WeakerAccess")
     protected void drain(boolean endOfStream) {
         if (endOfStream) {
             mMediaCodec.signalEndOfInputStream();

cameraview/src/main/gles/com/otaliastudios/cameraview/MediaEncoderEngine.java

@@ -19,6 +19,7 @@ import java.util.List;
 @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
 class MediaEncoderEngine {
 
+    @SuppressWarnings("WeakerAccess")
     final static int STOP_BY_USER = 0;
     final static int STOP_BY_MAX_DURATION = 1;
     final static int STOP_BY_MAX_SIZE = 2;
@@ -56,13 +57,14 @@ class MediaEncoderEngine {
             public void run() {
                 // Trying to convert the size constraints to duration constraints,
                 // because they are super easy to check.
-                // This is really naive & not accurate, but...
+                // This is really naive & probably not accurate, but...
                 int bitRate = 0;
                 for (MediaEncoder encoder : mEncoders) {
                     bitRate += encoder.getBitRate();
                 }
                 int bytePerSecond = bitRate / 8;
                 long sizeMaxDuration = (maxSize / bytePerSecond) * 1000L;
+
                 long finalMaxDuration = Long.MAX_VALUE;
                 if (maxSize > 0 && maxDuration > 0) {
                     mPossibleStopReason = sizeMaxDuration < maxDuration ? STOP_BY_MAX_SIZE : STOP_BY_MAX_DURATION;

cameraview/src/main/gles/com/otaliastudios/cameraview/TextureMediaEncoder.java

@@ -9,6 +9,7 @@ import android.opengl.EGLContext;
 import android.opengl.Matrix;
 import android.os.Build;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.annotation.RequiresApi;
 import android.util.Log;
 import android.view.Surface;
@@ -46,13 +47,13 @@ class TextureMediaEncoder extends VideoMediaEncoder<TextureMediaEncoder.Config>
     private EglWindowSurface mWindow;
     private EglViewport mViewport;
 
-    public TextureMediaEncoder(@NonNull Config config) {
+    TextureMediaEncoder(@NonNull Config config) {
         super(config);
     }
 
     @EncoderThread
     @Override
-    void prepare(MediaEncoderEngine.Controller controller, long maxLengthMillis) {
+    void prepare(@NonNull MediaEncoderEngine.Controller controller, long maxLengthMillis) {
         super.prepare(controller, maxLengthMillis);
         mEglCore = new EglCore(mConfig.eglContext, EglCore.FLAG_RECORDABLE);
         mWindow = new EglWindowSurface(mEglCore, mSurface, true);
@@ -90,7 +91,7 @@ class TextureMediaEncoder extends VideoMediaEncoder<TextureMediaEncoder.Config>
 
     @EncoderThread
     @Override
-    void notify(String event, Object data) {
+    void notify(@NonNull String event, @Nullable Object data) {
         if (event.equals(FRAME_EVENT)) {
             Frame frame = (Frame) data;
 

cameraview/src/main/gles/com/otaliastudios/cameraview/VideoMediaEncoder.java

@@ -22,8 +22,13 @@ import java.nio.ByteBuffer;
 @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
 abstract class VideoMediaEncoder<C extends VideoMediaEncoder.Config> extends MediaEncoder {
 
+    @SuppressWarnings("WeakerAccess")
     protected C mConfig;
+
+    @SuppressWarnings("WeakerAccess")
     protected Surface mSurface;
+
+    @SuppressWarnings("WeakerAccess")
     protected int mFrameNum = -1;
 
     static class Config {
@@ -50,7 +55,7 @@ abstract class VideoMediaEncoder<C extends VideoMediaEncoder.Config> extends Med
 
     @EncoderThread
     @Override
-    void prepare(MediaEncoderEngine.Controller controller, long maxLengthMillis) {
+    void prepare(@NonNull MediaEncoderEngine.Controller controller, long maxLengthMillis) {
         super.prepare(controller, maxLengthMillis);
         MediaFormat format = MediaFormat.createVideoFormat(mConfig.mimeType, mConfig.width, mConfig.height);
 

cameraview/src/main/java/com/otaliastudios/cameraview/AspectRatio.java

@@ -20,6 +20,7 @@ public class AspectRatio implements Comparable<AspectRatio> {
      * @param size the size
      * @return a (possibly cached) aspect ratio
      */
+    @NonNull
     public static AspectRatio of(Size size) {
         return AspectRatio.of(size.getWidth(), size.getHeight());
     }
@@ -30,6 +31,7 @@ public class AspectRatio implements Comparable<AspectRatio> {
      * @param y the height
      * @return a (possibly cached) aspect ratio
      */
+    @NonNull
     public static AspectRatio of(int x, int y) {
         int gcd = gcd(x, y);
         x /= gcd;
@@ -50,6 +52,8 @@ public class AspectRatio implements Comparable<AspectRatio> {
      * @param string a string of the format x:y where x and y are integers
      * @return a (possibly cached) aspect ratio
      */
+    @NonNull
+    @SuppressWarnings("WeakerAccess")
     public static AspectRatio parse(@NonNull String string) {
         String[] parts = string.split(":");
         if (parts.length != 2) {
@@ -76,7 +80,8 @@ public class AspectRatio implements Comparable<AspectRatio> {
         return mY;
     }
 
-    public boolean matches(Size size) {
+    @SuppressWarnings("WeakerAccess")
+    public boolean matches(@NonNull Size size) {
         int gcd = gcd(size.getWidth(), size.getHeight());
         int x = size.getWidth() / gcd;
         int y = size.getHeight() / gcd;
@@ -103,6 +108,7 @@ public class AspectRatio implements Comparable<AspectRatio> {
         return mX + ":" + mY;
     }
 
+    @SuppressWarnings("WeakerAccess")
     public float toFloat() {
         return (float) mX / mY;
     }
@@ -123,6 +129,7 @@ public class AspectRatio implements Comparable<AspectRatio> {
     }
 
     @SuppressWarnings("SuspiciousNameCombination")
+    @NonNull
     public AspectRatio inverse() {
         return AspectRatio.of(mY, mX);
     }

cameraview/src/main/java/com/otaliastudios/cameraview/Camera1.java

@@ -47,7 +47,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
         }
     };
 
-    Camera1(CameraView.CameraCallbacks callback) {
+    Camera1(@NonNull CameraView.CameraCallbacks callback) {
         super(callback);
         mMapper = new Mapper1();
     }
@@ -298,7 +298,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    public void onBufferAvailable(byte[] buffer) {
+    public void onBufferAvailable(@NonNull byte[] buffer) {
         // TODO: sync with handler?
         if (isCameraAvailable()) {
             mCamera.addCallbackBuffer(buffer);
@@ -327,7 +327,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setMode(Mode mode) {
+    void setMode(@NonNull Mode mode) {
         if (mode != mMode) {
             mMode = mode;
             schedule(null, true, new Runnable() {
@@ -340,7 +340,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setLocation(Location location) {
+    void setLocation(@Nullable Location location) {
         final Location oldLocation = mLocation;
         mLocation = location;
         schedule(mLocationTask, true, new Runnable() {
@@ -352,7 +352,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
         });
     }
 
-    private boolean applyLocation(Camera.Parameters params, Location oldLocation) {
+    private boolean applyLocation(@NonNull Camera.Parameters params, @Nullable Location oldLocation) {
         if (mLocation != null) {
             params.setGpsLatitude(mLocation.getLatitude());
             params.setGpsLongitude(mLocation.getLongitude());
@@ -364,7 +364,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setFacing(Facing facing) {
+    void setFacing(@NonNull Facing facing) {
         final Facing old = mFacing;
         if (facing != old) {
             mFacing = facing;
@@ -382,7 +382,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setWhiteBalance(WhiteBalance whiteBalance) {
+    void setWhiteBalance(@NonNull WhiteBalance whiteBalance) {
         final WhiteBalance old = mWhiteBalance;
         mWhiteBalance = whiteBalance;
         schedule(mWhiteBalanceTask, true, new Runnable() {
@@ -394,7 +394,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
         });
     }
 
-    private boolean applyWhiteBalance(Camera.Parameters params, WhiteBalance oldWhiteBalance) {
+    private boolean applyWhiteBalance(@NonNull Camera.Parameters params, @NonNull WhiteBalance oldWhiteBalance) {
         if (mCameraOptions.supports(mWhiteBalance)) {
             params.setWhiteBalance((String) mMapper.map(mWhiteBalance));
             return true;
@@ -404,7 +404,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setHdr(Hdr hdr) {
+    void setHdr(@NonNull Hdr hdr) {
         final Hdr old = mHdr;
         mHdr = hdr;
         schedule(mHdrTask, true, new Runnable() {
@@ -416,7 +416,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
         });
     }
 
-    private boolean applyHdr(Camera.Parameters params, Hdr oldHdr) {
+    private boolean applyHdr(@NonNull Camera.Parameters params, @NonNull Hdr oldHdr) {
         if (mCameraOptions.supports(mHdr)) {
             params.setSceneMode((String) mMapper.map(mHdr));
             return true;
@@ -444,7 +444,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
 
     @Override
-    void setAudio(Audio audio) {
+    void setAudio(@NonNull Audio audio) {
         if (mAudio != audio) {
             if (isTakingVideo()) {
                 LOG.w("Audio setting was changed while recording. " +
@@ -455,7 +455,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setFlash(Flash flash) {
+    void setFlash(@NonNull Flash flash) {
         final Flash old = mFlash;
         mFlash = flash;
         schedule(mFlashTask, true, new Runnable() {
@@ -468,7 +468,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
 
-    private boolean applyFlash(Camera.Parameters params, Flash oldFlash) {
+    private boolean applyFlash(@NonNull Camera.Parameters params, @NonNull Flash oldFlash) {
         if (mCameraOptions.supports(mFlash)) {
             params.setFlashMode((String) mMapper.map(mFlash));
             return true;
@@ -479,7 +479,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
 
     // Choose the best default focus, based on session type.
-    private void applyDefaultFocus(Camera.Parameters params) {
+    private void applyDefaultFocus(@NonNull Camera.Parameters params) {
         List<String> modes = params.getSupportedFocusModes();
 
         if (mMode == Mode.VIDEO &&
@@ -500,6 +500,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
         if (modes.contains(Camera.Parameters.FOCUS_MODE_FIXED)) {
             params.setFocusMode(Camera.Parameters.FOCUS_MODE_FIXED);
+            //noinspection UnnecessaryReturnStatement
             return;
         }
     }
@@ -552,7 +553,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
 
     @Override
-    void takePictureSnapshot(final AspectRatio viewAspectRatio) {
+    void takePictureSnapshot(@NonNull final AspectRatio viewAspectRatio) {
         LOG.v("takePictureSnapshot: scheduling");
         schedule(null, true, new Runnable() {
             @Override
@@ -573,7 +574,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    public void onPreviewFrame(byte[] data, Camera camera) {
+    public void onPreviewFrame(@NonNull byte[] data, Camera camera) {
         Frame frame = mFrameManager.getFrame(data,
                 System.currentTimeMillis(),
                 offset(REF_SENSOR, REF_OUTPUT),
@@ -782,7 +783,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
 
     @Override
-    void setZoom(final float zoom, final PointF[] points, final boolean notify) {
+    void setZoom(final float zoom, @Nullable final PointF[] points, final boolean notify) {
         schedule(mZoomTask, true, new Runnable() {
             @Override
             public void run() {
@@ -802,8 +803,8 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
     }
 
     @Override
-    void setExposureCorrection(final float EVvalue, final float[] bounds,
-                               final PointF[] points, final boolean notify) {
+    void setExposureCorrection(final float EVvalue, @NonNull final float[] bounds,
+                               @Nullable final PointF[] points, final boolean notify) {
         schedule(mExposureCorrectionTask, true, new Runnable() {
             @Override
             public void run() {
@@ -831,7 +832,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
 
     @Override
-    void startAutoFocus(@Nullable final Gesture gesture, final PointF point) {
+    void startAutoFocus(@Nullable final Gesture gesture, @NonNull final PointF point) {
         // Must get width and height from the UI thread.
         int viewWidth = 0, viewHeight = 0;
         if (mPreview != null && mPreview.hasSurface()) {
@@ -880,7 +881,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
         });
     }
 
-
+    @NonNull
     @WorkerThread
     private static List<Camera.Area> computeMeteringAreas(double viewClickX, double viewClickY,
                                                           int viewWidth, int viewHeight,
@@ -911,7 +912,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
         return list;
     }
 
-
+    @NonNull
     private static Rect computeMeteringArea(double centerX, double centerY, double size) {
         double delta = size / 2d;
         int top = (int) Math.max(centerY - delta, -1000);
@@ -928,7 +929,7 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
 
 
     @Nullable
-    private List<Size> sizesFromList(List<Camera.Size> sizes) {
+    private List<Size> sizesFromList(@Nullable List<Camera.Size> sizes) {
         if (sizes == null) return null;
         List<Size> result = new ArrayList<>(sizes.size());
         for (Camera.Size size : sizes) {
@@ -950,8 +951,5 @@ class Camera1 extends CameraController implements Camera.PreviewCallback, Camera
             }
         });
     }
-
-    // -----------------
-    // Additional helper info
 }
 

cameraview/src/main/java/com/otaliastudios/cameraview/CameraController.java

@@ -156,6 +156,7 @@ abstract class CameraController implements
 
     //region Start&Stop
 
+    @NonNull
     private String ss() {
         switch (mState) {
             case STATE_STOPPING: return "STATE_STOPPING";
@@ -273,11 +274,11 @@ abstract class CameraController implements
         mDeviceOrientation = deviceOrientation;
     }
 
-    final void setPictureSizeSelector(SizeSelector selector) {
+    final void setPictureSizeSelector(@NonNull SizeSelector selector) {
         mPictureSizeSelector = selector;
     }
 
-    final void setVideoSizeSelector(SizeSelector selector) {
+    final void setVideoSizeSelector(@NonNull SizeSelector selector) {
         mVideoSizeSelector = selector;
     }
 
@@ -289,7 +290,7 @@ abstract class CameraController implements
         mVideoMaxDuration = videoMaxDurationMillis;
     }
 
-    final void setVideoCodec(VideoCodec codec) {
+    final void setVideoCodec(@NonNull VideoCodec codec) {
         mVideoCodec = codec;
     }
 
@@ -306,35 +307,35 @@ abstract class CameraController implements
     //region Abstract setters and APIs
 
     // Should restart the session if active.
-    abstract void setMode(Mode mode);
+    abstract void setMode(@NonNull Mode mode);
 
     // Should restart the session if active.
-    abstract void setFacing(Facing facing);
+    abstract void setFacing(@NonNull Facing facing);
 
     // If closed, no-op. If opened, check supported and apply.
-    abstract void setZoom(float zoom, PointF[] points, boolean notify);
+    abstract void setZoom(float zoom, @Nullable PointF[] points, boolean notify);
 
     // If closed, no-op. If opened, check supported and apply.
-    abstract void setExposureCorrection(float EVvalue, float[] bounds, PointF[] points, boolean notify);
+    abstract void setExposureCorrection(float EVvalue, @NonNull float[] bounds, @Nullable PointF[] points, boolean notify);
 
     // If closed, keep. If opened, check supported and apply.
-    abstract void setFlash(Flash flash);
+    abstract void setFlash(@NonNull Flash flash);
 
     // If closed, keep. If opened, check supported and apply.
-    abstract void setWhiteBalance(WhiteBalance whiteBalance);
+    abstract void setWhiteBalance(@NonNull WhiteBalance whiteBalance);
 
     // If closed, keep. If opened, check supported and apply.
-    abstract void setHdr(Hdr hdr);
+    abstract void setHdr(@NonNull Hdr hdr);
 
     // If closed, keep. If opened, check supported and apply.
-    abstract void setLocation(Location location);
+    abstract void setLocation(@Nullable Location location);
 
     // Just set.
-    abstract void setAudio(Audio audio);
+    abstract void setAudio(@NonNull Audio audio);
 
     abstract void takePicture();
 
-    abstract void takePictureSnapshot(AspectRatio viewAspectRatio);
+    abstract void takePictureSnapshot(@NonNull AspectRatio viewAspectRatio);
 
     abstract void takeVideo(@NonNull File file);
 
@@ -355,14 +356,17 @@ abstract class CameraController implements
         return mCameraOptions;
     }
 
+    @NonNull
     final Facing getFacing() {
         return mFacing;
     }
 
+    @NonNull
     final Flash getFlash() {
         return mFlash;
     }
 
+    @NonNull
     final WhiteBalance getWhiteBalance() {
         return mWhiteBalance;
     }
@@ -383,18 +387,22 @@ abstract class CameraController implements
         return mVideoMaxDuration;
     }
 
+    @NonNull
     final Mode getMode() {
         return mMode;
     }
 
+    @NonNull
     final Hdr getHdr() {
         return mHdr;
     }
 
+    @Nullable
     final Location getLocation() {
         return mLocation;
     }
 
+    @NonNull
     final Audio getAudio() {
         return mAudio;
     }
@@ -403,10 +411,12 @@ abstract class CameraController implements
         return mAudioBitRate;
     }
 
+    @NonNull
     /* for tests */ final SizeSelector getPictureSizeSelector() {
         return mPictureSizeSelector;
     }
 
+    @NonNull
     /* for tests */ final SizeSelector getVideoSizeSelector() {
         return mVideoSizeSelector;
     }
@@ -469,12 +479,12 @@ abstract class CameraController implements
         return offset(reference1, reference2) % 180 != 0;
     }
 
-    final Size getPictureSize(int reference) {
+    final Size getPictureSize(@SuppressWarnings("SameParameterValue") int reference) {
         if (mCaptureSize == null || mMode == Mode.VIDEO) return null;
         return flip(REF_SENSOR, reference) ? mCaptureSize.flip() : mCaptureSize;
     }
 
-    final Size getVideoSize(int reference) {
+    final Size getVideoSize(@SuppressWarnings("SameParameterValue") int reference) {
         if (mCaptureSize == null || mMode == Mode.PICTURE) return null;
         return flip(REF_SENSOR, reference) ? mCaptureSize.flip() : mCaptureSize;
     }
@@ -496,6 +506,8 @@ abstract class CameraController implements
      * But when it does, the {@link CameraPreview.SurfaceCallback} should be called,
      * and this should be refreshed.
      */
+    @NonNull
+    @SuppressWarnings("WeakerAccess")
     protected final Size computeCaptureSize() {
         // We want to pass stuff into the REF_VIEW reference, not the sensor one.
         // This is already managed by CameraOptions, so we just flip again at the end.
@@ -517,7 +529,9 @@ abstract class CameraController implements
         return result;
     }
 
-    protected final Size computePreviewSize(List<Size> previewSizes) {
+    @NonNull
+    @SuppressWarnings("WeakerAccess")
+    protected final Size computePreviewSize(@NonNull List<Size> previewSizes) {
         // instead of flipping everything to REF_VIEW, we can just flip the
         // surface size from REF_VIEW to REF_SENSOR, and reflip at the end.
         AspectRatio targetRatio = AspectRatio.of(mCaptureSize.getWidth(), mCaptureSize.getHeight());

cameraview/src/main/java/com/otaliastudios/cameraview/CameraListener.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview;
 
 import android.graphics.PointF;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
 
 public abstract class CameraListener {
@@ -14,7 +15,7 @@ public abstract class CameraListener {
      * @param options camera supported options
      */
     @UiThread
-    public void onCameraOpened(CameraOptions options) {
+    public void onCameraOpened(@NonNull CameraOptions options) {
 
     }
 
@@ -57,7 +58,7 @@ public abstract class CameraListener {
      * @param result captured picture
      */
     @UiThread
-    public void onPictureTaken(PictureResult result) {
+    public void onPictureTaken(@NonNull PictureResult result) {
 
     }
 
@@ -68,7 +69,7 @@ public abstract class CameraListener {
      * @param result the video result
      */
     @UiThread
-    public void onVideoTaken(VideoResult result) {
+    public void onVideoTaken(@NonNull VideoResult result) {
 
     }
 
@@ -97,7 +98,7 @@ public abstract class CameraListener {
      * @param point coordinates with respect to CameraView.getWidth() and CameraView.getHeight()
      */
     @UiThread
-    public void onFocusStart(PointF point) {
+    public void onFocusStart(@NonNull PointF point) {
 
     }
 
@@ -112,7 +113,7 @@ public abstract class CameraListener {
      * @param point coordinates with respect to CameraView.getWidth() and CameraView.getHeight()
      */
     @UiThread
-    public void onFocusEnd(boolean successful, PointF point) {
+    public void onFocusEnd(boolean successful, @NonNull PointF point) {
 
     }
 
@@ -123,10 +124,10 @@ public abstract class CameraListener {
      *
      * @param newValue the new zoom value
      * @param bounds min and max bounds for newValue (fixed to 0 ... 1)
-     * @param fingers finger positions that caused the event
+     * @param fingers finger positions that caused the event, null if not caused by touch
      */
     @UiThread
-    public void onZoomChanged(float newValue, float[] bounds, PointF[] fingers) {
+    public void onZoomChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers) {
 
     }
 
@@ -137,10 +138,10 @@ public abstract class CameraListener {
      *
      * @param newValue the new correction value
      * @param bounds min and max bounds for newValue, as returned by {@link CameraOptions}
-     * @param fingers finger positions that caused the event
+     * @param fingers finger positions that caused the event, null if not caused by touch
      */
     @UiThread
-    public void onExposureCorrectionChanged(float newValue, float[] bounds, PointF[] fingers) {
+    public void onExposureCorrectionChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers) {
 
     }
 

cameraview/src/main/java/com/otaliastudios/cameraview/CameraOptions.java

@@ -36,7 +36,7 @@ public class CameraOptions {
 
     // Camera1 constructor.
     @SuppressWarnings("deprecation")
-    CameraOptions(Camera.Parameters params, boolean flipSizes) {
+    CameraOptions(@NonNull Camera.Parameters params, boolean flipSizes) {
         List<String> strings;
         Mapper mapper = new Mapper1();
 
@@ -107,7 +107,7 @@ public class CameraOptions {
 
     // Camera2 constructor.
     @TargetApi(21)
-    CameraOptions(CameraCharacteristics params) {}
+    CameraOptions(@NonNull CameraCharacteristics params) {}
 
 
     /**
@@ -116,7 +116,7 @@ public class CameraOptions {
      * @param control value to check
      * @return whether it's supported
      */
-    public boolean supports(Control control) {
+    public boolean supports(@NonNull Control control) {
         return getSupportedControls(control.getClass()).contains(control);
     }
 
@@ -128,7 +128,7 @@ public class CameraOptions {
      * @param action value to be checked
      * @return whether it's supported
      */
-    public boolean supports(GestureAction action) {
+    public boolean supports(@NonNull GestureAction action) {
         switch (action) {
             case FOCUS:
             case FOCUS_WITH_MARKER:
@@ -146,6 +146,7 @@ public class CameraOptions {
 
 
     @SuppressWarnings("unchecked")
+    @NonNull
     public <T extends Control> Collection<T> getSupportedControls(@NonNull Class<T> controlClass) {
         if (controlClass.equals(Audio.class)) {
             return (Collection<T>) Arrays.asList(Audio.values());
@@ -174,6 +175,7 @@ public class CameraOptions {
      *
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<Size> getSupportedPictureSizes() {
         return Collections.unmodifiableSet(supportedPictureSizes);
@@ -185,6 +187,7 @@ public class CameraOptions {
      *
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<AspectRatio> getSupportedPictureAspectRatios() {
         return Collections.unmodifiableSet(supportedPictureAspectRatio);
@@ -196,6 +199,7 @@ public class CameraOptions {
      *
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<Size> getSupportedVideoSizes() {
         return Collections.unmodifiableSet(supportedVideoSizes);
@@ -207,6 +211,7 @@ public class CameraOptions {
      *
      * @return a set of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<AspectRatio> getSupportedVideoAspectRatios() {
         return Collections.unmodifiableSet(supportedVideoAspectRatio);
@@ -220,6 +225,7 @@ public class CameraOptions {
      * @see Facing#FRONT
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<Facing> getSupportedFacing() {
         return Collections.unmodifiableSet(supportedFacing);
@@ -235,6 +241,7 @@ public class CameraOptions {
      * @see Flash#TORCH
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<Flash> getSupportedFlash() {
         return Collections.unmodifiableSet(supportedFlash);
@@ -251,6 +258,7 @@ public class CameraOptions {
      * @see WhiteBalance#CLOUDY
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<WhiteBalance> getSupportedWhiteBalance() {
         return Collections.unmodifiableSet(supportedWhiteBalance);
@@ -264,6 +272,7 @@ public class CameraOptions {
      * @see Hdr#ON
      * @return a collection of supported values.
      */
+    @SuppressWarnings("WeakerAccess")
     @NonNull
     public Collection<Hdr> getSupportedHdr() {
         return Collections.unmodifiableSet(supportedHdr);
@@ -275,6 +284,7 @@ public class CameraOptions {
      *
      * @return whether zoom is supported.
      */
+    @SuppressWarnings("WeakerAccess")
     public boolean isZoomSupported() {
         return zoomSupported;
     }
@@ -287,6 +297,7 @@ public class CameraOptions {
      *
      * @return whether auto focus is supported.
      */
+    @SuppressWarnings("WeakerAccess")
     public boolean isAutoFocusSupported() {
         return autoFocusSupported;
     }
@@ -300,6 +311,7 @@ public class CameraOptions {
      * @see #getExposureCorrectionMaxValue()
      * @return whether exposure correction is supported.
      */
+    @SuppressWarnings("WeakerAccess")
     public boolean isExposureCorrectionSupported() {
         return exposureCorrectionSupported;
     }
@@ -311,6 +323,7 @@ public class CameraOptions {
      *
      * @return min EV value
      */
+    @SuppressWarnings("WeakerAccess")
     public float getExposureCorrectionMinValue() {
         return exposureCorrectionMinValue;
     }
@@ -322,6 +335,7 @@ public class CameraOptions {
      *
      * @return max EV value
      */
+    @SuppressWarnings("WeakerAccess")
     public float getExposureCorrectionMaxValue() {
         return exposureCorrectionMaxValue;
     }

cameraview/src/main/java/com/otaliastudios/cameraview/CameraView.java

@@ -752,7 +752,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
             float max = options.getExposureCorrectionMaxValue();
             if (EVvalue < min) EVvalue = min;
             if (EVvalue > max) EVvalue = max;
-            mCameraController.setExposureCorrection(EVvalue, null, null, false);
+            float[] bounds = new float[]{min, max};
+            mCameraController.setExposureCorrection(EVvalue, bounds, null, false);
         }
     }
 
@@ -1561,10 +1562,10 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         void onShutter(boolean shouldPlaySound);
         void dispatchOnVideoTaken(VideoResult result);
         void dispatchOnPictureTaken(PictureResult result);
-        void dispatchOnFocusStart(@Nullable Gesture trigger, PointF where);
-        void dispatchOnFocusEnd(@Nullable Gesture trigger, boolean success, PointF where);
-        void dispatchOnZoomChanged(final float newValue, final PointF[] fingers);
-        void dispatchOnExposureCorrectionChanged(float newValue, float[] bounds, PointF[] fingers);
+        void dispatchOnFocusStart(@Nullable Gesture trigger, @NonNull PointF where);
+        void dispatchOnFocusEnd(@Nullable Gesture trigger, boolean success, @NonNull PointF where);
+        void dispatchOnZoomChanged(final float newValue, @Nullable final PointF[] fingers);
+        void dispatchOnExposureCorrectionChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers);
         void dispatchFrame(Frame frame);
         void dispatchError(CameraException exception);
     }
@@ -1651,7 +1652,7 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         }
 
         @Override
-        public void dispatchOnFocusStart(@Nullable final Gesture gesture, final PointF point) {
+        public void dispatchOnFocusStart(@Nullable final Gesture gesture, @NonNull final PointF point) {
             mLogger.i("dispatchOnFocusStart", gesture, point);
             mUiHandler.post(new Runnable() {
                 @Override
@@ -1669,7 +1670,7 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
 
         @Override
         public void dispatchOnFocusEnd(@Nullable final Gesture gesture, final boolean success,
-                                       final PointF point) {
+                                       @NonNull final PointF point) {
             mLogger.i("dispatchOnFocusEnd", gesture, success, point);
             mUiHandler.post(new Runnable() {
                 @Override
@@ -1707,7 +1708,7 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         }
 
         @Override
-        public void dispatchOnZoomChanged(final float newValue, final PointF[] fingers) {
+        public void dispatchOnZoomChanged(final float newValue, @Nullable final PointF[] fingers) {
             mLogger.i("dispatchOnZoomChanged", newValue);
             mUiHandler.post(new Runnable() {
                 @Override
@@ -1721,8 +1722,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
 
         @Override
         public void dispatchOnExposureCorrectionChanged(final float newValue,
-                                                        final float[] bounds,
-                                                        final PointF[] fingers) {
+                                                        @NonNull final float[] bounds,
+                                                        @Nullable final PointF[] fingers) {
             mLogger.i("dispatchOnExposureCorrectionChanged", newValue);
             mUiHandler.post(new Runnable() {
                 @Override

cameraview/src/main/java/com/otaliastudios/cameraview/Frame.java

@@ -1,6 +1,7 @@
 package com.otaliastudios.cameraview;
 
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 /**
  * A preview frame to be processed by {@link FrameProcessor}s.
@@ -19,7 +20,7 @@ public class Frame {
         mManager = manager;
     }
 
-    void set(byte[] data, long time, int rotation, Size size, int format) {
+    void set(@NonNull byte[] data, long time, int rotation, @NonNull Size size, int format) {
         this.mData = data;
         this.mTime = time;
         this.mRotation = rotation;
@@ -40,6 +41,8 @@ public class Frame {
      *
      * @return a frozen Frame
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public Frame freeze() {
         byte[] data = new byte[mData.length];
         System.arraycopy(mData, 0, data, 0, mData.length);
@@ -74,6 +77,7 @@ public class Frame {
      * Returns the frame data.
      * @return the frame data
      */
+    @NonNull
     public byte[] getData() {
         return mData;
     }
@@ -104,6 +108,7 @@ public class Frame {
      *
      * @return frame size
      */
+    @NonNull
     public Size getSize() {
         return mSize;
     }

cameraview/src/main/java/com/otaliastudios/cameraview/FrameManager.java

@@ -1,6 +1,9 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 import java.util.concurrent.LinkedBlockingQueue;
 
 /**
@@ -21,7 +24,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 class FrameManager {
 
     interface BufferCallback {
-        void onBufferAvailable(byte[] buffer);
+        void onBufferAvailable(@NonNull byte[] buffer);
     }
 
     private int mPoolSize;
@@ -29,7 +32,7 @@ class FrameManager {
     private BufferCallback mCallback;
     private LinkedBlockingQueue<Frame> mQueue;
 
-    FrameManager(int poolSize, BufferCallback callback) {
+    FrameManager(int poolSize, @Nullable BufferCallback callback) {
         mPoolSize = poolSize;
         mCallback = callback;
         mQueue = new LinkedBlockingQueue<>(mPoolSize);
@@ -71,14 +74,14 @@ class FrameManager {
      *
      * @return a new frame
      */
-    Frame getFrame(byte[] data, long time, int rotation, Size previewSize, int previewFormat) {
+    Frame getFrame(@NonNull byte[] data, long time, int rotation, @NonNull Size previewSize, int previewFormat) {
         Frame frame = mQueue.poll();
         if (frame == null) frame = new Frame(this);
         frame.set(data, time, rotation, previewSize, previewFormat);
         return frame;
     }
 
-    int allocate(int bitsPerPixel, Size previewSize) {
+    int allocate(int bitsPerPixel, @NonNull Size previewSize) {
         mBufferSize = getBufferSize(bitsPerPixel, previewSize);
         for (int i = 0; i < mPoolSize; i++) {
             mCallback.onBufferAvailable(new byte[mBufferSize]);
@@ -86,7 +89,7 @@ class FrameManager {
         return mBufferSize;
     }
 
-    private int getBufferSize(int bitsPerPixel, Size previewSize) {
+    private int getBufferSize(int bitsPerPixel, @NonNull Size previewSize) {
         long sizeInBits = previewSize.getHeight() * previewSize.getWidth() * bitsPerPixel;
         return (int) Math.ceil(sizeInBits / 8.0d);
     }

cameraview/src/main/java/com/otaliastudios/cameraview/FullPictureRecorder.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 import android.hardware.Camera;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.media.ExifInterface;
 
 import java.io.ByteArrayInputStream;
@@ -16,7 +18,7 @@ class FullPictureRecorder extends PictureRecorder {
 
     private Camera mCamera;
 
-    FullPictureRecorder(PictureResult stub, PictureResultListener listener, Camera camera) {
+    FullPictureRecorder(@NonNull PictureResult stub, @Nullable PictureResultListener listener, @NonNull Camera camera) {
         super(stub, listener);
         mCamera = camera;
 

cameraview/src/main/java/com/otaliastudios/cameraview/FullVideoRecorder.java

@@ -3,6 +3,8 @@ package com.otaliastudios.cameraview;
 import android.hardware.Camera;
 import android.media.CamcorderProfile;
 import android.media.MediaRecorder;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 /**
  * A {@link VideoRecorder} that uses {@link android.media.MediaRecorder} APIs.
@@ -15,7 +17,7 @@ class FullVideoRecorder extends VideoRecorder {
     private MediaRecorder mMediaRecorder;
     private CamcorderProfile mProfile;
 
-    FullVideoRecorder(VideoResult stub, VideoResultListener listener, Camera camera, int cameraId) {
+    FullVideoRecorder(@NonNull VideoResult stub, @Nullable VideoResultListener listener, @NonNull Camera camera, int cameraId) {
         super(stub, listener);
         mMediaRecorder = new MediaRecorder();
         mMediaRecorder.setCamera(camera);

cameraview/src/main/java/com/otaliastudios/cameraview/PictureRecorder.java

@@ -1,5 +1,6 @@
 package com.otaliastudios.cameraview;
 
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
 /**
@@ -12,13 +13,14 @@ abstract class PictureRecorder {
     /* tests */ PictureResult mResult;
     /* tests */ PictureResultListener mListener;
 
-    PictureRecorder(PictureResult stub, PictureResultListener listener) {
+    PictureRecorder(@NonNull PictureResult stub, @Nullable PictureResultListener listener) {
         mResult = stub;
         mListener = listener;
     }
 
     abstract void take();
 
+    @SuppressWarnings("WeakerAccess")
     protected void dispatchOnShutter(boolean didPlaySound) {
         if (mListener != null) mListener.onPictureShutter(didPlaySound);
     }

cameraview/src/main/java/com/otaliastudios/cameraview/PictureResult.java

@@ -93,7 +93,7 @@ public class PictureResult {
      * @param maxHeight the max. height of final bitmap
      * @param callback a callback to be notified of image decoding
      */
-    public void asBitmap(int maxWidth, int maxHeight, BitmapCallback callback) {
+    public void asBitmap(int maxWidth, int maxHeight, @NonNull BitmapCallback callback) {
         CameraUtils.decodeBitmap(getData(), maxWidth, maxHeight, rotation, callback);
     }
 
@@ -104,7 +104,9 @@ public class PictureResult {
      *
      * @param callback a callback to be notified of image decoding
      */
-    public void asBitmap(BitmapCallback callback) {
+    public void asBitmap(@NonNull BitmapCallback callback) {
         asBitmap(-1, -1, callback);
     }
+
+    // TODO toFile
 }

cameraview/src/main/java/com/otaliastudios/cameraview/SnapshotPictureRecorder.java

@@ -10,6 +10,7 @@ import android.hardware.Camera;
 import android.opengl.EGL14;
 import android.opengl.EGLContext;
 import android.opengl.Matrix;
+import android.support.annotation.NonNull;
 
 import java.io.ByteArrayOutputStream;
 
@@ -28,7 +29,8 @@ class SnapshotPictureRecorder extends PictureRecorder {
     private Size mSensorPreviewSize;
     private int mFormat;
 
-    SnapshotPictureRecorder(PictureResult stub, Camera1 controller, Camera camera, AspectRatio outputRatio) {
+    SnapshotPictureRecorder(@NonNull PictureResult stub, @NonNull Camera1 controller,
+                            @NonNull Camera camera, @NonNull AspectRatio outputRatio) {
         super(stub, controller);
         mController = controller;
         mPreview = controller.mPreview;
@@ -48,7 +50,7 @@ class SnapshotPictureRecorder extends PictureRecorder {
     }
 
     @SuppressLint("NewApi")
-    private void takeGl(final GlCameraPreview preview) {
+    private void takeGl(@NonNull final GlCameraPreview preview) {
         preview.addRendererFrameCallback(new GlCameraPreview.RendererFrameCallback() {
 
             int mTextureId;
@@ -145,7 +147,7 @@ class SnapshotPictureRecorder extends PictureRecorder {
     private void takeLegacy() {
         mCamera.setOneShotPreviewCallback(new Camera.PreviewCallback() {
             @Override
-            public void onPreviewFrame(final byte[] yuv, Camera camera) {
+            public void onPreviewFrame(@NonNull final byte[] yuv, Camera camera) {
                 dispatchOnShutter(false);
 
                 // Got to rotate the preview frame, since byte[] data here does not include

cameraview/src/main/java/com/otaliastudios/cameraview/SnapshotVideoRecorder.java

@@ -4,6 +4,7 @@ import android.graphics.SurfaceTexture;
 import android.opengl.EGL14;
 import android.os.Build;
 import android.os.Handler;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.annotation.RequiresApi;
 
@@ -31,7 +32,7 @@ class SnapshotVideoRecorder extends VideoRecorder implements GlCameraPreview.Ren
     private int mDesiredState = STATE_NOT_RECORDING;
     private int mTextureId = 0;
 
-    SnapshotVideoRecorder(VideoResult stub, VideoResultListener listener, GlCameraPreview preview) {
+    SnapshotVideoRecorder(@NonNull VideoResult stub, @Nullable VideoResultListener listener, @NonNull GlCameraPreview preview) {
         super(stub, listener);
         mPreview = preview;
         mPreview.addRendererFrameCallback(this);
@@ -55,7 +56,7 @@ class SnapshotVideoRecorder extends VideoRecorder implements GlCameraPreview.Ren
 
     @RendererThread
     @Override
-    public void onRendererFrame(SurfaceTexture surfaceTexture, float scaleX, float scaleY) {
+    public void onRendererFrame(@NonNull SurfaceTexture surfaceTexture, float scaleX, float scaleY) {
         if (mCurrentState == STATE_NOT_RECORDING && mDesiredState == STATE_RECORDING) {
             Size size = mResult.getSize();
             // Ensure width and height are divisible by 2, as I have read somewhere.

cameraview/src/main/java/com/otaliastudios/cameraview/VideoRecorder.java

@@ -1,5 +1,6 @@
 package com.otaliastudios.cameraview;
 
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
 import java.io.File;
@@ -14,7 +15,7 @@ abstract class VideoRecorder {
     /* tests */ VideoResult mResult;
     /* tests */ VideoResultListener mListener;
 
-    VideoRecorder(VideoResult stub, VideoResultListener listener) {
+    VideoRecorder(@NonNull VideoResult stub, @Nullable VideoResultListener listener) {
         mResult = stub;
         mListener = listener;
     }

cameraview/src/main/java/com/otaliastudios/cameraview/VideoResult.java

@@ -11,8 +11,13 @@ import java.io.File;
  */
 public class VideoResult {
 
+    @SuppressWarnings({"WeakerAccess", "unused"})
     public static final int REASON_USER = 0;
+
+    @SuppressWarnings("WeakerAccess")
     public static final int REASON_MAX_SIZE_REACHED = 1;
+
+    @SuppressWarnings("WeakerAccess")
     public static final int REASON_MAX_DURATION_REACHED = 2;
 
     boolean isSnapshot;

cameraview/src/main/options/com/otaliastudios/cameraview/Audio.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 /**
  * Audio values indicate whether to record audio stream when record video.
  *
@@ -30,6 +32,7 @@ public enum Audio implements Control {
         return value;
     }
 
+    @Nullable
     static Audio fromValue(int value) {
         Audio[] list = Audio.values();
         for (Audio action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/Facing.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview;
 
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
 /**
@@ -21,7 +22,8 @@ public enum Facing implements Control {
      */
     FRONT(1);
 
-    final static Facing DEFAULT(@Nullable Context context) {
+    @NonNull
+    static Facing DEFAULT(@Nullable Context context) {
         if (context == null) {
             return BACK;
         } else if (CameraUtils.hasCameraFacing(context, BACK)) {
@@ -45,6 +47,7 @@ public enum Facing implements Control {
         return value;
     }
 
+    @Nullable
     static Facing fromValue(int value) {
         Facing[] list = Facing.values();
         for (Facing action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/Flash.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 /**
  * Flash value indicates the flash mode to be used.
  *
@@ -51,6 +53,7 @@ public enum Flash implements Control {
         return value;
     }
 
+    @Nullable
     static Flash fromValue(int value) {
         Flash[] list = Flash.values();
         for (Flash action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/GestureAction.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 /**
  * Gestures actions are actions over camera controls that can be mapped to certain gestures over
  * the screen, using XML attributes or {@link CameraView#mapGesture(Gesture, GestureAction)}.
@@ -81,6 +83,7 @@ public enum GestureAction {
         return value;
     }
 
+    @Nullable
     static GestureAction fromValue(int value) {
         GestureAction[] list = GestureAction.values();
         for (GestureAction action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/Grid.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 /**
  * Grid values can be used to draw grid lines over the camera preview.
  *
@@ -42,6 +44,7 @@ public enum Grid implements Control {
         return value;
     }
 
+    @Nullable
     static Grid fromValue(int value) {
         Grid[] list = Grid.values();
         for (Grid action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/Hdr.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 /**
  * Hdr values indicate whether to use high dynamic range techniques when capturing pictures.
  *
@@ -30,6 +32,7 @@ public enum Hdr implements Control {
         return value;
     }
 
+    @Nullable
     static Hdr fromValue(int value) {
         Hdr[] list = Hdr.values();
         for (Hdr action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/Mode.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 import java.io.File;
 
 /**
@@ -42,6 +44,7 @@ public enum Mode implements Control {
         return value;
     }
 
+    @Nullable
     static Mode fromValue(int value) {
         Mode[] list = Mode.values();
         for (Mode action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/Preview.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
+
 /**
  * The preview engine to be used.
  *
@@ -40,6 +42,7 @@ public enum Preview implements Control {
         return value;
     }
 
+    @Nullable
     static Preview fromValue(int value) {
         Preview[] list = Preview.values();
         for (Preview action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/VideoCodec.java

@@ -1,6 +1,9 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
 /**
  * Constants for selecting the encoder of video recordings.
  * https://developer.android.com/guide/topics/media/media-formats.html#video-formats
@@ -37,6 +40,7 @@ public enum VideoCodec implements Control {
         return value;
     }
 
+    @Nullable
     static VideoCodec fromValue(int value) {
         VideoCodec[] list = VideoCodec.values();
         for (VideoCodec action : list) {

cameraview/src/main/options/com/otaliastudios/cameraview/WhiteBalance.java

@@ -1,6 +1,7 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.Nullable;
 
 /**
  * White balance values control the white balance settings.
@@ -61,6 +62,7 @@ public enum WhiteBalance implements Control {
         return value;
     }
 
+    @Nullable
     static WhiteBalance fromValue(int value) {
         WhiteBalance[] list = WhiteBalance.values();
         for (WhiteBalance action : list) {

cameraview/src/main/utils/com/otaliastudios/cameraview/CameraLogger.java

@@ -1,6 +1,7 @@
 package com.otaliastudios.cameraview;
 
 import android.support.annotation.IntDef;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.util.Log;
 
@@ -45,7 +46,7 @@ public final class CameraLogger {
          * @param message the log message
          * @param throwable an optional throwable
          */
-        void log(@LogLevel int level, String tag, String message, @Nullable Throwable throwable);
+        void log(@LogLevel int level, @NonNull String tag, @NonNull String message, @Nullable Throwable throwable);
     }
 
     static String lastMessage;
@@ -59,7 +60,7 @@ public final class CameraLogger {
         sLoggers = new ArrayList<>();
         sLoggers.add(new Logger() {
             @Override
-            public void log(int level, String tag, String message, @Nullable Throwable throwable) {
+            public void log(int level, @NonNull String tag, @NonNull String message, @Nullable Throwable throwable) {
                 switch (level) {
                     case LEVEL_VERBOSE: Log.v(tag, message, throwable); break;
                     case LEVEL_INFO: Log.i(tag, message, throwable); break;
@@ -70,7 +71,7 @@ public final class CameraLogger {
         });
     }
 
-    static CameraLogger create(String tag) {
+    static CameraLogger create(@NonNull String tag) {
         return new CameraLogger(tag);
     }
 
@@ -93,7 +94,8 @@ public final class CameraLogger {
      *
      * @param logger logger to add
      */
-    public static void registerLogger(Logger logger) {
+    @SuppressWarnings("WeakerAccess")
+    public static void registerLogger(@NonNull Logger logger) {
         sLoggers.add(logger);
     }
 
@@ -103,13 +105,15 @@ public final class CameraLogger {
      *
      * @param logger logger to remove
      */
-    public static void unregisterLogger(Logger logger) {
+    @SuppressWarnings("WeakerAccess")
+    public static void unregisterLogger(@NonNull Logger logger) {
         sLoggers.remove(logger);
     }
 
+    @NonNull
     private String mTag;
 
-    private CameraLogger(String tag) {
+    private CameraLogger(@NonNull String tag) {
         mTag = tag;
     }
 
@@ -117,41 +121,39 @@ public final class CameraLogger {
         return sLevel <= messageLevel && sLoggers.size() > 0;
     }
 
-    void v(Object... data) {
+    void v(@NonNull Object... data) {
         log(LEVEL_VERBOSE, data);
     }
 
-    void i(Object... data) {
+    void i(@NonNull Object... data) {
         log(LEVEL_INFO, data);
     }
 
-    void w(Object... data) {
+    void w(@NonNull Object... data) {
         log(LEVEL_WARNING, data);
     }
 
-    void e(Object... data) {
+    void e(@NonNull Object... data) {
         log(LEVEL_ERROR, data);
     }
 
-    private void log(@LogLevel int level, Object... data) {
+    private void log(@LogLevel int level, @NonNull Object... data) {
         if (!should(level)) return;
 
-        String message = "";
+        StringBuilder message = new StringBuilder();
         Throwable throwable = null;
-        final int size = data.length;
         for (Object object : data) {
             if (object instanceof Throwable) {
                 throwable = (Throwable) object;
             }
-            message += String.valueOf(object);
-            message += " ";
+            message.append(String.valueOf(object));
+            message.append(" ");
         }
-        message = message.trim();
         for (Logger logger : sLoggers) {
-            logger.log(level, mTag, message, throwable);
+            logger.log(level, mTag, message.toString().trim(), throwable);
         }
 
-        lastMessage = message;
+        lastMessage = message.toString();
         lastTag = mTag;
     }
 }

cameraview/src/main/utils/com/otaliastudios/cameraview/CameraUtils.java

@@ -30,7 +30,7 @@ public class CameraUtils {
      * @return whether device has cameras
      */
     @SuppressWarnings("WeakerAccess")
-    public static boolean hasCameras(Context context) {
+    public static boolean hasCameras(@NonNull Context context) {
         PackageManager manager = context.getPackageManager();
         // There's also FEATURE_CAMERA_EXTERNAL , should we support it?
         return manager.hasSystemFeature(PackageManager.FEATURE_CAMERA)
@@ -46,7 +46,7 @@ public class CameraUtils {
      * @param facing either {@link Facing#BACK} or {@link Facing#FRONT}
      * @return true if such sensor exists
      */
-    public static boolean hasCameraFacing(Context context, Facing facing) {
+    public static boolean hasCameraFacing(@NonNull Context context, @NonNull Facing facing) {
         int internal = new Mapper1().map(facing);
         Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
         for (int i = 0, count = Camera.getNumberOfCameras(); i < count; i++) {
@@ -66,7 +66,7 @@ public class CameraUtils {
      */
     @SuppressWarnings("WeakerAccess")
     @WorkerThread
-    public static void decodeBitmap(final byte[] source) {
+    public static void decodeBitmap(@NonNull final byte[] source) {
         decodeBitmap(source, Integer.MAX_VALUE, Integer.MAX_VALUE);
     }
 
@@ -80,7 +80,7 @@ public class CameraUtils {
      * @param callback a callback to be notified
      */
     @SuppressWarnings("WeakerAccess")
-    public static void decodeBitmap(final byte[] source, final BitmapCallback callback) {
+    public static void decodeBitmap(@NonNull final byte[] source, @NonNull final BitmapCallback callback) {
         decodeBitmap(source, Integer.MAX_VALUE, Integer.MAX_VALUE, callback);
     }
     
@@ -98,7 +98,7 @@ public class CameraUtils {
      * @param callback a callback to be notified
      */
     @SuppressWarnings("WeakerAccess")
-    public static void decodeBitmap(final byte[] source, final int maxWidth, final int maxHeight, final BitmapCallback callback) {
+    public static void decodeBitmap(@NonNull final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapCallback callback) {
         decodeBitmap(source, maxWidth, maxHeight, new BitmapFactory.Options(), callback);
     }
 
@@ -117,12 +117,12 @@ public class CameraUtils {
      * @param callback a callback to be notified
      */
     @SuppressWarnings("WeakerAccess")
-    public static void decodeBitmap(final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapFactory.Options options, final BitmapCallback callback) {
+    public static void decodeBitmap(@NonNull final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapFactory.Options options, @NonNull final BitmapCallback callback) {
         decodeBitmap(source, maxWidth, maxHeight, options, -1, callback);
     }
 
     @SuppressWarnings("WeakerAccess")
-    static void decodeBitmap(final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapFactory.Options options, final int rotation, final BitmapCallback callback) {
+    static void decodeBitmap(@NonNull final byte[] source, final int maxWidth, final int maxHeight, @NonNull final BitmapFactory.Options options, final int rotation, @NonNull final BitmapCallback callback) {
         final Handler ui = new Handler();
         WorkerHandler.run(new Runnable() {
             @Override
@@ -149,7 +149,7 @@ public class CameraUtils {
      * @param maxWidth the max allowed width
      * @param maxHeight the max allowed height
      */
-    static Bitmap decodeBitmap(byte[] source, int maxWidth, int maxHeight) {
+    static Bitmap decodeBitmap(@NonNull byte[] source, int maxWidth, int maxHeight) {
         return decodeBitmap(source, maxWidth, maxHeight, new BitmapFactory.Options());
     }
 
@@ -168,14 +168,14 @@ public class CameraUtils {
     @SuppressWarnings({"SuspiciousNameCombination", "WeakerAccess"})
     @Nullable
     @WorkerThread
-    public static Bitmap decodeBitmap(byte[] source, int maxWidth, int maxHeight, @NonNull BitmapFactory.Options options) {
+    public static Bitmap decodeBitmap(@NonNull byte[] source, int maxWidth, int maxHeight, @NonNull BitmapFactory.Options options) {
         return decodeBitmap(source, maxWidth, maxHeight, options, -1);
     }
 
     // Null: got OOM
     // TODO ignores flipping. but it should be super rare.
     @Nullable
-    static Bitmap decodeBitmap(byte[] source, int maxWidth, int maxHeight, @NonNull BitmapFactory.Options options, int rotation) {
+    static Bitmap decodeBitmap(@NonNull byte[] source, int maxWidth, int maxHeight, @NonNull BitmapFactory.Options options, int rotation) {
         if (maxWidth <= 0) maxWidth = Integer.MAX_VALUE;
         if (maxHeight <= 0) maxHeight = Integer.MAX_VALUE;
         int orientation;
@@ -220,6 +220,7 @@ public class CameraUtils {
                 if (orientation % 180 != 0) {
                     //noinspection SuspiciousNameCombination
                     outHeight = options.outWidth;
+                    //noinspection SuspiciousNameCombination
                     outWidth = options.outHeight;
                 }
 

cameraview/src/main/utils/com/otaliastudios/cameraview/CropHelper.java

@@ -1,11 +1,13 @@
 package com.otaliastudios.cameraview;
 
 import android.graphics.Rect;
+import android.support.annotation.NonNull;
 
 class CropHelper {
 
     // It's important that size and aspect ratio belong to the same reference.
-    static Rect computeCrop(Size currentSize, AspectRatio targetRatio) {
+    @NonNull
+    static Rect computeCrop(@NonNull Size currentSize, @NonNull AspectRatio targetRatio) {
         int currentWidth = currentSize.getWidth();
         int currentHeight = currentSize.getHeight();
         if (targetRatio.matches(currentSize)) {

cameraview/src/main/utils/com/otaliastudios/cameraview/OrientationHelper.java

@@ -20,10 +20,11 @@ class OrientationHelper {
         void onDeviceOrientationChanged(int deviceOrientation);
     }
 
-    OrientationHelper(Context context, @NonNull Callback callback) {
+    OrientationHelper(@NonNull Context context, @NonNull Callback callback) {
         mCallback = callback;
         mListener = new OrientationEventListener(context.getApplicationContext(), SensorManager.SENSOR_DELAY_NORMAL) {
 
+            @SuppressWarnings("ConstantConditions")
             @Override
             public void onOrientationChanged(int orientation) {
                 int or = 0;
@@ -47,7 +48,7 @@ class OrientationHelper {
         };
     }
 
-    void enable(Context context) {
+    void enable(@NonNull Context context) {
         Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
         switch (display.getRotation()) {
             case Surface.ROTATION_0: mDisplayOffset = 0; break;

cameraview/src/main/utils/com/otaliastudios/cameraview/RotationHelper.java

@@ -1,10 +1,17 @@
 package com.otaliastudios.cameraview;
 
 import android.graphics.Rect;
-
+import android.support.annotation.NonNull;
+
+/**
+ * This will only be used on low APIs or when GL surface is not available.
+ * This risks OOMs and was never a good tool.
+ */
+@SuppressWarnings("DeprecatedIsStillUsed")
+@Deprecated
 class RotationHelper {
 
-    static byte[] rotate(final byte[] yuv, final Size size, final int rotation) {
+    static byte[] rotate(@NonNull final byte[] yuv, @NonNull final Size size, final int rotation) {
         if (rotation == 0) return yuv;
         if (rotation % 90 != 0 || rotation < 0 || rotation > 270) {
             throw new IllegalArgumentException("0 <= rotation < 360, rotation % 90 == 0");

cameraview/src/main/utils/com/otaliastudios/cameraview/SizeSelectors.java

@@ -16,7 +16,7 @@ public class SizeSelectors {
      * sizes in a list.
      */
     public interface Filter {
-        boolean accepts(Size size);
+        boolean accepts(@NonNull Size size);
     }
 
     /**
@@ -26,6 +26,8 @@ public class SizeSelectors {
      * @param filter a filter
      * @return a new selector
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public static SizeSelector withFilter(@NonNull Filter filter) {
         return new FilterSelector(filter);
     }
@@ -37,10 +39,11 @@ public class SizeSelectors {
      * @param width the max width
      * @return a new selector
      */
+    @NonNull
     public static SizeSelector maxWidth(final int width) {
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getWidth() <= width;
             }
         });
@@ -53,10 +56,11 @@ public class SizeSelectors {
      * @param width the min width
      * @return a new selector
      */
+    @NonNull
     public static SizeSelector minWidth(final int width) {
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getWidth() >= width;
             }
         });
@@ -69,10 +73,12 @@ public class SizeSelectors {
      * @param height the max height
      * @return a new selector
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public static SizeSelector maxHeight(final int height) {
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getHeight() <= height;
             }
         });
@@ -85,10 +91,11 @@ public class SizeSelectors {
      * @param height the min height
      * @return a new selector
      */
+    @NonNull
     public static SizeSelector minHeight(final int height) {
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getHeight() >= height;
             }
         });
@@ -103,11 +110,13 @@ public class SizeSelectors {
      * @param delta a small tolerance value
      * @return a new selector
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public static SizeSelector aspectRatio(AspectRatio ratio, final float delta) {
         final float desired = ratio.toFloat();
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 float candidate = AspectRatio.of(size.getWidth(), size.getHeight()).toFloat();
                 return candidate >= desired - delta && candidate <= desired + delta;
             }
@@ -120,6 +129,8 @@ public class SizeSelectors {
      *
      * @return a new selector
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public static SizeSelector biggest() {
         return new SizeSelector() {
             @NonNull
@@ -138,6 +149,8 @@ public class SizeSelectors {
      *
      * @return a new selector
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public static SizeSelector smallest() {
         return new SizeSelector() {
             @NonNull
@@ -156,10 +169,12 @@ public class SizeSelectors {
      * @param area the max area
      * @return a new selector
      */
+    @NonNull
+    @SuppressWarnings("WeakerAccess")
     public static SizeSelector maxArea(final int area) {
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getHeight() * size.getWidth() <= area;
             }
         });
@@ -172,10 +187,12 @@ public class SizeSelectors {
      * @param area the min area
      * @return a new selector
      */
+    @SuppressWarnings("WeakerAccess")
+    @NonNull
     public static SizeSelector minArea(final int area) {
         return withFilter(new Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getHeight() * size.getWidth() >= area;
             }
         });
@@ -191,6 +208,7 @@ public class SizeSelectors {
      * @param selectors input selectors
      * @return a new selector
      */
+    @NonNull
     public static SizeSelector and(SizeSelector... selectors) {
         return new AndSelector(selectors);
     }
@@ -203,6 +221,7 @@ public class SizeSelectors {
      * @param selectors input selectors
      * @return a new selector
      */
+    @NonNull
     public static SizeSelector or(SizeSelector... selectors) {
         return new OrSelector(selectors);
     }

cameraview/src/main/utils/com/otaliastudios/cameraview/WorkerHandler.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview;
 
 import android.os.Handler;
 import android.os.HandlerThread;
+import android.support.annotation.NonNull;
 
 import java.lang.ref.WeakReference;
 import java.util.WeakHashMap;
@@ -16,7 +17,8 @@ class WorkerHandler {
     private final static CameraLogger LOG = CameraLogger.create(WorkerHandler.class.getSimpleName());
     private final static ConcurrentHashMap<String, WeakReference<WorkerHandler>> sCache = new ConcurrentHashMap<>(4);
 
-    public static WorkerHandler get(String name) {
+    @NonNull
+    public static WorkerHandler get(@NonNull String name) {
         if (sCache.containsKey(name)) {
             WorkerHandler cached = sCache.get(name).get();
             if (cached != null) {
@@ -39,14 +41,14 @@ class WorkerHandler {
     // Handy util to perform action in a fallback thread.
     // Not to be used for long-running operations since they will
     // block the fallback thread.
-    public static void run(Runnable action) {
+    public static void run(@NonNull Runnable action) {
         get("FallbackCameraThread").post(action);
     }
 
     private HandlerThread mThread;
     private Handler mHandler;
 
-    private WorkerHandler(String name) {
+    private WorkerHandler(@NonNull String name) {
         mThread = new HandlerThread(name);
         mThread.setDaemon(true);
         mThread.start();
@@ -57,15 +59,16 @@ class WorkerHandler {
         return mHandler;
     }
 
-    public void post(Runnable runnable) {
+    public void post(@NonNull Runnable runnable) {
         mHandler.post(runnable);
     }
 
+    @NonNull
     public Thread getThread() {
         return mThread;
     }
 
-    public static void destroy() {
+    static void destroy() {
         for (String key : sCache.keySet()) {
             WeakReference<WorkerHandler> ref = sCache.get(key);
             WorkerHandler handler = ref.get();

cameraview/src/main/views/com/otaliastudios/cameraview/CameraPreview.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview;
 
 import android.content.Context;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -33,21 +34,23 @@ abstract class CameraPreview<T extends View, Output> {
     protected int mInputStreamHeight;
     protected boolean mInputFlipped;
 
-    CameraPreview(Context context, ViewGroup parent, SurfaceCallback callback) {
+    CameraPreview(@NonNull Context context, @NonNull ViewGroup parent, @Nullable SurfaceCallback callback) {
         mView = onCreateView(context, parent);
         mSurfaceCallback = callback;
     }
 
     @NonNull
-    protected abstract T onCreateView(Context context, ViewGroup parent);
+    protected abstract T onCreateView(@NonNull Context context, @NonNull ViewGroup parent);
 
     @NonNull
     final T getView() {
         return mView;
     }
 
+    @NonNull
     abstract Class<Output> getOutputClass();
 
+    @NonNull
     abstract Output getOutput();
 
     // As far as I can see, these are the actual preview dimensions, as set in CameraParameters.
@@ -63,15 +66,17 @@ abstract class CameraPreview<T extends View, Output> {
         }
     }
 
+    @NonNull
     final Size getInputStreamSize() {
         return new Size(mInputStreamWidth, mInputStreamHeight);
     }
 
+    @NonNull
     final Size getOutputSurfaceSize() {
         return new Size(mOutputSurfaceWidth, mOutputSurfaceHeight);
     }
 
-    final void setSurfaceCallback(SurfaceCallback callback) {
+    final void setSurfaceCallback(@NonNull SurfaceCallback callback) {
         mSurfaceCallback = callback;
         // If surface already available, dispatch.
         if (mOutputSurfaceWidth != 0 || mOutputSurfaceHeight != 0) {
@@ -80,6 +85,7 @@ abstract class CameraPreview<T extends View, Output> {
     }
 
 
+    @SuppressWarnings("WeakerAccess")
     protected final void dispatchOnOutputSurfaceAvailable(int width, int height) {
         LOG.i("dispatchOnOutputSurfaceAvailable:", "w=", width, "h=", height);
         mOutputSurfaceWidth = width;
@@ -93,6 +99,7 @@ abstract class CameraPreview<T extends View, Output> {
 
     // As far as I can see, these are the view/surface dimensions.
     // This is called by subclasses.
+    @SuppressWarnings("WeakerAccess")
     protected final void dispatchOnOutputSurfaceSizeChanged(int width, int height) {
         LOG.i("dispatchOnOutputSurfaceSizeChanged:", "w=", width, "h=", height);
         if (width != mOutputSurfaceWidth || height != mOutputSurfaceHeight) {
@@ -105,6 +112,7 @@ abstract class CameraPreview<T extends View, Output> {
         }
     }
 
+    @SuppressWarnings("WeakerAccess")
     protected final void dispatchOnOutputSurfaceDestroyed() {
         mOutputSurfaceWidth = 0;
         mOutputSurfaceHeight = 0;

cameraview/src/main/views/com/otaliastudios/cameraview/GestureLayout.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview;
 
 import android.content.Context;
 import android.graphics.PointF;
+import android.support.annotation.NonNull;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
@@ -17,12 +18,12 @@ abstract class GestureLayout extends FrameLayout {
     protected Gesture mType;
     protected PointF[] mPoints;
 
-    public GestureLayout(Context context) {
+    public GestureLayout(@NonNull Context context) {
         super(context);
         onInitialize(context);
     }
 
-    protected void onInitialize(Context context) {
+    protected void onInitialize(@NonNull Context context) {
     }
 
     public void enable(boolean enable) {
@@ -35,15 +36,17 @@ abstract class GestureLayout extends FrameLayout {
 
     public abstract boolean onTouchEvent(MotionEvent event);
 
+    @NonNull
     public final Gesture getGestureType() {
         return mType;
     }
 
     // For tests.
-    void setGestureType(Gesture type) {
+    void setGestureType(@NonNull Gesture type) {
         mType = type;
     }
 
+    @NonNull
     public final PointF[] getPoints() {
         return mPoints;
     }

cameraview/src/main/views/com/otaliastudios/cameraview/GlCameraPreview.java

@@ -71,7 +71,7 @@ class GlCameraPreview extends CameraPreview<GLSurfaceView, SurfaceTexture> imple
     /* for tests */ float mScaleY = 1F;
     private float[] mScaleXY = new float[] { mScaleX, mScaleY };
 
-    GlCameraPreview(Context context, ViewGroup parent, SurfaceCallback callback) {
+    GlCameraPreview(@NonNull Context context, @NonNull ViewGroup parent, @Nullable SurfaceCallback callback) {
         super(context, parent, callback);
     }
 
@@ -103,7 +103,7 @@ class GlCameraPreview extends CameraPreview<GLSurfaceView, SurfaceTexture> imple
 
     @NonNull
     @Override
-    protected GLSurfaceView onCreateView(Context context, ViewGroup parent) {
+    protected GLSurfaceView onCreateView(@NonNull Context context, @NonNull ViewGroup parent) {
         ViewGroup root = (ViewGroup) LayoutInflater.from(context).inflate(R.layout.cameraview_gl_view, parent, false);
         GLSurfaceView glView = root.findViewById(R.id.gl_surface_view);
         glView.setEGLContextClientVersion(2);
@@ -236,11 +236,13 @@ class GlCameraPreview extends CameraPreview<GLSurfaceView, SurfaceTexture> imple
         }
     }
 
+    @NonNull
     @Override
     Class<SurfaceTexture> getOutputClass() {
         return SurfaceTexture.class;
     }
 
+    @NonNull
     @Override
     SurfaceTexture getOutput() {
         return mInputSurfaceTexture;

cameraview/src/main/views/com/otaliastudios/cameraview/GridLinesLayout.java

@@ -26,7 +26,6 @@ class GridLinesLayout extends View {
 
     Task<Integer> drawTask = new Task<>();
 
-
     public GridLinesLayout(@NonNull Context context) {
         this(context, null);
     }
@@ -45,11 +44,12 @@ class GridLinesLayout extends View {
         vert.setBounds(0, top, (int) width, bottom);
     }
 
+    @NonNull
     public Grid getGridMode() {
         return gridMode;
     }
 
-    public void setGridMode(Grid gridMode) {
+    public void setGridMode(@NonNull Grid gridMode) {
         this.gridMode = gridMode;
         postInvalidate();
     }
@@ -89,7 +89,7 @@ class GridLinesLayout extends View {
     }
 
     @Override
-    protected void onDraw(Canvas canvas) {
+    protected void onDraw(@NonNull Canvas canvas) {
         super.onDraw(canvas);
         drawTask.start();
         int count = getLineCount();

cameraview/src/main/views/com/otaliastudios/cameraview/PinchGestureLayout.java

@@ -1,8 +1,10 @@
 package com.otaliastudios.cameraview;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.PointF;
 import android.os.Build;
+import android.support.annotation.NonNull;
 import android.view.MotionEvent;
 import android.view.ScaleGestureDetector;
 
@@ -14,14 +16,12 @@ class PinchGestureLayout extends GestureLayout {
     private boolean mNotify;
     /* tests */ float mFactor = 0;
 
-
-    public PinchGestureLayout(Context context) {
+    public PinchGestureLayout(@NonNull Context context) {
         super(context);
     }
 
-
     @Override
-    protected void onInitialize(Context context) {
+    protected void onInitialize(@NonNull Context context) {
         super.onInitialize(context);
         mPoints = new PointF[]{ new PointF(0, 0), new PointF(0, 0) };
         mDetector = new ScaleGestureDetector(context, new ScaleGestureDetector.SimpleOnScaleGestureListener() {
@@ -42,6 +42,7 @@ class PinchGestureLayout extends GestureLayout {
     }
 
 
+    @SuppressLint("ClickableViewAccessibility")
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         if (!mEnabled) return false;

cameraview/src/main/views/com/otaliastudios/cameraview/ScrollGestureLayout.java

@@ -1,7 +1,9 @@
 package com.otaliastudios.cameraview;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.PointF;
+import android.support.annotation.NonNull;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 
@@ -14,13 +16,12 @@ class ScrollGestureLayout extends GestureLayout {
     private boolean mNotify;
     /* tests */ float mFactor;
 
-
-    public ScrollGestureLayout(Context context) {
+    public ScrollGestureLayout(@NonNull Context context) {
         super(context);
     }
 
     @Override
-    protected void onInitialize(Context context) {
+    protected void onInitialize(@NonNull Context context) {
         super.onInitialize(context);
         mPoints = new PointF[]{ new PointF(0, 0), new PointF(0, 0) };
         mDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@@ -51,7 +52,7 @@ class ScrollGestureLayout extends GestureLayout {
         mDetector.setIsLongpressEnabled(false); // Looks important.
     }
 
-
+    @SuppressLint("ClickableViewAccessibility")
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         if (!mEnabled) return false;
@@ -71,7 +72,6 @@ class ScrollGestureLayout extends GestureLayout {
         return mNotify;
     }
 
-
     @Override
     public float scaleValue(float currValue, float minValue, float maxValue) {
         float delta = mFactor; // -1 ... 1

cameraview/src/main/views/com/otaliastudios/cameraview/SurfaceCameraPreview.java

@@ -2,6 +2,7 @@ package com.otaliastudios.cameraview;
 
 import android.content.Context;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.LayoutInflater;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
@@ -18,13 +19,13 @@ class SurfaceCameraPreview extends CameraPreview<SurfaceView, SurfaceHolder> {
 
     private boolean mDispatched;
 
-    SurfaceCameraPreview(Context context, ViewGroup parent, SurfaceCallback callback) {
+    SurfaceCameraPreview(@NonNull Context context, @NonNull ViewGroup parent, @Nullable SurfaceCallback callback) {
         super(context, parent, callback);
     }
 
     @NonNull
     @Override
-    protected SurfaceView onCreateView(Context context, ViewGroup parent) {
+    protected SurfaceView onCreateView(@NonNull Context context, @NonNull ViewGroup parent) {
         View root = LayoutInflater.from(context).inflate(R.layout.cameraview_surface_view, parent, false);
         parent.addView(root, 0);
         SurfaceView surfaceView = root.findViewById(R.id.surface_view);
@@ -59,11 +60,13 @@ class SurfaceCameraPreview extends CameraPreview<SurfaceView, SurfaceHolder> {
         return surfaceView;
     }
 
+    @NonNull
     @Override
     SurfaceHolder getOutput() {
         return getView().getHolder();
     }
 
+    @NonNull
     @Override
     Class<SurfaceHolder> getOutputClass() {
         return SurfaceHolder.class;

cameraview/src/main/views/com/otaliastudios/cameraview/TapGestureLayout.java

@@ -2,8 +2,11 @@ package com.otaliastudios.cameraview;
 
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.PointF;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.GestureDetector;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
@@ -13,20 +16,18 @@ import android.widget.ImageView;
 
 class TapGestureLayout extends GestureLayout {
 
-
     private GestureDetector mDetector;
     private boolean mNotify;
 
     private FrameLayout mFocusMarkerContainer;
     private ImageView mFocusMarkerFill;
 
-    public TapGestureLayout(Context context) {
+    public TapGestureLayout(@NonNull Context context) {
         super(context);
     }
 
-
     @Override
-    protected void onInitialize(Context context) {
+    protected void onInitialize(@NonNull Context context) {
         super.onInitialize(context);
         mPoints = new PointF[]{ new PointF(0, 0) };
         mDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@@ -62,7 +63,7 @@ class TapGestureLayout extends GestureLayout {
         mFocusMarkerFill = findViewById(R.id.fill);
     }
 
-
+    @SuppressLint("ClickableViewAccessibility")
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         if (!mEnabled) return false;
@@ -100,7 +101,7 @@ class TapGestureLayout extends GestureLayout {
         }
     };
 
-    public void onFocusStart(PointF point) {
+    public void onFocusStart(@NonNull PointF point) {
         removeCallbacks(mFocusMarkerHideRunnable);
         mFocusMarkerContainer.clearAnimation(); // animate().setListener(null).cancel();
         mFocusMarkerFill.clearAnimation(); // animate().setListener(null).cancel();
@@ -128,7 +129,6 @@ class TapGestureLayout extends GestureLayout {
         });
     }
 
-
     public void onFocusEnd(boolean success) {
         if (success) {
             animate(mFocusMarkerContainer, 1, 0, 500, 0, null);
@@ -145,9 +145,8 @@ class TapGestureLayout extends GestureLayout {
         }
     }
 
-
-    private static void animate(View view, float scale, float alpha, long duration, long delay,
-                                Animator.AnimatorListener listener) {
+    private static void animate(@NonNull View view, float scale, float alpha, long duration, long delay,
+                                @Nullable Animator.AnimatorListener listener) {
         view.animate().scaleX(scale).scaleY(scale)
                 .alpha(alpha)
                 .setDuration(duration)

cameraview/src/main/views/com/otaliastudios/cameraview/TextureCameraPreview.java

@@ -4,6 +4,7 @@ import android.annotation.TargetApi;
 import android.content.Context;
 import android.graphics.SurfaceTexture;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.LayoutInflater;
 import android.view.TextureView;
 import android.view.View;
@@ -11,13 +12,13 @@ import android.view.ViewGroup;
 
 class TextureCameraPreview extends CameraPreview<TextureView, SurfaceTexture> {
 
-    TextureCameraPreview(Context context, ViewGroup parent, SurfaceCallback callback) {
+    TextureCameraPreview(@NonNull Context context, @NonNull ViewGroup parent, @Nullable SurfaceCallback callback) {
         super(context, parent, callback);
     }
 
     @NonNull
     @Override
-    protected TextureView onCreateView(Context context, ViewGroup parent) {
+    protected TextureView onCreateView(@NonNull Context context, @NonNull ViewGroup parent) {
         View root = LayoutInflater.from(context).inflate(R.layout.cameraview_texture_view, parent, false);
         parent.addView(root, 0);
         TextureView texture = root.findViewById(R.id.texture_view);
@@ -46,11 +47,13 @@ class TextureCameraPreview extends CameraPreview<TextureView, SurfaceTexture> {
         return texture;
     }
 
+    @NonNull
     @Override
     Class<SurfaceTexture> getOutputClass() {
         return SurfaceTexture.class;
     }
 
+    @NonNull
     @Override
     SurfaceTexture getOutput() {
         return getView().getSurfaceTexture();

cameraview/src/test/java/com/otaliastudios/cameraview/SizeSelectorsTest.java

@@ -1,6 +1,8 @@
 package com.otaliastudios.cameraview;
 
 
+import android.support.annotation.NonNull;
+
 import org.junit.Before;
 import org.junit.Test;
 
@@ -33,7 +35,7 @@ public class SizeSelectorsTest {
     public void testWithFilter() {
         SizeSelector selector = SizeSelectors.withFilter(new SizeSelectors.Filter() {
             @Override
-            public boolean accepts(Size size) {
+            public boolean accepts(@NonNull Size size) {
                 return size.getWidth() == 600;
             }
         });

demo/src/main/java/com/otaliastudios/cameraview/demo/CameraActivity.java

@@ -43,9 +43,9 @@ public class CameraActivity extends AppCompatActivity implements View.OnClickLis
         camera = findViewById(R.id.camera);
         camera.setLifecycleOwner(this);
         camera.addCameraListener(new CameraListener() {
-            public void onCameraOpened(CameraOptions options) { onOpened(options); }
-            public void onPictureTaken(PictureResult result) { onPicture(result); }
-            public void onVideoTaken(VideoResult result) { onVideo(result); }
+            public void onCameraOpened(@NonNull CameraOptions options) { onOpened(options); }
+            public void onPictureTaken(@NonNull PictureResult result) { onPicture(result); }
+            public void onVideoTaken(@NonNull VideoResult result) { onVideo(result); }
             public void onCameraError(@NonNull CameraException exception) {
                 onError(exception);
             }