Add screenshots

- permissions changed to allow access to external storage
- button added to interface
- code added to build the screenshot and save it to the user's Picture folder

app/src/main/AndroidManifest.xml

@@ -9,6 +9,7 @@
     package="com.affectiva.affdexme">
 
     <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
     <uses-feature
         android:name="android.hardware.camera"

app/src/main/java/com/affectiva/affdexme/DrawingView.java

@@ -19,11 +19,13 @@ import android.graphics.Rect;
 import android.graphics.Typeface;
 import android.os.Process;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.util.Pair;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
+import android.widget.Toast;
 
 import com.affectiva.android.affdex.sdk.detector.Face;
 
@@ -52,6 +54,7 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
     private SurfaceHolder surfaceHolder;
     private DrawingThread drawingThread; //DrawingThread object
     private DrawingViewConfig drawingViewConfig;
+    private DrawingThreadEventListener listener;
 
     //three constructors required of any custom view
     public DrawingView(Context context) {
@@ -73,11 +76,34 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
         return context.getResources().getIdentifier(name, "drawable", context.getPackageName());
     }
 
+    public void setEventListener(DrawingThreadEventListener listener) {
+        this.listener = listener;
+
+        if (drawingThread != null) {
+            drawingThread.setEventListener(listener);
+        }
+    }
+
+    public void requestBitmap() {
+        if (listener == null) {
+            String msg = "Attempted to request screenshot without first attaching event listener";
+            Log.e(LOG_TAG, msg);
+            Toast.makeText(getContext(), msg, Toast.LENGTH_SHORT).show();
+            return;
+        }
+        if (drawingThread == null || drawingThread.isStopped()) {
+            String msg = "Attempted to request screenshot without a running drawing thread";
+            Log.e(LOG_TAG, msg);
+            Toast.makeText(getContext(), msg, Toast.LENGTH_SHORT).show();
+            return;
+        }
+        drawingThread.requestCaptureBitmap = true;
+    }
+
     void initView() {
         surfaceHolder = getHolder(); //The SurfaceHolder object will be used by the thread to request canvas to draw on SurfaceView
         surfaceHolder.setFormat(PixelFormat.TRANSPARENT); //set to Transparent so this surfaceView does not obscure the one it is overlaying (the one displaying the camera).
         surfaceHolder.addCallback(this); //become a Listener to the three events below that SurfaceView generates
-
         drawingViewConfig = new DrawingViewConfig();
 
         //Default values
@@ -133,7 +159,7 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
 
         drawingViewConfig.setDominantEmotionLabelPaints(emotionLabelPaint, emotionValuePaint);
         drawingViewConfig.setDominantEmotionMetricBarConfig(metricBarPaint, metricBarWidth);
-        drawingThread = new DrawingThread(surfaceHolder, drawingViewConfig);
+        drawingThread = new DrawingThread(surfaceHolder, drawingViewConfig, listener);
 
         //statically load the emoji bitmaps on-demand and cache
         emojiMarkerBitmapToEmojiTypeMap = new HashMap<>();
@@ -147,7 +173,7 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
     @Override
     public void surfaceCreated(SurfaceHolder holder) {
         if (drawingThread.isStopped()) {
-            drawingThread = new DrawingThread(surfaceHolder, drawingViewConfig);
+            drawingThread = new DrawingThread(surfaceHolder, drawingViewConfig, listener);
         }
         drawingThread.start();
     }
@@ -261,6 +287,10 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
         }
     }
 
+    interface DrawingThreadEventListener {
+        void onBitmapGenerated(Bitmap bitmap);
+    }
+
     class FacesSharer {
         boolean isPointsMirrored;
         List<Face> facesToDraw;
@@ -279,9 +309,11 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
         private Paint boundingBoxPaint;
         private Paint dominantEmotionScoreBarPaint;
         private volatile boolean stopFlag = false; //boolean to indicate when thread has been told to stop
+        private volatile boolean requestCaptureBitmap = false; //boolean to indicate a snapshot of the surface has been requested
         private DrawingViewConfig config;
+        private DrawingThreadEventListener listener;
 
-        public DrawingThread(SurfaceHolder surfaceHolder, DrawingViewConfig con) {
+        public DrawingThread(SurfaceHolder surfaceHolder, DrawingViewConfig con, DrawingThreadEventListener listener) {
             mSurfaceHolder = surfaceHolder;
 
             //statically load the Appearance marker bitmaps so they only have to load once
@@ -303,10 +335,15 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
 
             config = con;
             sharer = new FacesSharer();
+            this.listener = listener;
 
             setThickness(config.drawThickness);
         }
 
+        public void setEventListener(DrawingThreadEventListener listener) {
+            this.listener = listener;
+        }
+
         void setValenceOfBoundingBox(float valence) {
             //prepare the color of the bounding box using the valence score. Red for -100, White for 0, and Green for +100, with linear interpolation in between.
             if (valence > 0) {
@@ -359,26 +396,40 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
                  * After we are done drawing, we let go of the canvas using SurfaceHolder.unlockCanvasAndPost()
                  * **/
                 Canvas c = null;
+                Canvas screenshotCanvas = null;
+                Bitmap screenshotBitmap = null;
                 try {
                     c = mSurfaceHolder.lockCanvas();
 
+                    if (requestCaptureBitmap) {
+                        Rect surfaceBounds = mSurfaceHolder.getSurfaceFrame();
+                        screenshotBitmap = Bitmap.createBitmap(surfaceBounds.width(), surfaceBounds.height(), Bitmap.Config.ARGB_8888);
+                        screenshotCanvas = new Canvas(screenshotBitmap);
+                        requestCaptureBitmap = false;
+                    }
+
                     if (c != null) {
                         synchronized (mSurfaceHolder) {
                             c.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR); //clear previous dots
-                            draw(c);
+                            draw(c, screenshotCanvas);
                         }
                     }
+
                 } finally {
                     if (c != null) {
                         mSurfaceHolder.unlockCanvasAndPost(c);
                     }
+                    if (screenshotBitmap != null && listener != null) {
+                        listener.onBitmapGenerated(Bitmap.createBitmap(screenshotBitmap));
+                        screenshotBitmap.recycle();
+                    }
                 }
             }
 
             config = null; //nullify object to avoid memory leak
         }
 
-        void draw(Canvas c) {
+        void draw(@NonNull Canvas c, @Nullable Canvas c2) {
             Face nextFaceToDraw;
             boolean mirrorPoints;
             boolean multiFaceMode;
@@ -400,6 +451,10 @@ public class DrawingView extends SurfaceView implements SurfaceHolder.Callback {
 
                 drawFaceAttributes(c, nextFaceToDraw, mirrorPoints, multiFaceMode);
 
+                if (c2 != null) {
+                    drawFaceAttributes(c2, nextFaceToDraw, false, multiFaceMode);
+                }
+
                 synchronized (sharer) {
                     mirrorPoints = sharer.isPointsMirrored;
 

app/src/main/java/com/affectiva/affdexme/ImageHelper.java

@@ -5,22 +5,31 @@
 
 package com.affectiva.affdexme;
 
+import android.content.ContentValues;
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
+import android.graphics.ImageFormat;
 import android.graphics.Matrix;
+import android.graphics.Rect;
+import android.graphics.YuvImage;
 import android.graphics.drawable.Drawable;
+import android.provider.MediaStore;
 import android.support.annotation.NonNull;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.widget.ImageView;
 
+import com.affectiva.android.affdex.sdk.Frame;
+
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.nio.ByteBuffer;
 
 public class ImageHelper {
 
@@ -30,7 +39,7 @@ public class ImageHelper {
     private ImageHelper() {
     }
 
-    public static boolean checkIfImageFileExists(@NonNull Context context, @NonNull String fileName) {
+    public static boolean checkIfImageFileExists(@NonNull final Context context, @NonNull final String fileName) {
 
         // path to /data/data/yourapp/app_data/images
         File directory = context.getDir("images", Context.MODE_PRIVATE);
@@ -41,7 +50,7 @@ public class ImageHelper {
         return imagePath.exists();
     }
 
-    public static boolean deleteImageFile(@NonNull Context context, @NonNull String fileName) {
+    public static boolean deleteImageFile(@NonNull final Context context, @NonNull final String fileName) {
         // path to /data/data/yourapp/app_data/images
         File directory = context.getDir("images", Context.MODE_PRIVATE);
 
@@ -51,7 +60,7 @@ public class ImageHelper {
         return imagePath.delete();
     }
 
-    public static void resizeAndSaveResourceImageToInternalStorage(@NonNull Context context, @NonNull String fileName, @NonNull String resourceName) throws FileNotFoundException {
+    public static void resizeAndSaveResourceImageToInternalStorage(@NonNull final Context context, @NonNull final String fileName, @NonNull final String resourceName) throws FileNotFoundException {
         final int resourceId = context.getResources().getIdentifier(resourceName, "drawable", context.getPackageName());
 
         if (resourceId == 0) {
@@ -61,7 +70,7 @@ public class ImageHelper {
         resizeAndSaveResourceImageToInternalStorage(context, fileName, resourceId);
     }
 
-    public static void resizeAndSaveResourceImageToInternalStorage(@NonNull Context context, @NonNull String fileName, int resourceId) {
+    public static void resizeAndSaveResourceImageToInternalStorage(@NonNull final Context context, @NonNull final String fileName, final int resourceId) {
         Resources resources = context.getResources();
         Bitmap sourceBitmap = BitmapFactory.decodeResource(resources, resourceId);
         Bitmap resizedBitmap = resizeBitmapForDeviceDensity(context, sourceBitmap);
@@ -70,7 +79,7 @@ public class ImageHelper {
         resizedBitmap.recycle();
     }
 
-    public static Bitmap resizeBitmapForDeviceDensity(@NonNull Context context, @NonNull Bitmap sourceBitmap) {
+    public static Bitmap resizeBitmapForDeviceDensity(@NonNull final Context context, @NonNull final Bitmap sourceBitmap) {
         DisplayMetrics metrics = context.getResources().getDisplayMetrics();
 
         int targetWidth = Math.round(sourceBitmap.getWidth() * metrics.density);
@@ -79,7 +88,7 @@ public class ImageHelper {
         return Bitmap.createScaledBitmap(sourceBitmap, targetWidth, targetHeight, false);
     }
 
-    public static void saveBitmapToInternalStorage(@NonNull Context context, @NonNull Bitmap bitmapImage, @NonNull String fileName) {
+    public static void saveBitmapToInternalStorage(@NonNull final Context context, @NonNull final Bitmap bitmapImage, @NonNull final String fileName) {
 
         // path to /data/data/yourapp/app_data/images
         File directory = context.getDir("images", Context.MODE_PRIVATE);
@@ -109,7 +118,7 @@ public class ImageHelper {
         }
     }
 
-    public static Bitmap loadBitmapFromInternalStorage(@NonNull Context applicationContext, @NonNull String fileName) {
+    public static Bitmap loadBitmapFromInternalStorage(@NonNull final Context applicationContext, @NonNull final String fileName) {
 
         // path to /data/data/yourapp/app_data/images
         File directory = applicationContext.getDir("images", Context.MODE_PRIVATE);
@@ -125,7 +134,7 @@ public class ImageHelper {
         }
     }
 
-    public static void preproccessImageIfNecessary(Context context, String fileName, String resourceName) {
+    public static void preproccessImageIfNecessary(@NonNull final Context context, @NonNull final String fileName, @NonNull final String resourceName) {
         // Set this to true to force the app to always load the images for debugging purposes
         final boolean DEBUG = false;
 
@@ -157,10 +166,10 @@ public class ImageHelper {
      * @param imageView source ImageView
      * @return 0: left, 1: top, 2: width, 3: height
      */
-    public static int[] getBitmapPositionInsideImageView(ImageView imageView) {
+    public static int[] getBitmapPositionInsideImageView(@NonNull final ImageView imageView) {
         int[] ret = new int[4];
 
-        if (imageView == null || imageView.getDrawable() == null)
+        if (imageView.getDrawable() == null)
             return ret;
 
         // Get image dimensions
@@ -197,4 +206,101 @@ public class ImageHelper {
 
         return ret;
     }
+
+    /**
+     * This is a HACK.
+     * We need to update the Android SDK to make this process cleaner.
+     * We should just be able to call frame.getBitmap() and have it return a bitmap no matter what type
+     * of frame it is.  If any conversion between file types needs to take place, it needs to happen
+     * inside the SDK layer and put the onus on the developer to know how to convert between YUV and ARGB.
+     * TODO: See above
+     *
+     * @param frame - The Frame containing the desired image
+     * @return - The Bitmap representation of the image
+     */
+    public static Bitmap getBitmapFromFrame(@NonNull final Frame frame) {
+        Bitmap bitmap;
+
+        if (frame instanceof Frame.BitmapFrame) {
+            bitmap = ((Frame.BitmapFrame) frame).getBitmap();
+        } else { //frame is ByteArrayFrame
+            switch (frame.getColorFormat()) {
+                case RGBA:
+                    bitmap = getBitmapFromRGBFrame(frame);
+                    break;
+                case YUV_NV21:
+                    bitmap = getBitmapFromYuvFrame(frame);
+                    break;
+                case UNKNOWN_TYPE:
+                default:
+                    Log.e(LOG_TAG, "Unable to get bitmap from unknown frame type");
+                    return null;
+            }
+        }
+
+        if (bitmap == null || frame.getTargetRotation().toDouble() == 0.0) {
+            return bitmap;
+        } else {
+            return rotateBitmap(bitmap, (float) frame.getTargetRotation().toDouble());
+        }
+    }
+
+    public static Bitmap getBitmapFromRGBFrame(@NonNull final Frame frame) {
+        byte[] pixels = ((Frame.ByteArrayFrame) frame).getByteArray();
+        Bitmap bitmap = Bitmap.createBitmap(frame.getWidth(), frame.getHeight(), Bitmap.Config.ARGB_8888);
+        bitmap.copyPixelsFromBuffer(ByteBuffer.wrap(pixels));
+        return bitmap;
+    }
+
+    public static Bitmap getBitmapFromYuvFrame(@NonNull final Frame frame) {
+        byte[] pixels = ((Frame.ByteArrayFrame) frame).getByteArray();
+        YuvImage yuvImage = new YuvImage(pixels, ImageFormat.NV21, frame.getWidth(), frame.getHeight(), null);
+        return convertYuvImageToBitmap(yuvImage);
+    }
+
+    /**
+     * Note: This conversion procedure is sloppy and may result in JPEG compression artifacts
+     *
+     * @param yuvImage - The YuvImage to convert
+     * @return - The converted Bitmap
+     */
+    public static Bitmap convertYuvImageToBitmap(@NonNull final YuvImage yuvImage) {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        yuvImage.compressToJpeg(new Rect(0, 0, yuvImage.getWidth(), yuvImage.getHeight()), 100, out);
+        byte[] imageBytes = out.toByteArray();
+        try {
+            out.close();
+        } catch (IOException e) {
+            Log.e(LOG_TAG, "Exception while closing output stream", e);
+        }
+        return BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
+    }
+
+    public static Bitmap rotateBitmap(@NonNull final Bitmap source, final float angle) {
+        Matrix matrix = new Matrix();
+        matrix.postRotate(angle);
+        return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix, true);
+    }
+
+    public static void saveBitmapToFileAsPng(@NonNull final Bitmap bitmap, @NonNull final File file) throws IOException {
+        try {
+            FileOutputStream outputStream = new FileOutputStream(file);
+            bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream);
+            bitmap.recycle();
+            outputStream.flush();
+            outputStream.close();
+        } catch (IOException e) {
+            throw new FileNotFoundException("Unable to save bitmap to file: " + file.getPath() + "\n" + e.getLocalizedMessage());
+        }
+    }
+
+    public static void addPngToGallery(@NonNull final Context context, @NonNull final File imageFile) {
+        ContentValues values = new ContentValues();
+
+        values.put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis());
+        values.put(MediaStore.Images.Media.MIME_TYPE, "image/png");
+        values.put(MediaStore.MediaColumns.DATA, imageFile.getAbsolutePath());
+
+        context.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
+    }
 }

app/src/main/java/com/affectiva/affdexme/MainActivity.java

@@ -11,15 +11,21 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Rect;
 import android.graphics.Typeface;
 import android.os.Bundle;
+import android.os.Environment;
 import android.os.SystemClock;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
 import android.support.v4.app.ActivityCompat;
 import android.support.v4.content.ContextCompat;
-import android.support.v7.app.AlertDialog;
+import android.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
+import android.text.format.DateFormat;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.KeyEvent;
@@ -42,9 +48,11 @@ import com.affectiva.android.affdex.sdk.detector.CameraDetector;
 import com.affectiva.android.affdex.sdk.detector.Detector;
 import com.affectiva.android.affdex.sdk.detector.Face;
 
+import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
+import java.util.Date;
 import java.util.List;
 import java.util.Locale;
 
@@ -80,17 +88,20 @@ import java.util.Locale;
 
 public class MainActivity extends AppCompatActivity
         implements Detector.FaceListener, Detector.ImageListener, CameraDetector.CameraEventListener,
-        View.OnTouchListener, ActivityCompat.OnRequestPermissionsResultCallback {
+        View.OnTouchListener, ActivityCompat.OnRequestPermissionsResultCallback, DrawingView.DrawingThreadEventListener {
 
-    public static final int MAX_SUPPORTED_FACES = 4;
+    public static final int MAX_SUPPORTED_FACES = 3;
+    public static final boolean STORE_RAW_SCREENSHOTS = false; // setting to enable saving the raw images when taking screenshots
     public static final int NUM_METRICS_DISPLAYED = 6;
     private static final String LOG_TAG = "AffdexMe";
-    private static final int AFFDEXME_PERMISSIONS_REQUEST = 42;  //value is arbitrary (between 0 and 255)
+    private static final int CAMERA_PERMISSIONS_REQUEST = 42;  //value is arbitrary (between 0 and 255)
+    private static final int EXTERNAL_STORAGE_PERMISSIONS_REQUEST = 73;
     int cameraPreviewWidth = 0;
     int cameraPreviewHeight = 0;
     CameraDetector.CameraType cameraType;
     boolean mirrorPoints = false;
     private boolean cameraPermissionsAvailable = false;
+    private boolean storagePermissionsAvailable = false;
     private CameraDetector detector = null;
     private RelativeLayout metricViewLayout;
     private LinearLayout leftMetricsLayout;
@@ -108,6 +119,8 @@ public class MainActivity extends AppCompatActivity
     private DrawingView drawingView; //SurfaceView containing its own thread, used to draw facial tracking dots
     private ImageButton settingsButton;
     private ImageButton cameraButton;
+    private ImageButton screenshotButton;
+    private Frame mostRecentFrame;
     private boolean isMenuVisible = false;
     private boolean isFPSVisible = false;
     private boolean isMenuShowingForFirstTime = true;
@@ -125,7 +138,7 @@ public class MainActivity extends AppCompatActivity
         preproccessMetricImages();
         setContentView(R.layout.activity_main);
         initializeUI();
-        checkForDangerousPermissions();
+        checkForCameraPermissions();
         determineCameraAvailability();
         initializeCameraDetector();
     }
@@ -153,8 +166,7 @@ public class MainActivity extends AppCompatActivity
         ImageHelper.preproccessImageIfNecessary(context, "unknown_noglasses.png", "unknown_noglasses");
     }
 
-
-    private void checkForDangerousPermissions() {
+    private void checkForCameraPermissions() {
         cameraPermissionsAvailable =
                 ContextCompat.checkSelfPermission(
                         getApplicationContext(),
@@ -168,35 +180,67 @@ public class MainActivity extends AppCompatActivity
                 // Show an explanation to the user *asynchronously* -- don't block
                 // this thread waiting for the user's response! After the user
                 // sees the explanation, try again to request the permission.
-                showPermissionExplanationDialog();
+                showPermissionExplanationDialog(CAMERA_PERMISSIONS_REQUEST);
             } else {
                 // No explanation needed, we can request the permission.
-                requestNeededPermissions();
+                requestCameraPermissions();
             }
         }
     }
 
-    private void requestNeededPermissions() {
-        List<String> neededPermissions = new ArrayList<>();
+    private void checkForStoragePermissions() {
+        storagePermissionsAvailable =
+                ContextCompat.checkSelfPermission(
+                        getApplicationContext(),
+                        Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
 
-        if (!cameraPermissionsAvailable) {
-            neededPermissions.add(Manifest.permission.CAMERA);
+        if (!storagePermissionsAvailable) {
+
+            // Should we show an explanation?
+            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
+
+                // Show an explanation to the user *asynchronously* -- don't block
+                // this thread waiting for the user's response! After the user
+                // sees the explanation, try again to request the permission.
+                showPermissionExplanationDialog(EXTERNAL_STORAGE_PERMISSIONS_REQUEST);
+            } else {
+                // No explanation needed, we can request the permission.
+                requestStoragePermissions();
+            }
+        } else {
+            takeScreenshot(screenshotButton);
         }
+    }
 
-        ActivityCompat.requestPermissions(
-                this,
-                neededPermissions.toArray(new String[neededPermissions.size()]),
-                AFFDEXME_PERMISSIONS_REQUEST);
+    private void requestStoragePermissions() {
+        if (!storagePermissionsAvailable) {
+            ActivityCompat.requestPermissions(
+                    this,
+                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
+                    EXTERNAL_STORAGE_PERMISSIONS_REQUEST);
 
-        // AFFDEXME_PERMISSIONS_REQUEST is an app-defined int constant that must be between 0 and 255.
-        // The callback method gets the result of the request.
+            // EXTERNAL_STORAGE_PERMISSIONS_REQUEST is an app-defined int constant that must be between 0 and 255.
+            // The callback method gets the result of the request.
+        }
+    }
+
+    private void requestCameraPermissions() {
+        if (!cameraPermissionsAvailable) {
+            ActivityCompat.requestPermissions(
+                    this,
+                    new String[]{Manifest.permission.CAMERA},
+                    CAMERA_PERMISSIONS_REQUEST);
+
+            // CAMERA_PERMISSIONS_REQUEST is an app-defined int constant that must be between 0 and 255.
+            // The callback method gets the result of the request.
+        }
     }
 
     @Override
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
 
-        if (requestCode == AFFDEXME_PERMISSIONS_REQUEST) {
+        if (requestCode == CAMERA_PERMISSIONS_REQUEST) {
             for (int i = 0; i < permissions.length; i++) {
                 String permission = permissions[i];
                 int grantResult = grantResults[i];
@@ -205,32 +249,61 @@ public class MainActivity extends AppCompatActivity
                     cameraPermissionsAvailable = (grantResult == PackageManager.PERMISSION_GRANTED);
                 }
             }
+
+            if (!cameraPermissionsAvailable) {
+                permissionsUnavailableLayout.setVisibility(View.VISIBLE);
+            } else {
+                permissionsUnavailableLayout.setVisibility(View.GONE);
+            }
         }
 
-        if (!cameraPermissionsAvailable) {
-            permissionsUnavailableLayout.setVisibility(View.VISIBLE);
-        } else {
-            permissionsUnavailableLayout.setVisibility(View.GONE);
+        if (requestCode == EXTERNAL_STORAGE_PERMISSIONS_REQUEST) {
+            for (int i = 0; i < permissions.length; i++) {
+                String permission = permissions[i];
+                int grantResult = grantResults[i];
+
+                if (permission.equals(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
+                    storagePermissionsAvailable = (grantResult == PackageManager.PERMISSION_GRANTED);
+                }
+            }
+
+            if (storagePermissionsAvailable) {
+                // resume taking the screenshot
+                takeScreenshot(screenshotButton);
+            }
         }
+
     }
 
-    private void showPermissionExplanationDialog() {
+    private void showPermissionExplanationDialog(int requestCode) {
         final AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
-                getApplicationContext());
+                MainActivity.this);
 
         // set title
         alertDialogBuilder.setTitle(getResources().getString(R.string.insufficient_permissions));
 
         // set dialog message
-        alertDialogBuilder
-                .setMessage(getResources().getString(R.string.permissions_needed_explanation))
-                .setCancelable(false)
-                .setPositiveButton(getResources().getString(R.string.understood), new DialogInterface.OnClickListener() {
-                    public void onClick(DialogInterface dialog, int id) {
-                        dialog.cancel();
-                        requestNeededPermissions();
-                    }
-                });
+        if (requestCode == CAMERA_PERMISSIONS_REQUEST) {
+            alertDialogBuilder
+                    .setMessage(getResources().getString(R.string.permissions_camera_needed_explanation))
+                    .setCancelable(false)
+                    .setPositiveButton(getResources().getString(R.string.understood), new DialogInterface.OnClickListener() {
+                        public void onClick(DialogInterface dialog, int id) {
+                            dialog.cancel();
+                            requestCameraPermissions();
+                        }
+                    });
+        } else if (requestCode == EXTERNAL_STORAGE_PERMISSIONS_REQUEST) {
+            alertDialogBuilder
+                    .setMessage(getResources().getString(R.string.permissions_storage_needed_explanation))
+                    .setCancelable(false)
+                    .setPositiveButton(getResources().getString(R.string.understood), new DialogInterface.OnClickListener() {
+                        public void onClick(DialogInterface dialog, int id) {
+                            dialog.cancel();
+                            requestStoragePermissions();
+                        }
+                    });
+        }
 
         // create alert dialog
         AlertDialog alertDialog = alertDialogBuilder.create();
@@ -239,7 +312,6 @@ public class MainActivity extends AppCompatActivity
         alertDialog.show();
     }
 
-
     /**
      * We check to make sure the device has a front-facing camera.
      * If it does not, we obscure the app with a notice informing the user they cannot
@@ -287,6 +359,7 @@ public class MainActivity extends AppCompatActivity
         drawingView = (DrawingView) findViewById(R.id.drawing_view);
         settingsButton = (ImageButton) findViewById(R.id.settings_button);
         cameraButton = (ImageButton) findViewById(R.id.camera_button);
+        screenshotButton = (ImageButton) findViewById(R.id.screenshot_button);
         progressBar = (ProgressBar) findViewById(R.id.progress_bar);
         pleaseWaitTextView = (TextView) findViewById(R.id.please_wait_textview);
         Button retryPermissionsButton = (Button) findViewById(R.id.retryPermissionsButton);
@@ -336,6 +409,9 @@ public class MainActivity extends AppCompatActivity
         //Attach event listeners to the menu and edit box
         activityLayout.setOnTouchListener(this);
 
+        //Attach event listerner to drawing view
+        drawingView.setEventListener(this);
+
         /*
          * This app sets the View.SYSTEM_UI_FLAG_HIDE_NAVIGATION flag. Unfortunately, this flag causes
          * Android to steal the first touch event after the navigation bar has been hidden, a touch event
@@ -356,7 +432,7 @@ public class MainActivity extends AppCompatActivity
         retryPermissionsButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                requestNeededPermissions();
+                requestCameraPermissions();
             }
         });
     }
@@ -381,7 +457,7 @@ public class MainActivity extends AppCompatActivity
     @Override
     public void onResume() {
         super.onResume();
-        checkForDangerousPermissions();
+        checkForCameraPermissions();
         restoreApplicationSettings();
         setMenuVisible(true);
         isMenuShowingForFirstTime = true;
@@ -576,7 +652,6 @@ public class MainActivity extends AppCompatActivity
         }
     }
 
-
     @Override
     public void onFaceDetectionStarted() {
         leftMetricsLayout.animate().alpha(1); //make left and right metrics appear
@@ -601,6 +676,8 @@ public class MainActivity extends AppCompatActivity
      */
     @Override
     public void onImageResults(List<Face> faces, Frame image, float timeStamp) {
+        mostRecentFrame = image;
+
         //If the faces object is null, we received an unprocessed frame
         if (faces == null) {
             return;
@@ -638,6 +715,104 @@ public class MainActivity extends AppCompatActivity
         }
     }
 
+    public void takeScreenshot(View view) {
+        // Check the permissions to see if we are allowed to save the screenshot
+        if (!storagePermissionsAvailable) {
+            checkForStoragePermissions();
+            return;
+        }
+
+        drawingView.requestBitmap();
+
+        /**
+         * A screenshot of the drawing view is generated and processing continues via the callback
+         * onBitmapGenerated() which calls processScreenshot().
+         */
+    }
+
+    private void processScreenshot(Bitmap drawingViewBitmap, boolean alsoSaveRaw) {
+        if (mostRecentFrame == null) {
+            Toast.makeText(getApplicationContext(), "No frame detected, aborting screenshot", Toast.LENGTH_SHORT).show();
+            return;
+        }
+
+        if (!storagePermissionsAvailable) {
+            checkForStoragePermissions();
+            return;
+        }
+
+        Bitmap faceBitmap = ImageHelper.getBitmapFromFrame(mostRecentFrame);
+
+        if (faceBitmap == null) {
+            Log.e(LOG_TAG, "Unable to generate bitmap for frame, aborting screenshot");
+            return;
+        }
+
+        metricViewLayout.setDrawingCacheEnabled(true);
+        Bitmap metricsBitmap = Bitmap.createBitmap(metricViewLayout.getDrawingCache());
+        metricViewLayout.setDrawingCacheEnabled(false);
+
+        Bitmap finalScreenshot = Bitmap.createBitmap(faceBitmap.getWidth(), faceBitmap.getHeight(), Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(finalScreenshot);
+        Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG);
+
+        canvas.drawBitmap(faceBitmap, 0, 0, paint);
+
+        float scaleFactor = ((float) faceBitmap.getWidth()) / ((float) drawingViewBitmap.getWidth());
+        int scaledHeight = Math.round(drawingViewBitmap.getHeight() * scaleFactor);
+        canvas.drawBitmap(drawingViewBitmap, null, new Rect(0, 0, faceBitmap.getWidth(), scaledHeight), paint);
+
+        scaleFactor = ((float) faceBitmap.getWidth()) / ((float) metricsBitmap.getWidth());
+        scaledHeight = Math.round(metricsBitmap.getHeight() * scaleFactor);
+        canvas.drawBitmap(metricsBitmap, null, new Rect(0, 0, faceBitmap.getWidth(), scaledHeight), paint);
+
+        metricsBitmap.recycle();
+        drawingViewBitmap.recycle();
+
+        Date now = new Date();
+        String timestamp = DateFormat.format("yyyy-MM-dd_hh-mm-ss", now).toString();
+        File pictureFolder = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "AffdexMe");
+        if (!pictureFolder.exists()) {
+            if (!pictureFolder.mkdir()) {
+                Log.e(LOG_TAG, "Unable to create directory: " + pictureFolder.getAbsolutePath());
+                return;
+            }
+        }
+
+        String screenshotFileName = timestamp + ".png";
+        File screenshotFile = new File(pictureFolder, screenshotFileName);
+
+        try {
+            ImageHelper.saveBitmapToFileAsPng(finalScreenshot, screenshotFile);
+        } catch (IOException e) {
+            String msg = "Unable to save screenshot";
+            Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_SHORT).show();
+            Log.e(LOG_TAG, msg, e);
+            return;
+        }
+        ImageHelper.addPngToGallery(getApplicationContext(), screenshotFile);
+
+        if (alsoSaveRaw) {
+            String rawScreenshotFileName = timestamp + "_raw.png";
+            File rawScreenshotFile = new File(pictureFolder, rawScreenshotFileName);
+
+            try {
+                ImageHelper.saveBitmapToFileAsPng(faceBitmap, rawScreenshotFile);
+            } catch (IOException e) {
+                String msg = "Unable to save screenshot";
+                Log.e(LOG_TAG, msg, e);
+            }
+            ImageHelper.addPngToGallery(getApplicationContext(), rawScreenshotFile);
+        }
+
+        faceBitmap.recycle();
+        finalScreenshot.recycle();
+
+        String fileSavedMessage = "Screenshot saved to: " + screenshotFile.getPath();
+        Toast.makeText(getApplicationContext(), fileSavedMessage, Toast.LENGTH_SHORT).show();
+        Log.d(LOG_TAG, fileSavedMessage);
+    }
+
     /**
      * Use the method that we saved in activateMetric() to get the metric score and display it
      */
@@ -723,6 +898,7 @@ public class MainActivity extends AppCompatActivity
         if (b) {
             settingsButton.setVisibility(View.VISIBLE);
             cameraButton.setVisibility(View.VISIBLE);
+            screenshotButton.setVisibility(View.VISIBLE);
 
             //We display the navigation bar again
             getWindow().getDecorView().setSystemUiVisibility(
@@ -740,6 +916,7 @@ public class MainActivity extends AppCompatActivity
                             | View.SYSTEM_UI_FLAG_FULLSCREEN);
             settingsButton.setVisibility(View.INVISIBLE);
             cameraButton.setVisibility(View.INVISIBLE);
+            screenshotButton.setVisibility(View.INVISIBLE);
         }
     }
 
@@ -845,7 +1022,6 @@ public class MainActivity extends AppCompatActivity
 
     }
 
-
     public void camera_button_click(View view) {
         //Toggle the camera setting
         setCameraType(cameraType == CameraDetector.CameraType.CAMERA_FRONT ? CameraDetector.CameraType.CAMERA_BACK : CameraDetector.CameraType.CAMERA_FRONT);
@@ -886,6 +1062,14 @@ public class MainActivity extends AppCompatActivity
             preferencesEditor.apply();
         }
     }
-}
-
 
+    @Override
+    public void onBitmapGenerated(@NonNull final Bitmap bitmap) {
+        runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                processScreenshot(bitmap, STORE_RAW_SCREENSHOTS);
+            }
+        });
+    }
+}

app/src/main/res/drawable/screenshot_button_selector.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  - Copyright (c) 2016 Affectiva Inc.
+  - See the file license.txt for copying permission.
+  -->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/screenshot_button_pressed" android:state_pressed="true" />
+    <item android:drawable="@drawable/screenshot_button" />
+</selector>

app/src/main/res/layout/activity_main.xml

@@ -58,6 +58,19 @@
         android:scaleType="fitCenter"
         android:src="@drawable/camera_button_selector" />
 
+    <ImageButton
+        android:id="@+id/screenshot_button"
+        android:layout_width="@dimen/settings_button_size"
+        android:layout_height="@dimen/settings_button_size"
+        android:layout_alignParentRight="true"
+        android:layout_below="@id/camera_button"
+        android:layout_margin="@dimen/settings_button_margin"
+        android:background="@null"
+        android:contentDescription="Take screenshot"
+        android:onClick="takeScreenshot"
+        android:scaleType="fitCenter"
+        android:src="@drawable/screenshot_button_selector" />
+
     <include layout="@layout/insufficent_permissions_panel" />
 
     <RelativeLayout

app/src/main/res/layout/insufficent_permissions_panel.xml

@@ -28,7 +28,7 @@
         android:layout_height="wrap_content"
         android:layout_marginBottom="@dimen/bottom_padding"
         android:gravity="center"
-        android:text="@string/permissions_needed_explanation" />
+        android:text="@string/permissions_camera_needed_explanation" />
 
     <Button
         android:id="@+id/retryPermissionsButton"

app/src/main/res/values/strings.xml

@@ -14,7 +14,8 @@
     <string name="settings_content_description">Settings</string>
 
     <string name="insufficient_permissions">Insufficient Permissions</string>
-    <string name="permissions_needed_explanation">This app requires the permission to access your camera to be able to gather facial images to process</string>
+    <string name="permissions_camera_needed_explanation">This app requires the permission to access your camera to be able to gather facial images for processing. No video is saved or used other than for immediate emotion processing.</string>
+    <string name="permissions_storage_needed_explanation">This app requires the permission to access your external storage to save screenshots.</string>
     <string name="error">Error</string>
     <string name="understood">Understood</string>
     <string name="retry">Retry</string>