Mirror image for Android (#399)

* Add mirrorImage support for Android

* Release resources after mirroring

* Mirror image only for TYPE_FRONT

* Remove unnecessary annotation

* Document mirrorImage for Android

* Improved compression and error handling

* Add support for mirroring on Android back camera too

android/src/main/java/com/lwansbrough/RCTCamera/RCTCameraModule.java

@@ -5,28 +5,48 @@
 
 package com.lwansbrough.RCTCamera;
 
+import android.annotation.TargetApi;
 import android.content.ContentValues;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Matrix;
 import android.hardware.Camera;
 import android.media.CamcorderProfile;
 import android.media.MediaActionSound;
 import android.media.MediaRecorder;
 import android.media.MediaScannerConnection;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Environment;
 import android.provider.MediaStore;
 import android.util.Base64;
 import android.util.Log;
 import android.view.Surface;
-import com.facebook.react.bridge.*;
 
-import javax.annotation.Nullable;
-import java.io.*;
+import com.facebook.react.bridge.Promise;
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.ReactContextBaseJavaModule;
+import com.facebook.react.bridge.ReactMethod;
+import com.facebook.react.bridge.ReadableMap;
+import com.facebook.react.bridge.WritableMap;
+import com.facebook.react.bridge.WritableNativeMap;
+
+import java.io.ByteArrayInputStream;
+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.io.InputStream;
 import java.text.SimpleDateFormat;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
-import java.util.Map;
 import java.util.List;
+import java.util.Map;
+
+import javax.annotation.Nullable;
 
 public class RCTCameraModule extends ReactContextBaseJavaModule
     implements MediaRecorder.OnInfoListener, LifecycleEventListener {
@@ -393,6 +413,50 @@ public class RCTCameraModule extends ReactContextBaseJavaModule
         return byteArray;
     }
 
+    private byte[] mirrorImage(byte[] data) {
+        ByteArrayInputStream inputStream = new ByteArrayInputStream(data);
+        Bitmap photo = BitmapFactory.decodeStream(inputStream);
+
+        Matrix m = new Matrix();
+        m.preScale(-1, 1);
+        Bitmap mirroredImage = Bitmap.createBitmap(photo, 0, 0, photo.getWidth(), photo.getHeight(), m, false);
+
+        byte[] result = null;
+
+        try {
+            result = compress(mirroredImage, 85);
+        } catch (OutOfMemoryError e) {
+            try {
+                result = compress(mirroredImage, 70);
+            } catch (OutOfMemoryError e2) {
+                e.printStackTrace();
+            }
+        }
+
+        try {
+            inputStream.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        return result;
+    }
+
+    private byte[] compress(Bitmap bitmap, int quality) throws OutOfMemoryError {
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
+
+        try {
+            return outputStream.toByteArray();
+        } finally {
+            try {
+                outputStream.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
     @ReactMethod
     public void capture(final ReadableMap options, final Promise promise) {
         int orientation = options.hasKey("orientation") ? options.getInt("orientation") : RCTCamera.getInstance().getOrientation();
@@ -435,10 +499,20 @@ public class RCTCameraModule extends ReactContextBaseJavaModule
             RCTCamera.getInstance().setCaptureQuality(options.getInt("type"), options.getString("quality"));
         }
 
+        final Boolean shouldMirror = options.hasKey("mirrorImage") && options.getBoolean("mirrorImage");
+
         RCTCamera.getInstance().adjustCameraRotationToDeviceOrientation(options.getInt("type"), deviceOrientation);
         camera.takePicture(null, null, new Camera.PictureCallback() {
             @Override
             public void onPictureTaken(byte[] data, Camera camera) {
+
+                if (shouldMirror) {
+                    data = mirrorImage(data);
+                    if (data == null) {
+                        promise.reject("Error mirroring image");
+                    }
+                }
+
                 camera.stopPreview();
                 camera.startPreview();
                 WritableMap response = new WritableNativeMap();