[camera]Nickcullen darkcamera fix

AUTHORS

@@ -22,3 +22,4 @@ Thomas Danner <thmsdnnr@gmail.com>
 Diego Velásquez <diego.velasquez.lopez@gmail.com>
 Hajime Nakamura <nkmrhj@gmail.com>
 Tuyển Vũ Xuân <netsoft1985@gmail.com>
+Nicholas Cullen <contact@nickcullen.net>

packages/camera/android/src/main/java/io/flutter/plugins/camera/CameraPlugin.java

@@ -26,6 +26,7 @@
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.util.Range;
 import android.util.Size;
 import android.view.Display;
 import android.view.OrientationEventListener;
@@ -289,6 +290,7 @@ private class Camera {
     private Size videoSize;
     private MediaRecorder mediaRecorder;
     private boolean recordingVideo;
+    private Range<Integer> aeFPSRange;
 
     Camera(final String cameraName, final String resolutionPreset, @NonNull final Result result) {
 
@@ -322,6 +324,8 @@ private class Camera {
         isFrontFacing =
             characteristics.get(CameraCharacteristics.LENS_FACING)
                 == CameraMetadata.LENS_FACING_FRONT;
+
+        setBestAERange(characteristics);
         computeBestCaptureSize(streamConfigurationMap);
         computeBestPreviewAndRecordingSize(streamConfigurationMap, minPreviewSize, captureSize);
 
@@ -395,6 +399,29 @@ private boolean hasAudioPermission() {
               == PackageManager.PERMISSION_GRANTED;
     }
 
+    private void setBestAERange(CameraCharacteristics characteristics) {
+      Range<Integer>[] fpsRanges =
+          characteristics.get(CameraCharacteristics.CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES);
+
+      if (fpsRanges.length <= 0) {
+        return;
+      }
+
+      Integer idx = 0;
+      Integer biggestDiference = 0;
+
+      for (Integer i = 0; i < fpsRanges.length; i++) {
+        Integer currentDifference = fpsRanges[i].getUpper() - fpsRanges[i].getLower();
+
+        if (currentDifference > biggestDiference) {
+          idx = i;
+          biggestDiference = currentDifference;
+        }
+      }
+
+      aeFPSRange = fpsRanges[idx];
+    }
+
     private void computeBestPreviewAndRecordingSize(
         StreamConfigurationMap streamConfigurationMap, Size minPreviewSize, Size captureSize) {
       Size[] sizes = streamConfigurationMap.getOutputSizes(SurfaceTexture.class);
@@ -738,8 +765,15 @@ public void onConfigured(@NonNull CameraCaptureSession session) {
               }
               try {
                 cameraCaptureSession = session;
+
                 captureRequestBuilder.set(
                     CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
+
+                if (Camera.this.aeFPSRange != null) {
+                  captureRequestBuilder.set(
+                      CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, Camera.this.aeFPSRange);
+                }
+
                 cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, null);
               } catch (CameraAccessException e) {
                 sendErrorEvent(e.getMessage());

packages/camera/pubspec.yaml

@@ -8,6 +8,7 @@ authors:
   - Quentin Le Guennec <quentin@tengio.com>
   - Koushik Ravikumar <koushik@tengio.com>
   - Nissim Dsilva <nissim@tengio.com>
+  - Nicholas Cullen <contact@nickcullen.net>
 
 homepage: https://github.com/flutter/plugins/tree/master/packages/camera