[camera] Provides a default exposure point if null

packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/exposurepoint/ExposurePointFeature.java

@@ -14,12 +14,14 @@
 import io.flutter.plugins.camera.features.CameraFeature;
 import io.flutter.plugins.camera.features.Point;
 import io.flutter.plugins.camera.features.sensororientation.SensorOrientationFeature;
+import java.util.Arrays;
 
 /** Exposure point controls where in the frame exposure metering will come from. */
 public class ExposurePointFeature extends CameraFeature<Point> {
 
   private Size cameraBoundaries;
   private Point exposurePoint;
+  private MeteringRectangle[] defaultExposureRectangle;
   private MeteringRectangle exposureRectangle;
   private final SensorOrientationFeature sensorOrientationFeature;
 
@@ -72,9 +74,14 @@ public void updateBuilder(CaptureRequest.Builder requestBuilder) {
     if (!checkIsSupported()) {
       return;
     }
-    requestBuilder.set(
-        CaptureRequest.CONTROL_AE_REGIONS,
-        exposureRectangle == null ? null : new MeteringRectangle[] {exposureRectangle});
+    if (defaultExposureRectangle == null) {
+      defaultExposureRectangle = requestBuilder.get(CaptureRequest.CONTROL_AE_REGIONS);
+    }
+    if (exposureRectangle != null) {
+      requestBuilder.set(CaptureRequest.CONTROL_AE_REGIONS, new MeteringRectangle[] {exposureRectangle});
+    } else if (shouldReset(requestBuilder)) {
+      requestBuilder.set(CaptureRequest.CONTROL_AE_REGIONS, defaultExposureRectangle);
+    }
   }
 
   private void buildExposureRectangle() {
@@ -96,4 +103,9 @@ private void buildExposureRectangle() {
               this.cameraBoundaries, this.exposurePoint.x, this.exposurePoint.y, orientation);
     }
   }
+
+ public boolean shouldReset(CaptureRequest.Builder requestBuilder) {
+    MeteringRectangle[] currentRectangles = requestBuilder.get(CaptureRequest.CONTROL_AE_REGIONS);
+    return currentRectangles == null || currentRectangles.length == 0;
+  }
 }

packages/camera/camera_android/android/src/test/java/io/flutter/plugins/camera/features/exposurepoint/ExposurePointFeatureTest.java

@@ -10,6 +10,7 @@
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.isNull;
+import static org.mockito.ArgumentMatchers.same;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
@@ -29,12 +30,15 @@
 import org.junit.Test;
 import org.mockito.MockedStatic;
 import org.mockito.Mockito;
+import java.util.Arrays;
 
 public class ExposurePointFeatureTest {
 
   Size mockCameraBoundaries;
   SensorOrientationFeature mockSensorOrientationFeature;
   DeviceOrientationManager mockDeviceOrientationManager;
+  MeteringRectangle[] mockDefaultExposureRectangle;
+  MeteringRectangle mockExposureRectangle;
 
   @Before
   public void setUp() {
@@ -290,7 +294,7 @@ public void updateBuilder_shouldNotSetMeteringRectangleWhenNoValidBoundariesAreS
 
     exposurePointFeature.updateBuilder(mockCaptureRequestBuilder);
 
-    verify(mockCaptureRequestBuilder, times(1)).set(any(), isNull());
+    verify(mockCaptureRequestBuilder, never()).set(any(), any());
   }
 
   @Test
@@ -308,6 +312,23 @@ public void updateBuilder_shouldNotSetMeteringRectangleWhenNoValidCoordsAreSuppl
     exposurePointFeature.updateBuilder(mockCaptureRequestBuilder);
     exposurePointFeature.setValue(new Point(null, 0d));
     exposurePointFeature.updateBuilder(mockCaptureRequestBuilder);
-    verify(mockCaptureRequestBuilder, times(3)).set(any(), isNull());
+
+    verify(mockCaptureRequestBuilder, never()).set(any(), any());
+  }
+
+  @Test
+  public void testShouldResetReturnsFalse() {
+    CaptureRequest.Builder mockCaptureRequestBuilder = mock(CaptureRequest.Builder.class);
+    MeteringRectangle[] defaultRectangles = new MeteringRectangle[1];
+    defaultRectangles[0] = mock(MeteringRectangle.class);
+    when(mockCaptureRequestBuilder.get(CaptureRequest.CONTROL_AE_REGIONS)).thenReturn(defaultRectangles);
+    mockCaptureRequestBuilder.set(CaptureRequest.CONTROL_AE_REGIONS, defaultRectangles);
+
+    ExposurePointFeature exposurePointFeature = mock(ExposurePointFeature.class);
+    exposurePointFeature.setCameraBoundaries(this.mockCameraBoundaries);
+    exposurePointFeature.setValue(new Point(0.5, 0.5));
+    exposurePointFeature.updateBuilder(mockCaptureRequestBuilder);
+
+    assertFalse(exposurePointFeature.shouldReset(mockCaptureRequestBuilder));
   }
-}
+}