Exposure correction support

camerakit/src/main/api16/com/flurgle/camerakit/Camera1.java

@@ -654,23 +654,39 @@ class Camera1 extends CameraController {
     }
 
     // -----------------
-    // Zoom stuff.
+    // Zoom and simpler stuff.
 
 
     @Override
     boolean setZoom(float zoom) {
         if (!isCameraOpened()) return false;
+        if (!mOptions.isZoomSupported()) return false;
         synchronized (mLock) {
             Camera.Parameters params = mCamera.getParameters();
-            if (!mOptions.isZoomSupported()) return false;
             float max = params.getMaxZoom();
             params.setZoom((int) (zoom * max));
             mCamera.setParameters(params);
-            return true;
         }
+        return true;
     }
 
 
+    @Override
+    boolean setExposureCorrection(float EVvalue) {
+        if (!isCameraOpened()) return false;
+        if (!mOptions.isExposureCorrectionSupported()) return false;
+        float max = mOptions.getExposureCorrectionMaxValue();
+        float min = mOptions.getExposureCorrectionMinValue();
+        EVvalue = EVvalue < min ? min : EVvalue > max ? max : EVvalue; // cap
+        synchronized (mLock) {
+            Camera.Parameters params = mCamera.getParameters();
+            int indexValue = (int) (EVvalue / params.getExposureCompensationStep());
+            params.setExposureCompensation(indexValue);
+            mCamera.setParameters(params);
+        }
+        return true;
+    }
+
     // -----------------
     // Tap to focus stuff.
 
@@ -681,25 +697,22 @@ class Camera1 extends CameraController {
         List<Camera.Area> meteringAreas2 = computeMeteringAreas(x, y);
         List<Camera.Area> meteringAreas1 = meteringAreas2.subList(0, 1);
         synchronized (mLock) {
+            // At this point we are sure that camera supports auto focus... right? Look at CameraView.onTouchEvent().
             Camera.Parameters params = mCamera.getParameters();
-            // TODO remove this check once CameraView.setFocus TODO is fixed.
-            boolean autofocusSupported = mOptions.getSupportedFocus().contains(CameraConstants.FOCUS_TAP);
-            if (autofocusSupported) {
-                int maxAF = params.getMaxNumFocusAreas();
-                int maxAE = params.getMaxNumMeteringAreas();
-                if (maxAF > 0) params.setFocusAreas(maxAF > 1 ? meteringAreas2 : meteringAreas1);
-                if (maxAE > 0) params.setMeteringAreas(maxAE > 1 ? meteringAreas2 : meteringAreas1);
-                params.setFocusMode((String) mMapper.mapFocus(FOCUS_TAP)); // auto
-                mCamera.setParameters(params);
-                mCameraCallbacks.dispatchOnFocusStart(x, y);
-                mCamera.autoFocus(new Camera.AutoFocusCallback() {
-                    @Override
-                    public void onAutoFocus(boolean success, Camera camera) {
-                        mCameraCallbacks.dispatchOnFocusEnd(success, x, y);
-                        postResetFocus();
-                    }
-                });
-            }
+            int maxAF = params.getMaxNumFocusAreas();
+            int maxAE = params.getMaxNumMeteringAreas();
+            if (maxAF > 0) params.setFocusAreas(maxAF > 1 ? meteringAreas2 : meteringAreas1);
+            if (maxAE > 0) params.setMeteringAreas(maxAE > 1 ? meteringAreas2 : meteringAreas1);
+            params.setFocusMode((String) mMapper.mapFocus(FOCUS_TAP)); // auto
+            mCamera.setParameters(params);
+            mCameraCallbacks.dispatchOnFocusStart(x, y);
+            mCamera.autoFocus(new Camera.AutoFocusCallback() {
+                @Override
+                public void onAutoFocus(boolean success, Camera camera) {
+                    mCameraCallbacks.dispatchOnFocusEnd(success, x, y);
+                    postResetFocus();
+                }
+            });
         }
     }
 

camerakit/src/main/base/com/flurgle/camerakit/CameraController.java

@@ -30,6 +30,7 @@ abstract class CameraController implements Preview.SurfaceCallback {
     abstract void onDeviceOrientation(int deviceOrientation);
 
     abstract boolean setZoom(float zoom);
+    abstract boolean setExposureCorrection(float EVvalue);
     abstract void setFacing(@Facing int facing);
     abstract void setFlash(@Flash int flash);
     abstract void setFocus(@Focus int focus);

camerakit/src/main/base/com/flurgle/camerakit/CameraOptions.java

@@ -23,6 +23,9 @@ public class CameraOptions {
 
     private boolean zoomSupported;
     private boolean videoSnapshotSupported;
+    private boolean exposureCorrectionSupported;
+    private float exposureCorrectionMinValue;
+    private float exposureCorrectionMaxValue;
 
 
     // Camera1 constructor.
@@ -62,6 +65,13 @@ public class CameraOptions {
 
         zoomSupported = params.isZoomSupported();
         videoSnapshotSupported = params.isVideoSnapshotSupported();
+
+        // Exposure correction
+        float step = params.getExposureCompensationStep();
+        exposureCorrectionMinValue = (float) params.getMinExposureCompensation() * step;
+        exposureCorrectionMaxValue = (float) params.getMaxExposureCompensation() * step;
+        exposureCorrectionSupported = params.getMinExposureCompensation() != 0
+                || params.getMaxExposureCompensation() != 0;
     }
 
 
@@ -149,4 +159,39 @@ public class CameraOptions {
     public boolean isVideoSnapshotSupported() {
         return videoSnapshotSupported;
     }
+
+
+    /**
+     * Whether exposure correction is supported. If this is false, calling
+     * {@link CameraView#setExposureCorrection(float)} has no effect.
+     *
+     * @see #getExposureCorrectionMinValue()
+     * @see #getExposureCorrectionMaxValue()
+     * @return whether exposure correction is supported.
+     */
+    public boolean isExposureCorrectionSupported() {
+        return exposureCorrectionSupported;
+    }
+
+
+    /**
+     * The minimum value of negative exposure correction, in EV stops.
+     * This is presumably negative or 0 if not supported.
+     *
+     * @return min EV value
+     */
+    public float getExposureCorrectionMinValue() {
+        return exposureCorrectionMinValue;
+    }
+
+
+    /**
+     * The maximum value of positive exposure correction, in EV stops.
+     * This is presumably positive or 0 if not supported.
+     *
+     * @return max EV value
+     */
+    public float getExposureCorrectionMaxValue() {
+        return exposureCorrectionMaxValue;
+    }
 }

camerakit/src/main/java/com/flurgle/camerakit/CameraView.java

@@ -509,6 +509,24 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
     }
 
 
+    /**
+     * Sets exposure adjustment, in EV stops. A positive value will mean brighter picture.
+     *
+     * If camera is not opened, this will have no effect.
+     * If {@link CameraOptions#isExposureCorrectionSupported()} is false, this will have no effect.
+     * The provided value should be between the bounds returned by {@link CameraOptions}, or it will
+     * be capped.
+     *
+     * @see CameraOptions#getExposureCorrectionMinValue()
+     * @see CameraOptions#getExposureCorrectionMaxValue()
+     *
+     * @param EVvalue exposure correction value.
+     */
+    public void setExposureCorrection(float EVvalue) {
+        mCameraController.setExposureCorrection(EVvalue);
+    }
+
+
     /**
      * Sets a zoom value. This is not guaranteed to be supported by the current device,
      * but you can take a look at {@link CameraOptions#isZoomSupported()}.
@@ -523,8 +541,7 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
             throw new IllegalArgumentException("Zoom value should be >= 0 and <= 1");
         }
         if (mCameraController.setZoom(zoom)) {
-            // Notify PinchToZoomLayout, just in case the call came from outside.
-            mPinchToZoomLayout.onExternalZoom(zoom);
+            mPinchToZoomLayout.onExternalZoom(zoom); // Notify PinchToZoomLayout
         }
     }