Lock AE and AWB before autofocus starts.

Now camera API specifies autofocus does not lock AE and AWB.
So the application locks AE/AWB when focus starts.
AE/AWB are unlocked when focus finishes or preview starts.

bug:5441274
Change-Id: Iddf21a413234bc3569187f4696d54099c362d008

1 files changed, 26 insertions, 0 deletions

diff --git a/src/com/android/camera/Camera.java b/src/com/android/camera/Camera.java
index 8cc5816..795c652 100644
--- a/src/com/android/camera/Camera.java
+++ b/src/com/android/camera/Camera.java
@@ -122,6 +122,9 @@ public class Camera extends ActivityBase implements FocusManager.Listener,
     private Parameters mInitialParams;
     private boolean mFocusAreaSupported;
     private boolean mMeteringAreaSupported;
+    private boolean mAeLockSupported;
+    private boolean mAwbLockSupported;
+    private boolean mAeAwbLock;
 
     private MyOrientationEventListener mOrientationListener;
     // The degrees of the device rotated clockwise from its natural orientation.
@@ -1357,7 +1360,19 @@ public class Camera extends ActivityBase implements FocusManager.Listener,
         // Do not do focus if there is not enough storage.
         if (pressed && !canTakePicture()) return;
 
+        // Lock AE and AWB so users can half-press shutter and recompose.
+        mAeAwbLock = pressed;
+        if (mAeAwbLock && (mAeLockSupported || mAwbLockSupported)) {
+            setCameraParameters(UPDATE_PARAM_PREFERENCE);
+        }
+
         mFocusManager.doFocus(pressed);
+
+        // Unlock AE and AWB after cancelAutoFocus. Camera API does not
+        // guarantee setParameters can be called during autofocus.
+        if (!mAeAwbLock && (mAeLockSupported || mAwbLockSupported)) {
+            setCameraParameters(UPDATE_PARAM_PREFERENCE);
+        }
     }
 
     @Override
@@ -1743,6 +1758,7 @@ public class Camera extends ActivityBase implements FocusManager.Listener,
 
         setPreviewDisplay(mSurfaceHolder);
         setDisplayOrientation();
+        mAeAwbLock = false; // Unlock AE and AWB.
         setCameraParameters(UPDATE_PARAM_ALL);
         // If the focus mode is continuous autofocus, call cancelAutoFocus to
         // resume it because it may have been paused by autoFocus call.
@@ -1816,6 +1832,14 @@ public class Camera extends ActivityBase implements FocusManager.Listener,
     }
 
     private void updateCameraParametersPreference() {
+        if (mAeLockSupported) {
+            mParameters.setAutoExposureLock(mAeAwbLock);
+        }
+
+        if (mAwbLockSupported) {
+            mParameters.setAutoWhiteBalanceLock(mAeAwbLock);
+        }
+
         if (mFocusAreaSupported) {
             mParameters.setFocusAreas(mFocusManager.getFocusAreas());
         }
@@ -2213,5 +2237,7 @@ public class Camera extends ActivityBase implements FocusManager.Listener,
                 && isSupported(Parameters.FOCUS_MODE_AUTO,
                         mInitialParams.getSupportedFocusModes()));
         mMeteringAreaSupported = (mInitialParams.getMaxNumMeteringAreas() > 0);
+        mAeLockSupported = mInitialParams.isAutoExposureLockSupported();
+        mAwbLockSupported = mInitialParams.isAutoWhiteBalanceLockSupported();
     }
 }