Missing docs about exposure, zoom and location

docs/_posts/2018-12-20-controls.md

@@ -137,3 +137,83 @@ Use 0 or a negative value to fallback to the encoder default. Defaults to 0.
 cameraView.setVideoBitRate(0);
 cameraView.setVideoBitRate(4000000);
 ```
+
+### Manual Focus
+
+There are many ways to focus a CameraView engine:
+
+- Continuous autofocus is activated by default, where present
+- User can start focus with a [Gesture](gestures.html)
+- The developer can start focus with the `startAutoFocus(float, float)` API. This action needs
+  the coordinates of a point to focus, with respect to the view width and height.
+
+The last two actions will trigger the focus callbacks:
+
+```java
+cameraView.addCameraListener(new CameraListener() {
+    
+    @Override
+    public void onFocusStart(@NonNull PointF point) {
+        // Auto focus was started by a gesture or by startAutoFocus(float, float).
+        // The camera is currently trying to focus around that area.
+        // This can be used to draw things on screen.
+    }
+
+    @Override
+    public void onFocusEnd(boolean successful, @NonNull PointF point) {
+        // Auto focus operation just ended. If successful, the camera will have converged
+        // to a new focus point, and possibly changed exposure and white balance as well.
+        // The point is the same that was passed to onFocusStart.
+    }
+});
+```
+
+Auto focus is not guaranteed to be supported: check the `CameraOptions` to be sure.
+
+### Zoom
+
+There are two ways to control the zoom value:
+
+- User can zoom in or out with a [Gesture](gestures.html)
+- The developer can start manual zoom with the `setZoom(float)` API, passing in a value between 0 and 1.
+
+Both actions will trigger the zoom callback, which can be used, for example, to draw a seek bar:
+
+```java
+cameraView.addCameraListener(new CameraListener() {
+    
+    @Override
+    public void onZoomChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers) {
+        // newValue: the new zoom value
+        // bounds: this is always [0, 1]
+        // fingers: if caused by touch gestures, these is the fingers position
+    }
+});
+```
+
+Zoom is not guaranteed to be supported: check the `CameraOptions` to be sure.
+
+### Exposure correction
+
+There are two ways to control the exposure correction value:
+
+- User can change the exposure correction with a [Gesture](gestures.html)
+- The developer can change this value with the `setExposureCorrection(float)` API, passing in the EV
+  value, in camera stops. This value should be contained in the minimum and maximum supported values,
+  as returned by `CameraOptions`.
+
+Both actions will trigger the exposure correction callback, which can be used, for example, to draw a seek bar:
+
+```java
+cameraView.addCameraListener(new CameraListener() {
+    
+    @UiThread
+    public void onExposureCorrectionChanged(float newValue, @NonNull float[] bounds, @Nullable PointF[] fingers) {
+        // newValue: the new correction value
+        // bounds: min and max bounds for newValue, as returned by {@link CameraOptions}
+        // fingers: finger positions that caused the event, null if not caused by touch
+    }
+});
+```
+
+EV correction is not guaranteed to be supported: check the `CameraOptions` to be sure.

docs/_posts/2018-12-20-more-features.md

@@ -16,7 +16,7 @@ date: 2018-12-20 20:41:20
     app:cameraGridColor="@color/black"/>
 ```
 
-#### cameraPlaySounds
+##### cameraPlaySounds
 
 Controls whether we should play platform-provided sounds during certain events
 (shutter click, focus completed). Please note that:
@@ -31,7 +31,7 @@ cameraView.setPlaySounds(true);
 cameraView.setPlaySounds(false);
 ```
 
-#### cameraGrid
+##### cameraGrid
 
 Lets you draw grids over the camera preview. Supported values are `off`, `draw3x3` and `draw4x4`
 for regular grids, and `drawPhi` for a grid based on the golden ratio constant, often used in photography.
@@ -44,7 +44,7 @@ cameraView.setGrid(Grid.DRAW_4X4);
 cameraView.setGrid(Grid.DRAW_PHI);
 ```
 
-#### cameraGridColor
+##### cameraGridColor
 
 Lets you choose the color for grid lines. 
 Defaults to a shade of grey.
@@ -54,24 +54,40 @@ cameraView.setGridColor(Color.WHITE);
 cameraView.setGridColor(Color.BLACK);
 ```
 
-### Undocumented features
+### UI Orientation
 
-Some features and APIs were not documented in this document, including:
+Within a Camera app, it's common to rotate buttons and other UI elements as the device is tilted around.
+We offer a handy callback giving you the right rotation that should be applied to UI elements for them
+to be consistent with what the user is seeing:
 
-- `CameraUtils` utilities
-- `CameraOptions` options
-- `CameraView.setLocation` APIs
+```java
+cameraView.addCameraListener(new CameraListener() {
+    @Override
+    public void onOrientationChanged(int orientation) {
+        // orientation is the counter-clockwise rotation that a View should have
+        // based on current device tilting and native activity orientation.
+    }
+});
+```
 
-For informations, please take a look at the javadocs or the source code. 
+### Location APIs
+
+You can plug in location tags into picture EXIF (for JPEGs) and video metadata by simply using `setLocation`.
+The location can be obtained from any location provider after getting appropriate permissions.
+This is not guaranteed to be appended into snapshots.
 
 |Method|Description|
 |------|-----------|
-|`setZoom(float)`, `getZoom()`|Sets a zoom value, where 0 means camera zoomed out and 1 means zoomed in. No-op if zoom is not supported, or camera not started.|
-|`setExposureCorrection(float)`, `getExposureCorrection()`|Sets exposure compensation EV value, in camera stops. No-op if this is not supported. Should be between the bounds returned by CameraOptions.|
 |`setLocation(Location)`|Sets location data to be appended to picture/video metadata.|
 |`setLocation(double, double)`|Sets latitude and longitude to be appended to picture/video metadata.|
 |`getLocation()`|Retrieves location data previously applied with setLocation().|
-|`startAutoFocus(float, float)`|Starts an autofocus process at the given coordinates, with respect to the view dimensions.|
 
+### Undocumented features
+
+Some features and APIs were not documented in this document, including:
 
+- `CameraUtils` utilities
+- `CameraOptions` options
+
+For informations, please take a look at the javadocs or the source code.