Improve camera documentation.
Change-Id: I3c9e5e6de5ce64b8d7d892483930238fa9cc247c
diff --git a/core/java/android/hardware/Camera.java b/core/java/android/hardware/Camera.java
index 19e578f..f72de67 100644
--- a/core/java/android/hardware/Camera.java
+++ b/core/java/android/hardware/Camera.java
@@ -1166,6 +1166,14 @@
*/
public static final String FOCUS_MODE_EDOF = "edof";
+ /**
+ * Continuous auto focus mode. The camera continuously tries to focus.
+ * This is ideal for shooting video or shooting photo of moving object.
+ * Auto focus starts when the parameter is set. Applications should not
+ * call {@link #autoFocus(AutoFocusCallback)} in this mode.
+ */
+ public static final String FOCUS_MODE_CONTINUOUS = "continuous";
+
// Indices for focus distance array.
/**
* The array index of near focus distance for use with
@@ -1186,16 +1194,6 @@
public static final int FOCUS_DISTANCE_FAR_INDEX = 2;
/**
- * Continuous focus mode. The camera continuously tries to focus. This
- * is ideal for shooting video or shooting photo of moving object.
- * Continuous focus starts when {@link #autoFocus(AutoFocusCallback)} is
- * called. Continuous focus stops when {@link #cancelAutoFocus()} is
- * called. AutoFocusCallback will be only called once as soon as the
- * picture is in focus.
- */
- public static final String FOCUS_MODE_CONTINUOUS = "continuous";
-
- /**
* The camera determines the exposure by giving more weight to the
* central part of the scene.
*/
@@ -1942,15 +1940,15 @@
/**
* Gets the current focus mode setting.
*
- * @return current focus mode. If the camera does not support
- * auto-focus, this should return {@link #FOCUS_MODE_FIXED}. If
- * the focus mode is not FOCUS_MODE_FIXED or {@link
- * #FOCUS_MODE_INFINITY}, applications should call {@link
- * #autoFocus(AutoFocusCallback)} to start the focus.
+ * @return current focus mode. This method will always return a non-null
+ * value. Applications should call {@link
+ * #autoFocus(AutoFocusCallback)} to start the focus if focus
+ * mode is FOCUS_MODE_AUTO or FOCUS_MODE_MACRO.
* @see #FOCUS_MODE_AUTO
* @see #FOCUS_MODE_INFINITY
* @see #FOCUS_MODE_MACRO
* @see #FOCUS_MODE_FIXED
+ * @see #FOCUS_MODE_CONTINUOUS
*/
public String getFocusMode() {
return get(KEY_FOCUS_MODE);
@@ -2152,8 +2150,14 @@
* #autoFocus(AutoFocusCallback)}, {@link #cancelAutoFocus}, or {@link
* #startPreview()}. Applications can call {@link #getParameters()}
* and this method anytime to get the latest focus distances. If the
- * focus mode is FOCUS_MODE_CONTINUOUS and autofocus has started, focus
- * distances may change from time to time.
+ * focus mode is FOCUS_MODE_CONTINUOUS, focus distances may change from
+ * time to time.
+ *
+ * This method is intended to estimate the distance between the camera
+ * and the subject. After autofocus, the subject distance may be within
+ * near and far focus distance. However, the precision depends on the
+ * camera hardware, autofocus algorithm, the focus area, and the scene.
+ * The error can be large and it should be only used as a reference.
*
* Far focus distance >= optimal focus distance >= near focus distance.
* If the focus distance is infinity, the value will be
diff --git a/include/camera/CameraParameters.h b/include/camera/CameraParameters.h
index e12a694..6a5d254 100644
--- a/include/camera/CameraParameters.h
+++ b/include/camera/CameraParameters.h
@@ -171,10 +171,9 @@
// Supported flash modes.
// Example value: "auto,on,off". Read only.
static const char KEY_SUPPORTED_FLASH_MODES[];
- // Current focus mode. If the camera does not support auto-focus, the value
- // should be FOCUS_MODE_FIXED. If the focus mode is not FOCUS_MODE_FIXED or
- // or FOCUS_MODE_INFINITY, applications should call
- // CameraHardwareInterface.autoFocus to start the focus.
+ // Current focus mode. This will not be empty. Applications should call
+ // CameraHardwareInterface.autoFocus to start the focus if focus mode is
+ // FOCUS_MODE_AUTO or FOCUS_MODE_MACRO.
// Example value: "auto" or FOCUS_MODE_XXX constants. Read/write.
static const char KEY_FOCUS_MODE[];
// Supported focus modes.
@@ -231,11 +230,16 @@
// be in focus. The object is sharpest at the optimal focus distance. The
// depth of field is the far focus distance minus near focus distance.
//
- // Applications can read this parameter anytime to get the latest focus
- // distances. If the focus mode is FOCUS_MODE_EDOF, the values may be all
- // 0, which means focus distance is not applicable. If the focus mode is
- // FOCUS_MODE_CONTINUOUS and autofocus has started, focus distances may
- // change from time to time.
+ // Focus distances may change after starting auto focus, canceling auto
+ // focus, or starting the preview. Applications can read this anytime to get
+ // the latest focus distances. If the focus mode is FOCUS_MODE_CONTINUOUS,
+ // focus distances may change from time to time.
+ //
+ // This is intended to estimate the distance between the camera and the
+ // subject. After autofocus, the subject distance may be within near and far
+ // focus distance. However, the precision depends on the camera hardware,
+ // autofocus algorithm, the focus area, and the scene. The error can be
+ // large and it should be only used as a reference.
//
// Far focus distance > optimal focus distance > near focus distance. If
// the far focus distance is infinity, the value should be "Infinity" (case
@@ -348,10 +352,10 @@
// continuously. Applications should not call
// CameraHardwareInterface.autoFocus in this mode.
static const char FOCUS_MODE_EDOF[];
- // Continuous focus mode. The camera continuously tries to focus. This is
- // ideal for shooting video or shooting photo of moving object. Continuous
- // focus starts when CameraHardwareInterface.autoFocus is called. Focus
- // callback will be only called once as soon as the picture is in focus.
+ // Continuous auto focus mode. The camera continuously tries to focus. This
+ // is ideal for shooting video or shooting photo of moving object. Auto
+ // focus starts when the parameter is set. Applications should not call
+ // CameraHardwareInterface.autoFocus in this mode.
static const char FOCUS_MODE_CONTINUOUS[];
// The camera determines the exposure by giving more weight to the
