Camera: hardware level related doc update

Codegen doc update + CameraDevice manual update about EXTERNAL
hardware level.

Test: check offline-sdk-docs output
Bug: 77861412
Change-Id: I70c87a176cf873cf8bec2037f973a94fe99aef2e

2 files changed, 34 insertions, 10 deletions

diff --git a/core/java/android/hardware/camera2/CameraCharacteristics.java b/core/java/android/hardware/camera2/CameraCharacteristics.java
index 32c6898e8c00..60e4ce29ab51 100644
--- a/core/java/android/hardware/camera2/CameraCharacteristics.java
+++ b/core/java/android/hardware/camera2/CameraCharacteristics.java
@@ -3136,12 +3136,26 @@ public final class CameraCharacteristics extends CameraMetadata<CameraCharacteri
      * the following code snippet can be used:</p>
      * <pre><code>// Returns true if the device supports the required hardware level, or better.
      * boolean isHardwareLevelSupported(CameraCharacteristics c, int requiredLevel) {
+     *     final int[] sortedHwLevels = {
+     *         CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY,
+     *         CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_EXTERNAL,
+     *         CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED,
+     *         CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_FULL,
+     *         CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_3
+     *     };
      *     int deviceLevel = c.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);
-     *     if (deviceLevel == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY) {
-     *         return requiredLevel == deviceLevel;
+     *     if (requiredLevel == deviceLevel) {
+     *         return true;
      *     }
-     *     // deviceLevel is not LEGACY, can use numerical sort
-     *     return requiredLevel &lt;= deviceLevel;
+     *
+     *     for (int sortedlevel : sortedHwLevels) {
+     *         if (sortedlevel == requiredLevel) {
+     *             return true;
+     *         } else if (sortedlevel == deviceLevel) {
+     *             return false;
+     *         }
+     *     }
+     *     return false; // Should never reach here
      * }
      * </code></pre>
      * <p>At a high level, the levels are:</p>
@@ -3155,6 +3169,8 @@ public final class CameraCharacteristics extends CameraMetadata<CameraCharacteri
      *   post-processing settings, and image capture at a high rate.</li>
      * <li><code>LEVEL_3</code> devices additionally support YUV reprocessing and RAW image capture, along
      *   with additional output stream configurations.</li>
+     * <li><code>EXTERNAL</code> devices are similar to <code>LIMITED</code> devices with exceptions like some sensor or
+     *   lens information not reorted or less stable framerates.</li>
      * </ul>
      * <p>See the individual level enums for full descriptions of the supported capabilities.  The
      * {@link CameraCharacteristics#REQUEST_AVAILABLE_CAPABILITIES android.request.availableCapabilities} entry describes the device's capabilities at a
diff --git a/core/java/android/hardware/camera2/CameraDevice.java b/core/java/android/hardware/camera2/CameraDevice.java
index f47d4640c09c..ce88697fa8db 100644
--- a/core/java/android/hardware/camera2/CameraDevice.java
+++ b/core/java/android/hardware/camera2/CameraDevice.java
@@ -44,19 +44,27 @@ import java.lang.annotation.RetentionPolicy;
  * {@link android.Manifest.permission#CAMERA Camera} permission in its manifest
  * in order to access camera devices.</p>
  *
- * <p>A given camera device may provide support at one of two levels: limited or
- * full. If a device only supports the limited level, then Camera2 exposes a
- * feature set that is roughly equivalent to the older
+ * <p>A given camera device may provide support at one of several levels defined
+ * in {@link CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL}.
+ * If a device supports {@link CameraMetadata#INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY LEGACY} level,
+ * the camera device is running in backward compatibility mode and has minimum camera2 API support.
+ * If a device supports the {@link CameraMetadata#INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED LIMITED}
+ * level, then Camera2 exposes a feature set that is roughly equivalent to the older
  * {@link android.hardware.Camera Camera} API, although with a cleaner and more
- * efficient interface.  Devices that implement the full level of support
+ * efficient interface.
+ * If a device supports the {@link CameraMetadata#INFO_SUPPORTED_HARDWARE_LEVEL_EXTERNAL EXTERNAL}
+ * level, then the device is a removable camera that provides similar but slightly less features
+ * as the {@link CameraMetadata#INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED LIMITED} level.
+ * Devices that implement the {@link CameraMetadata#INFO_SUPPORTED_HARDWARE_LEVEL_FULL FULL} or
+ * {@link CameraMetadata#INFO_SUPPORTED_HARDWARE_LEVEL_3 LEVEL3} level of support
  * provide substantially improved capabilities over the older camera
- * API. Applications that target the limited level devices will run unchanged on
- * the full-level devices; if your application requires a full-level device for
+ * API. If your application requires a full-level device for
  * proper operation, declare the "android.hardware.camera.level.full" feature in your
  * manifest.</p>
  *
  * @see CameraManager#openCamera
  * @see android.Manifest.permission#CAMERA
+ * @see CameraCharacteristics#INFO_SUPPORTED_HARDWARE_LEVEL
  */
 public abstract class CameraDevice implements AutoCloseable {