Improved comment about DrmStore.ConstraintsColumns

Change-Id: I89c588759dd409ac0252d686af12bfe4e105f3d5

2 files changed, 27 insertions, 6 deletions

diff --git a/drm/java/android/drm/DrmManagerClient.java b/drm/java/android/drm/DrmManagerClient.java
index 9a7194c..14d5fae 100755
--- a/drm/java/android/drm/DrmManagerClient.java
+++ b/drm/java/android/drm/DrmManagerClient.java
@@ -317,6 +317,7 @@ public class DrmManagerClient {
      *
      * @return A {@link android.content.ContentValues} instance that contains
      * key-value pairs representing the constraints. Null in case of failure.
+     * The keys are defined in {@link DrmStore.ConstraintsColumns}.
      */
     public ContentValues getConstraints(String path, int action) {
         if (null == path || path.equals("") || !DrmStore.Action.isValid(action)) {
diff --git a/drm/java/android/drm/DrmStore.java b/drm/java/android/drm/DrmStore.java
index ae311de..2f004cf 100755
--- a/drm/java/android/drm/DrmStore.java
+++ b/drm/java/android/drm/DrmStore.java
@@ -23,45 +23,65 @@ package android.drm;
 public class DrmStore {
     /**
      * Interface definition for the columns that represent DRM constraints.
+     * {@link android.drm.DrmManagerClient#getConstraints DrmManagerClient.getConstraints()}
+     * can be called by an application to find out the contraints on the
+     * {@link android.drm.DrmStore.Action actions} that can be performed
+     * on right-protected content. The constants defined in this interface
+     * represent three most common types of constraints: count-based,
+     * date-based, and duration-based. Two or more constraints can be used
+     * at the same time to represent more sophisticated constraints.
+     * In addition, user-defined constraint,
+     * {@link #EXTENDED_METADATA extended metadata}, can be
+     * used if these three types of constraints are not sufficient.
      */
     public interface ConstraintsColumns {
         /**
-         * The maximum repeat count.
+         * This is a count-based constraint. It represents the maximum
+         * repeat count that can be performed on an
+         * {@link android.drm.DrmStore.Action action}.
          * <p>
          * Type: INTEGER
          */
         public static final String MAX_REPEAT_COUNT = "max_repeat_count";
 
         /**
-         * The remaining repeat count.
+         * This is a count-based constraint. It represents the remaining
+         * repeat count that can be performed on an
+         * {@link android.drm.DrmStore.Action action}.
          * <p>
          * Type: INTEGER
          */
         public static final String REMAINING_REPEAT_COUNT = "remaining_repeat_count";
 
         /**
-         * The time before which the rights-protected file cannot be played/viewed.
+         * This is a date-based constraint. It represents the time before which
+         * an {@link android.drm.DrmStore.Action action} can be performed on
+         * the rights-protected content.
          * <p>
          * Type: TEXT
          */
         public static final String LICENSE_START_TIME = "license_start_time";
 
         /**
-         * The time after which the rights-protected file cannot be played/viewed.
+         * This is a date-based constaint. It represents the time after which
+         * an {@link android.drm.DrmStore.Action action} can not be performed on
+         * the rights-protected content.
          * <p>
          * Type: TEXT
          */
         public static final String LICENSE_EXPIRY_TIME = "license_expiry_time";
 
         /**
-         * The available time left before the license expires.
+         * This is a duration-based constaint. It represents the available time left
+         * before the license expires.
          * <p>
          * Type: TEXT
          */
         public static final String LICENSE_AVAILABLE_TIME = "license_available_time";
 
         /**
-         * The data stream for extended metadata.
+         * This is a user-defined constraint. It represents the additional constraint
+         * using extended metadata.
          * <p>
          * Type: TEXT
          */