Handle API review comments from the council.

 * MtpEvent: Remove public constructor since properties cannot be set
   directly.
 * MtpEvent: Move event constants from MtpConstants to MtpEvent class.
 * getPartialObject64: the byte[] must have indices of Integer.MAX_VALUE
   at most. Document as such.
 * sendObjectInfo: what happens if the transfer doesn’t succeed? How is
   the app notified? If there is a reason for the failure communicated,
   how does the app find this out? Add docs.
 * Add isOperationSupported(int) and isEventSupported(int) helpers.

Change-Id: Ifd80016d2ddd3b66d5c45f6da76b6133f0c9a617
Fixes: 28146379

11 files changed, 285 insertions, 134 deletions

diff --git a/api/current.txt b/api/current.txt
index 8e380360f848..dde9755e5b8c 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -23240,24 +23240,6 @@ package android.mtp {
     ctor public MtpConstants();
     method public static boolean isAbstractObject(int);
     field public static final int ASSOCIATION_TYPE_GENERIC_FOLDER = 1; // 0x1
-    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
-    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
-    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
-    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
-    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
-    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
-    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
-    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
-    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
-    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
-    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
-    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
-    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
-    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
-    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
-    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
-    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
-    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
     field public static final int FORMAT_3GP_CONTAINER = 47492; // 0xb984
     field public static final int FORMAT_AAC = 47363; // 0xb903
     field public static final int FORMAT_ABSTRACT_AUDIO_ALBUM = 47619; // 0xba03
@@ -23390,10 +23372,11 @@ package android.mtp {
     method public final int[] getOperationsSupported();
     method public final java.lang.String getSerialNumber();
     method public final java.lang.String getVersion();
+    method public boolean isEventSupported(int);
+    method public boolean isOperationSupported(int);
   }
 
   public class MtpEvent {
-    ctor public MtpEvent();
     method public int getDevicePropCode();
     method public int getEventCode();
     method public int getObjectFormatCode();
@@ -23404,6 +23387,24 @@ package android.mtp {
     method public int getParameter3();
     method public int getStorageId();
     method public int getTransactionId();
+    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
+    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
+    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
+    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
+    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
+    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
+    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
+    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
+    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
+    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
+    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
+    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
+    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
+    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
+    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
+    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
+    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
+    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
   }
 
   public final class MtpObjectInfo {
diff --git a/api/removed.txt b/api/removed.txt
index 8c6abdcfb09e..de8a7244d388 100644
--- a/api/removed.txt
+++ b/api/removed.txt
@@ -165,6 +165,31 @@ package android.media.tv {
 
 }
 
+package android.mtp {
+
+  public final class MtpConstants {
+    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
+    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
+    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
+    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
+    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
+    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
+    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
+    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
+    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
+    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
+    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
+    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
+    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
+    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
+    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
+    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
+    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
+    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
+  }
+
+}
+
 package android.net {
 
   public class SSLCertificateSocketFactory extends javax.net.ssl.SSLSocketFactory {
diff --git a/api/system-current.txt b/api/system-current.txt
index 672f63cae193..3f37d9c8f222 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -24976,24 +24976,6 @@ package android.mtp {
     ctor public MtpConstants();
     method public static boolean isAbstractObject(int);
     field public static final int ASSOCIATION_TYPE_GENERIC_FOLDER = 1; // 0x1
-    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
-    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
-    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
-    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
-    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
-    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
-    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
-    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
-    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
-    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
-    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
-    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
-    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
-    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
-    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
-    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
-    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
-    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
     field public static final int FORMAT_3GP_CONTAINER = 47492; // 0xb984
     field public static final int FORMAT_AAC = 47363; // 0xb903
     field public static final int FORMAT_ABSTRACT_AUDIO_ALBUM = 47619; // 0xba03
@@ -25126,10 +25108,11 @@ package android.mtp {
     method public final int[] getOperationsSupported();
     method public final java.lang.String getSerialNumber();
     method public final java.lang.String getVersion();
+    method public boolean isEventSupported(int);
+    method public boolean isOperationSupported(int);
   }
 
   public class MtpEvent {
-    ctor public MtpEvent();
     method public int getDevicePropCode();
     method public int getEventCode();
     method public int getObjectFormatCode();
@@ -25140,6 +25123,24 @@ package android.mtp {
     method public int getParameter3();
     method public int getStorageId();
     method public int getTransactionId();
+    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
+    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
+    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
+    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
+    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
+    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
+    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
+    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
+    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
+    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
+    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
+    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
+    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
+    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
+    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
+    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
+    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
+    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
   }
 
   public final class MtpObjectInfo {
diff --git a/api/system-removed.txt b/api/system-removed.txt
index 95734c111afb..844604ce1510 100644
--- a/api/system-removed.txt
+++ b/api/system-removed.txt
@@ -163,6 +163,31 @@ package android.media.tv {
 
 }
 
+package android.mtp {
+
+  public final class MtpConstants {
+    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
+    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
+    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
+    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
+    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
+    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
+    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
+    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
+    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
+    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
+    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
+    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
+    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
+    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
+    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
+    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
+    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
+    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
+  }
+
+}
+
 package android.net {
 
   public class SSLCertificateSocketFactory extends javax.net.ssl.SSLSocketFactory {
diff --git a/api/test-current.txt b/api/test-current.txt
index 61d57219d3bd..a7d9485ab09b 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -23308,24 +23308,6 @@ package android.mtp {
     ctor public MtpConstants();
     method public static boolean isAbstractObject(int);
     field public static final int ASSOCIATION_TYPE_GENERIC_FOLDER = 1; // 0x1
-    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
-    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
-    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
-    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
-    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
-    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
-    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
-    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
-    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
-    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
-    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
-    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
-    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
-    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
-    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
-    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
-    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
-    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
     field public static final int FORMAT_3GP_CONTAINER = 47492; // 0xb984
     field public static final int FORMAT_AAC = 47363; // 0xb903
     field public static final int FORMAT_ABSTRACT_AUDIO_ALBUM = 47619; // 0xba03
@@ -23458,10 +23440,11 @@ package android.mtp {
     method public final int[] getOperationsSupported();
     method public final java.lang.String getSerialNumber();
     method public final java.lang.String getVersion();
+    method public boolean isEventSupported(int);
+    method public boolean isOperationSupported(int);
   }
 
   public class MtpEvent {
-    ctor public MtpEvent();
     method public int getDevicePropCode();
     method public int getEventCode();
     method public int getObjectFormatCode();
@@ -23472,6 +23455,24 @@ package android.mtp {
     method public int getParameter3();
     method public int getStorageId();
     method public int getTransactionId();
+    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
+    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
+    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
+    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
+    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
+    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
+    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
+    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
+    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
+    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
+    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
+    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
+    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
+    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
+    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
+    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
+    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
+    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
   }
 
   public final class MtpObjectInfo {
diff --git a/api/test-removed.txt b/api/test-removed.txt
index 8c6abdcfb09e..de8a7244d388 100644
--- a/api/test-removed.txt
+++ b/api/test-removed.txt
@@ -165,6 +165,31 @@ package android.media.tv {
 
 }
 
+package android.mtp {
+
+  public final class MtpConstants {
+    field public static final int EVENT_CANCEL_TRANSACTION = 16385; // 0x4001
+    field public static final int EVENT_CAPTURE_COMPLETE = 16397; // 0x400d
+    field public static final int EVENT_DEVICE_INFO_CHANGED = 16392; // 0x4008
+    field public static final int EVENT_DEVICE_PROP_CHANGED = 16390; // 0x4006
+    field public static final int EVENT_DEVICE_RESET = 16395; // 0x400b
+    field public static final int EVENT_OBJECT_ADDED = 16386; // 0x4002
+    field public static final int EVENT_OBJECT_INFO_CHANGED = 16391; // 0x4007
+    field public static final int EVENT_OBJECT_PROP_CHANGED = 51201; // 0xc801
+    field public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 51202; // 0xc802
+    field public static final int EVENT_OBJECT_REFERENCES_CHANGED = 51203; // 0xc803
+    field public static final int EVENT_OBJECT_REMOVED = 16387; // 0x4003
+    field public static final int EVENT_REQUEST_OBJECT_TRANSFER = 16393; // 0x4009
+    field public static final int EVENT_STORAGE_INFO_CHANGED = 16396; // 0x400c
+    field public static final int EVENT_STORE_ADDED = 16388; // 0x4004
+    field public static final int EVENT_STORE_FULL = 16394; // 0x400a
+    field public static final int EVENT_STORE_REMOVED = 16389; // 0x4005
+    field public static final int EVENT_UNDEFINED = 16384; // 0x4000
+    field public static final int EVENT_UNREPORTED_STATUS = 16398; // 0x400e
+  }
+
+}
+
 package android.net {
 
   public class SSLCertificateSocketFactory extends javax.net.ssl.SSLSocketFactory {
diff --git a/media/java/android/mtp/MtpConstants.java b/media/java/android/mtp/MtpConstants.java
index 0dcc7180b156..5bbf2ec4b379 100644
--- a/media/java/android/mtp/MtpConstants.java
+++ b/media/java/android/mtp/MtpConstants.java
@@ -583,41 +583,41 @@ public final class MtpConstants {
      */
     public static final int ASSOCIATION_TYPE_GENERIC_FOLDER = 0x0001;
 
-    /** Event code for UNDEFINED event */
+    /** @removed */
     public static final int EVENT_UNDEFINED = 0x4000;
-    /** Event code for CANCEL_TRANSACTION event */
+    /** @removed */
     public static final int EVENT_CANCEL_TRANSACTION = 0x4001;
-    /** Event code for OBJECT_ADDED event */
+    /** @removed */
     public static final int EVENT_OBJECT_ADDED = 0x4002;
-    /** Event code for OBJECT_REMOVED event */
+    /** @removed */
     public static final int EVENT_OBJECT_REMOVED = 0x4003;
-    /** Event code for STORE_ADDED event */
+    /** @removed */
     public static final int EVENT_STORE_ADDED = 0x4004;
-    /** Event code for STORE_REMOVED event */
+    /** @removed */
     public static final int EVENT_STORE_REMOVED = 0x4005;
-    /** Event code for DEVICE_PROP_CHANGED event */
+    /** @removed */
     public static final int EVENT_DEVICE_PROP_CHANGED = 0x4006;
-    /** Event code for OBJECT_INFO_CHANGED event */
+    /** @removed */
     public static final int EVENT_OBJECT_INFO_CHANGED = 0x4007;
-    /** Event code for DEVICE_INFO_CHANGED event */
+    /** @removed */
     public static final int EVENT_DEVICE_INFO_CHANGED = 0x4008;
-    /** Event code for REQUEST_OBJECT_TRANSFER event */
+    /** @removed */
     public static final int EVENT_REQUEST_OBJECT_TRANSFER = 0x4009;
-    /** Event code for STORE_FULL event */
+    /** @removed */
     public static final int EVENT_STORE_FULL = 0x400A;
-    /** Event code for DEVICE_RESET event */
+    /** @removed */
     public static final int EVENT_DEVICE_RESET = 0x400B;
-    /** Event code for STORAGE_INFO_CHANGED event */
+    /** @removed */
     public static final int EVENT_STORAGE_INFO_CHANGED = 0x400C;
-    /** Event code for CAPTURE_COMPLETE event */
+    /** @removed */
     public static final int EVENT_CAPTURE_COMPLETE = 0x400D;
-    /** Event code for UNREPORTED_STATUS event */
+    /** @removed */
     public static final int EVENT_UNREPORTED_STATUS = 0x400E;
-    /** Event code for OBJECT_PROP_CHANGED event */
+    /** @removed */
     public static final int EVENT_OBJECT_PROP_CHANGED = 0xC801;
-    /** Event code for OBJECT_PROP_DESC_CHANGED event */
+    /** @removed */
     public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 0xC802;
-    /** Event code for OBJECT_REFERENCES_CHANGED event */
+    /** @removed */
     public static final int EVENT_OBJECT_REFERENCES_CHANGED = 0xC803;
 
     /** Operation code for GetDeviceInfo */
diff --git a/media/java/android/mtp/MtpDevice.java b/media/java/android/mtp/MtpDevice.java
index d0ef37c77055..a1fba823a7bd 100644
--- a/media/java/android/mtp/MtpDevice.java
+++ b/media/java/android/mtp/MtpDevice.java
@@ -169,8 +169,8 @@ public final class MtpDevice {
      * @param objectHandle handle of the object to read
      * @param offset Start index of reading range. It must be a non-negative value at most
      *     0xffffffff.
-     * @param size Size of reading range. It must be a non-negative value at most 0xffffffff. If
-     *     0xffffffff is specified, the method obtains the full bytes of object.
+     * @param size Size of reading range. It must be a non-negative value at most Integer.MAX_VALUE
+     *     or 0xffffffff. If 0xffffffff is specified, the method obtains the full bytes of object.
      * @param buffer Array to write data.
      * @return Size of bytes that are actually read.
      */
@@ -190,7 +190,7 @@ public final class MtpDevice {
      *
      * @param objectHandle handle of the object to read
      * @param offset Start index of reading range. It must be a non-negative value.
-     * @param size Size of reading range. It must be a non-negative value at most 0xffffffff.
+     * @param size Size of reading range. It must be a non-negative value at most Integer.MAX_VALUE.
      * @param buffer Array to write data.
      * @return Size of bytes that are actually read.
      * @see MtpConstants#OPERATION_GET_PARTIAL_OBJECT_64
@@ -317,7 +317,7 @@ public final class MtpDevice {
      * The returned {@link MtpObjectInfo} has the new object handle field filled in.
      *
      * @param info metadata of the entry
-     * @return object info of the created entry
+     * @return object info of the created entry or null if the operation failed.
      */
     public MtpObjectInfo sendObjectInfo(MtpObjectInfo info) {
         return native_send_object_info(info);
diff --git a/media/java/android/mtp/MtpDeviceInfo.java b/media/java/android/mtp/MtpDeviceInfo.java
index 2e4f4510b07b..86bd599e442c 100644
--- a/media/java/android/mtp/MtpDeviceInfo.java
+++ b/media/java/android/mtp/MtpDeviceInfo.java
@@ -16,8 +16,6 @@
 
 package android.mtp;
 
-import android.annotation.Nullable;
-
 /**
  * This class encapsulates information about an MTP device.
  * This corresponds to the DeviceInfo Dataset described in
@@ -112,7 +110,7 @@ public class MtpDeviceInfo {
      * @see MtpConstants#OPERATION_SET_OBJECT_REFERENCES
      * @see MtpConstants#OPERATION_SKIP
      */
-    public final @Nullable int[] getOperationsSupported() {
+    public final int[] getOperationsSupported() {
         return mOperationsSupported;
     }
 
@@ -120,26 +118,57 @@ public class MtpDeviceInfo {
      * Returns event code supported by the device.
      *
      * @return supported event code. Can be null if device does not provide the property.
-     * @see MtpConstants#EVENT_UNDEFINED
-     * @see MtpConstants#EVENT_CANCEL_TRANSACTION
-     * @see MtpConstants#EVENT_OBJECT_ADDED
-     * @see MtpConstants#EVENT_OBJECT_REMOVED
-     * @see MtpConstants#EVENT_STORE_ADDED
-     * @see MtpConstants#EVENT_STORE_REMOVED
-     * @see MtpConstants#EVENT_DEVICE_PROP_CHANGED
-     * @see MtpConstants#EVENT_OBJECT_INFO_CHANGED
-     * @see MtpConstants#EVENT_DEVICE_INFO_CHANGED
-     * @see MtpConstants#EVENT_REQUEST_OBJECT_TRANSFER
-     * @see MtpConstants#EVENT_STORE_FULL
-     * @see MtpConstants#EVENT_DEVICE_RESET
-     * @see MtpConstants#EVENT_STORAGE_INFO_CHANGED
-     * @see MtpConstants#EVENT_CAPTURE_COMPLETE
-     * @see MtpConstants#EVENT_UNREPORTED_STATUS
-     * @see MtpConstants#EVENT_OBJECT_PROP_CHANGED
-     * @see MtpConstants#EVENT_OBJECT_PROP_DESC_CHANGED
-     * @see MtpConstants#EVENT_OBJECT_REFERENCES_CHANGED
+     * @see MtpEvent#EVENT_UNDEFINED
+     * @see MtpEvent#EVENT_CANCEL_TRANSACTION
+     * @see MtpEvent#EVENT_OBJECT_ADDED
+     * @see MtpEvent#EVENT_OBJECT_REMOVED
+     * @see MtpEvent#EVENT_STORE_ADDED
+     * @see MtpEvent#EVENT_STORE_REMOVED
+     * @see MtpEvent#EVENT_DEVICE_PROP_CHANGED
+     * @see MtpEvent#EVENT_OBJECT_INFO_CHANGED
+     * @see MtpEvent#EVENT_DEVICE_INFO_CHANGED
+     * @see MtpEvent#EVENT_REQUEST_OBJECT_TRANSFER
+     * @see MtpEvent#EVENT_STORE_FULL
+     * @see MtpEvent#EVENT_DEVICE_RESET
+     * @see MtpEvent#EVENT_STORAGE_INFO_CHANGED
+     * @see MtpEvent#EVENT_CAPTURE_COMPLETE
+     * @see MtpEvent#EVENT_UNREPORTED_STATUS
+     * @see MtpEvent#EVENT_OBJECT_PROP_CHANGED
+     * @see MtpEvent#EVENT_OBJECT_PROP_DESC_CHANGED
+     * @see MtpEvent#EVENT_OBJECT_REFERENCES_CHANGED
      */
-    public final @Nullable int[] getEventsSupported() {
+    public final int[] getEventsSupported() {
         return mEventsSupported;
     }
+
+    /**
+     * Returns if the given operation is supported by the device or not.
+     * @param code Operation code.
+     * @return If the given operation is supported by the device or not.
+     */
+    public boolean isOperationSupported(int code) {
+        return isSupported(mOperationsSupported, code);
+    }
+
+    /**
+     * Returns if the given event is supported by the device or not.
+     * @param code Event code.
+     * @return If the given event is supported by the device or not.
+     */
+    public boolean isEventSupported(int code) {
+        return isSupported(mEventsSupported, code);
+    }
+
+    /**
+     * Returns if the code set contains code.
+     * @hide
+     */
+    private static boolean isSupported(int[] set, int code) {
+        for (final int element : set) {
+            if (element == code) {
+                return true;
+            }
+        }
+        return false;
+    }
 }
diff --git a/media/java/android/mtp/MtpEvent.java b/media/java/android/mtp/MtpEvent.java
index dc89a56cf0b3..9ca00e1956cb 100644
--- a/media/java/android/mtp/MtpEvent.java
+++ b/media/java/android/mtp/MtpEvent.java
@@ -21,7 +21,44 @@ package android.mtp;
  * This corresponds to the events described in appendix G of the MTP specification.
  */
 public class MtpEvent {
-    private int mEventCode = MtpConstants.EVENT_UNDEFINED;
+    /** Event code for UNDEFINED event */
+    public static final int EVENT_UNDEFINED = 0x4000;
+    /** Event code for CANCEL_TRANSACTION event */
+    public static final int EVENT_CANCEL_TRANSACTION = 0x4001;
+    /** Event code for OBJECT_ADDED event */
+    public static final int EVENT_OBJECT_ADDED = 0x4002;
+    /** Event code for OBJECT_REMOVED event */
+    public static final int EVENT_OBJECT_REMOVED = 0x4003;
+    /** Event code for STORE_ADDED event */
+    public static final int EVENT_STORE_ADDED = 0x4004;
+    /** Event code for STORE_REMOVED event */
+    public static final int EVENT_STORE_REMOVED = 0x4005;
+    /** Event code for DEVICE_PROP_CHANGED event */
+    public static final int EVENT_DEVICE_PROP_CHANGED = 0x4006;
+    /** Event code for OBJECT_INFO_CHANGED event */
+    public static final int EVENT_OBJECT_INFO_CHANGED = 0x4007;
+    /** Event code for DEVICE_INFO_CHANGED event */
+    public static final int EVENT_DEVICE_INFO_CHANGED = 0x4008;
+    /** Event code for REQUEST_OBJECT_TRANSFER event */
+    public static final int EVENT_REQUEST_OBJECT_TRANSFER = 0x4009;
+    /** Event code for STORE_FULL event */
+    public static final int EVENT_STORE_FULL = 0x400A;
+    /** Event code for DEVICE_RESET event */
+    public static final int EVENT_DEVICE_RESET = 0x400B;
+    /** Event code for STORAGE_INFO_CHANGED event */
+    public static final int EVENT_STORAGE_INFO_CHANGED = 0x400C;
+    /** Event code for CAPTURE_COMPLETE event */
+    public static final int EVENT_CAPTURE_COMPLETE = 0x400D;
+    /** Event code for UNREPORTED_STATUS event */
+    public static final int EVENT_UNREPORTED_STATUS = 0x400E;
+    /** Event code for OBJECT_PROP_CHANGED event */
+    public static final int EVENT_OBJECT_PROP_CHANGED = 0xC801;
+    /** Event code for OBJECT_PROP_DESC_CHANGED event */
+    public static final int EVENT_OBJECT_PROP_DESC_CHANGED = 0xC802;
+    /** Event code for OBJECT_REFERENCES_CHANGED event */
+    public static final int EVENT_OBJECT_REFERENCES_CHANGED = 0xC803;
+
+    private int mEventCode = EVENT_UNDEFINED;
 
     // Parameters for event. The interpretation of event parameters depends upon mEventCode.
     private int mParameter1;
@@ -29,6 +66,11 @@ public class MtpEvent {
     private int mParameter3;
 
     /**
+     * MtpEvent is instantiated by JNI.
+     */
+    private MtpEvent() {}
+
+    /**
      * Returns event code of MTP event.
      * See the USB-IF MTP specification for the details of event constants.
      * @return event code
@@ -53,26 +95,26 @@ public class MtpEvent {
     /**
      * Obtains objectHandle event parameter.
      *
-     * @see MtpConstants#EVENT_OBJECT_ADDED
-     * @see MtpConstants#EVENT_OBJECT_REMOVED
-     * @see MtpConstants#EVENT_OBJECT_INFO_CHANGED
-     * @see MtpConstants#EVENT_REQUEST_OBJECT_TRANSFER
-     * @see MtpConstants#EVENT_OBJECT_PROP_CHANGED
-     * @see MtpConstants#EVENT_OBJECT_REFERENCES_CHANGED
+     * @see #EVENT_OBJECT_ADDED
+     * @see #EVENT_OBJECT_REMOVED
+     * @see #EVENT_OBJECT_INFO_CHANGED
+     * @see #EVENT_REQUEST_OBJECT_TRANSFER
+     * @see #EVENT_OBJECT_PROP_CHANGED
+     * @see #EVENT_OBJECT_REFERENCES_CHANGED
      */
     public int getObjectHandle() {
         switch (mEventCode) {
-            case MtpConstants.EVENT_OBJECT_ADDED:
+            case EVENT_OBJECT_ADDED:
                 return mParameter1;
-            case MtpConstants.EVENT_OBJECT_REMOVED:
+            case EVENT_OBJECT_REMOVED:
                 return mParameter1;
-            case MtpConstants.EVENT_OBJECT_INFO_CHANGED:
+            case EVENT_OBJECT_INFO_CHANGED:
                 return mParameter1;
-            case MtpConstants.EVENT_REQUEST_OBJECT_TRANSFER:
+            case EVENT_REQUEST_OBJECT_TRANSFER:
                 return mParameter1;
-            case MtpConstants.EVENT_OBJECT_PROP_CHANGED:
+            case EVENT_OBJECT_PROP_CHANGED:
                 return mParameter1;
-            case MtpConstants.EVENT_OBJECT_REFERENCES_CHANGED:
+            case EVENT_OBJECT_REFERENCES_CHANGED:
                 return mParameter1;
             default:
                 throw new IllegalParameterAccess("objectHandle", mEventCode);
@@ -82,20 +124,20 @@ public class MtpEvent {
     /**
      * Obtains storageID event parameter.
      *
-     * @see MtpConstants#EVENT_STORE_ADDED
-     * @see MtpConstants#EVENT_STORE_REMOVED
-     * @see MtpConstants#EVENT_STORE_FULL
-     * @see MtpConstants#EVENT_STORAGE_INFO_CHANGED
+     * @see #EVENT_STORE_ADDED
+     * @see #EVENT_STORE_REMOVED
+     * @see #EVENT_STORE_FULL
+     * @see #EVENT_STORAGE_INFO_CHANGED
      */
     public int getStorageId() {
         switch (mEventCode) {
-            case MtpConstants.EVENT_STORE_ADDED:
+            case EVENT_STORE_ADDED:
                 return mParameter1;
-            case MtpConstants.EVENT_STORE_REMOVED:
+            case EVENT_STORE_REMOVED:
                 return mParameter1;
-            case MtpConstants.EVENT_STORE_FULL:
+            case EVENT_STORE_FULL:
                 return mParameter1;
-            case MtpConstants.EVENT_STORAGE_INFO_CHANGED:
+            case EVENT_STORAGE_INFO_CHANGED:
                 return mParameter1;
             default:
                 throw new IllegalParameterAccess("storageID", mEventCode);
@@ -105,11 +147,11 @@ public class MtpEvent {
     /**
      * Obtains devicePropCode event parameter.
      *
-     * @see MtpConstants#EVENT_DEVICE_PROP_CHANGED
+     * @see #EVENT_DEVICE_PROP_CHANGED
      */
     public int getDevicePropCode() {
         switch (mEventCode) {
-            case MtpConstants.EVENT_DEVICE_PROP_CHANGED:
+            case EVENT_DEVICE_PROP_CHANGED:
                 return mParameter1;
             default:
                 throw new IllegalParameterAccess("devicePropCode", mEventCode);
@@ -119,11 +161,11 @@ public class MtpEvent {
     /**
      * Obtains transactionID event parameter.
      *
-     * @see MtpConstants#EVENT_CAPTURE_COMPLETE
+     * @see #EVENT_CAPTURE_COMPLETE
      */
     public int getTransactionId() {
         switch (mEventCode) {
-            case MtpConstants.EVENT_CAPTURE_COMPLETE:
+            case EVENT_CAPTURE_COMPLETE:
                 return mParameter1;
             default:
                 throw new IllegalParameterAccess("transactionID", mEventCode);
@@ -133,14 +175,14 @@ public class MtpEvent {
     /**
      * Obtains objectPropCode event parameter.
      *
-     * @see MtpConstants#EVENT_OBJECT_PROP_CHANGED
-     * @see MtpConstants#EVENT_OBJECT_PROP_DESC_CHANGED
+     * @see #EVENT_OBJECT_PROP_CHANGED
+     * @see #EVENT_OBJECT_PROP_DESC_CHANGED
      */
     public int getObjectPropCode() {
         switch (mEventCode) {
-            case MtpConstants.EVENT_OBJECT_PROP_CHANGED:
+            case EVENT_OBJECT_PROP_CHANGED:
                 return mParameter2;
-            case MtpConstants.EVENT_OBJECT_PROP_DESC_CHANGED:
+            case EVENT_OBJECT_PROP_DESC_CHANGED:
                 return mParameter1;
             default:
                 throw new IllegalParameterAccess("objectPropCode", mEventCode);
@@ -150,11 +192,11 @@ public class MtpEvent {
     /**
      * Obtains objectFormatCode event parameter.
      *
-     * @see MtpConstants#EVENT_OBJECT_PROP_DESC_CHANGED
+     * @see #EVENT_OBJECT_PROP_DESC_CHANGED
      */
     public int getObjectFormatCode() {
         switch (mEventCode) {
-            case MtpConstants.EVENT_OBJECT_PROP_DESC_CHANGED:
+            case EVENT_OBJECT_PROP_DESC_CHANGED:
                 return mParameter2;
             default:
                 throw new IllegalParameterAccess("objectFormatCode", mEventCode);
diff --git a/media/jni/android_mtp_MtpDevice.cpp b/media/jni/android_mtp_MtpDevice.cpp
index 6e434b2756a5..1faa0c472b2e 100644
--- a/media/jni/android_mtp_MtpDevice.cpp
+++ b/media/jni/android_mtp_MtpDevice.cpp
@@ -244,7 +244,8 @@ android_mtp_MtpDevice_get_device_info(JNIEnv *env, jobject thiz)
     if (deviceInfo->mSerial)
         env->SetObjectField(info, field_deviceInfo_serialNumber,
             env->NewStringUTF(deviceInfo->mSerial));
-    if (deviceInfo->mOperations) {
+    assert(deviceInfo->mOperations);
+    {
         const size_t size = deviceInfo->mOperations->size();
         ScopedLocalRef<jintArray> operations(env, static_cast<jintArray>(env->NewIntArray(size)));
         {
@@ -259,7 +260,8 @@ android_mtp_MtpDevice_get_device_info(JNIEnv *env, jobject thiz)
             env->SetObjectField(info, field_deviceInfo_operationsSupported, operations.get());
         }
     }
-    if (deviceInfo->mEvents) {
+    assert(deviceInfo->mEvents);
+    {
         const size_t size = deviceInfo->mEvents->size();
         ScopedLocalRef<jintArray> events(env, static_cast<jintArray>(env->NewIntArray(size)));
         {