MTP: Send an Intent after an MTP session that resulted in media database modifications

Change-Id: Ib2796e9155350c67769502935a73cf98d6ae9c08
Signed-off-by: Mike Lockwood <lockwood@android.com>

core/java/android/provider/Mtp.java

@@ -34,6 +34,14 @@ public final class Mtp
     private static final String CONTENT_AUTHORITY_SLASH = "content://" + AUTHORITY + "/";
     private static final String CONTENT_AUTHORITY_DEVICE_SLASH = "content://" + AUTHORITY + "/device/";
 
+
+   /**
+     * Broadcast Action:  A broadcast to indicate the end of an MTP session with the host.
+     * This broadcast is only sent if MTP activity has modified the media database during the
+     * most recent MTP session
+     */
+    public static final String ACTION_MTP_SESSION_END = "android.provider.action.MTP_SESSION_END";
+
     /**
      * Contains list of all MTP/PTP devices
      */

media/java/android/media/MtpDatabase.java

@@ -19,12 +19,14 @@ package android.media;
 import android.content.Context;
 import android.content.ContentValues;
 import android.content.IContentProvider;
+import android.content.Intent;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.RemoteException;
 import android.provider.MediaStore.Audio;
 import android.provider.MediaStore.MediaColumns;
 import android.provider.MediaStore.MtpObjects;
+import android.provider.Mtp;
 import android.util.Log;
 
 /**
@@ -34,10 +36,14 @@ public class MtpDatabase {
 
     private static final String TAG = "MtpDatabase";
 
+    private final Context mContext;
     private final IContentProvider mMediaProvider;
     private final String mVolumeName;
     private final Uri mObjectsUri;
 
+    // true if the database has been modified in the current MTP session
+    private boolean mDatabaseModified;
+
     // FIXME - this should be passed in via the constructor
     private final int mStorageID = 0x00010001;
 
@@ -72,6 +78,7 @@ public class MtpDatabase {
     public MtpDatabase(Context context, String volumeName) {
         native_setup();
 
+        mContext = context;
         mMediaProvider = context.getContentResolver().acquireProvider("media");
         mVolumeName = volumeName;
         mObjectsUri = MtpObjects.getContentUri(volumeName);
@@ -89,6 +96,7 @@ public class MtpDatabase {
 
     private int beginSendObject(String path, int format, int parent,
                          int storage, long size, long modified) {
+        mDatabaseModified = true;
         ContentValues values = new ContentValues();
         values.put(MtpObjects.ObjectColumns.DATA, path);
         values.put(MtpObjects.ObjectColumns.FORMAT, format);
@@ -398,6 +406,7 @@ public class MtpDatabase {
 
     private int deleteFile(int handle) {
         Log.d(TAG, "deleteFile: " + handle);
+        mDatabaseModified = true;
         Uri uri = MtpObjects.getContentUri(mVolumeName, handle);
         try {
             if (mMediaProvider.delete(uri, null, null) == 1) {
@@ -440,6 +449,7 @@ public class MtpDatabase {
     }
 
     private int setObjectReferences(int handle, int[] references) {
+        mDatabaseModified = true;
         Uri uri = MtpObjects.getReferencesUri(mVolumeName, handle);
         int count = references.length;
         ContentValues[] valuesList = new ContentValues[count];
@@ -458,6 +468,20 @@ public class MtpDatabase {
         return MtpConstants.RESPONSE_GENERAL_ERROR;
     }
 
+    private void sessionStarted() {
+        Log.d(TAG, "sessionStarted");
+        mDatabaseModified = false;
+    }
+
+    private void sessionEnded() {
+        Log.d(TAG, "sessionEnded");
+        if (mDatabaseModified) {
+            Log.d(TAG, "sending ACTION_MTP_SESSION_END");
+            mContext.sendBroadcast(new Intent(Mtp.ACTION_MTP_SESSION_END));
+            mDatabaseModified = false;
+        }
+    }
+
     // used by the JNI code
     private int mNativeContext;
 

media/jni/android_media_MtpDatabase.cpp

@@ -52,6 +52,9 @@ static jmethodID method_getObjectFilePath;
 static jmethodID method_deleteFile;
 static jmethodID method_getObjectReferences;
 static jmethodID method_setObjectReferences;
+static jmethodID method_sessionStarted;
+static jmethodID method_sessionEnded;
+
 static jfieldID field_context;
 
 MtpDatabase* getMtpDatabase(JNIEnv *env, jobject database) {
@@ -135,6 +138,10 @@ public:
                                             MtpObjectFormat format);
 
     virtual MtpProperty*            getDevicePropertyDesc(MtpDeviceProperty property);
+
+    virtual void                    sessionStarted();
+
+    virtual void                    sessionEnded();
 };
 
 // ----------------------------------------------------------------------------
@@ -583,6 +590,18 @@ MtpProperty* MyMtpDatabase::getDevicePropertyDesc(MtpDeviceProperty property) {
     return NULL;
 }
 
+void MyMtpDatabase::sessionStarted() {
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    env->CallVoidMethod(mDatabase, method_sessionStarted);
+    checkAndClearExceptionFromCallback(env, __FUNCTION__);
+}
+
+void MyMtpDatabase::sessionEnded() {
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    env->CallVoidMethod(mDatabase, method_sessionEnded);
+    checkAndClearExceptionFromCallback(env, __FUNCTION__);
+}
+
 #endif // HAVE_ANDROID_OS
 
 // ----------------------------------------------------------------------------
@@ -701,6 +720,17 @@ int register_android_media_MtpDatabase(JNIEnv *env)
         LOGE("Can't find setObjectReferences");
         return -1;
     }
+    method_sessionStarted = env->GetMethodID(clazz, "sessionStarted", "()V");
+    if (method_sessionStarted == NULL) {
+        LOGE("Can't find sessionStarted");
+        return -1;
+    }
+    method_sessionEnded = env->GetMethodID(clazz, "sessionEnded", "()V");
+    if (method_sessionEnded == NULL) {
+        LOGE("Can't find sessionEnded");
+        return -1;
+    }
+
     field_context = env->GetFieldID(clazz, "mNativeContext", "I");
     if (field_context == NULL) {
         LOGE("Can't find MtpDatabase.mNativeContext");

media/mtp/MtpDatabase.h

@@ -93,6 +93,10 @@ public:
                                             MtpObjectFormat format) = 0;
 
     virtual MtpProperty*            getDevicePropertyDesc(MtpDeviceProperty property) = 0;
+
+    virtual void                    sessionStarted() = 0;
+
+    virtual void                    sessionEnded() = 0;
 };
 
 }; // namespace android

media/mtp/MtpServer.cpp

@@ -185,6 +185,9 @@ void MtpServer::run() {
             LOGV("skipping response\n");
         }
     }
+
+    if (mSessionOpen)
+        mDatabase->sessionEnded();
 }
 
 void MtpServer::sendObjectAdded(MtpObjectHandle handle) {
@@ -346,6 +349,9 @@ MtpResponseCode MtpServer::doOpenSession() {
     }
     mSessionID = mRequest.getParameter(1);
     mSessionOpen = true;
+
+    mDatabase->sessionStarted();
+
     return MTP_RESPONSE_OK;
 }
 
@@ -354,6 +360,7 @@ MtpResponseCode MtpServer::doCloseSession() {
         return MTP_RESPONSE_SESSION_NOT_OPEN;
     mSessionID = 0;
     mSessionOpen = false;
+    mDatabase->sessionEnded();
     return MTP_RESPONSE_OK;
 }