Improve Android 7 workaround behavior in combination with CATEGORIES/VCard4 contact groups

app/build.gradle

@@ -135,7 +135,7 @@ dependencies {
     compile group: 'com.madgag.spongycastle', name: 'prov', version: '1.54.0.0'
     compile group: 'com.google.code.gson', name: 'gson', version: '1.7.2'
     compile 'com.squareup.okhttp3:logging-interceptor:3.6.0'
-    provided 'org.projectlombok:lombok:1.16.12'
+    provided 'org.projectlombok:lombok:1.16.14'
 
     // for tests
     androidTestCompile('com.android.support.test:runner:0.5') {

app/src/main/java/com/etesync/syncadapter/resource/LocalAddressBook.java

@@ -19,6 +19,7 @@ import android.os.Bundle;
 import android.os.Parcel;
 import android.os.RemoteException;
 import android.provider.ContactsContract;
+import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
 import android.provider.ContactsContract.Groups;
 import android.provider.ContactsContract.RawContacts;
 import android.support.annotation.NonNull;
@@ -27,13 +28,16 @@ import com.etesync.syncadapter.App;
 
 import java.io.FileNotFoundException;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 import java.util.logging.Level;
 
 import at.bitfire.vcard4android.AndroidAddressBook;
 import at.bitfire.vcard4android.AndroidContact;
 import at.bitfire.vcard4android.AndroidGroup;
+import at.bitfire.vcard4android.CachedGroupMembership;
 import at.bitfire.vcard4android.ContactsStorageException;
 import lombok.Cleanup;
 
@@ -149,15 +153,6 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
         return null;
     }
 
-    public void deleteAll() throws ContactsStorageException {
-        try {
-            provider.delete(syncAdapterURI(RawContacts.CONTENT_URI), null, null);
-            provider.delete(syncAdapterURI(Groups.CONTENT_URI), null, null);
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't delete all local contacts and groups", e);
-        }
-    }
-
     @Override
     public long count() throws ContactsStorageException {
         try {
@@ -196,6 +191,38 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
         return (LocalGroup[])queryGroups(Groups.DIRTY + "!= 0 AND " + Groups.DELETED + "== 0", null);
     }
 
+    @NonNull LocalContact[] getByGroupMembership(long groupID) throws ContactsStorageException {
+        try {
+            @Cleanup Cursor cursor = provider.query(syncAdapterURI(ContactsContract.Data.CONTENT_URI),
+                    new String[] { RawContacts.Data.RAW_CONTACT_ID },
+                    "(" + GroupMembership.MIMETYPE + "=? AND " + GroupMembership.GROUP_ROW_ID + "=?) OR (" + CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?)",
+                    new String[] { GroupMembership.CONTENT_ITEM_TYPE, String.valueOf(groupID), CachedGroupMembership.CONTENT_ITEM_TYPE, String.valueOf(groupID) },
+                    null);
+
+            Set<Long> ids = new HashSet<>();
+            while (cursor != null && cursor.moveToNext())
+                ids.add(cursor.getLong(0));
+
+            LocalContact[] contacts = new LocalContact[ids.size()];
+            int i = 0;
+            for (Long id : ids)
+                contacts[i++] = new LocalContact(this, id, null, null);
+            return contacts;
+        } catch (RemoteException e) {
+            throw new ContactsStorageException("Couldn't query contacts", e);
+        }
+    }
+
+
+    public void deleteAll() throws ContactsStorageException {
+        try {
+            provider.delete(syncAdapterURI(RawContacts.CONTENT_URI), null, null);
+            provider.delete(syncAdapterURI(Groups.CONTENT_URI), null, null);
+        } catch(RemoteException e) {
+            throw new ContactsStorageException("Couldn't delete all local contacts and groups", e);
+        }
+    }
+
 
     /**
      * Finds the first group with the given title. If there is no group with this

app/src/main/java/com/etesync/syncadapter/resource/LocalContact.java

@@ -18,6 +18,7 @@ import android.provider.ContactsContract;
 import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
 import android.provider.ContactsContract.RawContacts.Data;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.text.TextUtils;
 
 import com.etesync.syncadapter.App;
@@ -184,30 +185,41 @@ public class LocalContact extends AndroidContact implements LocalResource {
 
     /**
      * Calculates a hash code from the contact's data (VCard) and group memberships.
+     * Attention: re-reads {@link #contact} from the database, discarding all changes in memory
      * @return hash code of contact data (including group memberships)
      */
     protected int dataHashCode() throws FileNotFoundException, ContactsStorageException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
             App.log.severe("dataHashCode() should not be called on Android <7");
 
+        // reset contact so that getContact() reads from database
+        contact = null;
+
         // groupMemberships is filled by getContact()
-        return getContact().hashCode() ^ groupMemberships.hashCode();
+        int dataHash = getContact().hashCode(),
+            groupHash = groupMemberships.hashCode();
+        App.log.finest("Calculated data hash = " + dataHash + ", group memberships hash = " + groupHash);
+        return dataHash ^ groupHash;
     }
 
-    public void updateHashCode() throws ContactsStorageException {
+    public void updateHashCode(@Nullable BatchOperation batch) throws ContactsStorageException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
             App.log.severe("updateHashCode() should not be called on Android <7");
 
-        // re-read from provider before calculating the hash because the Contact as parsed from
-        // the VCard is not the same as when read from the database
-        contact = null;
-
         ContentValues values = new ContentValues(1);
         try {
             int hashCode = dataHashCode();
             App.log.fine("Storing contact hash = " + hashCode);
             values.put(COLUMN_HASHCODE, hashCode);
-            addressBook.provider.update(rawContactSyncURI(), values, null, null);
+
+            if (batch == null)
+                addressBook.provider.update(rawContactSyncURI(), values, null, null);
+            else {
+                ContentProviderOperation.Builder builder = ContentProviderOperation
+                        .newUpdate(rawContactSyncURI())
+                        .withValues(values);
+                batch.enqueue(new BatchOperation.Operation(builder));
+            }
         } catch(FileNotFoundException|RemoteException e) {
             throw new ContactsStorageException("Couldn't store contact checksum", e);
         }
@@ -230,12 +242,14 @@ public class LocalContact extends AndroidContact implements LocalResource {
 
     public void addToGroup(BatchOperation batch, long groupID) {
         assertID();
+
         batch.enqueue(new BatchOperation.Operation(
                 ContentProviderOperation.newInsert(dataSyncURI())
                         .withValue(GroupMembership.MIMETYPE, GroupMembership.CONTENT_ITEM_TYPE)
                         .withValue(GroupMembership.RAW_CONTACT_ID, id)
                         .withValue(GroupMembership.GROUP_ROW_ID, groupID)
         ));
+        groupMemberships.add(groupID);
 
         batch.enqueue(new BatchOperation.Operation(
                 ContentProviderOperation.newInsert(dataSyncURI())
@@ -244,6 +258,7 @@ public class LocalContact extends AndroidContact implements LocalResource {
                         .withValue(CachedGroupMembership.GROUP_ID, groupID)
                         .withYieldAllowed(true)
         ));
+        cachedGroupMemberships.add(groupID);
     }
 
     public void removeGroupMemberships(BatchOperation batch) {
@@ -256,6 +271,8 @@ public class LocalContact extends AndroidContact implements LocalResource {
                         )
                         .withYieldAllowed(true)
         ));
+        groupMemberships.clear();
+        cachedGroupMemberships.clear();
     }
 
     /**

app/src/main/java/com/etesync/syncadapter/resource/LocalGroup.java

@@ -12,6 +12,7 @@ import android.content.ContentProviderOperation;
 import android.content.ContentUris;
 import android.content.ContentValues;
 import android.database.Cursor;
+import android.os.Build;
 import android.os.Parcel;
 import android.os.RemoteException;
 import android.provider.ContactsContract;
@@ -20,16 +21,19 @@ import android.provider.ContactsContract.Groups;
 import android.provider.ContactsContract.RawContacts;
 import android.provider.ContactsContract.RawContacts.Data;
 
+import com.etesync.syncadapter.App;
+
 import org.apache.commons.lang3.ArrayUtils;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 import java.util.UUID;
 import java.util.logging.Level;
 
-import com.etesync.syncadapter.App;
 import at.bitfire.vcard4android.AndroidAddressBook;
 import at.bitfire.vcard4android.AndroidGroup;
 import at.bitfire.vcard4android.AndroidGroupFactory;
@@ -162,15 +166,14 @@ public class LocalGroup extends AndroidGroup implements LocalResource {
                 long id = cursor.getLong(0);
                 App.log.fine("Assigning members to group " + id);
 
+                // required for workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+                Set<Long> changeContactIDs = new HashSet<>();
+
                 // delete all memberships and cached memberships for this group
-                batch.enqueue(new BatchOperation.Operation(
+                for (LocalContact contact : addressBook.getByGroupMembership(id)) {
-                        ContentProviderOperation.newDelete(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
+                    contact.removeGroupMemberships(batch);
-                                .withSelection(
+                    changeContactIDs.add(contact.getId());
-                                        "(" + GroupMembership.MIMETYPE + "=? AND " + GroupMembership.GROUP_ROW_ID + "=?) OR (" +
+                }
-                                              CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?)",
-                                        new String[] { GroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id), CachedGroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id) })
-                                .withYieldAllowed(true)
-                ));
 
                 // extract list of member UIDs
                 List<String> members = new LinkedList<>();
@@ -186,11 +189,19 @@ public class LocalGroup extends AndroidGroup implements LocalResource {
                     try {
                         LocalContact member = addressBook.findContactByUID(uid);
                         member.addToGroup(batch, id);
+                        changeContactIDs.add(member.getId());
                     } catch(FileNotFoundException e) {
                         App.log.log(Level.WARNING, "Group member not found: " + uid, e);
                     }
                 }
 
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
+                    // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+                    for (Long contactID : changeContactIDs) {
+                        LocalContact contact = new LocalContact(addressBook, contactID, null, null);
+                        contact.updateHashCode(batch);
+                    }
+
                 // remove pending memberships
                 batch.enqueue(new BatchOperation.Operation(
                         ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, id)))

app/src/main/java/com/etesync/syncadapter/syncadapter/ContactsSyncManager.java

@@ -208,7 +208,7 @@ public class ContactsSyncManager extends SyncManager {
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && local instanceof LocalContact)
             // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-            ((LocalContact)local).updateHashCode();
+            ((LocalContact)local).updateHashCode(null);
 
         return local;
     }