refactored group chat members into seperate screen

8 files changed, 362 insertions, 200 deletions

diff --git a/src/main/java/de/pixart/messenger/entities/MucOptions.java b/src/main/java/de/pixart/messenger/entities/MucOptions.java
index 01daad1bf..c1b776b9a 100644
--- a/src/main/java/de/pixart/messenger/entities/MucOptions.java
+++ b/src/main/java/de/pixart/messenger/entities/MucOptions.java
@@ -14,6 +14,7 @@ import java.util.Set;
 
 import de.pixart.messenger.Config;
 import de.pixart.messenger.R;
+import de.pixart.messenger.services.AvatarService;
 import de.pixart.messenger.services.MessageArchiveService;
 import de.pixart.messenger.utils.JidHelper;
 import de.pixart.messenger.utils.UIHelper;
@@ -45,6 +46,7 @@ public class MucOptions {
     private User self;
     private String password = null;
     private boolean tookProposedNickFromBookmark = false;
+
     public MucOptions(Conversation conversation) {
         this.account = conversation.getAccount();
         this.conversation = conversation;
@@ -102,7 +104,7 @@ public class MucOptions {
     }
 
     void notifyOfBookmarkNick(final String nick) {
-        final String normalized = normalize(account.getJid(),nick);
+        final String normalized = normalize(account.getJid(), nick);
         if (normalized != null && normalized.equals(getSelf().getFullJid().getResource())) {
             this.tookProposedNickFromBookmark = true;
         }
@@ -381,6 +383,21 @@ public class MucOptions {
         return subset;
     }
 
+    public static List<User> sub(List<User> users, int max) {
+        ArrayList<User> subset = new ArrayList<>();
+        HashSet<Jid> jids = new HashSet<>();
+        for (User user : users) {
+            jids.add(user.getAccount().getJid().asBareJid());
+            if (user.getRealJid() == null || (user.getRealJid().getLocal() != null && jids.add(user.getRealJid()))) {
+                subset.add(user);
+            }
+            if (subset.size() >= max) {
+                break;
+            }
+        }
+        return subset;
+    }
+
     public int getUserCount() {
         synchronized (users) {
             return users.size();
@@ -602,6 +619,7 @@ public class MucOptions {
 
         private int resId;
         private int rank;
+
         Affiliation(int rank, int resId) {
             this.resId = resId;
             this.rank = rank;
@@ -644,6 +662,7 @@ public class MucOptions {
 
         private int resId;
         private int rank;
+
         Role(int resId, int rank) {
             this.resId = resId;
             this.rank = rank;
@@ -702,7 +721,7 @@ public class MucOptions {
 
     }
 
-    public static class User implements Comparable<User> {
+    public static class User implements Comparable<User>, AvatarService.Avatarable {
         private Role role = Role.NONE;
         private Affiliation affiliation = Affiliation.NONE;
         private Jid realJid;
@@ -838,7 +857,7 @@ public class MucOptions {
             }
         }
 
-        private String getComparableName() {
+        public String getComparableName() {
             Contact contact = getContact();
             if (contact != null) {
                 return contact.getDisplayName();
@@ -863,5 +882,11 @@ public class MucOptions {
             this.chatState = chatState;
             return true;
         }
+
+        @Override
+        public int getAvatarBackgroundColor() {
+            final String seed = realJid != null ? realJid.asBareJid().toString() : null;
+            return UIHelper.getColorForName(seed == null ? getName() : seed);
+        }
     }
 }
diff --git a/src/main/java/de/pixart/messenger/services/AvatarService.java b/src/main/java/de/pixart/messenger/services/AvatarService.java
index 4ed01c42a..da5c449f9 100644
--- a/src/main/java/de/pixart/messenger/services/AvatarService.java
+++ b/src/main/java/de/pixart/messenger/services/AvatarService.java
@@ -39,6 +39,7 @@ import de.pixart.messenger.entities.Conversational;
 import de.pixart.messenger.entities.ListItem;
 import de.pixart.messenger.entities.Message;
 import de.pixart.messenger.entities.MucOptions;
+import de.pixart.messenger.ui.ConferenceDetailsActivity;
 import de.pixart.messenger.utils.UIHelper;
 import de.pixart.messenger.xmpp.OnAdvancedStreamFeaturesLoaded;
 import de.pixart.messenger.xmpp.XmppConnection;
@@ -75,13 +76,15 @@ public class AvatarService implements OnAdvancedStreamFeaturesLoaded {
 
     public Bitmap get(final Avatarable avatarable, final int size, final boolean cachedOnly) {
         if (avatarable instanceof Account) {
-            return get((Account) avatarable,size,cachedOnly);
+            return get((Account) avatarable, size, cachedOnly);
         } else if (avatarable instanceof Conversation) {
             return get((Conversation) avatarable, size, cachedOnly);
         } else if (avatarable instanceof Message) {
             return get((Message) avatarable, size, cachedOnly);
         } else if (avatarable instanceof ListItem) {
             return get((ListItem) avatarable, size, cachedOnly);
+        } else if (avatarable instanceof MucOptions.User) {
+            return get((MucOptions.User) avatarable, size, cachedOnly);
         }
         throw new AssertionError("AvatarService does not know how to generate avatar from "+avatarable.getClass().getName());
     }
diff --git a/src/main/java/de/pixart/messenger/ui/ConferenceDetailsActivity.java b/src/main/java/de/pixart/messenger/ui/ConferenceDetailsActivity.java
index 3508fef7c..92192de69 100644
--- a/src/main/java/de/pixart/messenger/ui/ConferenceDetailsActivity.java
+++ b/src/main/java/de/pixart/messenger/ui/ConferenceDetailsActivity.java
@@ -54,6 +54,7 @@ import de.pixart.messenger.services.XmppConnectionService;
 import de.pixart.messenger.services.XmppConnectionService.OnConversationUpdate;
 import de.pixart.messenger.services.XmppConnectionService.OnMucRosterUpdate;
 import de.pixart.messenger.ui.adapter.MediaAdapter;
+import de.pixart.messenger.ui.adapter.UserPreviewAdapter;
 import de.pixart.messenger.ui.interfaces.OnMediaLoaded;
 import de.pixart.messenger.ui.util.Attachment;
 import de.pixart.messenger.ui.util.AvatarWorkerTask;
@@ -78,15 +79,7 @@ import static de.pixart.messenger.utils.StringUtils.changed;
 
 public class ConferenceDetailsActivity extends XmppActivity implements OnConversationUpdate, OnMucRosterUpdate, XmppConnectionService.OnAffiliationChanged, XmppConnectionService.OnRoleChanged, XmppConnectionService.OnConfigurationPushed, TextWatcher, OnMediaLoaded {
     public static final String ACTION_VIEW_MUC = "view_muc";
-    private static final float INACTIVE_ALPHA = 0.4684f; //compromise between dark and light theme
     private Conversation mConversation;
-    private OnClickListener inviteListener = new OnClickListener() {
-
-        @Override
-        public void onClick(View v) {
-            inviteToConversation(mConversation);
-        }
-    };
     private OnClickListener destroyListener = new OnClickListener() {
         @Override
         public void onClick(View v) {
@@ -109,8 +102,8 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
     };
     private ActivityMucDetailsBinding binding;
     private MediaAdapter mMediaAdapter;
+    private UserPreviewAdapter mUserPreviewAdapter;
     private String uuid = null;
-    private User mSelectedUser = null;
 
     private boolean mAdvancedMode = false;
 
@@ -247,31 +240,6 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         }
     };
 
-    public static boolean cancelPotentialWork(User user, ImageView imageView) {
-        final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
-
-        if (bitmapWorkerTask != null) {
-            final User old = bitmapWorkerTask.o;
-            if (old == null || user != old) {
-                bitmapWorkerTask.cancel(true);
-            } else {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {
-        if (imageView != null) {
-            final Drawable drawable = imageView.getDrawable();
-            if (drawable instanceof AsyncDrawable) {
-                final AsyncDrawable asyncDrawable = (AsyncDrawable) drawable;
-                return asyncDrawable.getBitmapWorkerTask();
-            }
-        }
-        return null;
-    }
-
     @Override
     public void onConversationUpdate() {
         refreshUi();
@@ -292,14 +260,10 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         super.onCreate(savedInstanceState);
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_muc_details);
         this.binding.changeConferenceButton.setOnClickListener(this.mChangeConferenceSettings);
-        this.binding.invite.setOnClickListener(inviteListener);
-        this.binding.invite.setVisibility(View.GONE);
-        this.binding.invite.setOnClickListener(inviteListener);
         this.binding.destroy.setVisibility(View.GONE);
         this.binding.destroy.setOnClickListener(destroyListener);
         this.binding.leaveMuc.setVisibility(View.GONE);
         this.binding.addContactButton.setVisibility(View.GONE);
-        this.binding.mucMoreDetails.setVisibility(View.GONE);
         setSupportActionBar((Toolbar) binding.toolbar);
         configureActionBar(getSupportActionBar());
         this.binding.editNickButton.setOnClickListener(v -> quickEdit(mConversation.getMucOptions().getActualNick(),
@@ -342,9 +306,18 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
                 }
             }
         });
-        mMediaAdapter = new MediaAdapter(this, R.dimen.media_size);
+        this.mMediaAdapter = new MediaAdapter(this, R.dimen.media_size);
+        this.mUserPreviewAdapter = new UserPreviewAdapter();
         this.binding.media.setAdapter(mMediaAdapter);
+        this.binding.users.setAdapter(mUserPreviewAdapter);
         GridManager.setupLayoutManager(this, this.binding.media, R.dimen.media_size);
+        GridManager.setupLayoutManager(this, this.binding.users, R.dimen.media_size);
+        this.binding.invite.setOnClickListener(v -> inviteToConversation(mConversation));
+        this.binding.showUsers.setOnClickListener(v -> {
+            Intent intent = new Intent(this, MucUsersActivity.class);
+            intent.putExtra("uuid", mConversation.getUuid());
+            startActivity(intent);
+        });
     }
 
     @Override
@@ -470,36 +443,6 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
     }
 
     @Override
-    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
-        Object tag = v.getTag();
-        if (tag instanceof User) {
-            getMenuInflater().inflate(R.menu.muc_details_context, menu);
-            final User user = (User) tag;
-            this.mSelectedUser = user;
-            String name;
-            final Contact contact = user.getContact();
-            if (contact != null && contact.showInContactList()) {
-                name = contact.getDisplayName();
-            } else if (user.getRealJid() != null) {
-                name = user.getRealJid().asBareJid().toString();
-            } else {
-                name = user.getName();
-            }
-            menu.setHeaderTitle(name);
-            MucDetailsContextMenuHelper.configureMucDetailsContextMenu(this, menu, mConversation, user);
-        }
-        super.onCreateContextMenu(menu, v, menuInfo);
-    }
-
-    @Override
-    public boolean onContextItemSelected(MenuItem item) {
-        if (!MucDetailsContextMenuHelper.onContextItemSelected(item, mSelectedUser, mConversation, this)) {
-            return super.onContextItemSelected(item);
-        }
-        return true;
-    }
-
-    @Override
     public void onMediaLoaded(List<Attachment> attachments) {
         runOnUiThread(() -> {
             int limit = GridManager.getCurrentColumnCount(binding.media);
@@ -578,8 +521,8 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         } else {
             this.binding.detailsAccount.setVisibility(View.GONE);
         }
-        AvatarWorkerTask.loadAvatar(mConversation, binding.detailsMucAvatar, getPixel(Config.AVATAR_SIZE));
-        AvatarWorkerTask.loadAvatar(mConversation, binding.yourPhoto, R.dimen.avatar_on_details_screen_size);
+        AvatarWorkerTask.loadAvatar(mConversation, binding.detailsMucAvatar, R.dimen.avatar_big);
+        AvatarWorkerTask.loadAvatar(mConversation.getAccount(), binding.yourPhoto, R.dimen.avatar_on_details_screen_size);
 
         String roomName = mucOptions.getName();
         String subject = mucOptions.getSubject();
@@ -609,7 +552,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         }
         this.binding.mucYourNick.setText(EmojiWrapper.transform(mucOptions.getActualNick()));
         if (mucOptions.online()) {
-            this.binding.mucMoreDetails.setVisibility(View.VISIBLE);
+            this.binding.usersWrapper.setVisibility(View.VISIBLE);
             this.binding.mucSettings.setVisibility(View.VISIBLE);
             this.binding.mucInfoMore.setVisibility(this.mAdvancedMode ? View.VISIBLE : View.GONE);
             this.binding.jid.setVisibility(this.mAdvancedMode ? View.VISIBLE : View.GONE);
@@ -686,7 +629,7 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
                 });
             }
         } else {
-            this.binding.mucMoreDetails.setVisibility(View.GONE);
+            this.binding.usersWrapper.setVisibility(View.GONE);
             this.binding.mucInfoMore.setVisibility(View.GONE);
             this.binding.mucSettings.setVisibility(View.GONE);
         }
@@ -710,71 +653,36 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
             this.binding.notificationStatusButton.setImageResource(ic_notifications_none);
         }
 
-        final LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
-        this.binding.mucMembers.removeAllViews();
-        if (inflater == null) {
-            return;
-        }
-        final ArrayList<User> users = mucOptions.getUsers();
-        Collections.sort(users);
-        for (final User user : users) {
-            ContactBinding binding = DataBindingUtil.inflate(inflater, R.layout.contact, this.binding.mucMembers, false);
-            this.setListItemBackgroundOnView(binding.getRoot());
-            binding.getRoot().setOnClickListener(view1 -> highlightInMuc(mConversation, user.getName()));
-            registerForContextMenu(binding.getRoot());
-            binding.getRoot().setTag(user);
-            if (mAdvancedMode && user.getPgpKeyId() != 0) {
-                binding.key.setVisibility(View.VISIBLE);
-                binding.key.setOnClickListener(v -> viewPgpKey(user));
-                binding.key.setText(OpenPgpUtils.convertKeyIdToHex(user.getPgpKeyId()));
-            }
-            Contact contact = user.getContact();
-            String name = user.getName();
-            if (contact != null) {
-                binding.contactDisplayName.setText(EmojiWrapper.transform(contact.getDisplayName()));
-                binding.contactJid.setText((name != null ? EmojiWrapper.transform(name) + " \u2022 " : "") + getStatus(user));
+        List<User> users = mucOptions.getUsers();
+        Collections.sort(users, (a, b) -> {
+            if (b.getAffiliation().outranks(a.getAffiliation())) {
+                return 1;
+            } else if (a.getAffiliation().outranks(b.getAffiliation())) {
+                return -1;
             } else {
-                binding.contactDisplayName.setText(name == null ? "" : EmojiWrapper.transform(name));
-                binding.contactJid.setText(getStatus(user));
-
-            }
-            loadAvatar(user, binding.contactPhoto);
-            if (user.getRole() == MucOptions.Role.NONE) {
-                binding.contactJid.setAlpha(INACTIVE_ALPHA);
-                binding.key.setAlpha(INACTIVE_ALPHA);
-                binding.contactDisplayName.setAlpha(INACTIVE_ALPHA);
-                binding.contactPhoto.setAlpha(INACTIVE_ALPHA);
+                if (a.getAvatar() != null && b.getAvatar() == null) {
+                    return -1;
+                } else if (a.getAvatar() == null && b.getAvatar() != null) {
+                    return 1;
+                } else {
+                    return a.getComparableName().compareToIgnoreCase(b.getComparableName());
+                }
             }
-            this.binding.mucMembers.addView(binding.getRoot());
-        }
-        if (mConversation.getMucOptions().canInvite()) {
-            this.binding.invite.setVisibility(View.VISIBLE);
-        } else {
-            this.binding.invite.setVisibility(View.GONE);
-        }
+        });
+        this.mUserPreviewAdapter.setUserList(MucOptions.sub(users, GridManager.getCurrentColumnCount(binding.users)));
+        this.binding.invite.setVisibility(mucOptions.canInvite() ? View.VISIBLE : View.GONE);
     }
 
-    private String getStatus(User user) {
-        if (mAdvancedMode) {
-            return getString(user.getAffiliation().getResId()) +
-                    " (" + getString(user.getRole().getResId()) + ')';
+    public static String getStatus(Context context, User user, final boolean advanced) {
+        if (advanced) {
+            return String.format("%s (%s)", context.getString(user.getAffiliation().getResId()), context.getString(user.getRole().getResId()));
         } else {
-            return getString(user.getAffiliation().getResId());
+            return context.getString(user.getAffiliation().getResId());
         }
     }
 
-    private void viewPgpKey(User user) {
-        PgpEngine pgp = xmppConnectionService.getPgpEngine();
-        if (pgp != null) {
-            PendingIntent intent = pgp.getIntentForKey(user.getPgpKeyId());
-            if (intent != null) {
-                try {
-                    startIntentSenderForResult(intent.getIntentSender(), 0, null, 0, 0, 0);
-                } catch (SendIntentException ignored) {
-
-                }
-            }
-        }
+    private String getStatus(User user) {
+        return getStatus(this, user, mAdvancedMode);
     }
 
     @Override
@@ -816,28 +724,6 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
         });
     }
 
-    public void loadAvatar(User user, ImageView imageView) {
-        if (cancelPotentialWork(user, imageView)) {
-            final Bitmap bm = avatarService().get(user, getPixel(48), true);
-            if (bm != null) {
-                cancelPotentialWork(user, imageView);
-                imageView.setImageBitmap(bm);
-                imageView.setBackgroundColor(0x00000000);
-            } else {
-                String seed = user.getRealJid() != null ? user.getRealJid().asBareJid().toString() : null;
-                imageView.setBackgroundColor(UIHelper.getColorForName(seed == null ? user.getName() : seed));
-                imageView.setImageDrawable(null);
-                final BitmapWorkerTask task = new BitmapWorkerTask(imageView);
-                final AsyncDrawable asyncDrawable = new AsyncDrawable(getResources(), null, task);
-                imageView.setImageDrawable(asyncDrawable);
-                try {
-                    task.execute(user);
-                } catch (final RejectedExecutionException ignored) {
-                }
-            }
-        }
-    }
-
     @Override
     public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 
@@ -864,46 +750,4 @@ public class ConferenceDetailsActivity extends XmppActivity implements OnConvers
             }
         }
     }
-
-    static class AsyncDrawable extends BitmapDrawable {
-        private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
-
-        AsyncDrawable(Resources res, Bitmap bitmap, BitmapWorkerTask bitmapWorkerTask) {
-            super(res, bitmap);
-            bitmapWorkerTaskReference = new WeakReference<>(bitmapWorkerTask);
-        }
-
-        BitmapWorkerTask getBitmapWorkerTask() {
-            return bitmapWorkerTaskReference.get();
-        }
-    }
-
-    class BitmapWorkerTask extends AsyncTask<User, Void, Bitmap> {
-        private final WeakReference<ImageView> imageViewReference;
-        private User o = null;
-
-        private BitmapWorkerTask(ImageView imageView) {
-            imageViewReference = new WeakReference<>(imageView);
-        }
-
-        @Override
-        protected Bitmap doInBackground(User... params) {
-            this.o = params[0];
-            if (imageViewReference.get() == null) {
-                return null;
-            }
-            return avatarService().get(this.o, getPixel(48), isCancelled());
-        }
-
-        @Override
-        protected void onPostExecute(Bitmap bitmap) {
-            if (bitmap != null && !isCancelled()) {
-                final ImageView imageView = imageViewReference.get();
-                if (imageView != null) {
-                    imageView.setImageBitmap(bitmap);
-                    imageView.setBackgroundColor(0x00000000);
-                }
-            }
-        }
-    }
 }
diff --git a/src/main/java/de/pixart/messenger/ui/EditAccountActivity.java b/src/main/java/de/pixart/messenger/ui/EditAccountActivity.java
index 34330236f..47a7b2173 100644
--- a/src/main/java/de/pixart/messenger/ui/EditAccountActivity.java
+++ b/src/main/java/de/pixart/messenger/ui/EditAccountActivity.java
@@ -1058,7 +1058,7 @@ public class EditAccountActivity extends OmemoActivity implements OnAccountUpdat
 
         if (!mInitMode) {
             binding.avater.setVisibility(View.VISIBLE);
-            AvatarWorkerTask.loadAvatar(mAccount, binding.avater, getPixel(Config.AVATAR_SIZE));
+            AvatarWorkerTask.loadAvatar(mAccount, binding.avater, R.dimen.avatar_big);
             this.binding.accountJid.setEnabled(false);
         } else {
             binding.avater.setVisibility(View.GONE);
diff --git a/src/main/java/de/pixart/messenger/ui/MucUsersActivity.java b/src/main/java/de/pixart/messenger/ui/MucUsersActivity.java
new file mode 100644
index 000000000..ffefedc80
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/ui/MucUsersActivity.java
@@ -0,0 +1,71 @@
+package de.pixart.messenger.ui;
+
+import android.content.Intent;
+import android.databinding.DataBindingUtil;
+import android.os.Bundle;
+import android.support.v7.widget.Toolbar;
+import android.view.MenuItem;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+import de.pixart.messenger.R;
+import de.pixart.messenger.databinding.ActivityMucUsersBinding;
+import de.pixart.messenger.entities.Conversation;
+import de.pixart.messenger.entities.MucOptions;
+import de.pixart.messenger.services.XmppConnectionService;
+import de.pixart.messenger.ui.adapter.UserAdapter;
+import de.pixart.messenger.ui.util.MucDetailsContextMenuHelper;
+
+public class MucUsersActivity extends XmppActivity implements XmppConnectionService.OnRosterUpdate {
+
+    private UserAdapter userAdapter;
+
+    private Conversation mConversation = null;
+
+    @Override
+    protected void refreshUiReal() {
+    }
+
+    @Override
+    void onBackendConnected() {
+        final Intent intent = getIntent();
+        final String uuid = intent == null ? null : intent.getStringExtra("uuid");
+        if (uuid != null) {
+            mConversation = xmppConnectionService.findConversationByUuid(uuid);
+        }
+        loadAndSubmitUsers();
+    }
+
+    private void loadAndSubmitUsers() {
+        if (mConversation != null) {
+            ArrayList<MucOptions.User> users = mConversation.getMucOptions().getUsers();
+            Collections.sort(users);
+            userAdapter.submitList(users);
+        }
+    }
+
+    @Override
+    public boolean onContextItemSelected(MenuItem item) {
+        if (!MucDetailsContextMenuHelper.onContextItemSelected(item, userAdapter.getSelectedUser(), mConversation, this)) {
+            return super.onContextItemSelected(item);
+        }
+        return true;
+    }
+
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        ActivityMucUsersBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_muc_users);
+        setSupportActionBar((Toolbar) binding.toolbar);
+        configureActionBar(getSupportActionBar(), true);
+        this.userAdapter = new UserAdapter(true);
+        binding.list.setAdapter(this.userAdapter);
+    }
+
+
+    @Override
+    public void onRosterUpdate() {
+        loadAndSubmitUsers();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/de/pixart/messenger/ui/adapter/UserAdapter.java b/src/main/java/de/pixart/messenger/ui/adapter/UserAdapter.java
new file mode 100644
index 000000000..f6a15aff4
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/ui/adapter/UserAdapter.java
@@ -0,0 +1,146 @@
+package de.pixart.messenger.ui.adapter;
+
+import android.app.PendingIntent;
+import android.content.IntentSender;
+import android.databinding.DataBindingUtil;
+import android.support.annotation.NonNull;
+import android.support.v7.recyclerview.extensions.ListAdapter;
+import android.support.v7.util.DiffUtil;
+import android.support.v7.widget.RecyclerView;
+import android.view.ContextMenu;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.PopupMenu;
+
+import org.openintents.openpgp.util.OpenPgpUtils;
+
+import java.util.List;
+
+import de.pixart.messenger.R;
+import de.pixart.messenger.crypto.PgpEngine;
+import de.pixart.messenger.databinding.ContactBinding;
+import de.pixart.messenger.entities.Contact;
+import de.pixart.messenger.entities.MucOptions;
+import de.pixart.messenger.services.XmppConnectionService;
+import de.pixart.messenger.ui.ConferenceDetailsActivity;
+import de.pixart.messenger.ui.XmppActivity;
+import de.pixart.messenger.ui.util.AvatarWorkerTask;
+import de.pixart.messenger.ui.util.MucDetailsContextMenuHelper;
+
+public class UserAdapter extends ListAdapter<MucOptions.User, UserAdapter.ViewHolder> implements View.OnCreateContextMenuListener {
+
+    private MucOptions.User selectedUser = null;
+
+    static final DiffUtil.ItemCallback<MucOptions.User> DIFF = new DiffUtil.ItemCallback<MucOptions.User>() {
+        @Override
+        public boolean areItemsTheSame(@NonNull MucOptions.User a, @NonNull MucOptions.User b) {
+            return a == b;
+        }
+
+        @Override
+        public boolean areContentsTheSame(@NonNull MucOptions.User a, @NonNull MucOptions.User b) {
+            return a.equals(b);
+        }
+    };
+    private final boolean advancedMode;
+
+    public UserAdapter(final boolean advancedMode) {
+        super(DIFF);
+        this.advancedMode = advancedMode;
+    }
+
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int position) {
+        return new ViewHolder(DataBindingUtil.inflate(LayoutInflater.from(viewGroup.getContext()), R.layout.contact, viewGroup, false));
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder viewHolder, int position) {
+        final MucOptions.User user = getItem(position);
+        AvatarWorkerTask.loadAvatar(user, viewHolder.binding.contactPhoto, R.dimen.avatar);
+        viewHolder.binding.getRoot().setOnClickListener(v -> {
+            final XmppActivity activity = XmppActivity.find(v);
+            if (activity != null) {
+                activity.highlightInMuc(user.getConversation(), user.getName());
+            }
+        });
+        viewHolder.binding.getRoot().setTag(user);
+        viewHolder.binding.getRoot().setOnCreateContextMenuListener(this);
+        viewHolder.binding.getRoot().setOnLongClickListener(v -> {
+            selectedUser = user;
+            return false;
+        });
+        final String name = user.getName();
+        final Contact contact = user.getContact();
+        if (contact != null) {
+            viewHolder.binding.contactDisplayName.setText(contact.getDisplayName());
+            if (name != null) {
+                viewHolder.binding.contactJid.setText(String.format("%s \u2022 %s", name, ConferenceDetailsActivity.getStatus(viewHolder.binding.getRoot().getContext(), user, advancedMode)));
+            } else {
+                viewHolder.binding.contactJid.setText(ConferenceDetailsActivity.getStatus(viewHolder.binding.getRoot().getContext(), user, advancedMode));
+            }
+        } else {
+            viewHolder.binding.contactDisplayName.setText(name == null ? "" : name);
+            viewHolder.binding.contactJid.setText(ConferenceDetailsActivity.getStatus(viewHolder.binding.getRoot().getContext(), user, advancedMode));
+        }
+        if (advancedMode && user.getPgpKeyId() != 0) {
+            viewHolder.binding.key.setVisibility(View.VISIBLE);
+            viewHolder.binding.key.setOnClickListener(v -> {
+                final XmppActivity activity = XmppActivity.find(v);
+                final XmppConnectionService service = activity == null ? null : activity.xmppConnectionService;
+                final PgpEngine pgpEngine = service == null ? null : service.getPgpEngine();
+                if (pgpEngine != null) {
+                    PendingIntent intent = pgpEngine.getIntentForKey(user.getPgpKeyId());
+                    if (intent != null) {
+                        try {
+                            activity.startIntentSenderForResult(intent.getIntentSender(), 0, null, 0, 0, 0);
+                        } catch (IntentSender.SendIntentException ignored) {
+
+                        }
+                    }
+                }
+            });
+            viewHolder.binding.key.setText(OpenPgpUtils.convertKeyIdToHex(user.getPgpKeyId()));
+        }
+
+
+    }
+
+    public MucOptions.User getSelectedUser() {
+        return selectedUser;
+    }
+
+    @Override
+    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
+        final XmppActivity activity = XmppActivity.find(v);
+        final Object tag = v.getTag();
+        if (tag instanceof MucOptions.User && activity != null) {
+            activity.getMenuInflater().inflate(R.menu.muc_details_context, menu);
+            final MucOptions.User user = (MucOptions.User) tag;
+            String name;
+            final Contact contact = user.getContact();
+            if (contact != null && contact.showInContactList()) {
+                name = contact.getDisplayName();
+            } else if (user.getRealJid() != null) {
+                name = user.getRealJid().asBareJid().toString();
+            } else {
+                name = user.getName();
+            }
+            menu.setHeaderTitle(name);
+            MucDetailsContextMenuHelper.configureMucDetailsContextMenu(activity, menu, user.getConversation(), user);
+        }
+    }
+
+    class ViewHolder extends RecyclerView.ViewHolder {
+
+        private final ContactBinding binding;
+
+        private ViewHolder(ContactBinding binding) {
+            super(binding.getRoot());
+            this.binding = binding;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/de/pixart/messenger/ui/adapter/UserPreviewAdapter.java b/src/main/java/de/pixart/messenger/ui/adapter/UserPreviewAdapter.java
new file mode 100644
index 000000000..5104ef86c
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/ui/adapter/UserPreviewAdapter.java
@@ -0,0 +1,72 @@
+package de.pixart.messenger.ui.adapter;
+
+import android.databinding.DataBindingUtil;
+import android.support.annotation.NonNull;
+import android.support.v7.recyclerview.extensions.ListAdapter;
+import android.support.v7.widget.RecyclerView;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.ViewGroup;
+import android.widget.PopupMenu;
+
+import java.util.List;
+
+import de.pixart.messenger.R;
+import de.pixart.messenger.databinding.UserPreviewBinding;
+import de.pixart.messenger.entities.MucOptions;
+import de.pixart.messenger.ui.XmppActivity;
+import de.pixart.messenger.ui.util.AvatarWorkerTask;
+import de.pixart.messenger.ui.util.MucDetailsContextMenuHelper;
+
+public class UserPreviewAdapter extends ListAdapter<MucOptions.User, UserPreviewAdapter.ViewHolder> {
+
+    public UserPreviewAdapter() {
+        super(UserAdapter.DIFF);
+    }
+
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int position) {
+        return new ViewHolder(DataBindingUtil.inflate(LayoutInflater.from(viewGroup.getContext()), R.layout.user_preview, viewGroup, false));
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder viewHolder, int position) {
+        final MucOptions.User user = getItem(position);
+        AvatarWorkerTask.loadAvatar(user, viewHolder.binding.avatar, R.dimen.media_size);
+        viewHolder.binding.getRoot().setOnClickListener(v -> {
+            final XmppActivity activity = XmppActivity.find(v);
+            if (activity != null) {
+                activity.highlightInMuc(user.getConversation(), user.getName());
+            }
+        });
+        viewHolder.binding.getRoot().setOnLongClickListener(v -> {
+            final XmppActivity activity = XmppActivity.find(v);
+            if (activity == null) {
+                return true;
+            }
+            final PopupMenu popupMenu = new PopupMenu(activity, v);
+            popupMenu.inflate(R.menu.muc_details_context);
+            final Menu menu = popupMenu.getMenu();
+            MucDetailsContextMenuHelper.configureMucDetailsContextMenu(activity, menu, user.getConversation(), user);
+            popupMenu.setOnMenuItemClickListener(menuItem -> MucDetailsContextMenuHelper.onContextItemSelected(menuItem, user, user.getConversation(), activity));
+            popupMenu.show();
+            return true;
+        });
+    }
+
+    public void setUserList(List<MucOptions.User> users) {
+        submitList(users);
+    }
+
+
+    class ViewHolder extends RecyclerView.ViewHolder {
+
+        private final UserPreviewBinding binding;
+
+        private ViewHolder(UserPreviewBinding binding) {
+            super(binding.getRoot());
+            this.binding = binding;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/de/pixart/messenger/ui/util/GridManager.java b/src/main/java/de/pixart/messenger/ui/util/GridManager.java
index 0b445f3ec..9cad626ff 100644
--- a/src/main/java/de/pixart/messenger/ui/util/GridManager.java
+++ b/src/main/java/de/pixart/messenger/ui/util/GridManager.java
@@ -29,7 +29,8 @@ public class GridManager {
                 }
                 final ColumnInfo columnInfo = calculateColumnCount(context, recyclerView.getMeasuredWidth(), desiredSize);
                 Log.d(Config.LOGTAG, "final count " + columnInfo.count);
-                if (recyclerView.getAdapter().getItemCount() != 0) {
+                final RecyclerView.Adapter adapter = recyclerView.getAdapter();
+                if (adapter != null && adapter.getItemCount() != 0) {
                     Log.e(Config.LOGTAG, "adapter already has items; just go with it now");
                     return;
                 }