implement "load more" placeholder

app/src/main/java/com/keylesspalace/tusky/adapter/NotificationsAdapter.java

@@ -47,6 +47,7 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
     private static final int VIEW_TYPE_FOOTER = 1;
     private static final int VIEW_TYPE_STATUS_NOTIFICATION = 2;
     private static final int VIEW_TYPE_FOLLOW = 3;
+    private static final int VIEW_TYPE_PLACEHOLDER = 4;
 
     private List<NotificationViewData> notifications;
     private StatusActionListener statusListener;
@@ -88,6 +89,11 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
                         .inflate(R.layout.item_follow, parent, false);
                 return new FollowViewHolder(view);
             }
+            case VIEW_TYPE_PLACEHOLDER: {
+                View view = LayoutInflater.from(parent.getContext())
+                        .inflate(R.layout.item_status_placeholder, parent, false);
+                return new PlaceholderViewHolder(view);
+            }
         }
     }
 
@@ -121,6 +127,11 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
                     holder.setupButtons(notificationActionListener, notification.getAccount().id);
                     break;
                 }
+                case PLACEHOLDER: {
+                    PlaceholderViewHolder holder = (PlaceholderViewHolder) viewHolder;
+                    holder.setup(!notification.isPlaceholderLoading(), statusListener);
+                    break;
+                }
             }
         } else {
             FooterViewHolder holder = (FooterViewHolder) viewHolder;
@@ -151,6 +162,9 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
                 case FOLLOW: {
                     return VIEW_TYPE_FOLLOW;
                 }
+                case PLACEHOLDER: {
+                    return VIEW_TYPE_PLACEHOLDER;
+                }
             }
         }
     }

app/src/main/java/com/keylesspalace/tusky/adapter/PlaceholderViewHolder.java

@@ -0,0 +1,49 @@
+/* Copyright 2017 Andrew Dawson
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
+package com.keylesspalace.tusky.adapter;
+
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+import android.widget.Button;
+
+import com.keylesspalace.tusky.R;
+import com.keylesspalace.tusky.interfaces.StatusActionListener;
+
+public class PlaceholderViewHolder extends RecyclerView.ViewHolder {
+
+    private Button loadMoreButton;
+
+
+    PlaceholderViewHolder(View itemView) {
+        super(itemView);
+        loadMoreButton = itemView.findViewById(R.id.button_load_more);
+
+    }
+
+    public void setup(boolean enabled, final StatusActionListener listener){
+        loadMoreButton.setEnabled(enabled);
+        if(enabled) {
+            loadMoreButton.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    loadMoreButton.setEnabled(false);
+                    listener.onLoadMore(getAdapterPosition());
+                }
+            });
+        }
+    }
+
+}

app/src/main/java/com/keylesspalace/tusky/adapter/StatusBaseViewHolder.java

@@ -271,6 +271,9 @@ class StatusBaseViewHolder extends RecyclerView.ViewHolder {
             sensitiveMediaShow.setOnClickListener(new View.OnClickListener() {
                 @Override
                 public void onClick(View v) {
+                    if (getAdapterPosition() != RecyclerView.NO_POSITION) {
+                        listener.onContentHiddenChange(false, getAdapterPosition());
+                    }
                     v.setVisibility(View.GONE);
                     sensitiveMediaWarning.setVisibility(View.VISIBLE);
                 }

app/src/main/java/com/keylesspalace/tusky/adapter/TimelineAdapter.java

@@ -31,6 +31,7 @@ import java.util.List;
 public class TimelineAdapter extends RecyclerView.Adapter {
     private static final int VIEW_TYPE_STATUS = 0;
     private static final int VIEW_TYPE_FOOTER = 1;
+    private static final int VIEW_TYPE_PLACEHOLDER = 2;
 
     private List<StatusViewData> statuses;
     private StatusActionListener statusListener;
@@ -59,15 +60,26 @@ public class TimelineAdapter extends RecyclerView.Adapter {
                         .inflate(R.layout.item_footer, viewGroup, false);
                 return new FooterViewHolder(view);
             }
+            case VIEW_TYPE_PLACEHOLDER: {
+                View view = LayoutInflater.from(viewGroup.getContext())
+                        .inflate(R.layout.item_status_placeholder, viewGroup, false);
+                return new PlaceholderViewHolder(view);
+            }
         }
     }
 
     @Override
     public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
         if (position < statuses.size()) {
-            StatusViewHolder holder = (StatusViewHolder) viewHolder;
             StatusViewData status = statuses.get(position);
-            holder.setupWithStatus(status, statusListener, mediaPreviewEnabled);
+            if(status.isPlaceholder()) {
+                PlaceholderViewHolder holder = (PlaceholderViewHolder) viewHolder;
+                holder.setup(!status.isPlaceholderLoading(), statusListener);
+            } else {
+                StatusViewHolder holder = (StatusViewHolder) viewHolder;
+                holder.setupWithStatus(status, statusListener, mediaPreviewEnabled);
+            }
+
         } else {
             FooterViewHolder holder = (FooterViewHolder) viewHolder;
             holder.setState(footerState);
@@ -84,7 +96,11 @@ public class TimelineAdapter extends RecyclerView.Adapter {
         if (position == statuses.size()) {
             return VIEW_TYPE_FOOTER;
         } else {
-            return VIEW_TYPE_STATUS;
+            if(statuses.get(position).isPlaceholder()) {
+                return VIEW_TYPE_PLACEHOLDER;
+            } else {
+                return VIEW_TYPE_STATUS;
+            }
         }
     }
 

app/src/main/java/com/keylesspalace/tusky/entity/Notification.java

@@ -27,6 +27,7 @@ public class Notification {
         FAVOURITE,
         @SerializedName("follow")
         FOLLOW,
+        PLACEHOLDER
     }
 
     public Type type;

app/src/main/java/com/keylesspalace/tusky/entity/Status.java

@@ -27,6 +27,10 @@ import java.util.Date;
 import java.util.List;
 
 public class Status {
+    /*if placeholder == true, this is not a real status, but a placeholder "load more"
+    and the id represents the max_id for the request*/
+    public boolean placeholder;
+
     public String url;
 
     @SerializedName("reblogs_count")
@@ -106,19 +110,21 @@ public class Status {
     public static final int MAX_MEDIA_ATTACHMENTS = 4;
 
     @Override
-    public int hashCode() {
+    public boolean equals(Object o) {
-        return id.hashCode();
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Status status = (Status) o;
+
+        if (placeholder != status.placeholder) return false;
+        return id != null ? id.equals(status.id) : status.id == null;
     }
 
     @Override
-    public boolean equals(Object other) {
+    public int hashCode() {
-        if (this.id == null) {
+        int result = (placeholder ? 1 : 0);
-            return this == other;
+        result = 31 * result + (id != null ? id.hashCode() : 0);
-        } else if (!(other instanceof Status)) {
+        return result;
-            return false;
-        }
-        Status status = (Status) other;
-        return status.id.equals(this.id);
     }
 
     public static class MediaAttachment {

app/src/main/java/com/keylesspalace/tusky/fragment/NotificationsFragment.java

@@ -54,7 +54,6 @@ import com.keylesspalace.tusky.viewdata.NotificationViewData;
 import com.keylesspalace.tusky.viewdata.StatusViewData;
 
 import java.util.Iterator;
-import java.util.LinkedHashSet;
 import java.util.List;
 
 import retrofit2.Call;
@@ -65,11 +64,14 @@ public class NotificationsFragment extends SFragment implements
         SwipeRefreshLayout.OnRefreshListener, StatusActionListener,
         NotificationsAdapter.NotificationActionListener,
         SharedPreferences.OnSharedPreferenceChangeListener {
-    private static final String TAG = "Notifications"; // logging tag
+    private static final String TAG = "NotificationF"; // logging tag
+
+    private static final int LOAD_AT_ONCE = 30;
 
     private enum FetchEnd {
         TOP,
-        BOTTOM
+        BOTTOM,
+        MIDDLE
     }
 
     private SwipeRefreshLayout swipeRefreshLayout;
@@ -156,12 +158,10 @@ public class NotificationsFragment extends SFragment implements
         TabLayout layout = activity.findViewById(R.id.tab_layout);
         onTabSelectedListener = new TabLayout.OnTabSelectedListener() {
             @Override
-            public void onTabSelected(TabLayout.Tab tab) {
+            public void onTabSelected(TabLayout.Tab tab) {}
-            }
 
             @Override
-            public void onTabUnselected(TabLayout.Tab tab) {
+            public void onTabUnselected(TabLayout.Tab tab) {}
-            }
 
             @Override
             public void onTabReselected(TabLayout.Tab tab) {
@@ -220,7 +220,7 @@ public class NotificationsFragment extends SFragment implements
 
     @Override
     public void onRefresh() {
-        sendFetchNotificationsRequest(null, topId, FetchEnd.TOP);
+        sendFetchNotificationsRequest(null, topId, FetchEnd.TOP, -1);
     }
 
     @Override
@@ -252,8 +252,7 @@ public class NotificationsFragment extends SFragment implements
 
             @Override
             public void onFailure(@NonNull Call<Status> call, @NonNull Throwable t) {
-                Log.d(getClass().getSimpleName(), "Failed to reblog status: " + status.id);
+                Log.d(getClass().getSimpleName(), "Failed to reblog status: " + status.id, t);
-                t.printStackTrace();
             }
         });
     }
@@ -283,8 +282,7 @@ public class NotificationsFragment extends SFragment implements
 
             @Override
             public void onFailure(@NonNull Call<Status> call, @NonNull Throwable t) {
-                Log.d(getClass().getSimpleName(), "Failed to favourite status: " + status.id);
+                Log.d(getClass().getSimpleName(), "Failed to favourite status: " + status.id, t);
-                t.printStackTrace();
             }
         });
     }
@@ -321,7 +319,7 @@ public class NotificationsFragment extends SFragment implements
                         .setIsExpanded(expanded)
                         .createStatusViewData();
         NotificationViewData notificationViewData = new NotificationViewData(old.getType(),
-                old.getId(), old.getAccount(), statusViewData);
+                old.getId(), old.getAccount(), statusViewData, false);
         notifications.setPairedItem(position, notificationViewData);
         adapter.updateItemWithNotify(position, notificationViewData, false);
     }
@@ -334,11 +332,29 @@ public class NotificationsFragment extends SFragment implements
                         .setIsShowingSensitiveContent(isShowing)
                         .createStatusViewData();
         NotificationViewData notificationViewData = new NotificationViewData(old.getType(),
-                old.getId(), old.getAccount(), statusViewData);
+                old.getId(), old.getAccount(), statusViewData, false);
         notifications.setPairedItem(position, notificationViewData);
         adapter.updateItemWithNotify(position, notificationViewData, false);
     }
 
+    @Override
+    public void onLoadMore(int position) {
+        //check bounds before accessing list,
+        if (notifications.size() >= position && position > 0) {
+            String fromId = notifications.get(position - 1).id;
+            String toId = notifications.get(position + 1).id;
+            sendFetchNotificationsRequest(fromId, toId, FetchEnd.MIDDLE, position);
+
+            NotificationViewData old = notifications.getPairedItem(position);
+            NotificationViewData notificationViewData = new NotificationViewData(old.getType(),
+                    old.getId(), old.getAccount(), old.getStatusViewData(), true);
+            notifications.setPairedItem(position, notificationViewData);
+            adapter.updateItemWithNotify(position, notificationViewData, false);
+        } else {
+            Log.d(TAG, "error loading more");
+        }
+    }
+
     @Override
     public void onViewTag(String tag) {
         super.viewTag(tag);
@@ -385,7 +401,7 @@ public class NotificationsFragment extends SFragment implements
     }
 
     private void onLoadMore() {
-        sendFetchNotificationsRequest(bottomId, null, FetchEnd.BOTTOM);
+        sendFetchNotificationsRequest(bottomId, null, FetchEnd.BOTTOM, -1);
     }
 
     private void jumpToTop() {
@@ -394,7 +410,7 @@ public class NotificationsFragment extends SFragment implements
     }
 
     private void sendFetchNotificationsRequest(String fromId, String uptoId,
-                                               final FetchEnd fetchEnd) {
+                                               final FetchEnd fetchEnd, final int pos) {
         /* If there is a fetch already ongoing, record however many fetches are requested and
          * fulfill them after it's complete. */
         if (fetchEnd == FetchEnd.TOP && topLoading) {
@@ -418,7 +434,7 @@ public class NotificationsFragment extends SFragment implements
             });
         }
 
-        Call<List<Notification>> call = mastodonApi.notifications(fromId, uptoId, null);
+        Call<List<Notification>> call = mastodonApi.notifications(fromId, uptoId, LOAD_AT_ONCE);
 
         call.enqueue(new Callback<List<Notification>>() {
             @Override
@@ -426,22 +442,22 @@ public class NotificationsFragment extends SFragment implements
                                    @NonNull Response<List<Notification>> response) {
                 if (response.isSuccessful()) {
                     String linkHeader = response.headers().get("Link");
-                    onFetchNotificationsSuccess(response.body(), linkHeader, fetchEnd);
+                    onFetchNotificationsSuccess(response.body(), linkHeader, fetchEnd, pos);
                 } else {
-                    onFetchNotificationsFailure(new Exception(response.message()), fetchEnd);
+                    onFetchNotificationsFailure(new Exception(response.message()), fetchEnd, pos);
                 }
             }
 
             @Override
             public void onFailure(@NonNull Call<List<Notification>> call, @NonNull Throwable t) {
-                onFetchNotificationsFailure((Exception) t, fetchEnd);
+                onFetchNotificationsFailure((Exception) t, fetchEnd, pos);
             }
         });
         callList.add(call);
     }
 
     private void onFetchNotificationsSuccess(List<Notification> notifications, String linkHeader,
-                                             FetchEnd fetchEnd) {
+                                             FetchEnd fetchEnd, int pos) {
         List<HttpHeaderLink> links = HttpHeaderLink.parse(linkHeader);
         switch (fetchEnd) {
             case TOP: {
@@ -453,6 +469,10 @@ public class NotificationsFragment extends SFragment implements
                 update(notifications, null, uptoId);
                 break;
             }
+            case MIDDLE: {
+                insert(notifications, pos);
+                break;
+            }
             case BOTTOM: {
                 HttpHeaderLink next = HttpHeaderLink.findByRelationType(links, "next");
                 String fromId = null;
@@ -489,8 +509,8 @@ public class NotificationsFragment extends SFragment implements
         swipeRefreshLayout.setRefreshing(false);
     }
 
-    public void update(@Nullable List<Notification> newNotifications, @Nullable String fromId,
+    private void update(@Nullable List<Notification> newNotifications, @Nullable String fromId,
-                       @Nullable String uptoId) {
+                        @Nullable String uptoId) {
         if (ListUtils.isEmpty(newNotifications)) {
             return;
         }
@@ -501,8 +521,7 @@ public class NotificationsFragment extends SFragment implements
             topId = uptoId;
         }
         if (notifications.isEmpty()) {
-            // This construction removes duplicates while preserving order.
+            notifications.addAll(newNotifications);
-            notifications.addAll(new LinkedHashSet<>(newNotifications));
         } else {
             int index = notifications.indexOf(newNotifications.get(newNotifications.size() - 1));
             for (int i = 0; i < index; i++) {
@@ -510,6 +529,11 @@ public class NotificationsFragment extends SFragment implements
             }
             int newIndex = newNotifications.indexOf(notifications.get(0));
             if (newIndex == -1) {
+                if(index == -1 && newNotifications.size() >= LOAD_AT_ONCE) {
+                    Notification placeholder = new Notification();
+                    placeholder.type = Notification.Type.PLACEHOLDER;
+                    newNotifications.add(placeholder);
+                }
                 notifications.addAll(0, newNotifications);
             } else {
                 List<Notification> sublist = newNotifications.subList(0, newIndex);
@@ -519,7 +543,7 @@ public class NotificationsFragment extends SFragment implements
         adapter.update(notifications.getPairedCopy());
     }
 
-    public void addItems(List<Notification> newNotifications, @Nullable String fromId) {
+    private void addItems(List<Notification> newNotifications, @Nullable String fromId) {
         if (ListUtils.isEmpty(newNotifications)) {
             return;
         }
@@ -532,7 +556,7 @@ public class NotificationsFragment extends SFragment implements
             notifications.addAll(newNotifications);
             List<NotificationViewData> newViewDatas = notifications.getPairedCopy()
                     .subList(notifications.size() - newNotifications.size(),
-                            notifications.size() - 1);
+                            notifications.size());
             adapter.addItems(newViewDatas);
         }
     }
@@ -546,8 +570,15 @@ public class NotificationsFragment extends SFragment implements
         return false;
     }
 
-    private void onFetchNotificationsFailure(Exception exception, FetchEnd fetchEnd) {
+    private void onFetchNotificationsFailure(Exception exception, FetchEnd fetchEnd, int position) {
         swipeRefreshLayout.setRefreshing(false);
+        if(fetchEnd == FetchEnd.MIDDLE && notifications.getPairedItem(position).getType() == Notification.Type.PLACEHOLDER) {
+            NotificationViewData old = notifications.getPairedItem(position);
+            NotificationViewData notificationViewData = new NotificationViewData(old.getType(),
+                    old.getId(), old.getAccount(), old.getStatusViewData(), false);
+            notifications.setPairedItem(position, notificationViewData);
+            adapter.updateItemWithNotify(position, notificationViewData, true);
+        }
         Log.e(TAG, "Fetch failure: " + exception.getMessage());
         fulfillAnyQueuedFetches(fetchEnd);
     }
@@ -573,9 +604,29 @@ public class NotificationsFragment extends SFragment implements
         }
     }
 
+    private void insert(List<Notification> newNotifications, int pos) {
+
+        notifications.remove(pos);
+
+        if (ListUtils.isEmpty(newNotifications)) {
+            adapter.update(notifications.getPairedCopy());
+            return;
+        }
+
+        if(newNotifications.size() >= LOAD_AT_ONCE) {
+            Notification placeholder = new Notification();
+            placeholder.type = Notification.Type.PLACEHOLDER;
+            newNotifications.add(placeholder);
+        }
+
+        notifications.addAll(pos, newNotifications);
+        adapter.update(notifications.getPairedCopy());
+
+    }
+
     private void fullyRefresh() {
         adapter.clear();
         notifications.clear();
-        sendFetchNotificationsRequest(null, null, FetchEnd.TOP);
+        sendFetchNotificationsRequest(null, null, FetchEnd.TOP, -1);
     }
 }

app/src/main/java/com/keylesspalace/tusky/fragment/SFragment.java

@@ -21,6 +21,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.app.ActivityOptionsCompat;
 import android.support.v4.content.LocalBroadcastManager;
@@ -148,10 +149,10 @@ public abstract class SFragment extends BaseFragment implements AdapterItemRemov
         Call<Relationship> call = mastodonApi.muteAccount(id);
         call.enqueue(new Callback<Relationship>() {
             @Override
-            public void onResponse(Call<Relationship> call, Response<Relationship> response) {}
+            public void onResponse(@NonNull Call<Relationship> call, @NonNull Response<Relationship> response) {}
 
             @Override
-            public void onFailure(Call<Relationship> call, Throwable t) {}
+            public void onFailure(@NonNull Call<Relationship> call, @NonNull Throwable t) {}
         });
         callList.add(call);
         Intent intent = new Intent(TimelineReceiver.Types.MUTE_ACCOUNT);
@@ -164,10 +165,10 @@ public abstract class SFragment extends BaseFragment implements AdapterItemRemov
         Call<Relationship> call = mastodonApi.blockAccount(id);
         call.enqueue(new Callback<Relationship>() {
             @Override
-            public void onResponse(Call<Relationship> call, retrofit2.Response<Relationship> response) {}
+            public void onResponse(@NonNull Call<Relationship> call, @NonNull retrofit2.Response<Relationship> response) {}
 
             @Override
-            public void onFailure(Call<Relationship> call, Throwable t) {}
+            public void onFailure(@NonNull Call<Relationship> call, @NonNull Throwable t) {}
         });
         callList.add(call);
         Intent intent = new Intent(TimelineReceiver.Types.BLOCK_ACCOUNT);
@@ -180,10 +181,10 @@ public abstract class SFragment extends BaseFragment implements AdapterItemRemov
         Call<ResponseBody> call = mastodonApi.deleteStatus(id);
         call.enqueue(new Callback<ResponseBody>() {
             @Override
-            public void onResponse(Call<ResponseBody> call, retrofit2.Response<ResponseBody> response) {}
+            public void onResponse(@NonNull Call<ResponseBody> call, @NonNull retrofit2.Response<ResponseBody> response) {}
 
             @Override
-            public void onFailure(Call<ResponseBody> call, Throwable t) {}
+            public void onFailure(@NonNull Call<ResponseBody> call, @NonNull Throwable t) {}
         });
         callList.add(call);
     }

app/src/main/java/com/keylesspalace/tusky/fragment/TimelineFragment.java

@@ -20,6 +20,7 @@ import android.content.SharedPreferences;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.TabLayout;
@@ -51,7 +52,6 @@ import com.keylesspalace.tusky.view.EndlessOnScrollListener;
 import com.keylesspalace.tusky.viewdata.StatusViewData;
 
 import java.util.Iterator;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Locale;
 
@@ -63,10 +63,12 @@ public class TimelineFragment extends SFragment implements
         SwipeRefreshLayout.OnRefreshListener,
         StatusActionListener,
         SharedPreferences.OnSharedPreferenceChangeListener {
-    private static final String TAG = "Timeline"; // logging tag
+    private static final String TAG = "TimelineF"; // logging tag
     private static final String KIND_ARG = "kind";
     private static final String HASHTAG_OR_ID_ARG = "hashtag_or_id";
 
+    private static final int LOAD_AT_ONCE = 30;
+
     public enum Kind {
         HOME,
         PUBLIC_LOCAL,
@@ -79,6 +81,7 @@ public class TimelineFragment extends SFragment implements
     private enum FetchEnd {
         TOP,
         BOTTOM,
+        MIDDLE
     }
 
     private SwipeRefreshLayout swipeRefreshLayout;
@@ -178,12 +181,10 @@ public class TimelineFragment extends SFragment implements
             TabLayout layout = getActivity().findViewById(R.id.tab_layout);
             onTabSelectedListener = new TabLayout.OnTabSelectedListener() {
                 @Override
-                public void onTabSelected(TabLayout.Tab tab) {
+                public void onTabSelected(TabLayout.Tab tab) {}
-                }
 
                 @Override
-                public void onTabUnselected(TabLayout.Tab tab) {
+                public void onTabUnselected(TabLayout.Tab tab) {}
-                }
 
                 @Override
                 public void onTabReselected(TabLayout.Tab tab) {
@@ -218,7 +219,7 @@ public class TimelineFragment extends SFragment implements
                         } else if (!composeButton.isShown()) {
                             composeButton.show();
                         }
-                }
+                    }
                 }
 
                 @Override
@@ -250,7 +251,7 @@ public class TimelineFragment extends SFragment implements
 
     @Override
     public void onRefresh() {
-        sendFetchTimelineRequest(null, topId, FetchEnd.TOP);
+        sendFetchTimelineRequest(null, topId, FetchEnd.TOP, -1);
     }
 
     @Override
@@ -263,7 +264,7 @@ public class TimelineFragment extends SFragment implements
         final Status status = statuses.get(position);
         super.reblogWithCallback(status, reblog, new Callback<Status>() {
             @Override
-            public void onResponse(Call<Status> call, retrofit2.Response<Status> response) {
+            public void onResponse(@NonNull Call<Status> call, @NonNull Response<Status> response) {
                 if (response.isSuccessful()) {
                     status.reblogged = reblog;
 
@@ -280,9 +281,8 @@ public class TimelineFragment extends SFragment implements
             }
 
             @Override
-            public void onFailure(Call<Status> call, Throwable t) {
+            public void onFailure(@NonNull Call<Status> call, @NonNull Throwable t) {
-                Log.d(TAG, "Failed to reblog status " + status.id);
+                Log.d(TAG, "Failed to reblog status " + status.id, t);
-                t.printStackTrace();
             }
         });
     }
@@ -293,7 +293,7 @@ public class TimelineFragment extends SFragment implements
 
         super.favouriteWithCallback(status, favourite, new Callback<Status>() {
             @Override
-            public void onResponse(Call<Status> call, retrofit2.Response<Status> response) {
+            public void onResponse(@NonNull Call<Status> call, @NonNull Response<Status> response) {
                 if (response.isSuccessful()) {
                     status.favourited = favourite;
 
@@ -310,9 +310,8 @@ public class TimelineFragment extends SFragment implements
             }
 
             @Override
-            public void onFailure(Call<Status> call, Throwable t) {
+            public void onFailure(@NonNull Call<Status> call, @NonNull Throwable t) {
-                Log.d(TAG, "Failed to favourite status " + status.id);
+                Log.d(TAG, "Failed to favourite status " + status.id, t);
-                t.printStackTrace();
             }
         });
     }
@@ -343,6 +342,24 @@ public class TimelineFragment extends SFragment implements
         adapter.changeItem(position, newViewData, false);
     }
 
+    @Override
+    public void onLoadMore(int position) {
+        //check bounds before accessing list,
+        if (statuses.size() >= position && position > 0) {
+            String fromId = statuses.get(position - 1).id;
+            String toId = statuses.get(position + 1).id;
+            sendFetchTimelineRequest(fromId, toId, FetchEnd.MIDDLE, position);
+
+            StatusViewData newViewData = new StatusViewData.Builder(statuses.getPairedItem(position))
+                    .setPlaceholderLoading(true).createStatusViewData();
+            statuses.setPairedItem(position, newViewData);
+            adapter.changeItem(position, newViewData, false);
+
+        } else {
+            Log.d(TAG, "error loading more");
+        }
+    }
+
     @Override
     public void onViewMedia(String[] urls, int urlIndex, Status.MediaAttachment.Type type,
                             View view) {
@@ -427,12 +444,12 @@ public class TimelineFragment extends SFragment implements
     }
 
     private void onLoadMore() {
-        sendFetchTimelineRequest(bottomId, null, FetchEnd.BOTTOM);
+        sendFetchTimelineRequest(bottomId, null, FetchEnd.BOTTOM, -1);
     }
 
     private void fullyRefresh() {
         adapter.clear();
-        sendFetchTimelineRequest(null, null, FetchEnd.TOP);
+        sendFetchTimelineRequest(null, null, FetchEnd.TOP, -1);
     }
 
     private boolean jumpToTopAllowed() {
@@ -456,20 +473,20 @@ public class TimelineFragment extends SFragment implements
             case HOME:
                 return api.homeTimeline(fromId, uptoId, null);
             case PUBLIC_FEDERATED:
-                return api.publicTimeline(null, fromId, uptoId, null);
+                return api.publicTimeline(null, fromId, uptoId, LOAD_AT_ONCE);
             case PUBLIC_LOCAL:
-                return api.publicTimeline(true, fromId, uptoId, null);
+                return api.publicTimeline(true, fromId, uptoId, LOAD_AT_ONCE);
             case TAG:
-                return api.hashtagTimeline(tagOrId, null, fromId, uptoId, null);
+                return api.hashtagTimeline(tagOrId, null, fromId, uptoId, LOAD_AT_ONCE);
             case USER:
-                return api.accountStatuses(tagOrId, fromId, uptoId, null);
+                return api.accountStatuses(tagOrId, fromId, uptoId, LOAD_AT_ONCE);
             case FAVOURITES:
-                return api.favourites(fromId, uptoId, null);
+                return api.favourites(fromId, uptoId, LOAD_AT_ONCE);
         }
     }
 
     private void sendFetchTimelineRequest(@Nullable String fromId, @Nullable String uptoId,
-                                          final FetchEnd fetchEnd) {
+                                          final FetchEnd fetchEnd, final int pos) {
         /* If there is a fetch already ongoing, record however many fetches are requested and
          * fulfill them after it's complete. */
         if (fetchEnd == FetchEnd.TOP && topLoading) {
@@ -495,18 +512,18 @@ public class TimelineFragment extends SFragment implements
 
         Callback<List<Status>> callback = new Callback<List<Status>>() {
             @Override
-            public void onResponse(Call<List<Status>> call, Response<List<Status>> response) {
+            public void onResponse(@NonNull Call<List<Status>> call, @NonNull Response<List<Status>> response) {
                 if (response.isSuccessful()) {
                     String linkHeader = response.headers().get("Link");
-                    onFetchTimelineSuccess(response.body(), linkHeader, fetchEnd);
+                    onFetchTimelineSuccess(response.body(), linkHeader, fetchEnd, pos);
                 } else {
-                    onFetchTimelineFailure(new Exception(response.message()), fetchEnd);
+                    onFetchTimelineFailure(new Exception(response.message()), fetchEnd, pos);
                 }
             }
 
             @Override
-            public void onFailure(Call<List<Status>> call, Throwable t) {
+            public void onFailure(@NonNull Call<List<Status>> call, @NonNull Throwable t) {
-                onFetchTimelineFailure((Exception) t, fetchEnd);
+                onFetchTimelineFailure((Exception) t, fetchEnd, pos);
             }
         };
 
@@ -515,8 +532,9 @@ public class TimelineFragment extends SFragment implements
         listCall.enqueue(callback);
     }
 
-    public void onFetchTimelineSuccess(List<Status> statuses, String linkHeader,
+    private void onFetchTimelineSuccess(List<Status> statuses, String linkHeader,
-                                       FetchEnd fetchEnd) {
+                                        FetchEnd fetchEnd, int pos) {
+        boolean fullFetch = statuses.size() >= LOAD_AT_ONCE;
         filterStatuses(statuses);
         List<HttpHeaderLink> links = HttpHeaderLink.parse(linkHeader);
         switch (fetchEnd) {
@@ -526,7 +544,11 @@ public class TimelineFragment extends SFragment implements
                 if (previous != null) {
                     uptoId = previous.uri.getQueryParameter("since_id");
                 }
-                updateStatuses(statuses, null, uptoId);
+                updateStatuses(statuses, null, uptoId, fullFetch);
+                break;
+            }
+            case MIDDLE: {
+                insertStatuses(statuses,fullFetch, pos);
                 break;
             }
             case BOTTOM: {
@@ -546,7 +568,7 @@ public class TimelineFragment extends SFragment implements
                     if (previous != null) {
                         uptoId = previous.uri.getQueryParameter("since_id");
                     }
-                    updateStatuses(statuses, fromId, uptoId);
+                    updateStatuses(statuses, fromId, uptoId, fullFetch);
                 }
                 break;
             }
@@ -560,8 +582,17 @@ public class TimelineFragment extends SFragment implements
         swipeRefreshLayout.setRefreshing(false);
     }
 
-    public void onFetchTimelineFailure(Exception exception, FetchEnd fetchEnd) {
+    private void onFetchTimelineFailure(Exception exception, FetchEnd fetchEnd, int position) {
         swipeRefreshLayout.setRefreshing(false);
+
+        if(fetchEnd == FetchEnd.MIDDLE && statuses.getPairedItem(position).isPlaceholder()) {
+
+            StatusViewData newViewData = new StatusViewData.Builder(statuses.getPairedItem(position))
+                    .setPlaceholderLoading(false).createStatusViewData();
+            statuses.setPairedItem(position, newViewData);
+            adapter.changeItem(position, newViewData, true);
+        }
+
         Log.e(TAG, "Fetch Failure: " + exception.getMessage());
         fulfillAnyQueuedFetches(fetchEnd);
     }
@@ -587,7 +618,7 @@ public class TimelineFragment extends SFragment implements
         }
     }
 
-    protected void filterStatuses(List<Status> statuses) {
+    private void filterStatuses(List<Status> statuses) {
         Iterator<Status> it = statuses.iterator();
         while (it.hasNext()) {
             Status status = it.next();
@@ -599,7 +630,7 @@ public class TimelineFragment extends SFragment implements
     }
 
     private void updateStatuses(List<Status> newStatuses, @Nullable String fromId,
-                                @Nullable String toId) {
+                                @Nullable String toId, boolean fullFetch) {
         if (ListUtils.isEmpty(newStatuses)) {
             return;
         }
@@ -610,16 +641,21 @@ public class TimelineFragment extends SFragment implements
             topId = toId;
         }
         if (statuses.isEmpty()) {
-            // This construction removes duplicates while preserving order.
+            statuses.addAll(newStatuses);
-            statuses.addAll(new LinkedHashSet<>(newStatuses));
         } else {
             Status lastOfNew = newStatuses.get(newStatuses.size() - 1);
             int index = statuses.indexOf(lastOfNew);
+
             for (int i = 0; i < index; i++) {
                 statuses.remove(0);
             }
             int newIndex = newStatuses.indexOf(statuses.get(0));
             if (newIndex == -1) {
+                if(index == -1 && fullFetch) {
+                    Status placeholder = new Status();
+                    placeholder.placeholder = true;
+                    newStatuses.add(placeholder);
+                }
                 statuses.addAll(0, newStatuses);
             } else {
                 statuses.addAll(0, newStatuses.subList(0, newIndex));
@@ -641,7 +677,7 @@ public class TimelineFragment extends SFragment implements
             if (BuildConfig.DEBUG && newStatuses.size() != newViewDatas.size()) {
                 String error = String.format(Locale.getDefault(),
                         "Incorrectly got statusViewData sublist." +
-                        " newStatuses.size == %d newViewDatas.size == %d, statuses.size == %d",
+                                " newStatuses.size == %d newViewDatas.size == %d, statuses.size == %d",
                         newStatuses.size(), newViewDatas.size(), statuses.size());
                 throw new AssertionError(error);
             }
@@ -652,6 +688,28 @@ public class TimelineFragment extends SFragment implements
         }
     }
 
+    private void insertStatuses(List<Status> newStatuses, boolean fullFetch, int pos) {
+
+        if(statuses.get(pos).placeholder) {
+            statuses.remove(pos);
+        }
+
+        if (ListUtils.isEmpty(newStatuses)) {
+            adapter.update(statuses.getPairedCopy());
+            return;
+        }
+
+        if(fullFetch) {
+            Status placeholder = new Status();
+            placeholder.placeholder = true;
+            newStatuses.add(placeholder);
+        }
+
+        statuses.addAll(pos, newStatuses);
+        adapter.update(statuses.getPairedCopy());
+
+    }
+
     private static boolean findStatus(List<Status> statuses, String id) {
         for (Status status : statuses) {
             if (status.id.equals(id)) {

app/src/main/java/com/keylesspalace/tusky/fragment/ViewThreadFragment.java

@@ -243,6 +243,11 @@ public class ViewThreadFragment extends SFragment implements
         adapter.setItem(position, newViewData, false);
     }
 
+    @Override
+    public void onLoadMore(int pos) {
+
+    }
+
     @Override
     public void onViewTag(String tag) {
         super.viewTag(tag);

app/src/main/java/com/keylesspalace/tusky/interfaces/StatusActionListener.java

@@ -29,4 +29,5 @@ public interface StatusActionListener extends LinkListener {
     void onOpenReblog(int position);
     void onExpandedChange(boolean expanded, int position);
     void onContentHiddenChange(boolean isShowing, int position);
+    void onLoadMore(int position);
 }

app/src/main/java/com/keylesspalace/tusky/util/ViewDataUtils.java

@@ -1,3 +1,18 @@
+/* Copyright 2017 Andrew Dawson
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
 package com.keylesspalace.tusky.util;
 
 import android.arch.core.util.Function;
@@ -19,6 +34,11 @@ public final class ViewDataUtils {
     @Nullable
     public static StatusViewData statusToViewData(@Nullable Status status) {
         if (status == null) return null;
+        if(status.placeholder) {
+            return new StatusViewData.Builder().setId(status.id)
+                    .setPlaceholder(true)
+                    .createStatusViewData();
+        }
         Status visibleStatus = status.reblog == null ? status : status.reblog;
         return new StatusViewData.Builder().setId(status.id)
                 .setAttachments(visibleStatus.attachments)
@@ -61,7 +81,7 @@ public final class ViewDataUtils {
 
     public static NotificationViewData notificationToViewData(Notification notification) {
         return new NotificationViewData(notification.type, notification.id, notification.account,
-                statusToViewData(notification.status));
+                statusToViewData(notification.status), false);
     }
 
     public static List<NotificationViewData> notificationListToViewDataList(

app/src/main/java/com/keylesspalace/tusky/viewdata/NotificationViewData.java

@@ -1,3 +1,18 @@
+/* Copyright 2017 Andrew Dawson
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
 package com.keylesspalace.tusky.viewdata;
 
 import com.keylesspalace.tusky.entity.Account;
@@ -12,13 +27,15 @@ public final class NotificationViewData {
     private final String id;
     private final Account account;
     private final StatusViewData statusViewData;
+    private final boolean placeholderLoading;
 
     public NotificationViewData(Notification.Type type, String id, Account account,
-                                StatusViewData statusViewData) {
+                                StatusViewData statusViewData, boolean placeholderLoading) {
         this.type = type;
         this.id = id;
         this.account = account;
         this.statusViewData = statusViewData;
+        this.placeholderLoading = placeholderLoading;
     }
 
     public Notification.Type getType() {
@@ -36,4 +53,8 @@ public final class NotificationViewData {
     public StatusViewData getStatusViewData() {
         return statusViewData;
     }
+
+    public boolean isPlaceholderLoading() {
+        return placeholderLoading;
+    }
 }

app/src/main/java/com/keylesspalace/tusky/viewdata/StatusViewData.java

@@ -1,3 +1,18 @@
+/* Copyright 2017 Andrew Dawson
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
 package com.keylesspalace.tusky.viewdata;
 
 import android.support.annotation.Nullable;
@@ -48,13 +63,18 @@ public final class StatusViewData {
     @Nullable
     private final Card card;
 
+    private final boolean placeholder;
+
+    private final boolean placeholderLoading;
+
     public StatusViewData(String id, Spanned content, boolean reblogged, boolean favourited,
-                          String spoilerText, Status.Visibility visibility, Status.MediaAttachment[] attachments,
+                          @Nullable String spoilerText, Status.Visibility visibility, Status.MediaAttachment[] attachments,
-                          String rebloggedByUsername, String rebloggedAvatar, boolean sensitive, boolean isExpanded,
+                          @Nullable String rebloggedByUsername, @Nullable String rebloggedAvatar, boolean sensitive, boolean isExpanded,
                           boolean isShowingSensitiveWarning, String userFullName, String nickname, String avatar,
-                          Date createdAt, String reblogsCount, String favouritesCount, String inReplyToId,
+                          Date createdAt, String reblogsCount, String favouritesCount, @Nullable String inReplyToId,
-                          Status.Mention[] mentions, String senderId, boolean rebloggingEnabled,
+                          @Nullable Status.Mention[] mentions, String senderId, boolean rebloggingEnabled,
-                          Status.Application application, List<Status.Emoji> emojis, Card card) {
+                          Status.Application application, List<Status.Emoji> emojis, @Nullable Card card,
+                          boolean placeholder, boolean placeholderLoading) {
         this.id = id;
         this.content = content;
         this.reblogged = reblogged;
@@ -80,6 +100,8 @@ public final class StatusViewData {
         this.application = application;
         this.emojis = emojis;
         this.card = card;
+        this.placeholder = placeholder;
+        this.placeholderLoading = placeholderLoading;
     }
 
     public String getId() {
@@ -183,10 +205,19 @@ public final class StatusViewData {
         return emojis;
     }
 
+    @Nullable
     public Card getCard() {
         return card;
     }
 
+    public boolean isPlaceholder() {
+        return placeholder;
+    }
+
+    public boolean isPlaceholderLoading() {
+        return placeholderLoading;
+    }
+
     public static class Builder {
         private String id;
         private Spanned content;
@@ -213,6 +244,8 @@ public final class StatusViewData {
         private Status.Application application;
         private List<Status.Emoji> emojis;
         private Card card;
+        private boolean placeholder;
+        private boolean placeholderLoading;
 
         public Builder() {
         }
@@ -243,6 +276,8 @@ public final class StatusViewData {
             application = viewData.application;
             emojis = viewData.getEmojis();
             card = viewData.getCard();
+            placeholder = viewData.isPlaceholder();
+            placeholderLoading = viewData.isPlaceholderLoading();
 
         }
 
@@ -371,12 +406,25 @@ public final class StatusViewData {
             return this;
         }
 
+        public Builder setPlaceholder(boolean placeholder) {
+            this.placeholder = placeholder;
+            return this;
+        }
+
+        public Builder setPlaceholderLoading(boolean placeholderLoading) {
+            this.placeholderLoading = placeholderLoading;
+            return this;
+        }
+
         public StatusViewData createStatusViewData() {
             if (this.emojis == null) emojis = Collections.emptyList();
+            if (this.createdAt == null) createdAt = new Date();
+
             return new StatusViewData(id, content, reblogged, favourited, spoilerText, visibility,
                     attachments, rebloggedByUsername, rebloggedAvatar, isSensitive, isExpanded,
                     isShowingSensitiveContent, userFullName, nickname, avatar, createdAt, reblogsCount,
-                    favouritesCount, inReplyToId, mentions, senderId, rebloggingEnabled, application, emojis, card);
+                    favouritesCount, inReplyToId, mentions, senderId, rebloggingEnabled, application,
+                    emojis, card, placeholder, placeholderLoading);
         }
     }
 }

app/src/main/res/layout/item_status_placeholder.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Button xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/button_load_more"
+    style="@style/Widget.AppCompat.Button.Borderless"
+    android:layout_width="match_parent"
+    android:layout_height="72dp"
+    android:text="@string/load_more_placeholder_text"
+    android:textColor="?attr/colorAccent" />

app/src/main/res/values/strings.xml

@@ -233,5 +233,6 @@
     <string name="follows_you">Follows you</string>
     <string name="pref_title_alway_show_sensitive_media">Always show all nsfw content</string>
     <string name="replying_to">Replying to @%s</string>
+    <string name="load_more_placeholder_text">load more</string>
 
 </resources>