Add support for collapsible statuses when they exceed 500 characters (#825)

* Update Gradle plugin to work with Android Studio 3.3 Canary

Android Studio 3.1.4 Stable doesn't render layout previews in this project
for whatever reason. Switching to the latest 3.3 Canary release fixes the
issue without affecting Gradle scripts but requires the new Android Gradle
plugin to match the new Android Studio release.

This commit will be reverted once development on the feature is done.

* Update gradle build script to allow installing debug builds alongside store version

This will allow developers, testers, etc to work on Tusky will not having to worry
about overwriting, uninstalling, fiddling with a preinstalled application which would
mean having to login again every time the development cycle starts/finishes and
manually reinstalling the app.

* Add UI changes to support collapsing statuses

The button uses subtle styling to not be distracting like the CW button on the timeline
The button is toggleable, full width to match the status textbox hitbox width and also
is shorter to not be too intrusive between the status text and images, or the post below

* Update status data model to store whether the message has been collapsed

* Update status action listener to notify of collapsed state changing

Provide stubs in all implementing classes and mark as TODO the stubs that
require a proper implementation for the feature to work.

* Add implementation code to handle status collapse/expand in timeline

Code has not been added elsewhere to simplify testing.
Once the code will be considered stable it will be also included in other
status action listener implementers.

* Add preferences so that users can toggle the collapsing of long posts

This is currently limited to a simple toggle, it would be nice to implement
a more advanced UI to offer the user more control over the feature.

* Update Gradle plugin to work with latest Android Studio 3.3 Canary 8

Just like the other commit, this will be reverted once the feature is working.
I simply don't want to deal with what changes in my installation of Android
Studio 3.1.4 Stable which breaks the layout preview rendering.

* Update data models and utils for statuses to better handle collapsing

I forgot that data isn't available from the API and can't really be built
from scratch using existing data due to preferences.
A new, extra boolean should fix the issue.

* Fix search breaking due to newly introduced variables in utils classes

* Fix timeline breaking due to newly introduced variables in utils classes

* Fix item status text for collapsed toggle being shown in the wrong state

* Update timeline fragment to refresh the list when collapsed settings change

* Add support for status content collapse in timeline viewholder

* Fix view holder truncating posts using temporary debug settings at 50 chars

* Add toggle support to notification layout as well

* Add support for collapsed statuses to search results

* Add support for expandable content to notifications too

* Update codebase with some suggested changes by @charlang

* Update more code with more suggestions and move null-safety into view data

* Update even more code with even more suggested code changes

* Revert a0a41ca and 0ee004d (Android Studio 3.1 to Android Studio 3.3 updates)

* Add an input filter utility class to reuse code for trimming statuses

* Update UI of statuses to show a taller collapsible button

* Update notification fragment logging to simplify null checks

* Add smartness to SmartLengthInputFilter such as word trimming and runway

* Fix posts with show more button even if bad ratio didn't collapse

* Fix thread view showing button but not collapsing by implementing the feature

* Fix spannable losing spans when collapsed and restore length to 500 characters

* Remove debug build suffix as per request

* Fix all the merging happened in f66d689, 623cad2 and 7056ba5

* Fix notification button spanning full width rather than content width

* Add a way to access a singleton to smart filter and use clearer code

* Update view holders using smart input filters to use more singletons

* Fix code style lacking spaces before boolean checks in ifs and others

* Remove all code related to collapsibility preferences, strings included

* Update style to match content warning toggle button

* Update strings to give cleaner differentiation between CW and collapse

* Update smart filter code to use fully qualified names to avoid confusion

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

@@ -25,6 +25,7 @@ import android.support.annotation.Nullable;
 import android.support.v4.content.ContextCompat;
 import android.support.v4.text.BidiFormatter;
 import android.support.v7.widget.RecyclerView;
+import android.text.InputFilter;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
 import android.text.TextUtils;
@@ -46,6 +47,7 @@ import com.keylesspalace.tusky.interfaces.StatusActionListener;
 import com.keylesspalace.tusky.util.CustomEmojiHelper;
 import com.keylesspalace.tusky.util.DateUtils;
 import com.keylesspalace.tusky.util.LinkHelper;
+import com.keylesspalace.tusky.util.SmartLengthInputFilter;
 import com.keylesspalace.tusky.viewdata.NotificationViewData;
 import com.keylesspalace.tusky.viewdata.StatusViewData;
 import com.squareup.picasso.Picasso;
@@ -62,6 +64,9 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
     private static final int VIEW_TYPE_FOLLOW = 2;
     private static final int VIEW_TYPE_PLACEHOLDER = 3;
 
+    private static final InputFilter[] COLLAPSE_INPUT_FILTER = new InputFilter[] { SmartLengthInputFilter.INSTANCE };
+    private static final InputFilter[] NO_INPUT_FILTER = new InputFilter[0];
+
     private List<NotificationViewData> notifications;
     private StatusActionListener statusListener;
     private NotificationActionListener notificationActionListener;
@@ -243,6 +248,14 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
 
         void onExpandedChange(boolean expanded, int position);
 
+        /**
+         * Called when the status {@link android.widget.ToggleButton} responsible for collapsing long
+         * status content is interacted with.
+         *
+         * @param isCollapsed Whether the status content is shown in a collapsed state or fully.
+         * @param position    The position of the status in the list.
+         */
+        void onNotificationContentCollapsedChange(boolean isCollapsed, int position);
     }
 
     private static class FollowViewHolder extends RecyclerView.ViewHolder {
@@ -305,6 +318,7 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
         private final ImageView notificationAvatar;
         private final TextView contentWarningDescriptionTextView;
         private final ToggleButton contentWarningButton;
+        private final ToggleButton contentCollapseButton; // TODO: This code SHOULD be based on StatusBaseViewHolder
 
         private String accountId;
         private String notificationId;
@@ -328,6 +342,7 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
             notificationAvatar = itemView.findViewById(R.id.notification_notification_avatar);
             contentWarningDescriptionTextView = itemView.findViewById(R.id.notification_content_warning_description);
             contentWarningButton = itemView.findViewById(R.id.notification_content_warning_button);
+            contentCollapseButton = itemView.findViewById(R.id.button_toggle_notification_content);
 
             int darkerFilter = Color.rgb(123, 123, 123);
             statusAvatar.setColorFilter(darkerFilter, PorterDuff.Mode.MULTIPLY);
@@ -350,7 +365,6 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
             statusContent.setVisibility(show ? View.VISIBLE : View.GONE);
             statusAvatar.setVisibility(show ? View.VISIBLE : View.GONE);
             notificationAvatar.setVisibility(show ? View.VISIBLE : View.GONE);
-
         }
 
         private void setDisplayName(String name, List<Emoji> emojis) {
@@ -508,11 +522,30 @@ public class NotificationsAdapter extends RecyclerView.Adapter {
             Spanned content = statusViewData.getContent();
             List<Emoji> emojis = statusViewData.getStatusEmojis();
 
+            if (statusViewData.isCollapsible() && (notificationViewData.isExpanded() || !hasSpoiler)) {
+                contentCollapseButton.setOnCheckedChangeListener((buttonView, isChecked) -> {
+                    int position = getAdapterPosition();
+                    if (position != RecyclerView.NO_POSITION && notificationActionListener != null) {
+                        notificationActionListener.onNotificationContentCollapsedChange(isChecked, position);
+                    }
+                });
+
+                contentCollapseButton.setVisibility(View.VISIBLE);
+                if (statusViewData.isCollapsed()) {
+                    contentCollapseButton.setChecked(true);
+                    statusContent.setFilters(COLLAPSE_INPUT_FILTER);
+                } else {
+                    contentCollapseButton.setChecked(false);
+                    statusContent.setFilters(NO_INPUT_FILTER);
+                }
+            } else {
+                contentCollapseButton.setVisibility(View.GONE);
+                statusContent.setFilters(NO_INPUT_FILTER);
+            }
+
             Spanned emojifiedText = CustomEmojiHelper.emojifyText(content, emojis, statusContent);
-
             LinkHelper.setClickableText(statusContent, emojifiedText, statusViewData.getMentions(), listener);
 
-
             Spanned emojifiedContentWarning =
                     CustomEmojiHelper.emojifyString(statusViewData.getSpoilerText(), statusViewData.getStatusEmojis(), contentWarningDescriptionTextView);
             contentWarningDescriptionTextView.setText(emojifiedContentWarning);

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

@@ -53,8 +53,10 @@ public class SearchResultsAdapter extends RecyclerView.Adapter {
     private LinkListener linkListener;
     private StatusActionListener statusListener;
 
-    public SearchResultsAdapter(boolean mediaPreviewsEnabled, boolean alwaysShowSensitiveMedia,
+    public SearchResultsAdapter(boolean mediaPreviewsEnabled,
-                                LinkListener linkListener, StatusActionListener statusListener,
+                                boolean alwaysShowSensitiveMedia,
+                                LinkListener linkListener,
+                                StatusActionListener statusListener,
                                 boolean useAbsoluteTime) {
 
         this.accountList = Collections.emptyList();
@@ -153,7 +155,10 @@ public class SearchResultsAdapter extends RecyclerView.Adapter {
             accountList = results.getAccounts();
             statusList = results.getStatuses();
             for(Status status: results.getStatuses()) {
-                concreteStatusList.add(ViewDataUtils.statusToViewData(status, alwaysShowSensitiveMedia));
+                concreteStatusList.add(ViewDataUtils.statusToViewData(
+                        status,
+                        alwaysShowSensitiveMedia
+                ));
             }
             hashtagList = results.getHashtags();
 

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

@@ -7,6 +7,7 @@ import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v7.content.res.AppCompatResources;
 import android.support.v7.widget.RecyclerView;
+import android.text.InputFilter;
 import android.text.Spanned;
 import android.text.TextUtils;
 import android.view.View;
@@ -25,6 +26,7 @@ import com.keylesspalace.tusky.util.CustomEmojiHelper;
 import com.keylesspalace.tusky.util.DateUtils;
 import com.keylesspalace.tusky.util.HtmlUtils;
 import com.keylesspalace.tusky.util.LinkHelper;
+import com.keylesspalace.tusky.util.SmartLengthInputFilter;
 import com.keylesspalace.tusky.util.ThemeUtils;
 import com.keylesspalace.tusky.viewdata.StatusViewData;
 import com.mikepenz.iconics.utils.Utils;
@@ -39,6 +41,9 @@ import at.connyduck.sparkbutton.SparkButton;
 import at.connyduck.sparkbutton.SparkEventListener;
 
 abstract class StatusBaseViewHolder extends RecyclerView.ViewHolder {
+    private static final InputFilter[] COLLAPSE_INPUT_FILTER = new InputFilter[] { SmartLengthInputFilter.INSTANCE };
+    private static final InputFilter[] NO_INPUT_FILTER = new InputFilter[0];
+
     private View container;
     private TextView displayName;
     private TextView username;
@@ -60,6 +65,7 @@ abstract class StatusBaseViewHolder extends RecyclerView.ViewHolder {
     private View sensitiveMediaShow;
     private TextView mediaLabel;
     private ToggleButton contentWarningButton;
+    private ToggleButton contentCollapseButton;
 
     ImageView avatar;
     TextView timestampInfo;
@@ -97,6 +103,7 @@ abstract class StatusBaseViewHolder extends RecyclerView.ViewHolder {
         mediaLabel = itemView.findViewById(R.id.status_media_label);
         contentWarningDescription = itemView.findViewById(R.id.status_content_warning_description);
         contentWarningButton = itemView.findViewById(R.id.status_content_warning_button);
+        contentCollapseButton = itemView.findViewById(R.id.button_toggle_content);
 
         this.useAbsoluteTime = useAbsoluteTime;
         shortSdf = new SimpleDateFormat("HH:mm:ss", Locale.getDefault());
@@ -492,7 +499,6 @@ abstract class StatusBaseViewHolder extends RecyclerView.ViewHolder {
         setUsername(status.getNickname());
         setCreatedAt(status.getCreatedAt());
         setIsReply(status.getInReplyToId() != null);
-        setContent(status.getContent(), status.getMentions(), status.getStatusEmojis(), listener);
         setAvatar(status.getAvatar(), status.getRebloggedAvatar());
         setReblogged(status.isReblogged());
         setFavourited(status.isFavourited());
@@ -523,7 +529,31 @@ abstract class StatusBaseViewHolder extends RecyclerView.ViewHolder {
         } else {
             setSpoilerText(status.getSpoilerText(), status.getStatusEmojis(), status.isExpanded(), listener);
         }
+
+        // When viewing threads this ViewHolder is used and the main post does not have a collapse
+        // button by design so avoid crashing the app when that happens
+        if (contentCollapseButton != null) {
+            if (status.isCollapsible() && (status.isExpanded() || status.getSpoilerText() == null || status.getSpoilerText().isEmpty())) {
+                contentCollapseButton.setOnCheckedChangeListener((buttonView, isChecked) -> {
+                    int position = getAdapterPosition();
+                    if (position != RecyclerView.NO_POSITION)
+                        listener.onContentCollapsedChange(isChecked, position);
+                });
+
+                contentCollapseButton.setVisibility(View.VISIBLE);
+                if (status.isCollapsed()) {
+                    contentCollapseButton.setChecked(true);
+                    content.setFilters(COLLAPSE_INPUT_FILTER);
+                } else {
+                    contentCollapseButton.setChecked(false);
+                    content.setFilters(NO_INPUT_FILTER);
+                }
+            } else {
+                contentCollapseButton.setVisibility(View.GONE);
+                content.setFilters(NO_INPUT_FILTER);
+            }
         }
 
-
+        setContent(status.getContent(), status.getMentions(), status.getStatusEmojis(), listener);
+    }
 }

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

@@ -149,7 +149,10 @@ public class NotificationsFragment extends SFragment implements
         public NotificationViewData apply(Either<Placeholder, Notification> input) {
             if (input.isRight()) {
                 Notification notification = input.getAsRight();
-                return ViewDataUtils.notificationToViewData(notification, alwaysShowSensitiveMedia);
+                return ViewDataUtils.notificationToViewData(
+                        notification,
+                        alwaysShowSensitiveMedia
+                );
             } else {
                 return new NotificationViewData.Placeholder(false);
             }
@@ -493,6 +496,52 @@ public class NotificationsFragment extends SFragment implements
         }
     }
 
+    @Override
+    public void onContentCollapsedChange(boolean isCollapsed, int position) {
+        if (position < 0 || position >= notifications.size()) {
+            Log.e(TAG, String.format("Tried to access out of bounds status position: %d of %d", position, notifications.size() - 1));
+            return;
+        }
+
+        NotificationViewData notification = notifications.getPairedItem(position);
+        if (!(notification instanceof NotificationViewData.Concrete)) {
+            Log.e(TAG, String.format(
+                    "Expected NotificationViewData.Concrete, got %s instead at position: %d of %d",
+                    notification == null ? "null" : notification.getClass().getSimpleName(),
+                    position,
+                    notifications.size() - 1
+            ));
+            return;
+        }
+
+        StatusViewData.Concrete status = ((NotificationViewData.Concrete) notification).getStatusViewData();
+        StatusViewData.Concrete updatedStatus = new StatusViewData.Builder(status)
+                .setCollapsed(isCollapsed)
+                .createStatusViewData();
+
+        NotificationViewData.Concrete concreteNotification = (NotificationViewData.Concrete) notification;
+        NotificationViewData updatedNotification = new NotificationViewData.Concrete(
+                concreteNotification.getType(),
+                concreteNotification.getId(),
+                concreteNotification.getAccount(),
+                updatedStatus,
+                concreteNotification.isExpanded()
+        );
+        notifications.setPairedItem(position, updatedNotification);
+        adapter.updateItemWithNotify(position, updatedNotification, false);
+
+        // Since we cannot notify to the RecyclerView right away because it may be scrolling
+        // we run this when the RecyclerView is done doing measurements and other calculations.
+        // To test this is not bs: try getting a notification while scrolling, without wrapping
+        // notifyItemChanged in a .post() call. App will crash.
+        recyclerView.post(() -> adapter.notifyItemChanged(position, notification));
+    }
+
+    @Override
+    public void onNotificationContentCollapsedChange(boolean isCollapsed, int position) {
+        onContentCollapsedChange(isCollapsed, position);
+    }
+
     @Override
     public void onViewTag(String tag) {
         super.viewTag(tag);
@@ -557,6 +606,11 @@ public class NotificationsFragment extends SFragment implements
             // already loaded everything
             return;
         }
+
+        // Check for out-of-bounds when loading
+        // This is required to allow full-timeline reloads of collapsible statuses when the settings
+        // change.
+        if (notifications.size() > 0) {
             Either<Placeholder, Notification> last = notifications.get(notifications.size() - 1);
             if (last.isRight()) {
                 notifications.add(Either.left(Placeholder.getInstance()));
@@ -564,6 +618,7 @@ public class NotificationsFragment extends SFragment implements
                 notifications.setPairedItem(notifications.size() - 1, viewData);
                 recyclerView.post(() -> adapter.addItems(Collections.singletonList(viewData)));
             }
+        }
 
         sendFetchNotificationsRequest(bottomId, null, FetchEnd.BOTTOM, -1);
     }

app/src/main/java/com/keylesspalace/tusky/fragment/SearchFragment.kt

@@ -52,7 +52,6 @@ class SearchFragment : SFragment(), StatusActionListener, Injectable {
     private var mediaPreviewEnabled = true
     private var useAbsoluteTime = false
 
-
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.fragment_search, container, false)
     }
@@ -65,7 +64,12 @@ class SearchFragment : SFragment(), StatusActionListener, Injectable {
 
         searchRecyclerView.addItemDecoration(DividerItemDecoration(view.context, DividerItemDecoration.VERTICAL))
         searchRecyclerView.layoutManager = LinearLayoutManager(view.context)
-        searchAdapter = SearchResultsAdapter(mediaPreviewEnabled, alwaysShowSensitiveMedia, this, this, useAbsoluteTime)
+        searchAdapter = SearchResultsAdapter(
+                mediaPreviewEnabled,
+                alwaysShowSensitiveMedia,
+                this,
+                this,
+                useAbsoluteTime)
         searchRecyclerView.adapter = searchAdapter
 
     }
@@ -137,17 +141,22 @@ class SearchFragment : SFragment(), StatusActionListener, Injectable {
 
     override fun onReblog(reblog: Boolean, position: Int) {
         val status = searchAdapter.getStatusAtPosition(position)
-        if(status != null) {
+        if (status != null) {
             timelineCases.reblogWithCallback(status, reblog, object: Callback<Status> {
                 override fun onResponse(call: Call<Status>?, response: Response<Status>?) {
                     status.reblogged = true
-                    searchAdapter.updateStatusAtPosition(ViewDataUtils.statusToViewData(status, alwaysShowSensitiveMedia), position)
+                    searchAdapter.updateStatusAtPosition(
+                            ViewDataUtils.statusToViewData(
+                                    status,
+                                    alwaysShowSensitiveMedia
+                            ),
+                            position
+                    )
                 }
 
                 override fun onFailure(call: Call<Status>?, t: Throwable?) {
                     Log.d(TAG, "Failed to reblog status " + status.id, t)
                 }
-
             })
         }
     }
@@ -158,7 +167,13 @@ class SearchFragment : SFragment(), StatusActionListener, Injectable {
             timelineCases.favouriteWithCallback(status, favourite, object: Callback<Status> {
                 override fun onResponse(call: Call<Status>?, response: Response<Status>?) {
                     status.favourited = true
-                    searchAdapter.updateStatusAtPosition(ViewDataUtils.statusToViewData(status, alwaysShowSensitiveMedia), position)
+                    searchAdapter.updateStatusAtPosition(
+                            ViewDataUtils.statusToViewData(
+                                    status,
+                                    alwaysShowSensitiveMedia
+                            ),
+                            position
+                    )
                 }
 
                 override fun onFailure(call: Call<Status>?, t: Throwable?) {
@@ -214,6 +229,21 @@ class SearchFragment : SFragment(), StatusActionListener, Injectable {
         // not needed here, search is not paginated
     }
 
+    override fun onContentCollapsedChange(isCollapsed: Boolean, position: Int) {
+        // TODO: No out-of-bounds check in getConcreteStatusAtPosition
+        val status = searchAdapter.getConcreteStatusAtPosition(position)
+        if(status == null) {
+            Log.e(TAG, String.format("Tried to access status but got null at position: %d", position))
+            return
+        }
+
+        val updatedStatus = StatusViewData.Builder(status)
+                .setCollapsed(isCollapsed)
+                .createStatusViewData()
+        searchAdapter.updateStatusAtPosition(updatedStatus, position)
+        searchRecyclerView.post { searchAdapter.notifyItemChanged(position, updatedStatus) }
+    }
+
     companion object {
         const val TAG = "SearchFragment"
     }

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

@@ -158,7 +158,10 @@ public class TimelineFragment extends SFragment implements
                 public StatusViewData apply(Either<Placeholder, Status> input) {
                     Status status = input.getAsRightOrNull();
                     if (status != null) {
-                        return ViewDataUtils.statusToViewData(status, alwaysShowSensitiveMedia);
+                        return ViewDataUtils.statusToViewData(
+                                status,
+                                alwaysShowSensitiveMedia
+                        );
                     } else {
                         Placeholder placeholder = input.getAsLeft();
                         return new StatusViewData.Placeholder(placeholder.id, false);
@@ -239,8 +242,7 @@ public class TimelineFragment extends SFragment implements
     }
 
     private void setupTimelinePreferences() {
-        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(
+        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
-                getActivity());
         preferences.registerOnSharedPreferenceChangeListener(this);
         alwaysShowSensitiveMedia = preferences.getBoolean("alwaysShowSensitiveMedia", false);
         boolean mediaPreviewEnabled = preferences.getBoolean("mediaPreviewEnabled", true);
@@ -566,6 +568,33 @@ public class TimelineFragment extends SFragment implements
         }
     }
 
+    @Override
+    public void onContentCollapsedChange(boolean isCollapsed, int position) {
+        if (position < 0 || position >= statuses.size()) {
+            Log.e(TAG, String.format("Tried to access out of bounds status position: %d of %d", position, statuses.size() - 1));
+            return;
+        }
+
+        StatusViewData status = statuses.getPairedItem(position);
+        if (!(status instanceof StatusViewData.Concrete)) {
+            // Statuses PairedList contains a base type of StatusViewData.Concrete and also doesn't
+            // check for null values when adding values to it although this doesn't seem to be an issue.
+            Log.e(TAG, String.format(
+                    "Expected StatusViewData.Concrete, got %s instead at position: %d of %d",
+                    status == null ? "<null>" : status.getClass().getSimpleName(),
+                    position,
+                    statuses.size() -1
+            ));
+            return;
+        }
+
+        StatusViewData updatedStatus = new StatusViewData.Builder((StatusViewData.Concrete) status)
+                .setCollapsed(isCollapsed)
+                .createStatusViewData();
+        statuses.setPairedItem(position, updatedStatus);
+        updateAdapter();
+    }
+
     @Override
     public void onViewMedia(int position, int attachmentIndex, View view) {
         Status status = statuses.get(position).getAsRightOrNull();
@@ -650,6 +679,7 @@ public class TimelineFragment extends SFragment implements
             case "alwaysShowSensitiveMedia": {
                 //it is ok if only newly loaded statuses are affected, no need to fully refresh
                 alwaysShowSensitiveMedia = sharedPreferences.getBoolean("alwaysShowSensitiveMedia", false);
+                break;
             }
         }
     }

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

@@ -55,6 +55,7 @@ import com.keylesspalace.tusky.interfaces.StatusActionListener;
 import com.keylesspalace.tusky.network.MastodonApi;
 import com.keylesspalace.tusky.network.TimelineCases;
 import com.keylesspalace.tusky.util.PairedList;
+import com.keylesspalace.tusky.util.SmartLengthInputFilter;
 import com.keylesspalace.tusky.util.ThemeUtils;
 import com.keylesspalace.tusky.util.ViewDataUtils;
 import com.keylesspalace.tusky.view.ConversationLineItemDecoration;
@@ -98,7 +99,10 @@ public final class ViewThreadFragment extends SFragment implements
             new PairedList<>(new Function<Status, StatusViewData.Concrete>() {
                 @Override
                 public StatusViewData.Concrete apply(Status input) {
-                    return ViewDataUtils.statusToViewData(input, alwaysShowSensitiveMedia);
+                    return ViewDataUtils.statusToViewData(
+                            input,
+                            alwaysShowSensitiveMedia
+                    );
                 }
             });
 
@@ -355,6 +359,36 @@ public final class ViewThreadFragment extends SFragment implements
 
     }
 
+    @Override
+    public void onContentCollapsedChange(boolean isCollapsed, int position) {
+        if (position < 0 || position >= statuses.size()) {
+            Log.e(TAG, String.format("Tried to access out of bounds status position: %d of %d", position, statuses.size() - 1));
+            return;
+        }
+
+        StatusViewData.Concrete status = statuses.getPairedItem(position);
+        if (status == null) {
+            // Statuses PairedList contains a base type of StatusViewData.Concrete and also doesn't
+            // check for null values when adding values to it although this doesn't seem to be an issue.
+            Log.e(TAG, String.format(
+                    "Expected StatusViewData.Concrete, got null instead at position: %d of %d",
+                    position,
+                    statuses.size() - 1
+            ));
+            return;
+        }
+
+        StatusViewData.Concrete updatedStatus = new StatusViewData.Builder(status)
+                .setCollapsible(!SmartLengthInputFilter.hasBadRatio(
+                        status.getContent(),
+                        SmartLengthInputFilter.LENGTH_DEFAULT
+                ))
+                .setCollapsed(isCollapsed)
+                .createStatusViewData();
+        statuses.setPairedItem(position, updatedStatus);
+        recyclerView.post(() -> adapter.setItem(position, updatedStatus, true));
+    }
+
     @Override
     public void onViewTag(String tag) {
         super.viewTag(tag);

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

@@ -28,4 +28,13 @@ public interface StatusActionListener extends LinkListener {
     void onExpandedChange(boolean expanded, int position);
     void onContentHiddenChange(boolean isShowing, int position);
     void onLoadMore(int position);
+
+    /**
+     * Called when the status {@link android.widget.ToggleButton} responsible for collapsing long
+     * status content is interacted with.
+     *
+     * @param isCollapsed Whether the status content is shown in a collapsed state or fully.
+     * @param position    The position of the status in the list.
+     */
+    void onContentCollapsedChange(boolean isCollapsed, int position);
 }

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

@@ -0,0 +1,154 @@
+/*
+ * Copyright 2018 Diego Rossi (@_HellPie)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package com.keylesspalace.tusky.util;
+
+import android.text.InputFilter;
+import android.text.SpannableStringBuilder;
+import android.text.Spanned;
+
+/**
+ * A customized version of {@link android.text.InputFilter.LengthFilter} which allows smarter
+ * constraints and adds better visuals such as:
+ * <ul>
+ *     <li>Ellipsis at the end of the constrained text to show continuation.</li>
+ *     <li>Trimming of invisible characters (new lines, spaces, etc.) from the constrained text.</li>
+ *     <li>Constraints end at the end of the last "word", before a whitespace.</li>
+ *     <li>Expansion of the limit by up to 10 characters to facilitate the previous constraint.</li>
+ *     <li>Constraints are not applied if the percentage of hidden content is too small.</li>
+ * </ul>
+ *
+ * Some of these features are configurable through at instancing time.
+ */
+public class SmartLengthInputFilter implements InputFilter {
+
+    /**
+     * Defines how many characters to extend beyond the limit to cut at the end of the word on the
+     * boundary of it rather than cutting at the word preceding that one.
+     */
+    private static final int RUNWAY = 10;
+
+    /**
+     * Default for maximum status length on Mastodon and default collapsing length on Pleroma.
+     */
+    public static final int LENGTH_DEFAULT = 500;
+
+    /**
+     * Stores a reusable singleton instance of a {@link SmartLengthInputFilter} already configured
+     * to the default maximum length of {@value #LENGTH_DEFAULT}.
+     */
+    public static final SmartLengthInputFilter INSTANCE = new SmartLengthInputFilter(LENGTH_DEFAULT);
+
+    private final int max;
+    private final boolean allowRunway;
+    private final boolean skipIfBadRatio;
+
+    /**
+     * Creates a new {@link SmartLengthInputFilter} instance with a predefined maximum length and
+     * all the smart constraint features this class supports.
+     *
+     * @param max The maximum length before trimming. May change based on other constraints.
+     */
+    public SmartLengthInputFilter(int max) {
+        this(max, true, true);
+    }
+
+    /**
+     * Fully configures a new {@link SmartLengthInputFilter} to fine tune the state of the supported
+     * smart constraints this class supports.
+     *
+     * @param max            The maximum length before trimming.
+     * @param allowRunway    Whether to extend {@param max} by an extra 10 characters
+     *                       and trim precisely at the end of the closest word.
+     * @param skipIfBadRatio Whether to skip trimming entirely if the trimmed content
+     *                       will be less than 25% of the shown content.
+     */
+    public SmartLengthInputFilter(int max, boolean allowRunway, boolean skipIfBadRatio) {
+        this.max = max;
+        this.allowRunway = allowRunway;
+        this.skipIfBadRatio = skipIfBadRatio;
+    }
+
+    /**
+     * Calculates if it's worth trimming the message at a specific limit or if the content that will
+     * be hidden will not be enough to justify the operation.
+     *
+     * @param message The message to trim.
+     * @param limit   The maximum length after trimming.
+     * @return        Whether the message should be trimmed or not.
+     */
+    public static boolean hasBadRatio(Spanned message, int limit) {
+        return (double) limit / message.length() > 0.75;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
+        // Code originally imported from InputFilter.LengthFilter but heavily customized.
+        // https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/text/InputFilter.java#175
+
+        int sourceLength = source.length();
+        int keep = max - (dest.length() - (dend - dstart));
+        if (keep <= 0) return "";
+        if (keep >= end - start) return null; // keep original
+
+        keep += start;
+
+        // Enable skipping trimming if the ratio is not good enough
+        if (skipIfBadRatio && (double)keep / sourceLength > 0.75)
+            return null;
+
+        // Enable trimming at the end of the closest word if possible
+        if (allowRunway && Character.isLetterOrDigit(source.charAt(keep))) {
+            int boundary;
+
+            // Android N+ offer a clone of the ICU APIs in Java for better internationalization and
+            // unicode support. Using the ICU version of BreakIterator grants better support for
+            // those without having to add the ICU4J library at a minimum Api trade-off.
+            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
+                android.icu.text.BreakIterator iterator = android.icu.text.BreakIterator.getWordInstance();
+                iterator.setText(source.toString());
+                boundary = iterator.following(keep);
+                if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep);
+            } else {
+                java.text.BreakIterator iterator = java.text.BreakIterator.getWordInstance();
+                iterator.setText(source.toString());
+                boundary = iterator.following(keep);
+                if (keep - boundary > RUNWAY) boundary = iterator.preceding(keep);
+            }
+
+            keep = boundary;
+        } else {
+
+            // If no runway is allowed simply remove whitespaces if present
+            while (Character.isWhitespace(source.charAt(keep - 1))) {
+                --keep;
+                if (keep == start) return "";
+            }
+        }
+
+        if (Character.isHighSurrogate(source.charAt(keep - 1))) {
+            --keep;
+            if (keep == start) return "";
+        }
+
+        if (source instanceof Spanned) {
+            return new SpannableStringBuilder(source, start, keep).append("…");
+        } else {
+            return source.subSequence(start, keep) + "…";
+        }
+    }
+}

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

@@ -58,12 +58,25 @@ public final class ViewDataUtils {
                 .setApplication(visibleStatus.getApplication())
                 .setStatusEmojis(visibleStatus.getEmojis())
                 .setAccountEmojis(visibleStatus.getAccount().getEmojis())
+                .setCollapsible(!SmartLengthInputFilter.hasBadRatio(
+                        visibleStatus.getContent(),
+                        SmartLengthInputFilter.LENGTH_DEFAULT
+                ))
+                .setCollapsed(true)
                 .createStatusViewData();
     }
 
-    public static NotificationViewData.Concrete notificationToViewData(Notification notification, boolean alwaysShowSensitiveData) {
+    public static NotificationViewData.Concrete notificationToViewData(Notification notification,
-        return new NotificationViewData.Concrete(notification.getType(), notification.getId(), notification.getAccount(),
+                                                                       boolean alwaysShowSensitiveData) {
-                statusToViewData(notification.getStatus(), alwaysShowSensitiveData), false);
+        return new NotificationViewData.Concrete(
+                notification.getType(),
+                notification.getId(),
+                notification.getAccount(),
+                statusToViewData(
+                        notification.getStatus(),
+                        alwaysShowSensitiveData
+                ),
+                false
+        );
     }
-
 }

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

@@ -18,6 +18,8 @@ package com.keylesspalace.tusky.viewdata;
 import com.keylesspalace.tusky.entity.Account;
 import com.keylesspalace.tusky.entity.Notification;
 
+import io.reactivex.annotations.NonNull;
+
 /**
  * Created by charlag on 12/07/2017.
  *
@@ -37,11 +39,12 @@ public abstract class NotificationViewData {
         private final Notification.Type type;
         private final String id;
         private final Account account;
+        @NonNull
         private final StatusViewData.Concrete statusViewData;
         private final boolean isExpanded;
 
         public Concrete(Notification.Type type, String id, Account account,
-                        StatusViewData.Concrete statusViewData, boolean isExpanded) {
+                        @NonNull StatusViewData.Concrete statusViewData, boolean isExpanded) {
             this.type = type;
             this.id = id;
             this.account = account;
@@ -61,6 +64,7 @@ public abstract class NotificationViewData {
             return account;
         }
 
+        @NonNull
         public StatusViewData.Concrete getStatusViewData() {
             return statusViewData;
         }

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

@@ -80,6 +80,8 @@ public abstract class StatusViewData {
         private final List<Emoji> accountEmojis;
         @Nullable
         private final Card card;
+        private final boolean isCollapsible; /** Whether the status meets the requirement to be collapse */
+        private final boolean isCollapsed; /** Whether the status is shown partially or fully */
 
         public Concrete(String id, Spanned content, boolean reblogged, boolean favourited,
                         @Nullable String spoilerText, Status.Visibility visibility, List<Attachment> attachments,
@@ -87,7 +89,8 @@ public abstract class StatusViewData {
                         boolean isShowingContent, String userFullName, String nickname, String avatar,
                         Date createdAt, int reblogsCount, int favouritesCount, @Nullable String inReplyToId,
                         @Nullable Status.Mention[] mentions, String senderId, boolean rebloggingEnabled,
-                        Status.Application application, List<Emoji> statusEmojis, List<Emoji> accountEmojis, @Nullable Card card) {
+                        Status.Application application, List<Emoji> statusEmojis, List<Emoji> accountEmojis, @Nullable Card card,
+                        boolean isCollapsible, boolean isCollapsed) {
             this.id = id;
             this.content = content;
             this.reblogged = reblogged;
@@ -114,6 +117,8 @@ public abstract class StatusViewData {
             this.statusEmojis = statusEmojis;
             this.accountEmojis = accountEmojis;
             this.card = card;
+            this.isCollapsible = isCollapsible;
+            this.isCollapsed = isCollapsed;
         }
 
         public String getId() {
@@ -226,6 +231,26 @@ public abstract class StatusViewData {
             return card;
         }
 
+        /**
+         * Specifies whether the content of this post is allowed to be collapsed or if it should show
+         * all content regardless.
+         *
+         * @return Whether the post is collapsible or never collapsed.
+         */
+        public boolean isCollapsible() {
+            return isCollapsible;
+        }
+
+        /**
+         * Specifies whether the content of this post is currently limited in visibility to the first
+         * 500 characters or not.
+         *
+         * @return Whether the post is collapsed or fully expanded.
+         */
+        public boolean isCollapsed() {
+            return isCollapsed;
+        }
+
         @Override public long getViewDataId() {
             // Chance of collision is super low and impact of mistake is low as well
             return getId().hashCode();
@@ -260,7 +285,8 @@ public abstract class StatusViewData {
                     Objects.equals(application, concrete.application) &&
                     Objects.equals(statusEmojis, concrete.statusEmojis) &&
                     Objects.equals(accountEmojis, concrete.accountEmojis) &&
-                Objects.equals(card, concrete.card);
+                    Objects.equals(card, concrete.card)
+                    && isCollapsed == concrete.isCollapsed;
         }
     }
 
@@ -334,6 +360,8 @@ public abstract class StatusViewData {
         private List<Emoji> statusEmojis;
         private List<Emoji> accountEmojis;
         private Card card;
+        private boolean isCollapsible; /** Whether the status meets the requirement to be collapsed */
+        private boolean isCollapsed; /** Whether the status is shown partially or fully */
 
         public Builder() {
         }
@@ -365,6 +393,8 @@ public abstract class StatusViewData {
             statusEmojis = viewData.getStatusEmojis();
             accountEmojis = viewData.getAccountEmojis();
             card = viewData.getCard();
+            isCollapsible = viewData.isCollapsible();
+            isCollapsed = viewData.isCollapsed();
         }
 
         public Builder setId(String id) {
@@ -497,6 +527,30 @@ public abstract class StatusViewData {
             return this;
         }
 
+        /**
+         * Configure the {@link com.keylesspalace.tusky.viewdata.StatusViewData} to support collapsing
+         * its content limiting the visible length when collapsed at 500 characters,
+         *
+         * @param collapsible Whether the status should support being collapsed or not.
+         * @return This {@link com.keylesspalace.tusky.viewdata.StatusViewData.Builder} instance.
+         */
+        public Builder setCollapsible(boolean collapsible) {
+            isCollapsible = collapsible;
+            return this;
+        }
+
+        /**
+         * Configure the {@link com.keylesspalace.tusky.viewdata.StatusViewData} to start in a collapsed
+         * state, hiding partially the content of the post if it exceeds a certain amount of characters.
+         *
+         * @param collapsed Whether to show the full content of the status or not.
+         * @return This {@link com.keylesspalace.tusky.viewdata.StatusViewData.Builder} instance.
+         */
+        public Builder setCollapsed(boolean collapsed) {
+            isCollapsed = collapsed;
+            return this;
+        }
+
         public StatusViewData.Concrete createStatusViewData() {
             if (this.statusEmojis == null) statusEmojis = Collections.emptyList();
             if (this.accountEmojis == null) accountEmojis = Collections.emptyList();
@@ -506,7 +560,7 @@ public abstract class StatusViewData {
                     attachments, rebloggedByUsername, rebloggedAvatar, isSensitive, isExpanded,
                     isShowingContent, userFullName, nickname, avatar, createdAt, reblogsCount,
                     favouritesCount, inReplyToId, mentions, senderId, rebloggingEnabled, application,
-                    statusEmojis, accountEmojis, card);
+                    statusEmojis, accountEmojis, card, isCollapsible, isCollapsed);
         }
     }
 }

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

@@ -135,11 +135,32 @@
         android:textSize="?attr/status_text_medium"
         tools:text="This is a status" />
 
+    <ToggleButton
+            android:id="@+id/button_toggle_content"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_toEndOf="@id/status_avatar"
+            android:layout_below="@id/status_content"
+            android:textOff="@string/status_content_show_less"
+            android:textOn="@string/status_content_show_more"
+            android:background="?attr/content_warning_button"
+            android:minHeight="0dp"
+            android:minWidth="150dp"
+            android:paddingBottom="4dp"
+            android:paddingLeft="16dp"
+            android:paddingRight="16dp"
+            android:paddingTop="4dp"
+            android:layout_marginTop="4dp"
+            android:layout_marginBottom="4dp"
+            android:textAllCaps="true"
+            android:textSize="?attr/status_text_medium"
+            android:visibility="gone" />
+
     <android.support.constraint.ConstraintLayout
         android:id="@+id/status_media_preview_container"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_below="@+id/status_content"
+        android:layout_below="@+id/button_toggle_content"
         android:layout_marginTop="@dimen/status_media_preview_margin_top"
         android:layout_toEndOf="@+id/status_avatar">
 

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

@@ -115,6 +115,28 @@
         android:textSize="?attr/status_text_medium"
         tools:text="Example status here" />
 
+
+    <ToggleButton
+            android:id="@+id/button_toggle_notification_content"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_toEndOf="@id/notification_status_avatar"
+            android:layout_below="@id/notification_content"
+            android:textOff="@string/status_content_show_less"
+            android:textOn="@string/status_content_show_more"
+            android:background="?attr/content_warning_button"
+            android:minHeight="0dp"
+            android:minWidth="150dp"
+            android:paddingBottom="4dp"
+            android:paddingLeft="16dp"
+            android:paddingRight="16dp"
+            android:paddingTop="4dp"
+            android:layout_marginTop="4dp"
+            android:layout_marginBottom="4dp"
+            android:textAllCaps="true"
+            android:textSize="?attr/status_text_medium"
+            android:visibility="gone"  />
+
     <com.keylesspalace.tusky.view.RoundedImageView
         android:id="@+id/notification_status_avatar"
         android:layout_width="48dp"

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

@@ -47,6 +47,8 @@
     <string name="status_sensitive_media_directions">Click to view</string>
     <string name="status_content_warning_show_more">Show More</string>
     <string name="status_content_warning_show_less">Show Less</string>
+    <string name="status_content_show_more">Expand</string>
+    <string name="status_content_show_less">Collapse</string>
 
     <string name="footer_empty">Nothing here. Pull down to refresh!</string>
 

app/src/main/res/xml/preferences.xml

@@ -41,7 +41,6 @@
             android:dependency="mediaPreviewEnabled"
             android:key="alwaysShowSensitiveMedia"
             android:title="@string/pref_title_alway_show_sensitive_media" />
-
         <CheckBoxPreference
             android:defaultValue="false"
             android:key="absoluteTimeView"

gradle/wrapper/gradle-wrapper.properties

@@ -1,4 +1,4 @@
-#Fri Apr 06 21:32:27 MSK 2018
+#Thu Aug 28 15:18:36 CEST 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME