fix recent emoji pane

1) Make recent list properly update and invalidate.
2) Show most-recently-used first.
3) Refactoring

Closes #3171
// FREEBIE

src/org/thoughtcrime/securesms/components/emoji/EmojiDrawer.java

@@ -16,7 +16,6 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
-import android.widget.LinearLayout;
 import android.widget.RelativeLayout;
 
 import com.astuetz.PagerSlidingTabStrip;
@@ -38,6 +37,7 @@ public class EmojiDrawer extends Fragment {
   private KeyboardAwareLinearLayout container;
   private ViewPager                 pager;
   private PagerSlidingTabStrip      strip;
+  private RecentEmojiPageModel      recentModel;
 
   public static EmojiDrawer newInstance(@ArrayRes int categories, @ArrayRes int icons) {
     final EmojiDrawer fragment = new EmojiDrawer();
@@ -104,6 +104,7 @@ public class EmojiDrawer extends Fragment {
                                                          getArguments().getInt("icons")),
                                            new EmojiSelectionListener() {
                                              @Override public void onEmojiSelected(int emojiCode) {
+                                               recentModel.onCodePointSelected(emojiCode);
                                                composeText.insertEmoji(emojiCode);
                                              }
                                            }));
@@ -114,7 +115,8 @@ public class EmojiDrawer extends Fragment {
     final int[] icons = ResUtil.getResourceIds(getActivity(), iconsRes);
     final int[] pages = ResUtil.getResourceIds(getActivity(), pagesRes);
     final List<EmojiPageModel> models = new LinkedList<>();
-    models.add(new RecentEmojiPageModel(getActivity()));
+    recentModel = new RecentEmojiPageModel(getActivity());
+    models.add(recentModel);
     for (int i = 0; i < icons.length; i++) {
       models.add(new StaticEmojiPageModel(icons[i], getResources().getIntArray(pages[i])));
     }

src/org/thoughtcrime/securesms/components/emoji/EmojiEditText.java

@@ -3,29 +3,26 @@ package org.thoughtcrime.securesms.components.emoji;
 import android.content.Context;
 import android.support.v7.widget.AppCompatEditText;
 import android.util.AttributeSet;
-import android.util.Log;
 
-import org.thoughtcrime.securesms.components.emoji.EmojiProvider.InvalidatingPageLoadedListener;
 
 public class EmojiEditText extends AppCompatEditText {
   public EmojiEditText(Context context) {
     super(context);
-    init();
   }
 
   public EmojiEditText(Context context, AttributeSet attrs) {
     super(context, attrs);
-    init();
   }
 
   public EmojiEditText(Context context, AttributeSet attrs,
                        int defStyleAttr)
   {
     super(context, attrs, defStyleAttr);
-    init();
   }
 
-  private void init() {
+  @Override public void setText(CharSequence text, BufferType type) {
+    super.setText(EmojiProvider.getInstance(getContext()).emojify(text, EmojiProvider.EMOJI_SMALL, new PostInvalidateCallback(this)),
+                  BufferType.SPANNABLE);
   }
 
   public void insertEmoji(int codePoint) {
@@ -34,7 +31,7 @@ public class EmojiEditText extends AppCompatEditText {
     final char[]       chars = Character.toChars(codePoint);
     final CharSequence text  = EmojiProvider.getInstance(getContext()).emojify(new String(chars),
                                                                                EmojiProvider.EMOJI_SMALL,
-                                                                               new InvalidatingPageLoadedListener(this));
+                                                                               new PostInvalidateCallback(this));
 
     getText().replace(Math.min(start, end), Math.max(start, end), text);
     setSelection(end + chars.length);

src/org/thoughtcrime/securesms/components/emoji/EmojiPageFragment.java

@@ -17,7 +17,7 @@ import android.widget.GridView;
 import android.widget.ImageView;
 
 import org.thoughtcrime.securesms.R;
-import org.thoughtcrime.securesms.components.emoji.EmojiProvider.InvalidatingPageLoadedListener;
+import org.thoughtcrime.securesms.components.emoji.EmojiPageModel.OnModelChangedListener;
 
 public class EmojiPageFragment extends Fragment {
   private static final String TAG = EmojiPageFragment.class.getSimpleName();
@@ -42,11 +42,16 @@ public class EmojiPageFragment extends Fragment {
     grid.setColumnWidth(getResources().getDimensionPixelSize(R.dimen.emoji_drawer_size) + 2 * getResources().getDimensionPixelSize(R.dimen.emoji_drawer_item_padding));
     grid.setOnItemClickListener(new OnItemClickListener() {
       @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-        model.onCodePointSelected((Integer)view.getTag());
         if (listener != null) listener.onEmojiSelected((Integer)view.getTag());
       }
     });
     grid.setAdapter(new EmojiGridAdapter(getActivity(), model));
+    model.setOnModelChangedListener(new OnModelChangedListener() {
+      @Override public void onModelChanged() {
+        ((EmojiGridAdapter)grid.getAdapter()).notifyDataSetChanged();
+      }
+    });
+
     return view;
   }
 
@@ -99,9 +104,7 @@ public class EmojiPageFragment extends Fragment {
 
       final Integer       unicodeTag = model.getCodePoints()[position];
       final EmojiProvider provider   = EmojiProvider.getInstance(context);
-      final Drawable      drawable   = provider.getEmojiDrawable(unicodeTag,
+      final Drawable      drawable   = provider.getEmojiDrawable(unicodeTag, EmojiProvider.EMOJI_HUGE);
-                                                                 EmojiProvider.EMOJI_HUGE,
-                                                                 new InvalidatingPageLoadedListener(view));
 
       view.setImageDrawable(drawable);
       view.setPadding(pad, pad, pad, pad);

src/org/thoughtcrime/securesms/components/emoji/EmojiPageModel.java

@@ -1,7 +1,16 @@
 package org.thoughtcrime.securesms.components.emoji;
 
-public interface EmojiPageModel {
+public abstract class EmojiPageModel {
-  int getIconRes();
+  protected OnModelChangedListener listener;
-  int[] getCodePoints();
+
-  void onCodePointSelected(int codePoint);
+  public abstract int getIconRes();
+  public abstract int[] getCodePoints();
+
+  public void setOnModelChangedListener(OnModelChangedListener listener) {
+    this.listener = listener;
+  }
+
+  interface OnModelChangedListener {
+    void onModelChanged();
+  }
 }

src/org/thoughtcrime/securesms/components/emoji/EmojiProvider.java

@@ -8,18 +8,20 @@ import android.graphics.Paint;
 import android.graphics.PixelFormat;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
+import android.graphics.drawable.Drawable.Callback;
+import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.Looper;
 import android.text.Spannable;
 import android.text.SpannableStringBuilder;
-import android.text.style.ImageSpan;
 import android.util.Log;
 import android.util.SparseArray;
-import android.view.View;
 
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.util.BitmapDecodingException;
 import org.thoughtcrime.securesms.util.BitmapUtil;
+import org.thoughtcrime.securesms.util.FutureTaskListener;
+import org.thoughtcrime.securesms.util.ListenableFutureTask;
 import org.thoughtcrime.securesms.util.ResUtil;
 import org.thoughtcrime.securesms.util.Util;
 
@@ -27,17 +29,14 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.lang.ref.SoftReference;
 import java.util.Arrays;
-import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Callable;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 public class EmojiProvider {
-  private static final    String                             TAG      = EmojiProvider.class.getSimpleName();
+  private static final    String        TAG      = EmojiProvider.class.getSimpleName();
-  private static final    ExecutorService                    executor = Util.newSingleThreadedLifoExecutor();
+  private static volatile EmojiProvider instance = null;
-  private static volatile EmojiProvider                      instance = null;
+  private static final    Paint         paint    = new Paint();
-  private static final    SparseArray<SoftReference<Bitmap>> bitmaps  = new SparseArray<>();
-  private static final    Paint                              paint    = new Paint();
-  private static final    Handler                            handler  = new Handler(Looper.getMainLooper());
   static { paint.setFilterBitmap(true); }
 
   private final SparseArray<DrawInfo> offsets = new SparseArray<>();
@@ -55,7 +54,7 @@ public class EmojiProvider {
 
   private final Context context;
   private final int     bigDrawSize;
-  private final int[]   pages;
+  private final Handler handler = new Handler(Looper.getMainLooper());
 
   public static EmojiProvider getInstance(Context context) {
     if (instance == null) {
@@ -69,72 +68,28 @@ public class EmojiProvider {
   }
 
   private EmojiProvider(Context context) {
-    this.context = context.getApplicationContext();
+    int[] pages = ResUtil.getResourceIds(context, R.array.emoji_categories);
+
+    this.context     = context.getApplicationContext();
     this.bigDrawSize = context.getResources().getDimensionPixelSize(R.dimen.emoji_drawer_size);
-    this.pages = ResUtil.getResourceIds(context, R.array.emoji_categories);
     for (int i = 0; i < pages.length; i++) {
-      final int[] page = context.getResources().getIntArray(pages[i]);
+      final EmojiPageBitmap page = new EmojiPageBitmap(i);
-      for (int j = 0; j < page.length; j++) {
+      final int[] codePoints = context.getResources().getIntArray(pages[i]);
-        offsets.put(page[j], new DrawInfo(i, j));
+      for (int j = 0; j < codePoints.length; j++) {
+        offsets.put(codePoints[j], new DrawInfo(page, j));
       }
     }
   }
 
-  private void preloadPage(final int page, final PageLoadedListener pageLoadListener) {
+  public CharSequence emojify(CharSequence text, double size, Callback callback) {
-    executor.submit(new Runnable() {
-      @Override
-      public void run() {
-        try {
-          loadPage(page);
-          if (pageLoadListener != null) {
-            pageLoadListener.onPageLoaded();
-          }
-        } catch (IOException ioe) {
-          Log.w(TAG, ioe);
-        }
-      }
-    });
-  }
-
-  private void loadPage(int page) throws IOException {
-    if (page < 0 || page >= pages.length) {
-      throw new IndexOutOfBoundsException("can't load page that doesn't exist");
-    }
-
-    if (bitmaps.get(page) != null && bitmaps.get(page).get() != null) return;
-
-    try {
-      final String file = "emoji_" + page + "_wrapped.png";
-      final InputStream measureStream = context.getAssets().open(file);
-      final InputStream bitmapStream  = context.getAssets().open(file);
-      final Bitmap      bitmap        = BitmapUtil.createScaledBitmap(measureStream, bitmapStream, (float) bigDrawSize / (float) EMOJI_RAW_SIZE);
-      bitmaps.put(page, new SoftReference<>(bitmap));
-      Log.w(TAG, "onPageLoaded(" + page + ")");
-    } catch (IOException ioe) {
-      Log.w(TAG, ioe);
-      throw ioe;
-    } catch (BitmapDecodingException bde) {
-      Log.w(TAG, bde);
-      throw new AssertionError("emoji sprite asset is corrupted or android decoding is broken");
-    }
-  }
-
-  public CharSequence emojify(CharSequence text, PageLoadedListener pageLoadedListener) {
-    return emojify(text, EMOJI_LARGE, pageLoadedListener);
-  }
-
-  public CharSequence emojify(CharSequence text, double size, PageLoadedListener pageLoadedListener) {
     Matcher                matches = EMOJI_RANGE.matcher(text);
     SpannableStringBuilder builder = new SpannableStringBuilder(text);
 
     while (matches.find()) {
       int codePoint = matches.group().codePointAt(0);
-      Drawable drawable = getEmojiDrawable(codePoint, size, pageLoadedListener);
+      Drawable drawable = getEmojiDrawable(codePoint, size);
       if (drawable != null) {
-        ImageSpan imageSpan = new ImageSpan(drawable, ImageSpan.ALIGN_BOTTOM);
+        builder.setSpan(new InvalidatingDrawableSpan(drawable, callback), matches.start(), matches.end(),
-        char[] chars = new char[matches.end() - matches.start()];
-        Arrays.fill(chars, ' ');
-        builder.setSpan(imageSpan, matches.start(), matches.end(),
                         Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
       }
     }
@@ -142,51 +97,52 @@ public class EmojiProvider {
     return builder;
   }
 
-  public Drawable getEmojiDrawable(int emojiCode, double size, PageLoadedListener pageLoadedListener) {
+  public Drawable getEmojiDrawable(int emojiCode, double size) {
-    return getEmojiDrawable(offsets.get(emojiCode), size, pageLoadedListener);
+    return getEmojiDrawable(offsets.get(emojiCode), size);
   }
 
-  private Drawable getEmojiDrawable(DrawInfo drawInfo, double size, PageLoadedListener pageLoadedListener) {
+  private Drawable getEmojiDrawable(DrawInfo drawInfo, double size) {
-    if (drawInfo == null) {
+    if (drawInfo == null) return null;
-      return null;
+
-    }
+    final EmojiDrawable drawable = new EmojiDrawable(drawInfo, bigDrawSize);
-    final Drawable drawable = new EmojiDrawable(drawInfo, bigDrawSize);
     drawable.setBounds(0, 0, (int)((double)bigDrawSize * size), (int)((double)bigDrawSize * size));
-    if (bitmaps.get(drawInfo.page) == null || bitmaps.get(drawInfo.page).get() == null) {
+    drawInfo.page.get().addListener(new FutureTaskListener<Bitmap>() {
-      preloadPage(drawInfo.page, pageLoadedListener);
+      @Override public void onSuccess(final Bitmap result) {
-    }
+        handler.post(new Runnable() {
+          @Override public void run() {
+            drawable.setBitmap(result);
+          }
+        });
+      }
+
+      @Override public void onFailure(Throwable error) {
+        Log.w(TAG, error);
+      }
+    });
     return drawable;
   }
 
   public class EmojiDrawable extends Drawable {
     private final        int    index;
-    private final        int    page;
     private final        int    emojiSize;
     private              Bitmap bmp;
 
+    @Override public int getIntrinsicWidth() {
+      return emojiSize;
+    }
+
+    @Override public int getIntrinsicHeight() {
+      return emojiSize;
+    }
+
     public EmojiDrawable(DrawInfo info, int emojiSize) {
       this.index     = info.index;
-      this.page      = info.page;
       this.emojiSize = emojiSize;
     }
 
     @Override
     public void draw(Canvas canvas) {
-      if (bitmaps.get(page) == null || bitmaps.get(page).get() == null) {
+      if (bmp == null) return;
-        preloadPage(page, new PageLoadedListener() {
-          @Override public void onPageLoaded() {
-            handler.post(new Runnable() {
-              @Override public void run() {
-                invalidateSelf();
-              }
-            });
-          }
-        });
-        return;
-      }
-      if (bmp == null) {
-        bmp = bitmaps.get(page).get();
-      }
 
       Rect b = copyBounds();
 
@@ -202,6 +158,12 @@ public class EmojiProvider {
                         paint);
     }
 
+    public void setBitmap(Bitmap bitmap) {
+      Util.assertMainThread();
+      bmp = bitmap;
+      invalidateSelf();
+    }
+
     @Override
     public int getOpacity() {
       return PixelFormat.TRANSLUCENT;
@@ -212,39 +174,13 @@ public class EmojiProvider {
 
     @Override
     public void setColorFilter(ColorFilter cf) { }
-
-    @Override
-    public String toString() {
-      return "EmojiDrawable{" +
-          "page=" + page +
-          ", index=" + index +
-          '}';
-    }
-  }
-
-  public static class InvalidatingPageLoadedListener implements PageLoadedListener {
-    private final View view;
-
-    public InvalidatingPageLoadedListener(final View view) {
-      this.view = view;
-    }
-
-    @Override
-    public void onPageLoaded() {
-      view.postInvalidate();
-    }
-
-    @Override
-    public String toString() {
-      return "InvalidatingPageLoadedListener{}";
-    }
   }
 
   class DrawInfo {
-    int page;
+    EmojiPageBitmap page;
-    int index;
+    int             index;
 
-    public DrawInfo(final int page, final int index) {
+    public DrawInfo(final EmojiPageBitmap page, final int index) {
       this.page = page;
       this.index = index;
     }
@@ -258,7 +194,67 @@ public class EmojiProvider {
     }
   }
 
-  interface PageLoadedListener {
+  private class EmojiPageBitmap {
-    void onPageLoaded();
+    private int                          page;
+    private SoftReference<Bitmap>        bitmapReference;
+    private ListenableFutureTask<Bitmap> task;
+
+    public EmojiPageBitmap(int page) {
+      this.page = page;
+    }
+
+    private ListenableFutureTask<Bitmap> get() {
+      Util.assertMainThread();
+
+      if (bitmapReference != null && bitmapReference.get() != null) {
+        return new ListenableFutureTask<>(bitmapReference.get());
+      } else if (task != null) {
+        return task;
+      } else {
+        Callable<Bitmap> callable = new Callable<Bitmap>() {
+          @Override public Bitmap call() throws Exception {
+            try {
+              Log.w(TAG, "loading page " + page);
+              return loadPage();
+            } catch (IOException ioe) {
+              Log.w(TAG, ioe);
+            }
+            return null;
+          }
+        };
+        task = new ListenableFutureTask<>(callable);
+        new AsyncTask<Void, Void, Void>() {
+          @Override protected Void doInBackground(Void... params) {
+            task.run();
+            return null;
+          }
+
+          @Override protected void onPostExecute(Void aVoid) {
+            task = null;
+          }
+        }.execute();
+      }
+      return task;
+    }
+
+    private Bitmap loadPage() throws IOException {
+      if (bitmapReference != null && bitmapReference.get() != null) return bitmapReference.get();
+
+      try {
+        final String file = "emoji_" + page + "_wrapped.png";
+        final InputStream measureStream = context.getAssets().open(file);
+        final InputStream bitmapStream = context.getAssets().open(file);
+        final Bitmap bitmap = BitmapUtil.createScaledBitmap(measureStream, bitmapStream, (float)bigDrawSize / (float)EMOJI_RAW_SIZE);
+        bitmapReference = new SoftReference<>(bitmap);
+        Log.w(TAG, "onPageLoaded(" + page + ")");
+        return bitmap;
+      } catch (IOException ioe) {
+        Log.w(TAG, ioe);
+        throw ioe;
+      } catch (BitmapDecodingException bde) {
+        Log.w(TAG, bde);
+        throw new AssertionError("emoji sprite asset is corrupted or android decoding is broken");
+      }
+    }
   }
 }

src/org/thoughtcrime/securesms/components/emoji/EmojiTextView.java

@@ -1,45 +1,26 @@
 package org.thoughtcrime.securesms.components.emoji;
 
-import android.annotation.TargetApi;
 import android.content.Context;
-import android.graphics.Rect;
-import android.os.Build.VERSION_CODES;
 import android.support.v7.widget.AppCompatTextView;
-import android.text.method.TransformationMethod;
 import android.util.AttributeSet;
-import android.view.View;
-
-import org.thoughtcrime.securesms.components.emoji.EmojiProvider.InvalidatingPageLoadedListener;
 
 public class EmojiTextView extends AppCompatTextView {
   public EmojiTextView(Context context) {
     super(context);
-    init();
   }
 
   public EmojiTextView(Context context, AttributeSet attrs) {
     super(context, attrs);
-    init();
   }
 
   public EmojiTextView(Context context, AttributeSet attrs, int defStyleAttr) {
     super(context, attrs, defStyleAttr);
-    init();
   }
 
-  private void init() {
+  @Override public void setText(CharSequence text, BufferType type) {
-    setTransformationMethod(new EmojiTransformationMethod());
+    super.setText(EmojiProvider.getInstance(getContext()).emojify(text,
-  }
-
-  private static class EmojiTransformationMethod implements TransformationMethod {
-
-    @Override public CharSequence getTransformation(CharSequence source, View view) {
-      return EmojiProvider.getInstance(view.getContext()).emojify(source,
                                                                   EmojiProvider.EMOJI_SMALL,
-                                                                  new InvalidatingPageLoadedListener(view));
+                                                                  new PostInvalidateCallback(this)),
-    }
+                  BufferType.SPANNABLE);
-
-    @Override public void onFocusChanged(View view, CharSequence sourceText, boolean focused,
-                                         int direction, Rect previouslyFocusedRect) { }
   }
 }

src/org/thoughtcrime/securesms/components/emoji/InvalidatingDrawableSpan.java

@@ -0,0 +1,12 @@
+package org.thoughtcrime.securesms.components.emoji;
+
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.Drawable.Callback;
+import android.text.style.ImageSpan;
+
+public class InvalidatingDrawableSpan extends ImageSpan {
+  public InvalidatingDrawableSpan(Drawable drawable, Callback callback) {
+    super(drawable, ALIGN_BOTTOM);
+    drawable.setCallback(callback);
+  }
+}

src/org/thoughtcrime/securesms/components/emoji/PostInvalidateCallback.java

@@ -0,0 +1,25 @@
+package org.thoughtcrime.securesms.components.emoji;
+
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.Drawable.Callback;
+import android.view.View;
+
+public class PostInvalidateCallback implements Callback {
+  private final View view;
+
+  public PostInvalidateCallback(View view) {
+    this.view = view;
+  }
+
+  @Override public void invalidateDrawable(Drawable who) {
+    view.postInvalidate();
+  }
+
+  @Override public void scheduleDrawable(Drawable who, Runnable what, long when) {
+
+  }
+
+  @Override public void unscheduleDrawable(Drawable who, Runnable what) {
+
+  }
+}

src/org/thoughtcrime/securesms/components/emoji/RecentEmojiPageModel.java

@@ -18,13 +18,14 @@ import java.io.IOException;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 
-public class RecentEmojiPageModel implements EmojiPageModel {
+public class RecentEmojiPageModel extends EmojiPageModel {
   private static final String TAG                  = RecentEmojiPageModel.class.getSimpleName();
   private static final String EMOJI_LRU_PREFERENCE = "pref_recent_emoji";
   private static final int    EMOJI_LRU_SIZE       = 50;
 
   private final SharedPreferences      prefs;
   private final LinkedHashSet<Integer> recentlyUsed;
+  private       OnModelChangedListener listener;
 
   public RecentEmojiPageModel(Context context) {
     this.prefs        = PreferenceManager.getDefaultSharedPreferences(context);
@@ -50,10 +51,11 @@ public class RecentEmojiPageModel implements EmojiPageModel {
   }
 
   @Override public int[] getCodePoints() {
-    return toPrimitiveArray(recentlyUsed);
+    return toReversePrimitiveArray(recentlyUsed);
   }
 
-  @Override public void onCodePointSelected(int codePoint) {
+  public void onCodePointSelected(int codePoint) {
+    Log.w(TAG, "onCodePointSelected(" + codePoint + ")");
     recentlyUsed.remove(codePoint);
     recentlyUsed.add(codePoint);
 
@@ -80,6 +82,12 @@ public class RecentEmojiPageModel implements EmojiPageModel {
         return null;
       }
     }.execute();
+
+    if (listener != null) listener.onModelChanged();
+  }
+
+  @Override public void setOnModelChangedListener(OnModelChangedListener listener) {
+    this.listener = listener;
   }
 
   private LinkedHashSet<Integer> fromHexString(@Nullable LinkedHashSet<String> stringSet) {
@@ -100,11 +108,11 @@ public class RecentEmojiPageModel implements EmojiPageModel {
     return stringSet;
   }
 
-  private int[] toPrimitiveArray(@NonNull LinkedHashSet<Integer> integerSet) {
+  private int[] toReversePrimitiveArray(@NonNull LinkedHashSet<Integer> integerSet) {
     int[] ints = new int[integerSet.size()];
-    int i = 0;
+    int i = integerSet.size() - 1;
     for (Integer integer : integerSet) {
-      ints[i++] = integer;
+      ints[i--] = integer;
     }
     return ints;
   }

src/org/thoughtcrime/securesms/components/emoji/StaticEmojiPageModel.java

@@ -3,7 +3,7 @@ package org.thoughtcrime.securesms.components.emoji;
 import android.support.annotation.DrawableRes;
 import android.support.annotation.NonNull;
 
-public class StaticEmojiPageModel implements EmojiPageModel {
+public class StaticEmojiPageModel extends EmojiPageModel {
   @DrawableRes private final int   icon;
   @NonNull     private final int[] codePoints;
 
@@ -19,6 +19,4 @@ public class StaticEmojiPageModel implements EmojiPageModel {
   @NonNull public int[] getCodePoints() {
     return codePoints;
   }
-
-  @Override public void onCodePointSelected(int codePoint) { }
 }

src/org/thoughtcrime/securesms/util/Util.java

@@ -24,6 +24,7 @@ import android.graphics.Typeface;
 import android.os.Build;
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
+import android.os.Looper;
 import android.provider.Telephony;
 import android.telephony.TelephonyManager;
 import android.text.Spannable;
@@ -296,4 +297,10 @@ public class Util {
   public static boolean isMmsCapable(Context context) {
     return (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) || OutgoingLegacyMmsConnection.isConnectionPossible(context);
   }
+
+  public static void assertMainThread() {
+    if (Looper.myLooper() != Looper.getMainLooper()) {
+      throw new AssertionError("Main-thread assertion failed.");
+    }
+  }
 }