Anrimian

public class HideFabScrollListener extends RecyclerView.OnScrollListener {

    private static final int TRANSLATE_HIDE_DURATION_MILLIS = 200;
    private static final int TRANSLATE_SHOW_DURATION_MILLIS = 170;

    private View fab;

    private Animator hideAnimator;
    private Animator showAnimator;

Anrimian

public class DefaultInsertionPredicate<S, T> implements InsertionPredicate<S, T> {

    @Override
    public boolean canInsert(@Nonnull Section<S, T> section, @Nonnull T item) {
        return true;
    }
}

Anrimian

public class StickyHeaderViewManager<T> {

    @Nonnull
    private View headerView;

    @Nonnull
    private RecyclerView recyclerView;

    @Nonnull

Anrimian

public class MultiTypeAdapter extends RecyclerView.Adapter {

    private final List<ViewHolderBuilder> builders;
    private final List<Item> items;

    MultiTypeAdapter(List<Item> items, List<ViewHolderBuilder> builders) {
        this.items = items;
        this.builders = builders;
    }

Anrimian

import android.support.constraint.motion.MotionLayout;
import android.support.v4.view.ViewCompat;

public class MotionLayoutUtils {

    public static void setProgress(MotionLayout motionLayout, float progress) {
        if (ViewCompat.isLaidOut(motionLayout)) {
            motionLayout.setProgress(progress);
        } else {
            motionLayout.post(() -> motionLayout.setProgress(progress));

Anrimian

import android.os.Bundle;

import com.arellomobile.mvp.MvpDelegate;
import com.google.android.material.bottomsheet.BottomSheetDialogFragment;

import androidx.fragment.app.Fragment;

public class MvpBottomSheetDialogFragment extends BottomSheetDialogFragment {

Anrimian

Improved solution from so answer, with copy-paste support

Credit card input filter example:

yourEditText.setFilters(new InputFilter[]{
            new InputFilter.LengthFilter(23),
            new SpacesInputFilter(23, new int[]{4, 9, 14, 19}, ' '),
});

Anrimian

public class DialogFragmentRunner<T extends DialogFragment> {

    private final FragmentManager fragmentManager;
    private final String tag;
    private final Callback<T> fragmentInitializer;

    public DialogFragmentRunner(FragmentManager fragmentManager,
                                String tag,
                                Callback<T> fragmentInitializer) {
        this.fragmentManager = fragmentManager;

Anrimian

public class BitmapLruCache<K> extends LruCache<K, Bitmap> {

    /**
     * @param maxSize for caches that do not override {@link #sizeOf}, this is
     *                the maximum number of entries in the cache. For all other caches,
     *                this is the maximum sum of the sizes of the entries in this cache.
     */
    public BitmapLruCache(int maxSize) {
        super(maxSize);
    }

Anrimian

import android.app.AlertDialog
import android.content.Context
import android.graphics.Color
import android.os.Build
import android.view.ViewGroup
import android.widget.LinearLayout
import android.widget.TextView
import androidx.core.content.ContextCompat
import androidx.core.graphics.ColorUtils