Add React With Any Search and update UX.

app/src/main/java/org/thoughtcrime/securesms/util/InsetItemDecoration.kt

@@ -0,0 +1,47 @@
+package org.thoughtcrime.securesms.util
+
+import android.graphics.Rect
+import android.view.View
+import androidx.recyclerview.widget.RecyclerView
+
+private typealias Predicate = (view: View, parent: RecyclerView) -> Boolean
+private val ALWAYS_TRUE: Predicate = { _, _ -> true }
+
+/**
+ * Externally configurable inset "setter" for recycler views.
+ *
+ * Primary constructor provides full external control of view insets.
+ * Secondary constructors provide basic predicate based insets on the horizontal and vertical.
+ */
+open class InsetItemDecoration(
+  private val setInset: SetInset
+) : RecyclerView.ItemDecoration() {
+
+  constructor(horizontalInset: Int = 0, verticalInset: Int = 0) : this(horizontalInset, verticalInset, ALWAYS_TRUE)
+  constructor(horizontalInset: Int = 0, verticalInset: Int = 0, predicate: Predicate) : this(horizontalInset, horizontalInset, verticalInset, verticalInset, predicate)
+  constructor(leftInset: Int = 0, rightInset: Int = 0, topInset: Int = 0, bottomInset: Int = 0, predicate: Predicate = ALWAYS_TRUE) : this(
+    setInset = object : SetInset() {
+      override fun setInset(outRect: Rect, view: View, parent: RecyclerView) {
+        if (predicate == ALWAYS_TRUE || predicate.invoke(view, parent)) {
+          outRect.left = leftInset
+          outRect.right = rightInset
+          outRect.top = topInset
+          outRect.bottom = bottomInset
+        }
+      }
+    }
+  )
+
+  override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
+    super.getItemOffsets(outRect, view, parent, state)
+    setInset.setInset(outRect, view, parent)
+  }
+
+  abstract class SetInset {
+    abstract fun setInset(outRect: Rect, view: View, parent: RecyclerView)
+
+    fun getPosition(view: View, parent: RecyclerView): Int {
+      return parent.getChildAdapterPosition(view)
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/util/MappingAdapter.java

@@ -15,8 +15,13 @@ import androidx.recyclerview.widget.RecyclerView;
 import org.whispersystems.libsignal.util.guava.Function;
 
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
+
+import kotlin.collections.CollectionsKt;
+import kotlin.jvm.functions.Function1;
 
 /**
  * A reusable and composable {@link androidx.recyclerview.widget.RecyclerView.Adapter} built on-top of {@link ListAdapter} to
@@ -103,6 +108,21 @@ public class MappingAdapter extends ListAdapter<MappingModel<?>, MappingViewHold
     holder.bind(getItem(position));
   }
 
+  public <T extends MappingModel<T>> int indexOfFirst(@NonNull Class<T> clazz, @NonNull Function1<T, Boolean> predicate) {
+    return CollectionsKt.indexOfFirst(getCurrentList(), m -> {
+      //noinspection unchecked
+      return clazz.isAssignableFrom(m.getClass()) && predicate.invoke((T) m);
+    });
+  }
+
+  public @NonNull Optional<MappingModel<?>> getModel(int index) {
+    List<MappingModel<?>> currentList = getCurrentList();
+    if (index >= 0 && index < currentList.size()) {
+      return Optional.ofNullable(currentList.get(index));
+    }
+    return Optional.empty();
+  }
+
   private static class MappingDiffCallback extends DiffUtil.ItemCallback<MappingModel<?>> {
     @Override
     public boolean areItemsTheSame(@NonNull MappingModel oldItem, @NonNull MappingModel newItem) {

app/src/main/java/org/thoughtcrime/securesms/util/MappingModelList.java

@@ -6,11 +6,59 @@ import com.annimon.stream.Collector;
 import com.annimon.stream.function.BiConsumer;
 import com.annimon.stream.function.Function;
 import com.annimon.stream.function.Supplier;
+import com.google.common.collect.Sets;
 
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Set;
+import java.util.function.BinaryOperator;
 
 public class MappingModelList extends ArrayList<MappingModel<?>> {
 
+  public MappingModelList() { }
+
+  public MappingModelList(@NonNull Collection<? extends MappingModel<?>> c) {
+    super(c);
+  }
+
+  public static @NonNull MappingModelList singleton(@NonNull MappingModel<?> model) {
+    MappingModelList list = new MappingModelList();
+    list.add(model);
+    return list;
+  }
+
+  public static @NonNull java.util.stream.Collector<MappingModel<?>, MappingModelList, MappingModelList> collect() {
+    return new java.util.stream.Collector<MappingModel<?>, MappingModelList, MappingModelList>() {
+      @Override
+      public java.util.function.Supplier<MappingModelList> supplier() {
+        return MappingModelList::new;
+      }
+
+      @Override
+      public java.util.function.BiConsumer<MappingModelList, MappingModel<?>> accumulator() {
+        return MappingModelList::add;
+      }
+
+      @Override
+      public BinaryOperator<MappingModelList> combiner() {
+        return (left, right) -> {
+          left.addAll(right);
+          return left;
+        };
+      }
+
+      @Override
+      public java.util.function.Function<MappingModelList, MappingModelList> finisher() {
+        return java.util.function.Function.identity();
+      }
+
+      @Override
+      public Set<Characteristics> characteristics() {
+        return Sets.immutableEnumSet(Characteristics.IDENTITY_FINISH);
+      }
+    };
+  }
+
   public static @NonNull Collector<MappingModel<?>, MappingModelList, MappingModelList> toMappingModelList() {
     return new Collector<MappingModel<?>, MappingModelList, MappingModelList>() {
       @Override