Add ScrollToPositionDelegate and install in calls log fragment.

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

@@ -5,6 +5,7 @@ import android.widget.TextView
 import androidx.annotation.DrawableRes
 import androidx.constraintlayout.widget.ConstraintLayout
 import androidx.constraintlayout.widget.ConstraintSet
+import androidx.core.view.doOnNextLayout
 
 var View.visible: Boolean
   get() {
@@ -31,6 +32,17 @@ inline fun View.doOnEachLayout(crossinline action: (view: View) -> Unit): View.O
   return listener
 }
 
+/**
+ * OnLayout gets called prior to the view *actually* being laid out. This
+ * method will wait until the next layout and then post the action to happen
+ * afterwards.
+ */
+inline fun View.doAfterNextLayout(crossinline action: () -> Unit) {
+  doOnNextLayout {
+    post { action() }
+  }
+}
+
 fun TextView.setRelativeDrawables(
   @DrawableRes start: Int = 0,
   @DrawableRes top: Int = 0,

app/src/main/java/org/thoughtcrime/securesms/util/adapter/mapping/PagingMappingAdapter.java

@@ -45,6 +45,35 @@ public class PagingMappingAdapter<Key> extends MappingAdapter {
     }
   }
 
+  public boolean isAvailableAround(int position) {
+    int start = position - 10;
+    int end   = position + 10;
+
+    if (isRangeAvailable(start, end)) {
+      return true;
+    } else {
+      getItem(position);
+      return false;
+    }
+  }
+
+  protected final boolean isRangeAvailable(int start, int end) {
+    if (end <= start || start >= getItemCount() || end <= 0) {
+      return false;
+    }
+
+    int clampedStart = Math.max(0, start);
+    int clampedEnd   = Math.min(getItemCount(), end);
+
+    for (int i = clampedStart; i < clampedEnd; i++) {
+      if (super.getItem(i) == null) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
   @Override
   public int getItemViewType(int position) {
     MappingModel<?> item = getItem(position);