Focusing on item highlighted coming from search result

There are two cases that require different approach:
1. No scrolling or only a bit of scrolling is required to reach desired
   item - then we can focus the item straight away.
2. We're still scrolling when highlighting is started - after
   DELAY_COLLAPSE_DURATION_MILLIS + DELAY_HIGHLIGHT_DURATION_MILLIS.
   Then we need to wait till we reach the element/stop scrolling and focus
   afterwards.

Test: case 1: search for any setting, press enter and see if keyboard is focused
on search result
Test: case 2: search for setting that requires a lot of scrolling, e.g.
"display cutout" and see if it's get the focus after selecting
Fixes: 307902050

Change-Id: Ifa0738748184e78074099e33e09e5d8df198177e

src/com/android/settings/SettingsPreferenceFragment.java

@@ -479,6 +479,7 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
                 mDialogFragment.dismiss();
                 mDialogFragment = null;
             }
+            getListView().clearOnScrollListeners();
         }
         super.onDetach();
     }

src/com/android/settings/widget/HighlightablePreferenceGroupAdapter.java

@@ -29,12 +29,14 @@ import android.util.Log;
 import android.util.TypedValue;
 import android.view.View;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.VisibleForTesting;
 import androidx.preference.PreferenceGroup;
 import androidx.preference.PreferenceGroupAdapter;
 import androidx.preference.PreferenceScreen;
 import androidx.preference.PreferenceViewHolder;
 import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.ViewHolder;
 
 import com.android.settings.R;
 import com.android.settings.SettingsPreferenceFragment;
@@ -159,15 +161,32 @@ public class HighlightablePreferenceGroupAdapter extends PreferenceGroupAdapter
         root.postDelayed(() -> {
             if (ensureHighlightPosition()) {
                 recyclerView.smoothScrollToPosition(mHighlightPosition);
+                highlightAndFocusTargetItem(recyclerView, mHighlightPosition);
             }
         }, DELAY_HIGHLIGHT_DURATION_MILLIS);
+    }
 
-        // Highlight preference after 900 milliseconds.
+    private void highlightAndFocusTargetItem(RecyclerView recyclerView, int highlightPosition) {
-        root.postDelayed(() -> {
+        ViewHolder target = recyclerView.findViewHolderForAdapterPosition(highlightPosition);
-            if (ensureHighlightPosition()) {
+        if (target != null) { // view already visible
-                notifyItemChanged(mHighlightPosition);
+            notifyItemChanged(mHighlightPosition);
-            }
+            target.itemView.requestFocus();
-        }, DELAY_COLLAPSE_DURATION_MILLIS + DELAY_HIGHLIGHT_DURATION_MILLIS);
+        } else { // otherwise we're about to scroll to that view (but we might not be scrolling yet)
+            recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+                @Override
+                public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
+                    if (newState == RecyclerView.SCROLL_STATE_IDLE) {
+                        notifyItemChanged(mHighlightPosition);
+                        ViewHolder target = recyclerView
+                                .findViewHolderForAdapterPosition(highlightPosition);
+                        if (target != null) {
+                            target.itemView.requestFocus();
+                        }
+                        recyclerView.removeOnScrollListener(this);
+                    }
+                }
+            });
+        }
     }
 
     /**