Adding support for highlighting preference in sub-screens

Change-Id: I1d5c0a7457a31755951b2f6be70a61a2d84463cf
diff --git a/res/layout/launcher_preference.xml b/res/layout/launcher_preference.xml
deleted file mode 100644
index ed0ea7c..0000000
--- a/res/layout/launcher_preference.xml
+++ /dev/null
@@ -1,27 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright (C) 2018 The Android Open Source Project
-
-     Licensed under the Apache License, Version 2.0 (the "License");
-     you may not use this file except in compliance with the License.
-     You may obtain a copy of the License at
-
-          http://www.apache.org/licenses/LICENSE-2.0
-
-     Unless required by applicable law or agreed to in writing, software
-     distributed under the License is distributed on an "AS IS" BASIS,
-     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-     See the License for the specific language governing permissions and
-     limitations under the License.
--->
-
-<com.android.launcher3.views.HighlightableListView
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@android:id/list"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:cacheColorHint="@android:color/transparent"
-    android:clipToPadding="false"
-    android:drawSelectorOnTop="false"
-    android:orientation="vertical"
-    android:scrollbarAlwaysDrawVerticalTrack="true"
-    android:scrollbarStyle="outsideOverlay" />
\ No newline at end of file
diff --git a/src/com/android/launcher3/SettingsActivity.java b/src/com/android/launcher3/SettingsActivity.java
index 7fa0e52..c9bd32b 100644
--- a/src/com/android/launcher3/SettingsActivity.java
+++ b/src/com/android/launcher3/SettingsActivity.java
@@ -16,6 +16,7 @@
 
 package com.android.launcher3;
 
+import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.Dialog;
@@ -26,22 +27,25 @@
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
+import android.os.Build;
 import android.os.Bundle;
 import android.preference.ListPreference;
 import android.preference.Preference;
 import android.preference.PreferenceFragment;
+import android.preference.PreferenceScreen;
 import android.provider.Settings;
 import android.text.TextUtils;
-import android.view.LayoutInflater;
 import android.view.View;
-import android.view.ViewGroup;
 import android.widget.Adapter;
+import android.widget.ListView;
 
 import com.android.launcher3.graphics.IconShapeOverride;
 import com.android.launcher3.notification.NotificationListener;
+import com.android.launcher3.util.ListViewHighlighter;
 import com.android.launcher3.util.SettingsObserver;
 import com.android.launcher3.views.ButtonPreference;
-import com.android.launcher3.views.HighlightableListView;
+
+import java.util.Objects;
 
 /**
  * Settings activity for Launcher. Currently implements the following setting: Allow rotation
@@ -85,12 +89,6 @@
         private boolean mPreferenceHighlighted = false;
 
         @Override
-        public View onCreateView(LayoutInflater inflater, ViewGroup container,
-                Bundle savedInstanceState) {
-            return inflater.inflate(R.layout.launcher_preference, container, false);
-        }
-
-        @Override
         public void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
             if (savedInstanceState != null) {
@@ -145,12 +143,25 @@
         }
 
         private void highlightPreference() {
-            HighlightableListView list = getView().findViewById(android.R.id.list);
             Preference pref = findPreference(mPreferenceKey);
-            Adapter adapter = list.getAdapter();
-            if (adapter == null) {
+            if (pref == null || getPreferenceScreen() == null) {
                 return;
             }
+            PreferenceScreen screen = getPreferenceScreen();
+            if (Utilities.ATLEAST_OREO) {
+                screen = selectPreferenceRecursive(pref, screen);
+            }
+            if (screen == null) {
+                return;
+            }
+
+            View root = screen.getDialog() != null
+                    ? screen.getDialog().getWindow().getDecorView() : getView();
+            ListView list = root.findViewById(android.R.id.list);
+            if (list == null || list.getAdapter() == null) {
+                return;
+            }
+            Adapter adapter = list.getAdapter();
 
             // Find the position
             int position = -1;
@@ -160,7 +171,7 @@
                     break;
                 }
             }
-            list.highlightPosition(position);
+            new ListViewHighlighter(list, position);
             mPreferenceHighlighted = true;
         }
 
@@ -172,6 +183,25 @@
             }
             super.onDestroy();
         }
+
+        @TargetApi(Build.VERSION_CODES.O)
+        private PreferenceScreen selectPreferenceRecursive(
+                Preference pref, PreferenceScreen topParent) {
+            if (!(pref.getParent() instanceof PreferenceScreen)) {
+                return null;
+            }
+
+            PreferenceScreen parent = (PreferenceScreen) pref.getParent();
+            if (Objects.equals(parent.getKey(), topParent.getKey())) {
+                return parent;
+            } else if (selectPreferenceRecursive(parent, topParent) != null) {
+                ((PreferenceScreen) parent.getParent())
+                        .onItemClick(null, null, parent.getOrder(), 0);
+                return parent;
+            } else {
+                return null;
+            }
+        }
     }
 
     /**
diff --git a/src/com/android/launcher3/util/ListViewHighlighter.java b/src/com/android/launcher3/util/ListViewHighlighter.java
new file mode 100644
index 0000000..ecad2af
--- /dev/null
+++ b/src/com/android/launcher3/util/ListViewHighlighter.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.util;
+
+import android.animation.ArgbEvaluator;
+import android.animation.ObjectAnimator;
+import android.animation.ValueAnimator;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import android.support.v4.graphics.ColorUtils;
+import android.view.View;
+import android.view.View.OnLayoutChangeListener;
+import android.widget.AbsListView;
+import android.widget.AbsListView.OnScrollListener;
+import android.widget.AbsListView.RecyclerListener;
+import android.widget.ListView;
+
+import com.android.launcher3.R;
+
+/**
+ * Utility class to scroll and highlight a list view item
+ */
+public class ListViewHighlighter implements OnScrollListener, RecyclerListener,
+        OnLayoutChangeListener {
+
+    private final ListView mListView;
+    private int mPosHighlight;
+
+    private boolean mColorAnimated = false;
+
+    public ListViewHighlighter(ListView listView, int posHighlight) {
+        mListView = listView;
+        mPosHighlight = posHighlight;
+        mListView.setOnScrollListener(this);
+        mListView.setRecyclerListener(this);
+        mListView.addOnLayoutChangeListener(this);
+
+        mListView.post(this::tryHighlight);
+    }
+
+    @Override
+    public void onLayoutChange(View v, int left, int top, int right, int bottom,
+            int oldLeft, int oldTop, int oldRight, int oldBottom) {
+        mListView.post(this::tryHighlight);
+    }
+
+    private void tryHighlight() {
+        if (mPosHighlight < 0 || mListView.getChildCount() == 0) {
+            return;
+        }
+        if (!highlightIfVisible(mListView.getFirstVisiblePosition(),
+                mListView.getLastVisiblePosition())) {
+            mListView.smoothScrollToPosition(mPosHighlight);
+        }
+    }
+
+    @Override
+    public void onScrollStateChanged(AbsListView absListView, int i) { }
+
+    @Override
+    public void onScroll(AbsListView view, int firstVisibleItem,
+            int visibleItemCount, int totalItemCount) {
+        highlightIfVisible(firstVisibleItem, firstVisibleItem + visibleItemCount);
+    }
+
+    private boolean highlightIfVisible(int start, int end) {
+        if (mPosHighlight < 0 || mListView.getChildCount() == 0) {
+            return false;
+        }
+        if (start > mPosHighlight || mPosHighlight > end) {
+            return false;
+        }
+        highlightView(mListView.getChildAt(mPosHighlight - start));
+
+        // finish highlight
+        mListView.setOnScrollListener(null);
+        mListView.removeOnLayoutChangeListener(this);
+
+        mPosHighlight = -1;
+        return true;
+    }
+
+    @Override
+    public void onMovedToScrapHeap(View view) {
+        unhighlightView(view);
+    }
+
+    private void highlightView(View view) {
+        if (Boolean.TRUE.equals(view.getTag(R.id.view_highlighted))) {
+            // already highlighted
+        } else {
+            view.setTag(R.id.view_highlighted, true);
+            view.setTag(R.id.view_unhighlight_background, view.getBackground());
+            view.setBackground(getHighlightBackground());
+            view.postDelayed(() -> {
+                unhighlightView(view);
+            }, 15000L);
+        }
+    }
+
+    private void unhighlightView(View view) {
+        if (Boolean.TRUE.equals(view.getTag(R.id.view_highlighted))) {
+            Object background = view.getTag(R.id.view_unhighlight_background);
+            if (background instanceof Drawable) {
+                view.setBackground((Drawable) background);
+            }
+            view.setTag(R.id.view_unhighlight_background, null);
+            view.setTag(R.id.view_highlighted, false);
+        }
+    }
+
+    private ColorDrawable getHighlightBackground() {
+        int color = ColorUtils.setAlphaComponent(Themes.getColorAccent(mListView.getContext()), 26);
+        if (mColorAnimated) {
+            return new ColorDrawable(color);
+        }
+        mColorAnimated = true;
+        ColorDrawable bg = new ColorDrawable(Color.WHITE);
+        ObjectAnimator anim = ObjectAnimator.ofInt(bg, "color", Color.WHITE, color);
+        anim.setEvaluator(new ArgbEvaluator());
+        anim.setDuration(200L);
+        anim.setRepeatMode(ValueAnimator.REVERSE);
+        anim.setRepeatCount(4);
+        anim.start();
+        return bg;
+    }
+}
diff --git a/src/com/android/launcher3/views/HighlightableListView.java b/src/com/android/launcher3/views/HighlightableListView.java
deleted file mode 100644
index 7da979f..0000000
--- a/src/com/android/launcher3/views/HighlightableListView.java
+++ /dev/null
@@ -1,138 +0,0 @@
-/*
- * Copyright (C) 2018 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.launcher3.views;
-
-import android.animation.ArgbEvaluator;
-import android.animation.ObjectAnimator;
-import android.animation.ValueAnimator;
-import android.content.Context;
-import android.graphics.Color;
-import android.graphics.drawable.ColorDrawable;
-import android.graphics.drawable.Drawable;
-import android.support.v4.graphics.ColorUtils;
-import android.util.AttributeSet;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.HeaderViewListAdapter;
-import android.widget.ListAdapter;
-import android.widget.ListView;
-
-import com.android.launcher3.R;
-import com.android.launcher3.util.Themes;
-
-import java.util.ArrayList;
-
-/**
- * Extension of list view with support for element highlighting.
- */
-public class HighlightableListView extends ListView {
-
-    private int mPosHighlight = -1;
-    private boolean mColorAnimated = false;
-
-    public HighlightableListView(Context context) {
-        super(context);
-    }
-
-    public HighlightableListView(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    public HighlightableListView(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-    }
-
-    @Override
-    public void setAdapter(ListAdapter adapter) {
-        super.setAdapter(new HighLightAdapter(adapter));
-    }
-
-    public void highlightPosition(int pos) {
-        if (mPosHighlight == pos) {
-            return;
-        }
-
-        mColorAnimated = false;
-        mPosHighlight = pos;
-        setSelection(mPosHighlight);
-
-        int start = getFirstVisiblePosition();
-        int end = getLastVisiblePosition();
-        if (start <= mPosHighlight && mPosHighlight <= end) {
-            highlightView(getChildAt(mPosHighlight - start));
-        }
-    }
-
-    private void highlightView(View view) {
-        if (Boolean.TRUE.equals(view.getTag(R.id.view_highlighted))) {
-            // already highlighted
-        } else {
-            view.setTag(R.id.view_highlighted, true);
-            view.setTag(R.id.view_unhighlight_background, view.getBackground());
-            view.setBackground(getHighlightBackground());
-            view.postDelayed(() -> {
-                mPosHighlight = -1;
-                unhighlightView(view);
-            }, 15000L);
-        }
-    }
-
-    private void unhighlightView(View view) {
-        if (Boolean.TRUE.equals(view.getTag(R.id.view_highlighted))) {
-            Object background = view.getTag(R.id.view_unhighlight_background);
-            if (background instanceof Drawable) {
-                view.setBackground((Drawable) background);
-            }
-            view.setTag(R.id.view_unhighlight_background, null);
-            view.setTag(R.id.view_highlighted, false);
-        }
-    }
-
-    private class HighLightAdapter extends HeaderViewListAdapter {
-        public HighLightAdapter(ListAdapter adapter) {
-            super(new ArrayList<>(), new ArrayList<>(), adapter);
-        }
-
-        @Override
-        public View getView(int position, View convertView, ViewGroup parent) {
-            View view =  super.getView(position, convertView, parent);
-
-            if (position == mPosHighlight) {
-                highlightView(view);
-            } else {
-                unhighlightView(view);
-            }
-            return view;
-        }
-    }
-
-    private ColorDrawable getHighlightBackground() {
-        int color = ColorUtils.setAlphaComponent(Themes.getColorAccent(getContext()), 26);
-        if (mColorAnimated) {
-            return new ColorDrawable(color);
-        }
-        mColorAnimated = true;
-        ColorDrawable bg = new ColorDrawable(Color.WHITE);
-        ObjectAnimator anim = ObjectAnimator.ofInt(bg, "color", Color.WHITE, color);
-        anim.setEvaluator(new ArgbEvaluator());
-        anim.setDuration(200L);
-        anim.setRepeatMode(ValueAnimator.REVERSE);
-        anim.setRepeatCount(4);
-        anim.start();
-        return bg;
-    }
-}