Adding support for prefenrece search in QuickStep

Bug: 62292864
Change-Id: Ic112626ca9c5942c91ced4ab42e64cbce4657701
diff --git a/src/com/android/launcher3/SettingsActivity.java b/src/com/android/launcher3/SettingsActivity.java
index 6a4e93b..7fa0e52 100644
--- a/src/com/android/launcher3/SettingsActivity.java
+++ b/src/com/android/launcher3/SettingsActivity.java
@@ -31,11 +31,17 @@
 import android.preference.Preference;
 import android.preference.PreferenceFragment;
 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 com.android.launcher3.graphics.IconShapeOverride;
 import com.android.launcher3.notification.NotificationListener;
 import com.android.launcher3.util.SettingsObserver;
 import com.android.launcher3.views.ButtonPreference;
+import com.android.launcher3.views.HighlightableListView;
 
 /**
  * Settings activity for Launcher. Currently implements the following setting: Allow rotation
@@ -48,6 +54,10 @@
     /** Hidden field Settings.Secure.ENABLED_NOTIFICATION_LISTENERS */
     private static final String NOTIFICATION_ENABLED_LISTENERS = "enabled_notification_listeners";
 
+    private static final String EXTRA_FRAGMENT_ARG_KEY = ":settings:fragment_args_key";
+    private static final int DELAY_HIGHLIGHT_DURATION_MILLIS = 600;
+    private static final String SAVE_HIGHLIGHTED_KEY = "android:preference_highlighted";
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -55,11 +65,15 @@
         if (savedInstanceState == null) {
             // Display the fragment as the main content.
             getFragmentManager().beginTransaction()
-                    .replace(android.R.id.content, new LauncherSettingsFragment())
+                    .replace(android.R.id.content, getNewFragment())
                     .commit();
         }
     }
 
+    protected PreferenceFragment getNewFragment() {
+        return new LauncherSettingsFragment();
+    }
+
     /**
      * This fragment shows the launcher preferences.
      */
@@ -67,9 +81,22 @@
 
         private IconBadgingObserver mIconBadgingObserver;
 
+        private String mPreferenceKey;
+        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) {
+                mPreferenceHighlighted = savedInstanceState.getBoolean(SAVE_HIGHLIGHTED_KEY);
+            }
+
             getPreferenceManager().setSharedPreferencesName(LauncherFiles.SHARED_PREFERENCES_KEY);
             addPreferencesFromResource(R.xml.launcher_preferences);
 
@@ -101,6 +128,43 @@
         }
 
         @Override
+        public void onSaveInstanceState(Bundle outState) {
+            super.onSaveInstanceState(outState);
+            outState.putBoolean(SAVE_HIGHLIGHTED_KEY, mPreferenceHighlighted);
+        }
+
+        @Override
+        public void onResume() {
+            super.onResume();
+
+            Intent intent = getActivity().getIntent();
+            mPreferenceKey = intent.getStringExtra(EXTRA_FRAGMENT_ARG_KEY);
+            if (isAdded() && !mPreferenceHighlighted && !TextUtils.isEmpty(mPreferenceKey)) {
+                getView().postDelayed(this::highlightPreference, DELAY_HIGHLIGHT_DURATION_MILLIS);
+            }
+        }
+
+        private void highlightPreference() {
+            HighlightableListView list = getView().findViewById(android.R.id.list);
+            Preference pref = findPreference(mPreferenceKey);
+            Adapter adapter = list.getAdapter();
+            if (adapter == null) {
+                return;
+            }
+
+            // Find the position
+            int position = -1;
+            for (int i = adapter.getCount() - 1; i >= 0; i--) {
+                if (pref == adapter.getItem(i)) {
+                    position = i;
+                    break;
+                }
+            }
+            list.highlightPosition(position);
+            mPreferenceHighlighted = true;
+        }
+
+        @Override
         public void onDestroy() {
             if (mIconBadgingObserver != null) {
                 mIconBadgingObserver.unregister();
diff --git a/src/com/android/launcher3/views/HighlightableListView.java b/src/com/android/launcher3/views/HighlightableListView.java
new file mode 100644
index 0000000..7da979f
--- /dev/null
+++ b/src/com/android/launcher3/views/HighlightableListView.java
@@ -0,0 +1,138 @@
+/*
+ * 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;
+    }
+}