Prevent wifi icon from disappearing

Made changes to WifiSettings that customizes
the preference icon so that the icon is never
null. This greatly reduces jittering.

Bug: 29979747
Change-Id: I3d2767310513389c09a37e34674a304278f4d0de

res/drawable/ic_wifi_signal_0.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright (C) 2015 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+  android:width="26dp"
+  android:height="24dp"
+  android:viewportWidth="26"
+  android:viewportHeight="24">
+  <path
+    android:fillAlpha="0.3"
+    android:fillColor="?attr/wifi_signal_color"
+    android:pathData="M13.0,22.0L25.6,6.5C25.1,6.1 20.3,2.1 13.0,2.1S0.9,6.1 0.4,6.5L13.0,22.0L13.0,22.0L13.0,22.0L13.0,22.0L13.0,22.0z"/>
+</vector>

src/com/android/settings/wifi/LongPressAccessPointPreference.java

@@ -17,21 +17,8 @@ package com.android.settings.wifi;
 
 import android.app.Fragment;
 import android.content.Context;
-import android.content.pm.PackageManager;
-import android.graphics.drawable.Drawable;
-import android.graphics.drawable.StateListDrawable;
-import android.net.wifi.WifiConfiguration;
-import android.os.Looper;
-import android.os.UserHandle;
-import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceViewHolder;
-import android.text.TextUtils;
 import android.util.AttributeSet;
-import android.util.SparseArray;
-import android.view.View;
-import android.widget.TextView;
-
-import com.android.settings.R;
 import com.android.settingslib.wifi.AccessPoint;
 import com.android.settingslib.wifi.AccessPointPreference;
 
@@ -51,6 +38,12 @@ public class LongPressAccessPointPreference extends AccessPointPreference {
         mFragment = fragment;
     }
 
+    public LongPressAccessPointPreference(AccessPoint accessPoint, Context context,
+            UserBadgeCache cache, boolean forSavedNetworks, int iconResId, Fragment fragment) {
+        super(accessPoint, context, cache, iconResId, forSavedNetworks);
+        mFragment = fragment;
+    }
+
     @Override
     public void onBindViewHolder(final PreferenceViewHolder view) {
         super.onBindViewHolder(view);

src/com/android/settings/wifi/WifiSettings.java

@@ -71,7 +71,6 @@ import com.android.settingslib.wifi.AccessPoint.AccessPointListener;
 import com.android.settingslib.wifi.AccessPointPreference;
 import com.android.settingslib.wifi.WifiStatusTracker;
 import com.android.settingslib.wifi.WifiTracker;
-
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -630,10 +629,10 @@ public class WifiSettings extends RestrictedSettingsFragment
                         }
                         LongPressAccessPointPreference
                                 preference = new LongPressAccessPointPreference(accessPoint,
-                                getPrefContext(), mUserBadgeCache, false, this);
+                                getPrefContext(), mUserBadgeCache, false,
+                                R.drawable.ic_wifi_signal_0, this);
                         preference.setKey(key);
                         preference.setOrder(index++);
-
                         if (mOpenSsid != null && mOpenSsid.equals(accessPoint.getSsidStr())
                                 && !accessPoint.isSaved()
                                 && accessPoint.getSecurity() != AccessPoint.SECURITY_NONE) {
@@ -642,6 +641,7 @@ public class WifiSettings extends RestrictedSettingsFragment
                         }
                         getPreferenceScreen().addPreference(preference);
                         accessPoint.setListener(this);
+                        preference.refresh();
                     }
                 }
                 removeCachedPrefs(getPreferenceScreen());