Some Tethering code to SettingsLib and use in QS

Change-Id: I640c84d4e42d2f1955db8cd6e473b6acac64dd39
diff --git a/packages/SettingsLib/src/com/android/settingslib/TetherUtil.java b/packages/SettingsLib/src/com/android/settingslib/TetherUtil.java
new file mode 100644
index 0000000..58e5e29a
--- /dev/null
+++ b/packages/SettingsLib/src/com/android/settingslib/TetherUtil.java
@@ -0,0 +1,106 @@
+/*
+ * 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.
+ */
+package com.android.settingslib;
+
+import android.app.ActivityManager;
+import android.content.ComponentName;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.res.Resources;
+import android.net.ConnectivityManager;
+import android.net.wifi.WifiManager;
+import android.os.SystemProperties;
+import android.os.UserHandle;
+import android.provider.Settings;
+
+public class TetherUtil {
+
+    // Types of tethering.
+    public static final int TETHERING_INVALID   = -1;
+    public static final int TETHERING_WIFI      = 0;
+    public static final int TETHERING_USB       = 1;
+    public static final int TETHERING_BLUETOOTH = 2;
+
+    // Extras used for communicating with the TetherService.
+    public static final String EXTRA_ADD_TETHER_TYPE = "extraAddTetherType";
+    public static final String EXTRA_REM_TETHER_TYPE = "extraRemTetherType";
+    public static final String EXTRA_SET_ALARM = "extraSetAlarm";
+    /**
+     * Tells the service to run a provision check now.
+     */
+    public static final String EXTRA_RUN_PROVISION = "extraRunProvision";
+    /**
+     * Enables wifi tethering if the provision check is successful. Used by
+     * QS to enable tethering.
+     */
+    public static final String EXTRA_ENABLE_WIFI_TETHER = "extraEnableWifiTether";
+
+    public static ComponentName TETHER_SERVICE = ComponentName.unflattenFromString(Resources
+            .getSystem().getString(com.android.internal.R.string.config_wifi_tether_enable));
+
+    public static boolean setWifiTethering(boolean enable, Context context) {
+        final WifiManager wifiManager =
+                (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
+        final ContentResolver cr = context.getContentResolver();
+        /**
+         * Disable Wifi if enabling tethering
+         */
+        int wifiState = wifiManager.getWifiState();
+        if (enable && ((wifiState == WifiManager.WIFI_STATE_ENABLING) ||
+                    (wifiState == WifiManager.WIFI_STATE_ENABLED))) {
+            wifiManager.setWifiEnabled(false);
+            Settings.Global.putInt(cr, Settings.Global.WIFI_SAVED_STATE, 1);
+        }
+
+        boolean success = wifiManager.setWifiApEnabled(null, enable);
+        /**
+         *  If needed, restore Wifi on tether disable
+         */
+        if (!enable) {
+            int wifiSavedState = Settings.Global.getInt(cr, Settings.Global.WIFI_SAVED_STATE, 0);
+            if (wifiSavedState == 1) {
+                wifiManager.setWifiEnabled(true);
+                Settings.Global.putInt(cr, Settings.Global.WIFI_SAVED_STATE, 0);
+            }
+        }
+        return success;
+    }
+
+    public static boolean isWifiTetherEnabled(Context context) {
+        WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
+        return wifiManager.getWifiApState() == WifiManager.WIFI_AP_STATE_ENABLED;
+    }
+
+    public static boolean isProvisioningNeeded(Context context) {
+        // Keep in sync with other usage of config_mobile_hotspot_provision_app.
+        // ConnectivityManager#enforceTetherChangePermission
+        String[] provisionApp = context.getResources().getStringArray(
+                com.android.internal.R.array.config_mobile_hotspot_provision_app);
+        if (SystemProperties.getBoolean("net.tethering.noprovisioning", false)
+                || provisionApp == null) {
+            return false;
+        }
+        return (provisionApp.length == 2);
+    }
+
+    public static boolean isTetheringSupported(Context context) {
+        final ConnectivityManager cm =
+                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        final boolean isSecondaryUser = ActivityManager.getCurrentUser() != UserHandle.USER_OWNER;
+        return !isSecondaryUser && cm.isTetheringSupported();
+    }
+
+}