First pass at USB-only tether settings.

bug:2281900
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 74092e5..ebd7637 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -168,6 +168,16 @@
             </intent-filter>
         </activity>
 
+        <activity android:name=".TetherSettings"
+                android:configChanges="orientation|keyboardHidden"
+                android:launchMode="singleTask">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.VOICE_LAUNCH" />
+            </intent-filter>
+        </activity>
+
         <activity android:name=".vpn.VpnSettings"
                 android:configChanges="orientation|keyboardHidden"
                 android:launchMode="singleTask">
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 0d40330..d145841 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -1256,6 +1256,27 @@
     <!-- Main settings screen, Call settings summary for item to go into call settings -->
     <string name="call_settings_summary">Set up voicemail, call forwarding, call waiting, caller ID</string>
 
+    <!-- Tethering controls, item title to go into the tethering settings -->
+    <string name="tether_settings_title">Tethering settings</string>
+    <!-- Tethering controls, the item summary for the user to go into the tethering settings -->
+    <string name="tether_settings_summary">Set up and manage tethering</string>
+
+    <!-- Title of the screen for adjusting tethering settings -->
+    <string name="tether_screen_title">Tethering settings</string>
+
+    <!-- Tethering notification toggle - controls whether a notification will appear when a tetherable connection becomes available -->
+    <string name="enable_tether_notice_checkbox">Notifications</string>
+    <!-- Tethering notification summary explains the notification toggle -->
+    <string name="enable_tether_notice_checkbox_summary">Show a notification when USB tethering is available</string>
+    <!-- USB Tethering options -->
+    <string name="usb_tethering_button_text">USB tethering</string>
+    <!-- USB available subtext - shown when USB is connected but not currently being tethered -->
+    <string name="usb_tethering_available_subtext">USB connected, select to tether</string>
+    <!-- USB tethered subtext - shown when USB is connected and being tethered -->
+    <string name="usb_tethering_active_subtext">Connected, select to disconnect</string>
+    <!-- USB unavailable subtext - shown when USB is not connected -->
+    <string name="usb_tethering_unavailable_subtext">USB not connected</string>
+
     <!-- Wireless controls, item title to go into the network settings -->
     <string name="network_settings_title">Mobile networks</string>
     <!-- Wireless controls, the item summary for the user to go into the network settings -->
diff --git a/res/xml/tether_prefs.xml b/res/xml/tether_prefs.xml
new file mode 100644
index 0000000..321129f
--- /dev/null
+++ b/res/xml/tether_prefs.xml
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2008 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.
+-->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+        android:title="@string/tether_screen_title">
+
+    <PreferenceScreen
+        android:key="usb_tether_settings"
+        android:title="@string/usb_tethering_button_text"
+        android:widgetLayout="@*android:layout/preference_dialog" >
+        <intent
+            android:action="android.intent.action.MAIN"
+            android:targetPackage="android"
+            android:targetClass="com.android.internal.app.TetherActivity" />
+    </PreferenceScreen>
+
+    <CheckBoxPreference
+        android:key="enable_tether_notice"
+        android:title="@string/enable_tether_notice_checkbox"
+        android:summary="@string/enable_tether_notice_checkbox_summary"/>
+
+</PreferenceScreen>
diff --git a/res/xml/wireless_settings.xml b/res/xml/wireless_settings.xml
index 2493021..9977505 100644
--- a/res/xml/wireless_settings.xml
+++ b/res/xml/wireless_settings.xml
@@ -57,6 +57,15 @@
     </PreferenceScreen>
 
     <PreferenceScreen
+        android:title="@string/tether_settings_title"
+        android:summary="@string/tether_settings_summary">
+        <intent
+            android:action="android.intent.action.MAIN"
+            android:targetPackage="com.android.settings"
+            android:targetClass="com.android.settings.TetherSettings" />
+    </PreferenceScreen>
+
+    <PreferenceScreen
         android:key="vpn_settings"
         android:title="@string/vpn_settings_title"
         android:summary="@string/vpn_settings_summary" >
diff --git a/src/com/android/settings/TetherSettings.java b/src/com/android/settings/TetherSettings.java
new file mode 100644
index 0000000..0a63de3
--- /dev/null
+++ b/src/com/android/settings/TetherSettings.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2008 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.settings;
+
+import android.os.Bundle;
+import android.os.SystemProperties;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.ConnectivityManager;
+import android.preference.Preference;
+import android.preference.PreferenceActivity;
+import android.preference.PreferenceScreen;
+import android.preference.CheckBoxPreference;
+import android.provider.Settings;
+import android.util.Log;
+
+/*
+ * Displays preferences for Tethering.
+ */
+public class TetherSettings extends PreferenceActivity {
+
+    private static final String ENABLE_TETHER_NOTICE = "enable_tether_notice";
+    private static final String USB_TETHER_SETTINGS = "usb_tether_settings";
+
+    private CheckBoxPreference mEnableTetherNotice;
+    private PreferenceScreen mUsbTether;
+
+    private BroadcastReceiver mTetherChangeReceiver;
+
+    @Override
+    protected void onCreate(Bundle icicle) {
+        super.onCreate(icicle);
+
+        addPreferencesFromResource(R.xml.tether_prefs);
+
+        mEnableTetherNotice = (CheckBoxPreference) findPreference(ENABLE_TETHER_NOTICE);
+        mUsbTether = (PreferenceScreen) findPreference(USB_TETHER_SETTINGS);
+    }
+
+    private class TetherChangeReceiver extends BroadcastReceiver {
+        public void onReceive(Context content, Intent intent) {
+            updateState(intent.getIntExtra(ConnectivityManager.EXTRA_AVAILABLE_TETHER_COUNT,0)>0,
+                    intent.getIntExtra(ConnectivityManager.EXTRA_ACTIVE_TETHER_COUNT,0)>0);
+        }
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        mEnableTetherNotice.setChecked(Settings.Secure.getInt(getContentResolver(),
+                Settings.Secure.TETHER_NOTIFY, 0) != 0);
+
+        IntentFilter filter = new IntentFilter(ConnectivityManager.ACTION_TETHER_STATE_CHANGED);
+        mTetherChangeReceiver = new TetherChangeReceiver();
+        registerReceiver(mTetherChangeReceiver, filter);
+
+        ConnectivityManager cm =
+                (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
+        updateState(cm.getTetherableIfaces().length>0, cm.getTetheredIfaces().length>0);
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        unregisterReceiver(mTetherChangeReceiver);
+        mTetherChangeReceiver = null;
+    }
+
+    private void updateState(boolean isAvailable, boolean isTethered) {
+        if (isTethered) {
+            mUsbTether.setSummary(R.string.usb_tethering_active_subtext);
+            mUsbTether.setEnabled(true);
+        } else if (isAvailable) {
+            mUsbTether.setSummary(R.string.usb_tethering_available_subtext);
+            mUsbTether.setEnabled(true);
+        } else {
+            mUsbTether.setSummary(R.string.usb_tethering_unavailable_subtext);
+            mUsbTether.setEnabled(false);
+        }
+    }
+
+    @Override
+    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
+
+        if (preference == mEnableTetherNotice) {
+            boolean newState = mEnableTetherNotice.isChecked();
+            Settings.Secure.putInt(getContentResolver(),
+                    Settings.Secure.TETHER_NOTIFY, newState ? 1 : 0);
+            return true;
+        }
+        return false;
+    }
+
+}