Add ethernet tether option into AllInOneTetherSettings

Create controller for ethernet tether preference in
AllInOneTetherSettings and corresponding test.

Test: AllInOneTetherSettingsTest; UsbTetherPreferenceControllerTest;
BluetoothTetherPreferenceControllerTest;
EthernetTetherPreferenceControllerTest;
WifiTetherDisablePreferenceControllerTest; TetherEnablerTest
Bug: 153690620

Change-Id: I8918d5c8a82c521b00eb3c712af80c2041778595

src/com/android/settings/network/EthernetTetherPreferenceController.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2020 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.network;
+
+import android.content.Context;
+import android.net.EthernetManager;
+import android.net.TetheringManager;
+import android.os.Handler;
+import android.os.Looper;
+import android.text.TextUtils;
+
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.OnLifecycleEvent;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+/**
+ * This controller helps to manage the switch state and visibility of ethernet tether switch
+ * preference.
+ */
+public final class EthernetTetherPreferenceController extends TetherBasePreferenceController {
+
+    private final String mEthernetRegex;
+    private final EthernetManager mEthernetManager;
+    @VisibleForTesting
+    EthernetManager.Listener mEthernetListener;
+
+    public EthernetTetherPreferenceController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+        mEthernetRegex = context.getString(
+                com.android.internal.R.string.config_ethernet_iface_regex);
+        mEthernetManager = (EthernetManager) context.getSystemService(Context.ETHERNET_SERVICE);
+    }
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_START)
+    public void onStart() {
+        mEthernetListener = new EthernetManager.Listener() {
+            @Override
+            public void onAvailabilityChanged(String iface, boolean isAvailable) {
+                new Handler(Looper.getMainLooper()).post(() -> updateState(mPreference));
+            }
+        };
+        mEthernetManager.addListener(mEthernetListener);
+    }
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
+    public void onStop() {
+        mEthernetManager.removeListener(mEthernetListener);
+        mEthernetListener = null;
+    }
+
+    @Override
+    public boolean shouldEnable() {
+        String[] available = mCm.getTetherableIfaces();
+        for (String s : available) {
+            if (s.matches(mEthernetRegex)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public boolean shouldShow() {
+        return !TextUtils.isEmpty(mEthernetRegex);
+    }
+
+    @Override
+    public int getTetherType() {
+        return TetheringManager.TETHERING_ETHERNET;
+    }
+}