Create Helper Classes for WifiTrackerLib

- Create a WifiTrackerBase for the base worker thread

- Create a SavedWifiHelper for the saved Wi-Fi network tracker

Bug: 258542666
Test: manual test
atest -c WifiTrackerBaseTest \
         SavedWifiHelperTest

Change-Id: Ie6b2f5b348367376da96737acdf5b8e65ecaf067

src/com/android/settings/wifi/helper/SavedWifiHelper.java

@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2022 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.wifi.helper;
+
+import android.annotation.TestApi;
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.wifi.WifiManager;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+
+import androidx.annotation.GuardedBy;
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+import androidx.lifecycle.Lifecycle;
+
+import com.android.wifitrackerlib.SavedNetworkTracker;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Helper for saved Wi-Fi networks tracker from WifiTrackerLib.
+ */
+public class SavedWifiHelper extends WifiTrackerBase {
+    private static final String TAG = "SavedWifiHelper";
+
+    private static final Object sInstanceLock = new Object();
+    @TestApi
+    @GuardedBy("sInstanceLock")
+    private static Map<Context, SavedWifiHelper> sTestInstances;
+
+    protected SavedNetworkTracker mSavedNetworkTracker;
+
+    /**
+     * Static method to create a SavedWifiHelper class.
+     *
+     * @param context   The Context this is associated with.
+     * @param lifecycle The lifecycle this is associated with.
+     * @return an instance of {@link SavedWifiHelper} object.
+     */
+    public static SavedWifiHelper getInstance(@NonNull Context context,
+            @NonNull Lifecycle lifecycle) {
+        synchronized (sInstanceLock) {
+            if (sTestInstances != null && sTestInstances.containsKey(context)) {
+                SavedWifiHelper testInstance = sTestInstances.get(context);
+                Log.w(TAG, "The context owner use a test instance:" + testInstance);
+                return testInstance;
+            }
+            return new SavedWifiHelper(context, lifecycle);
+        }
+    }
+
+    /**
+     * A convenience method to set pre-prepared instance or mock(SavedWifiHelper.class) for
+     * testing.
+     *
+     * @param context  The Context this is associated with.
+     * @param instance of {@link SavedWifiHelper} object.
+     * @hide
+     */
+    @TestApi
+    @VisibleForTesting
+    public static void setTestInstance(@NonNull Context context, SavedWifiHelper instance) {
+        synchronized (sInstanceLock) {
+            if (sTestInstances == null) sTestInstances = new ConcurrentHashMap<>();
+            Log.w(TAG, "Set a test instance by context:" + context);
+            sTestInstances.put(context, instance);
+        }
+    }
+
+    public SavedWifiHelper(@NonNull Context context, @NonNull Lifecycle lifecycle) {
+        this(context, lifecycle, null);
+    }
+
+    @VisibleForTesting
+    protected SavedWifiHelper(@NonNull Context context, @NonNull Lifecycle lifecycle,
+            SavedNetworkTracker saveNetworkTracker) {
+        super(lifecycle);
+        mSavedNetworkTracker = (saveNetworkTracker != null) ? saveNetworkTracker
+                : createSavedNetworkTracker(context, lifecycle);
+    }
+
+    @VisibleForTesting
+    protected SavedNetworkTracker createSavedNetworkTracker(@NonNull Context context,
+            @NonNull Lifecycle lifecycle) {
+        return new SavedNetworkTracker(lifecycle, context.getApplicationContext(),
+                context.getApplicationContext().getSystemService(WifiManager.class),
+                context.getApplicationContext().getSystemService(ConnectivityManager.class),
+                new Handler(Looper.getMainLooper()),
+                getWorkerThreadHandler(),
+                ELAPSED_REALTIME_CLOCK,
+                MAX_SCAN_AGE_MILLIS,
+                SCAN_INTERVAL_MILLIS,
+                null /* SavedNetworkTrackerCallback */);
+    }
+
+    @Override
+    protected String getTag() {
+        return TAG;
+    }
+
+    public SavedNetworkTracker getSavedNetworkTracker() {
+        return mSavedNetworkTracker;
+    }
+
+    /**
+     * Returns true when the certificate is being used by a saved network or network suggestion.
+     */
+    public boolean isCertificateInUse(String certAlias) {
+        return mSavedNetworkTracker.isCertificateRequired(certAlias);
+    }
+
+    /**
+     * Returns a list of network names which is using the certificate alias.
+     *
+     * @return a list of network names.
+     */
+    public List<String> getCertificateNetworkNames(String certAlias) {
+        return mSavedNetworkTracker.getCertificateRequesterNames(certAlias);
+    }
+}

src/com/android/settings/wifi/helper/WifiTrackerBase.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2022 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.wifi.helper;
+
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Process;
+import android.os.SimpleClock;
+import android.os.SystemClock;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+import androidx.lifecycle.DefaultLifecycleObserver;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleOwner;
+
+import java.time.Clock;
+import java.time.ZoneOffset;
+
+/**
+ * Base class for the WifiTrackerLib related classes.
+ */
+public class WifiTrackerBase implements DefaultLifecycleObserver {
+    private static final String TAG = "WifiTrackerBase";
+
+    // Max age of tracked WifiEntries
+    protected static final long MAX_SCAN_AGE_MILLIS = 15_000;
+    // Interval between initiating Wi-Fi Tracker scans
+    protected static final long SCAN_INTERVAL_MILLIS = 10_000;
+    // Clock used for evaluating the age of scans
+    protected static final Clock ELAPSED_REALTIME_CLOCK = new SimpleClock(ZoneOffset.UTC) {
+        @Override
+        public long millis() {
+            return SystemClock.elapsedRealtime();
+        }
+    };
+
+    @VisibleForTesting
+    protected HandlerThread mWorkerThread;
+
+    public WifiTrackerBase(@NonNull Lifecycle lifecycle) {
+        this(lifecycle, null /* handlerThread */);
+    }
+
+    @VisibleForTesting
+    protected WifiTrackerBase(@NonNull Lifecycle lifecycle, HandlerThread handlerThread) {
+        lifecycle.addObserver(this);
+        mWorkerThread = (handlerThread != null) ? handlerThread :
+                new HandlerThread(getTag()
+                        + "{" + Integer.toHexString(System.identityHashCode(this)) + "}",
+                        Process.THREAD_PRIORITY_BACKGROUND);
+        mWorkerThread.start();
+    }
+
+    protected String getTag() {
+        return TAG;
+    }
+
+    @Override
+    public void onDestroy(@NonNull LifecycleOwner owner) {
+        mWorkerThread.quit();
+    }
+
+    /** Returns the worker thread handler. */
+    public Handler getWorkerThreadHandler() {
+        return mWorkerThread.getThreadHandler();
+    }
+}