Convert ScanBinder to Kotlin

This follows `AdvertiseBinder.kt` and is useful for the following
reasons:
- Null Safety
- Conciseness

Bug: 394958283
Bug: 401837157
Test: atest ScanBinderTest
Test: atest ScanControllerTest
Flag: EXEMPT refactor no-op
Change-Id: Ib32738126743fa0935642589cc70e846074ab9c1

4 files changed, 156 insertions, 194 deletions

diff --git a/android/app/src/com/android/bluetooth/le_scan/ScanBinder.java b/android/app/src/com/android/bluetooth/le_scan/ScanBinder.java
deleted file mode 100644
index 2e905e087a..0000000000
--- a/android/app/src/com/android/bluetooth/le_scan/ScanBinder.java
+++ /dev/null
@@ -1,182 +0,0 @@
-/*
- * Copyright (C) 2025 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.bluetooth.le_scan;
-
-import android.app.PendingIntent;
-import android.bluetooth.BluetoothDevice;
-import android.bluetooth.IBluetoothScan;
-import android.bluetooth.le.IPeriodicAdvertisingCallback;
-import android.bluetooth.le.IScannerCallback;
-import android.bluetooth.le.ScanFilter;
-import android.bluetooth.le.ScanResult;
-import android.bluetooth.le.ScanSettings;
-import android.content.AttributionSource;
-import android.os.WorkSource;
-import android.util.Log;
-
-import java.util.List;
-
-class ScanBinder extends IBluetoothScan.Stub {
-    private static final String TAG = ScanBinder.class.getSimpleName();
-
-    private ScanController mScanController;
-
-    ScanBinder(ScanController scanController) {
-        mScanController = scanController;
-    }
-
-    @Override
-    public void registerScanner(
-            IScannerCallback callback, WorkSource workSource, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.registerScanner(callback, workSource, source);
-    }
-
-    @Override
-    public void unregisterScanner(int scannerId, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.unregisterScanner(scannerId, source);
-    }
-
-    @Override
-    public void startScan(
-            int scannerId,
-            ScanSettings settings,
-            List<ScanFilter> filters,
-            AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.startScan(scannerId, settings, filters, source);
-    }
-
-    @Override
-    public void startScanForIntent(
-            PendingIntent intent,
-            ScanSettings settings,
-            List<ScanFilter> filters,
-            AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.registerPiAndStartScan(intent, settings, filters, source);
-    }
-
-    @Override
-    public void stopScan(int scannerId, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.stopScan(scannerId, source);
-    }
-
-    @Override
-    public void stopScanForIntent(PendingIntent intent, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.stopScan(intent, source);
-    }
-
-    @Override
-    public void flushPendingBatchResults(int scannerId, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.flushPendingBatchResults(scannerId, source);
-    }
-
-    @Override
-    public void registerSync(
-            ScanResult scanResult,
-            int skip,
-            int timeout,
-            IPeriodicAdvertisingCallback callback,
-            AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.registerSync(scanResult, skip, timeout, callback, source);
-    }
-
-    @Override
-    public void unregisterSync(IPeriodicAdvertisingCallback callback, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.unregisterSync(callback, source);
-    }
-
-    @Override
-    public void transferSync(
-            BluetoothDevice bda, int serviceData, int syncHandle, AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.transferSync(bda, serviceData, syncHandle, source);
-    }
-
-    @Override
-    public void transferSetInfo(
-            BluetoothDevice bda,
-            int serviceData,
-            int advHandle,
-            IPeriodicAdvertisingCallback callback,
-            AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return;
-        }
-        scanController.transferSetInfo(bda, serviceData, advHandle, callback, source);
-    }
-
-    @Override
-    public int numHwTrackFiltersAvailable(AttributionSource source) {
-        ScanController scanController = getScanController();
-        if (scanController == null) {
-            return 0;
-        }
-        return scanController.numHwTrackFiltersAvailable(source);
-    }
-
-    void clearScanController() {
-        mScanController = null;
-    }
-
-    private ScanController getScanController() {
-        ScanController controller = mScanController;
-        if (controller != null && controller.isAvailable()) {
-            return controller;
-        }
-        Log.e(TAG, "getScanController() - ScanController requested, but not available!");
-        return null;
-    }
-}
diff --git a/android/app/src/com/android/bluetooth/le_scan/ScanBinder.kt b/android/app/src/com/android/bluetooth/le_scan/ScanBinder.kt
new file mode 100644
index 0000000000..bd5bd6e111
--- /dev/null
+++ b/android/app/src/com/android/bluetooth/le_scan/ScanBinder.kt
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2025 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.bluetooth.le_scan
+
+import android.app.PendingIntent
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.IBluetoothScan
+import android.bluetooth.le.IPeriodicAdvertisingCallback
+import android.bluetooth.le.IScannerCallback
+import android.bluetooth.le.ScanFilter
+import android.bluetooth.le.ScanResult
+import android.bluetooth.le.ScanSettings
+import android.content.AttributionSource
+import android.os.WorkSource
+import android.util.Log
+
+class ScanBinder(private val mScanController: ScanController) : IBluetoothScan.Stub() {
+
+    companion object {
+        private val TAG = ScanBinder::class.java.simpleName
+    }
+
+    @Volatile private var mIsAvailable = true
+
+    fun cleanup() {
+        mIsAvailable = false
+    }
+
+    private fun getScanController(): ScanController? {
+        if (mIsAvailable) {
+            return mScanController
+        } else {
+            Log.e(TAG, "getScanController() - ScanController requested, but not available!")
+            return null
+        }
+    }
+
+    override fun registerScanner(
+        callback: IScannerCallback,
+        workSource: WorkSource?,
+        source: AttributionSource,
+    ) {
+        getScanController()?.let { scanController ->
+            scanController.registerScanner(callback, workSource, source)
+        }
+    }
+
+    override fun unregisterScanner(scannerId: Int, source: AttributionSource) {
+        getScanController()?.let { scanController ->
+            scanController.unregisterScanner(scannerId, source)
+        }
+    }
+
+    override fun startScan(
+        scannerId: Int,
+        settings: ScanSettings?,
+        filters: List<ScanFilter>?,
+        source: AttributionSource,
+    ) {
+        getScanController()?.let { scanController ->
+            scanController.startScan(scannerId, settings, filters, source)
+        }
+    }
+
+    override fun startScanForIntent(
+        intent: PendingIntent,
+        settings: ScanSettings?,
+        filters: List<ScanFilter>?,
+        source: AttributionSource,
+    ) {
+        getScanController()?.let { scanController ->
+            scanController.registerPiAndStartScan(intent, settings, filters, source)
+        }
+    }
+
+    override fun stopScan(scannerId: Int, source: AttributionSource) {
+        getScanController()?.let { scanController -> scanController.stopScan(scannerId, source) }
+    }
+
+    override fun stopScanForIntent(intent: PendingIntent, source: AttributionSource) {
+        getScanController()?.let { scanController -> scanController.stopScan(intent, source) }
+    }
+
+    override fun flushPendingBatchResults(scannerId: Int, source: AttributionSource) {
+        getScanController()?.let { scanController ->
+            scanController.flushPendingBatchResults(scannerId, source)
+        }
+    }
+
+    override fun registerSync(
+        scanResult: ScanResult,
+        skip: Int,
+        timeout: Int,
+        callback: IPeriodicAdvertisingCallback,
+        source: AttributionSource,
+    ) {
+        getScanController()?.let { scanController ->
+            scanController.registerSync(scanResult, skip, timeout, callback, source)
+        }
+    }
+
+    override fun unregisterSync(callback: IPeriodicAdvertisingCallback, source: AttributionSource) {
+        getScanController()?.let { scanController ->
+            scanController.unregisterSync(callback, source)
+        }
+    }
+
+    override fun transferSync(
+        device: BluetoothDevice,
+        serviceData: Int,
+        syncHandle: Int,
+        source: AttributionSource,
+    ) {
+        getScanController()?.let { scanController ->
+            scanController.transferSync(device, serviceData, syncHandle, source)
+        }
+    }
+
+    override fun transferSetInfo(
+        device: BluetoothDevice,
+        serviceData: Int,
+        advHandle: Int,
+        callback: IPeriodicAdvertisingCallback,
+        source: AttributionSource,
+    ) {
+        getScanController()?.let { scanController ->
+            scanController.transferSetInfo(device, serviceData, advHandle, callback, source)
+        }
+    }
+
+    override fun numHwTrackFiltersAvailable(source: AttributionSource): Int {
+        return getScanController()?.let { scanController ->
+            scanController.numHwTrackFiltersAvailable(source)
+        } ?: 0
+    }
+}
diff --git a/android/app/src/com/android/bluetooth/le_scan/ScanController.java b/android/app/src/com/android/bluetooth/le_scan/ScanController.java
index 07ff67b65b..82b8e10dd7 100644
--- a/android/app/src/com/android/bluetooth/le_scan/ScanController.java
+++ b/android/app/src/com/android/bluetooth/le_scan/ScanController.java
@@ -72,11 +72,9 @@ import libcore.util.HexEncoding;
 
 import com.google.protobuf.ByteString;
 
-import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Deque;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -137,7 +135,6 @@ public class ScanController {
 
     private volatile boolean mTestModeEnabled = false;
     private ScannerMap mScannerMap = new ScannerMap();
-    private boolean mIsAvailable;
     private Handler mTestModeHandler;
 
     public ScanController(AdapterService adapterService) {
@@ -165,7 +162,6 @@ public class ScanController {
                 };
         mMainLooper = adapterService.getMainLooper();
         mBinder = new ScanBinder(this);
-        mIsAvailable = true;
         mScanThread = new HandlerThread("BluetoothScanManager");
         mScanThread.start();
         mAppOps = mAdapterService.getSystemService(AppOpsManager.class);
@@ -182,18 +178,13 @@ public class ScanController {
 
     public void cleanup() {
         Log.i(TAG, "Cleanup ScanController");
-        mIsAvailable = false;
-        mBinder.clearScanController();
+        mBinder.cleanup();
         mScanThread.quitSafely();
         mScannerMap.clear();
         mScanManager.cleanup();
         mPeriodicScanManager.cleanup();
     }
 
-    boolean isAvailable() {
-        return mIsAvailable;
-    }
-
     ScannerMap getScannerMap() {
         return mScannerMap;
     }
diff --git a/android/app/tests/unit/src/com/android/bluetooth/le_scan/ScanBinderTest.java b/android/app/tests/unit/src/com/android/bluetooth/le_scan/ScanBinderTest.java
index 7687fb381d..61c7df48b8 100644
--- a/android/app/tests/unit/src/com/android/bluetooth/le_scan/ScanBinderTest.java
+++ b/android/app/tests/unit/src/com/android/bluetooth/le_scan/ScanBinderTest.java
@@ -21,7 +21,6 @@ import static com.android.bluetooth.TestUtils.getTestDevice;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
 
 import android.app.PendingIntent;
 import android.bluetooth.BluetoothDevice;
@@ -67,7 +66,6 @@ public class ScanBinderTest {
 
     @Before
     public void setUp() {
-        when(mScanController.isAvailable()).thenReturn(true);
         mBinder = new ScanBinder(mScanController);
     }
 
@@ -188,4 +186,9 @@ public class ScanBinderTest {
         mBinder.numHwTrackFiltersAvailable(mAttributionSource);
         verify(mScanController).numHwTrackFiltersAvailable(mAttributionSource);
     }
+
+    @Test
+    public void cleanup_doesNotCrash() {
+        mBinder.cleanup();
+    }
 }