Introduce BluetoothAdapter.getDefaultAdapter().

This is the main entry point to the Bluetooth APIs, and returns the default
local Bluetooth adapter.

It replaces context.getSystemService(Context.BLUETOOTH_SERVICE). This was
never in a public SDK release.

DrNo: eastham
Bug: 2158765
Joke: Why can't you play cards in the jungle? Because there's too many cheetas!
Change-Id: Ieed8be009ee5aba621cb69090ee8c8a9c19c840d

2 files changed, 34 insertions, 7 deletions

diff --git a/core/java/android/bluetooth/BluetoothAdapter.java b/core/java/android/bluetooth/BluetoothAdapter.java
index 8ce911d..cc35b7d 100644
--- a/core/java/android/bluetooth/BluetoothAdapter.java
+++ b/core/java/android/bluetooth/BluetoothAdapter.java
@@ -20,9 +20,11 @@ import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
 import android.os.Binder;
 import android.os.Handler;
+import android.os.IBinder;
 import android.os.Message;
 import android.os.ParcelUuid;
 import android.os.RemoteException;
+import android.os.ServiceManager;
 import android.util.Log;
 
 import java.io.IOException;
@@ -36,10 +38,8 @@ import java.util.UUID;
 /**
  * Represents the local Bluetooth adapter.
  *
- * <p>Use {@link android.content.Context#getSystemService} with {@link
- * android.content.Context#BLUETOOTH_SERVICE} to get the default local
- * Bluetooth adapter. On most Android devices there is only one local
- * Bluetotoh adapter.
+ * <p>Use {@link #getDefaultAdapter} to get the default local Bluetooth
+ * adapter.
  *
  * <p>Use the {@link BluetoothDevice} class for operations on remote Bluetooth
  * devices.
@@ -257,12 +257,40 @@ public final class BluetoothAdapter {
      */
     public static final String EXTRA_LOCAL_NAME = "android.bluetooth.adapter.extra.LOCAL_NAME";
 
+    /** @hide */
+    public static final String BLUETOOTH_SERVICE = "bluetooth";
+
     private static final int ADDRESS_LENGTH = 17;
 
+    /**
+     * Lazyily initialized singleton. Guaranteed final after first object
+     * constructed.
+     */
+    private static BluetoothAdapter sAdapter;
+
     private final IBluetooth mService;
 
     /**
-     * Do not use this constructor. Use Context.getSystemService() instead.
+     * Get a handle to the default local Bluetooth adapter.
+     * <p>Currently Android only supports one Bluetooth adapter, but the API
+     * could be extended to support more. This will always return the default
+     * adapter.
+     * @return the default local adapter, or null if Bluetooth is not supported
+     *         on this hardware platform
+     */
+    public static synchronized BluetoothAdapter getDefaultAdapter() {
+        if (sAdapter == null) {
+            IBinder b = ServiceManager.getService(BluetoothAdapter.BLUETOOTH_SERVICE);
+            if (b != null) {
+                IBluetooth service = IBluetooth.Stub.asInterface(b);
+                sAdapter = new BluetoothAdapter(service);
+            }
+        }
+        return sAdapter;
+    }
+
+    /**
+     * Use {@link #getDefaultAdapter} to get the BluetoothAdapter instance.
      * @hide
      */
     public BluetoothAdapter(IBluetooth service) {
diff --git a/core/java/android/bluetooth/BluetoothDevice.java b/core/java/android/bluetooth/BluetoothDevice.java
index ce975c2..9c23746 100644
--- a/core/java/android/bluetooth/BluetoothDevice.java
+++ b/core/java/android/bluetooth/BluetoothDevice.java
@@ -18,7 +18,6 @@ package android.bluetooth;
 
 import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
-import android.content.Context;
 import android.os.IBinder;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -328,7 +327,7 @@ public final class BluetoothDevice implements Parcelable {
     /*package*/ static IBluetooth getService() {
         synchronized (BluetoothDevice.class) {
             if (sService == null) {
-                IBinder b = ServiceManager.getService(Context.BLUETOOTH_SERVICE);
+                IBinder b = ServiceManager.getService(BluetoothAdapter.BLUETOOTH_SERVICE);
                 if (b == null) {
                     throw new RuntimeException("Bluetooth service not available");
                 }