Improve Bluetooth tethering UI usability.

- Updated hint text for BT tethering checkbox to
  "[Sharing|not sharing] this [tablet|phone]'s mobile data connection".
- Show correct hint text when user enters tethering screen.
- Show correct status after user enables tethering when Bluetooth is off.
  When BluetoothPan.setBluetoothTethering(true) is called with BT off,
  BluetoothPanProfileHandler will add a broadcast receiver to enable
  tethering after BT turns on. This happens too late to show the correct
  status when TetherSettings gets the adapter state changed event, so set
  a flag (mBluetoothEnableForTether) instead, and call setBluetoothTethering
  ourselves after the state changes to ON. Also, clear the flag if the
  adapter state changes to OFF or ERROR.
- Show correct status when user enables tethering, then disables Bluetooth,
  then returns to the tethering screen. Previously it would show
  Bluetooth tethering enabled, even though adapter state was OFF.
- Show the number of connected devices in tethering preference screen.
- Distinguish between PANU and NAP in device profiles screen, and show
  appropriate text to clarify the direction of tethering.
- Remove profiles from device profiles list when the device removes the UUID
  (e.g. Mac OS X turning NAP on/off) and after a NAP disconnection when the
  remote device only supports PANU.

Bug: 3414575
Change-Id: I2c0830876d5b9bddb293e57c4d3ca74f105911b8

src/com/android/settings/bluetooth/PanProfile.java

@@ -25,14 +25,19 @@ import android.content.Context;
 
 import com.android.settings.R;
 
+import java.util.HashMap;
 import java.util.List;
 
 /**
- * PanProfile handles Bluetooth PAN profile.
+ * PanProfile handles Bluetooth PAN profile (NAP and PANU).
  */
 final class PanProfile implements LocalBluetoothProfile {
     private BluetoothPan mService;
 
+    // Tethering direction for each device
+    private final HashMap<BluetoothDevice, Integer> mDeviceRoleMap =
+            new HashMap<BluetoothDevice, Integer>();
+
     static final String NAME = "PAN";
 
     // Order of this profile in device profiles list
@@ -111,8 +116,12 @@ final class PanProfile implements LocalBluetoothProfile {
         return R.string.bluetooth_profile_pan;
     }
 
-    public int getDisconnectResource() {
-        return R.string.bluetooth_disconnect_pan_profile;
+    public int getDisconnectResource(BluetoothDevice device) {
+        if (isLocalRoleNap(device)) {
+            return R.string.bluetooth_disconnect_pan_nap_profile;
+        } else {
+            return R.string.bluetooth_disconnect_pan_user_profile;
+        }
     }
 
     public int getSummaryResourceForDevice(BluetoothDevice device) {
@@ -122,7 +131,11 @@ final class PanProfile implements LocalBluetoothProfile {
                 return R.string.bluetooth_pan_profile_summary_use_for;
 
             case BluetoothProfile.STATE_CONNECTED:
-                return R.string.bluetooth_pan_profile_summary_connected;
+                if (isLocalRoleNap(device)) {
+                    return R.string.bluetooth_pan_nap_profile_summary_connected;
+                } else {
+                    return R.string.bluetooth_pan_user_profile_summary_connected;
+                }
 
             default:
                 return Utils.getConnectionStateSummary(state);
@@ -132,4 +145,17 @@ final class PanProfile implements LocalBluetoothProfile {
     public int getDrawableResource(BluetoothClass btClass) {
         return R.drawable.ic_bt_network_pan;
     }
+
+    // Tethering direction determines UI strings.
+    void setLocalRole(BluetoothDevice device, int role) {
+        mDeviceRoleMap.put(device, role);
+    }
+
+    boolean isLocalRoleNap(BluetoothDevice device) {
+        if (mDeviceRoleMap.containsKey(device)) {
+            return mDeviceRoleMap.get(device) == BluetoothPan.LOCAL_NAP_ROLE;
+        } else {
+            return false;
+        }
+    }
 }