Android: Make `Just Works` bonding really work

In case bond state has been changed due to access to a restricted handle,
Android never completes the operation which triggered the devices to bind
and thus never fires on(Characteristic|Descriptor)(Read|Write) callback,
causing TimeoutRunnable to interrupt pending job,
albeit the read/write job hasn't been actually executed by the peripheral;
re-add the currently pending job to the queue's head and re-run it.

Change-Id: Idd69c885a439a26e2819746d703a92778370e4ba
Reviewed-by: Evgeniy Gagarin <eeiaao@gmail.com>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>
(cherry picked from commit b7b40e4222999be5eed5da3239886329c84bf731)

1 files changed, 66 insertions, 0 deletions

diff --git a/src/android/bluetooth/src/org/qtproject/qt5/android/bluetooth/QtBluetoothLE.java b/src/android/bluetooth/src/org/qtproject/qt5/android/bluetooth/QtBluetoothLE.java
index e9717a1d..96243af8 100644
--- a/src/android/bluetooth/src/org/qtproject/qt5/android/bluetooth/QtBluetoothLE.java
+++ b/src/android/bluetooth/src/org/qtproject/qt5/android/bluetooth/QtBluetoothLE.java
@@ -52,7 +52,10 @@ import android.bluetooth.le.ScanCallback;
 import android.bluetooth.le.ScanFilter;
 import android.bluetooth.le.ScanResult;
 import android.bluetooth.le.ScanSettings;
+import android.content.BroadcastReceiver;
 import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
 import android.os.Build;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -125,6 +128,60 @@ public class QtBluetoothLE {
         private int pendingJobHandle = -1;
     };
 
+    // In case bond state has been changed due to access to a restricted handle,
+    // Android never completes the operation which triggered the devices to bind
+    // and thus never fires on(Characteristic|Descriptor)(Read|Write) callback,
+    // causing TimeoutRunnable to interrupt pending job,
+    // albeit the read/write job hasn't been actually executed by the peripheral;
+    // re-add the currently pending job to the queue's head and re-run it.
+    // If, by some reason, bonding process has been interrupted, either
+    // re-add the currently pending job to the queue's head and re-run it.
+    private class BondStateBroadcastReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (mBluetoothGatt == null)
+                return;
+
+            final BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
+            if (device == null || !device.getAddress().equals(mBluetoothGatt.getDevice().getAddress()))
+                return;
+
+            final int bondState = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE, -1);
+            final int previousBondState = intent.getIntExtra(BluetoothDevice.EXTRA_PREVIOUS_BOND_STATE, -1);
+
+            if (bondState == BluetoothDevice.BOND_BONDING) {
+                    synchronized (readWriteQueue) {
+                        if (pendingJob == null || pendingJob.jobType == IoJobType.Mtu)
+                            return;
+                    }
+
+                    timeoutHandler.removeCallbacksAndMessages(null);
+                    handleForTimeout.set(HANDLE_FOR_RESET);
+            } else if (previousBondState == BluetoothDevice.BOND_BONDING && (bondState == BluetoothDevice.BOND_BONDED || bondState == BluetoothDevice.BOND_NONE)) {
+                    synchronized (readWriteQueue) {
+                        if (pendingJob == null || pendingJob.jobType == IoJobType.Mtu)
+                            return;
+
+                        readWriteQueue.addFirst(pendingJob);
+                        pendingJob = null;
+                    }
+
+                    performNextIO();
+            } else if (previousBondState == BluetoothDevice.BOND_BONDED && bondState == BluetoothDevice.BOND_NONE) {
+                // peripheral or central removed the bond information;
+                // if it was peripheral, the connection attempt would fail with PIN_OR_KEY_MISSING,
+                // which is handled by Android by broadcasting ACTION_BOND_STATE_CHANGED
+                // with new state BOND_NONE, without actually deleting the bond information :facepalm:
+                // if we get there, it is safer to delete it now, by invoking the undocumented API call
+                try {
+                    device.getClass().getMethod("removeBond").invoke(device);
+                } catch (Exception ex) {
+                    ex.printStackTrace();
+                }
+            }
+        }
+    };
+    private BroadcastReceiver bondStateBroadcastReceiver = null;
 
     /* Pointer to the Qt object that "owns" the Java object */
     @SuppressWarnings({"CanBeFinal", "WeakerAccess"})
@@ -218,6 +275,11 @@ public class QtBluetoothLE {
             //This must be in sync with QLowEnergyController::ControllerState
             switch (newState) {
                 case BluetoothProfile.STATE_DISCONNECTED:
+                    if (bondStateBroadcastReceiver != null) {
+                        qtContext.unregisterReceiver(bondStateBroadcastReceiver);
+                        bondStateBroadcastReceiver = null;
+                    }
+
                     qLowEnergyController_State = 0;
                     // we disconnected -> get rid of data from previous run
                     resetData();
@@ -233,6 +295,10 @@ public class QtBluetoothLE {
                     mBluetoothGatt = null;
                     break;
                 case BluetoothProfile.STATE_CONNECTED:
+                    if (bondStateBroadcastReceiver == null) {
+                        bondStateBroadcastReceiver = new BondStateBroadcastReceiver();
+                        qtContext.registerReceiver(bondStateBroadcastReceiver, new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED));
+                    }
                     qLowEnergyController_State = 2;
             }