Add connect to McuMgrTransport for use in FirmwareUpgradeManager. (#37)

Author: bgiori

mcumgr-ble/src/main/java/io/runtime/mcumgr/ble/McuMgrBleTransport.java

@@ -13,6 +13,7 @@
 import android.content.Context;
 import android.os.Build;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.Log;
 
 import org.slf4j.Logger;
@@ -382,6 +383,57 @@ public void onRequestFailed(@NonNull final BluetoothDevice device, final int sta
         .enqueue();
     }
 
+    @Override
+    public void connect(@Nullable final ConnectionCallback callback) {
+        if (isConnected()) {
+            if (callback != null) {
+                callback.onConnected();
+            }
+            return;
+        }
+        connect(mDevice)
+                .retry(3, 100)
+                .done(new SuccessCallback() {
+                    @Override
+                    public void onRequestCompleted(@NonNull BluetoothDevice device) {
+                        notifyConnected();
+                        if (callback == null) {
+                            return;
+                        }
+                        callback.onConnected();
+                    }
+                })
+                .fail(new FailCallback() {
+                    @Override
+                    public void onRequestFailed(@NonNull BluetoothDevice device, int status) {
+                        if (callback == null) {
+                            return;
+                        }
+                        switch (status) {
+                            case REASON_DEVICE_DISCONNECTED:
+                                callback.onError(new McuMgrException("Device has disconnected"));
+                                break;
+                            case REASON_DEVICE_NOT_SUPPORTED:
+                                callback.onError(new McuMgrException("Device does not support SMP Service"));
+                                break;
+                            case REASON_REQUEST_FAILED:
+                                // This could be thrown only if the manager was requested to connect for
+                                // a second time and to a different device than the one that's already
+                                // connected. This may not happen here.
+                                callback.onError(new McuMgrException("Other device already connected"));
+                                break;
+                            case REASON_BLUETOOTH_DISABLED:
+                                callback.onError(new McuMgrException("Bluetooth adapter disabled"));
+                                break;
+                            default:
+                                callback.onError(new McuMgrException(GattError.parseConnectionError(status)));
+                                break;
+                        }
+                    }
+                })
+                .enqueue();
+    }
+
     @Override
     public void release() {
         disconnect().enqueue();

mcumgr-core/src/main/java/io/runtime/mcumgr/McuMgrTransport.java

@@ -8,6 +8,7 @@
 package io.runtime.mcumgr;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import io.runtime.mcumgr.exception.McuMgrException;
 import io.runtime.mcumgr.response.McuMgrResponse;
@@ -20,18 +21,52 @@
  */
 public interface McuMgrTransport {
 
+    /**
+     * Receives connection state changes independent of explicit calls to
+     * {@link #connect} or {@link #release}.
+     * <p>
+     * To add or remove an observer, use {@link #addObserver} and
+     * {@link #removeObserver} respectively.
+     */
     interface ConnectionObserver {
         /**
-         * A method called when the connection to the device has been established.
+         * Called when the connection to the device has been established.
          */
         void onConnected();
 
         /**
-         * A method called when the connection to the device has been lost.
+         * Called when the connection to the device has been lost.
          */
         void onDisconnected();
     }
 
+    /**
+     * Receives callbacks from an explicit call to {@link #connect}.
+     */
+    interface ConnectionCallback {
+        /**
+         * Called when connection attempt succeeds or is already open when {@link #connect} is
+         * called.
+         */
+        void onConnected();
+
+        /**
+         * Called when the transporter has decided not to connect to the transporter at this time.
+         *
+         * This method is useful for transporters who do not wish to allow the caller of
+         * {@link #connect} to manage the connection or would rather wait to connect until
+         * necessary.
+         */
+        void onDeferred();
+
+        /**
+         * Called when the connection attempt has failed.
+         *
+         * @param t The connection failure reason.
+         */
+        void onError(@NotNull Throwable t);
+    }
+
     /**
      * Gets the scheme for this transport (see {@link McuMgrScheme}).
      *
@@ -51,8 +86,7 @@ interface ConnectionObserver {
      * @throws McuMgrException thrown on error. Set the cause of the error if caused by a different
      *                         type of exception.
      */
-    @NotNull
-    <T extends McuMgrResponse> T send(@NotNull byte[] payload, @NotNull Class<T> responseType)
+    @NotNull <T extends McuMgrResponse> T send(@NotNull byte[] payload, @NotNull Class<T> responseType)
             throws McuMgrException;
 
     /**
@@ -68,6 +102,14 @@ <T extends McuMgrResponse> T send(@NotNull byte[] payload, @NotNull Class<T> res
     <T extends McuMgrResponse> void send(@NotNull byte[] payload, @NotNull Class<T> responseType,
                                          @NotNull McuMgrCallback<T> callback);
 
+    /**
+     * Connect the transporter to the remote device. The callback must be called if supplied, even
+     * if the transport connection is already opened.
+     *
+     * @param callback An optional callback to receive the result of the connection attempt.
+     */
+    void connect(@Nullable ConnectionCallback callback);
+
     /**
      * Releases the transport connection. When the connection is already closed this method does
      * nothing.