Adding a CallService & CallServiceProvider concrete classes.

First step in no longer using ICallService and ICallServiceProviders
directly.
Adds a generic ServiceBinder class to manage binding/unbinding.

Change-Id: I7d26958dd85a99316dbd5e70caba3fd91d35911b
diff --git a/src/com/android/telecomm/CallServiceProviderWrapper.java b/src/com/android/telecomm/CallServiceProviderWrapper.java
new file mode 100644
index 0000000..044d370
--- /dev/null
+++ b/src/com/android/telecomm/CallServiceProviderWrapper.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2014, 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.telecomm;
+
+import android.content.ComponentName;
+import android.os.Binder;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.telecomm.ICallServiceLookupResponse;
+import android.telecomm.ICallServiceProvider;
+import android.util.Log;
+
+/**
+ * Wrapper for {@link ICallServiceProvider}s, handles binding to {@link ICallServiceProvider} and
+ * keeps track of when the object can safely be unbound. Other classes should not use
+ * {@link ICallServiceProvider} directly and instead should use this class to invoke methods of
+ * {@link ICallServiceProvider}.
+ * TODO(santoscordon): Keep track of when the service can be safely unbound.
+ * TODO(santoscordon): Look into combining with android.telecomm.CallServiceProvider.
+ */
+public class CallServiceProviderWrapper extends ServiceBinder<ICallServiceProvider> {
+    /**
+     * The service action used to bind to ICallServiceProvider implementations.
+     * TODO(santoscordon): Move this to TelecommConstants.
+     */
+    static final String CALL_SERVICE_PROVIDER_ACTION = ICallServiceProvider.class.getName();
+
+    private static final String TAG = CallServiceProviderWrapper.class.getSimpleName();
+
+    /** The actual service implementation. */
+    private ICallServiceProvider mServiceInterface;
+
+    /**
+     * The class to notify when the binding succeeds or fails.
+     */
+    private final CallServiceFinder mFinder;
+
+    /**
+     * Creates a call-service provider for the specified component.
+     */
+    public CallServiceProviderWrapper(ComponentName componentName, CallServiceFinder finder) {
+        super(CALL_SERVICE_PROVIDER_ACTION, componentName);
+        mFinder = finder;
+    }
+
+    /** {@inheritDoc} */
+    @Override public void handleSuccessfulConnection(IBinder binder) {
+        mServiceInterface = ICallServiceProvider.Stub.asInterface(binder);
+        mFinder.registerProvider(getComponentName(), this);
+    }
+
+    /** {@inheritDoc} */
+    @Override public void handleFailedConnection() {
+        mFinder.unregisterProvider(getComponentName());
+        // TODO(santoscordon): Notify CallServiceFinder.
+    }
+
+    /** {@inheritDoc} */
+    @Override public void handleServiceDisconnected() {
+        mServiceInterface = null;
+        // TODO(santoscordon): fill in.
+    }
+
+    /** See {@link ICallServiceProvider#lookupCallServices}. */
+    public void lookupCallServices(ICallServiceLookupResponse response) {
+        try {
+            if (mServiceInterface == null) {
+                Log.wtf(TAG, "lookupCallServices() invoked while the service is unbound.");
+            } else {
+                mServiceInterface.lookupCallServices(response);
+            }
+        } catch (RemoteException e) {
+            Log.e(TAG, "Failed to lookupCallServices.", e);
+        }
+    }
+}