Add new public API to allow call screening

This CL adds a new service that the default dialer can implement to
screen incoming calls.

If the service is implemented then Telecom uses it to decide if a call
should be shown to the user or rejected.

Note, I initially tried to simply extend InCallService instead of
creating a whole new service. The problem with this approach is that:
  - this breaks some in call services which show UI as soon as they are
    bound to
  - the in call service lifecycle is tightly coupled to adding and
    removing calls. Call screening happens before a call is added which
    makes it a bad fit to in call service
  - call screening is a function of only the default dialer's in call
    service but the existing code also binds to "controller" call
    services

For these reasons it seemed simpler to just create a new optional
service.

BUG: 22857261
Change-Id: I53f2ef93360e0af19b6ce45af21026be6cf3a7f3
diff --git a/telecomm/java/android/telecom/Call.java b/telecomm/java/android/telecom/Call.java
index 3859294..de902025 100644
--- a/telecomm/java/android/telecom/Call.java
+++ b/telecomm/java/android/telecom/Call.java
@@ -265,6 +265,7 @@
         // Next PROPERTY value: 0x00000040
         //******************************************************************************************
 
+        private final String mTelecomCallId;
         private final Uri mHandle;
         private final int mHandlePresentation;
         private final String mCallerDisplayName;
@@ -414,6 +415,11 @@
             return builder.toString();
         }
 
+        /** {@hide} */
+        public String getTelecomCallId() {
+            return mTelecomCallId;
+        }
+
         /**
          * @return The handle (e.g., phone number) to which the {@code Call} is currently
          * connected.
@@ -567,6 +573,7 @@
 
         /** {@hide} */
         public Details(
+                String telecomCallId,
                 Uri handle,
                 int handlePresentation,
                 String callerDisplayName,
@@ -581,6 +588,7 @@
                 StatusHints statusHints,
                 Bundle extras,
                 Bundle intentExtras) {
+            mTelecomCallId = telecomCallId;
             mHandle = handle;
             mHandlePresentation = handlePresentation;
             mCallerDisplayName = callerDisplayName;
@@ -596,6 +604,26 @@
             mExtras = extras;
             mIntentExtras = intentExtras;
         }
+
+        /** {@hide} */
+        public static Details createFromParcelableCall(ParcelableCall parcelableCall) {
+            return new Details(
+                    parcelableCall.getId(),
+                    parcelableCall.getHandle(),
+                    parcelableCall.getHandlePresentation(),
+                    parcelableCall.getCallerDisplayName(),
+                    parcelableCall.getCallerDisplayNamePresentation(),
+                    parcelableCall.getAccountHandle(),
+                    parcelableCall.getCapabilities(),
+                    parcelableCall.getProperties(),
+                    parcelableCall.getDisconnectCause(),
+                    parcelableCall.getConnectTimeMillis(),
+                    parcelableCall.getGatewayInfo(),
+                    parcelableCall.getVideoState(),
+                    parcelableCall.getStatusHints(),
+                    parcelableCall.getExtras(),
+                    parcelableCall.getIntentExtras());
+        }
     }
 
     public static abstract class Callback {
@@ -1022,21 +1050,7 @@
     /** {@hide} */
     final void internalUpdate(ParcelableCall parcelableCall, Map<String, Call> callIdMap) {
         // First, we update the internal state as far as possible before firing any updates.
-        Details details = new Details(
-                parcelableCall.getHandle(),
-                parcelableCall.getHandlePresentation(),
-                parcelableCall.getCallerDisplayName(),
-                parcelableCall.getCallerDisplayNamePresentation(),
-                parcelableCall.getAccountHandle(),
-                parcelableCall.getCapabilities(),
-                parcelableCall.getProperties(),
-                parcelableCall.getDisconnectCause(),
-                parcelableCall.getConnectTimeMillis(),
-                parcelableCall.getGatewayInfo(),
-                parcelableCall.getVideoState(),
-                parcelableCall.getStatusHints(),
-                parcelableCall.getExtras(),
-                parcelableCall.getIntentExtras());
+        Details details = Details.createFromParcelableCall(parcelableCall);
         boolean detailsChanged = !Objects.equals(mDetails, details);
         if (detailsChanged) {
             mDetails = details;
diff --git a/telecomm/java/android/telecom/CallScreeningService.java b/telecomm/java/android/telecom/CallScreeningService.java
new file mode 100644
index 0000000..1b6e162
--- /dev/null
+++ b/telecomm/java/android/telecom/CallScreeningService.java
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2016 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 android.telecom;
+
+import android.annotation.SdkConstant;
+import android.app.Service;
+import android.content.Intent;
+import android.os.Handler;
+import android.os.IBinder;
+import android.os.Looper;
+import android.os.Message;
+import android.os.RemoteException;
+
+import com.android.internal.os.SomeArgs;
+import com.android.internal.telecom.ICallScreeningService;
+import com.android.internal.telecom.ICallScreeningAdapter;
+
+/**
+ * This service can be implemented by the default dialer (see
+ * {@link TelecomManager#getDefaultDialerPackage()}) to allow or disallow incoming calls before
+ * they are shown to a user.
+ * <p>
+ * Below is an example manifest registration for a {@code CallScreeningService}.
+ * <pre>
+ * {@code
+ * <service android:name="your.package.YourCallScreeningServiceImplementation"
+ *          android:permission="android.permission.BIND_SCREENING_SERVICE">
+ *      <intent-filter>
+ *          <action android:name="android.telecom.CallScreeningService"/>
+ *      </intent-filter>
+ * </service>
+ * }
+ * </pre>
+ */
+public abstract class CallScreeningService extends Service {
+    /**
+     * The {@link Intent} that must be declared as handled by the service.
+     */
+    @SdkConstant(SdkConstant.SdkConstantType.SERVICE_ACTION)
+    public static final String SERVICE_INTERFACE = "android.telecom.CallScreeningService";
+
+    private static final int MSG_SCREEN_CALL = 1;
+
+    private final Handler mHandler = new Handler(Looper.getMainLooper()) {
+        @Override
+        public void handleMessage(Message msg) {
+            switch (msg.what) {
+                case MSG_SCREEN_CALL:
+                    SomeArgs args = (SomeArgs) msg.obj;
+                    try {
+                        mCallScreeningAdapter = (ICallScreeningAdapter) args.arg1;
+                        onScreenCall(
+                                Call.Details.createFromParcelableCall((ParcelableCall) args.arg2));
+                    } finally {
+                        args.recycle();
+                    }
+                    break;
+            }
+        }
+    };
+
+    private final class CallScreeningBinder extends ICallScreeningService.Stub {
+        @Override
+        public void screenCall(ICallScreeningAdapter adapter, ParcelableCall call) {
+            Log.v(this, "screenCall");
+            SomeArgs args = SomeArgs.obtain();
+            args.arg1 = adapter;
+            args.arg2 = call;
+            mHandler.obtainMessage(MSG_SCREEN_CALL, args).sendToTarget();
+        }
+    }
+
+    private ICallScreeningAdapter mCallScreeningAdapter;
+
+    /*
+     * Information about how to respond to an incoming call.
+     */
+    public class CallResponse {
+        private final boolean mShouldDisallowCall;
+        private final boolean mShouldRejectCall;
+        private final boolean mShouldSkipCallLog;
+        private final boolean mShouldSkipNotification;
+
+        private CallResponse(
+                boolean shouldDisallowCall,
+                boolean shouldRejectCall,
+                boolean shouldSkipCallLog,
+                boolean shouldSkipNotification) {
+            if (!shouldDisallowCall
+                    && (shouldRejectCall || shouldSkipCallLog || shouldSkipNotification)) {
+                throw new IllegalStateException("Invalid response state for allowed call.");
+            }
+
+            mShouldDisallowCall = shouldDisallowCall;
+            mShouldRejectCall = shouldRejectCall;
+            mShouldSkipCallLog = shouldSkipCallLog;
+            mShouldSkipNotification = shouldSkipNotification;
+        }
+
+        /*
+         * @return Whether the incoming call should be blocked.
+         */
+        public boolean getDisallowCall() {
+            return mShouldDisallowCall;
+        }
+
+        /*
+         * @return Whether the incoming call should be disconnected as if the user had manually
+         * rejected it.
+         */
+        public boolean getRejectCall() {
+            return mShouldRejectCall;
+        }
+
+        /*
+         * @return Whether the incoming call should not be displayed in the call log.
+         */
+        public boolean getSkipCallLog() {
+            return mShouldSkipCallLog;
+        }
+
+        /*
+         * @return Whether a missed call notification should not be shown for the incoming call.
+         */
+        public boolean getSkipNotification() {
+            return mShouldSkipNotification;
+        }
+
+        public class Builder {
+            private boolean mShouldDisallowCall;
+            private boolean mShouldRejectCall;
+            private boolean mShouldSkipCallLog;
+            private boolean mShouldSkipNotification;
+
+            /*
+             * Sets whether the incoming call should be blocked.
+             */
+            public Builder setDisallowCall(boolean shouldDisallowCall) {
+                mShouldDisallowCall = shouldDisallowCall;
+                return this;
+            }
+
+            /*
+             * Sets whether the incoming call should be disconnected as if the user had manually
+             * rejected it. This property should only be set to true if the call is disallowed.
+             */
+            public Builder setRejectCall(boolean shouldRejectCall) {
+                mShouldRejectCall = shouldRejectCall;
+                return this;
+            }
+
+            /*
+             * Sets whether the incoming call should not be displayed in the call log. This property
+             * should only be set to true if the call is disallowed.
+             */
+            public Builder setSkipCallLog(boolean shouldSkipCallLog) {
+                mShouldSkipCallLog = shouldSkipCallLog;
+                return this;
+            }
+
+            /*
+             * Sets whether a missed call notification should not be shown for the incoming call.
+             * This property should only be set to true if the call is disallowed.
+             */
+            public Builder setSkipNotification(boolean shouldSkipNotification) {
+                mShouldSkipNotification = shouldSkipNotification;
+                return this;
+            }
+
+            public CallResponse build() {
+                return new CallResponse(
+                        mShouldDisallowCall,
+                        mShouldRejectCall,
+                        mShouldSkipCallLog,
+                        mShouldSkipNotification);
+            }
+       }
+    }
+
+    public CallScreeningService() {
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        Log.v(this, "onBind");
+        return new CallScreeningBinder();
+    }
+
+    @Override
+    public boolean onUnbind(Intent intent) {
+        Log.v(this, "onUnbind");
+        return false;
+    }
+
+    /**
+     * Called when a new incoming call is added.
+     * {@link CallScreeningService#respondToCall(Call.Details, CallScreeningService.CallResponse)}
+     * should be called to allow or disallow the call.
+     *
+     * @param callDetails Information about a new incoming call, see {@link Call.Details}.
+     */
+    public abstract void onScreenCall(Call.Details callDetails);
+
+    /**
+     * Responds to the given call, either allowing it or disallowing it.
+     *
+     * @param callDetails The call to allow.
+     * @param response The {@link CallScreeningService.CallResponse} which contains information
+     * about how to respond to a call.
+     */
+    public final void respondToCall(Call.Details callDetails, CallResponse response) {
+        try {
+            if (response.getDisallowCall()) {
+                mCallScreeningAdapter.disallowCall(
+                        callDetails.getTelecomCallId(),
+                        response.getRejectCall(),
+                        !response.getSkipCallLog(),
+                        !response.getSkipNotification());
+            } else {
+                mCallScreeningAdapter.allowCall(callDetails.getTelecomCallId());
+            }
+        } catch (RemoteException e) {
+        }
+    }
+}