Adding call state constants to Telecomm.

Change-Id: I40675477a96c9a74a17782870c5824702466e6cc

telecomm/java/android/telecomm/CallState.java

@@ -0,0 +1,64 @@
+/*
+ * 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 android.telecomm;
+
+/**
+ * Defines call-state constants of the different states in which a call can exist. Although states
+ * have the notion of normal transitions, due to the volatile nature of telephony systems, code
+ * that uses these states should be resilient to unexpected state changes outside of what is
+ * considered traditional.
+ */
+public final class CallState {
+    /**
+     * Indicates that a call is new and not connected. This is used as the default state internally
+     * within Telecomm and should not be used between Telecomm and call services.
+     * @hide
+     */
+    static final int NEW = 1;
+
+    /**
+     * Indicates that a call is outgoing and in the dialing state. A call transitions to this state
+     * once an outgoing call has begun (e.g., user presses the dial button in Dialer). Calls in this
+     * state usually transition to {@link #ACTIVE} if the call was answered or {@link #DISCONNECTED}
+     * if the call was disconnected somehow (e.g., failure or cancellation of the call by the user).
+     */
+    static final int DIALING = 2;
+
+    /**
+     * Indicates that a call is incoming and the user still has the option of answering, rejecting,
+     * or doing nothing with the call. This state is usually associated with some type of audible
+     * ringtone. Normal transitions are to {@link #ACTIVE} if answered or {@link #DISCONNECTED}
+     * otherwise.
+     */
+    static final int RINGING = 3;
+
+    /**
+     * Indicates that a call is currently connected to another party and a communication channel is
+     * open between them. The normal transition to this state is by the user answering a
+     * {@link #DIALING} call or a {@link #RINGING} call being answered by the other party.
+     */
+    static final int ACTIVE = 4;
+
+    /**
+     * Indicates that a call is currently disconnected. All states can transition to this state
+     * by the call service giving notice that the connection has been severed. When the user
+     * explicitly ends a call, it will not transition to this state until the call service confirms
+     * the disconnection or communication was lost to the call service currently responsible for
+     * this call (e.g., call service crashes).
+     */
+    static final int DISCONNECTED = 5;
+}