ExtViews: Add action and meta-data

Services that extend KeyguardExternalViewProviderService should also
include this newly defined action in an intent-filter within the
<service> tag in their AndroidManifest.xml.  These services can also
include meta-data that defines a configuration xml which will be used
to define a settings activity that can be launched within a yet to
be defined settings/configuration UI.

Change-Id: I0a5ca09cf6f63413d067f89a9757137102dd09f6
TICKET: CYNGNOS-1687

samples/externalviews/keyguardviewprovider/AndroidManifest.xml

@@ -27,6 +27,13 @@
     <application android:label="@string/app_name" android:icon="@drawable/ic_launcher">
         <service android:name=".SampleKeyguardProviderService"
                 android:exported="true">
+            <intent-filter>
+                <action android:name="cyanogenmod.externalviews.KeyguardExternalViewProviderService" />
+            </intent-filter>
+            <meta-data
+                android:name="cyanogenmod.externalviews.keyguard"
+                android:resource="@xml/mylockscreen" />
         </service>
+        <activity android:name=".Settings" />
     </application>
 </manifest>

samples/externalviews/keyguardviewprovider/res/xml/mylockscreen.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<lockscreen xmlns:android="http://schemas.android.com/apk/res/android"
+    android:settingsActivity="org.cyanogenmod.samples.keyguardextview.Settings"/>

samples/externalviews/keyguardviewprovider/src/org/cyanogenmod/samples/keyguardextview/Settings.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod 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 org.cyanogenmod.samples.keyguardextview;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+public class Settings extends Activity {
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main);
+    }
+}

src/java/cyanogenmod/externalviews/KeyguardExternalViewProviderService.java

@@ -57,6 +57,26 @@ public abstract class KeyguardExternalViewProviderService extends Service {
     private static final String TAG = KeyguardExternalViewProviderService.class.getSimpleName();
     private static final boolean DEBUG = false;
 
+    /**
+     * The action that must be declared as handled by this service.
+     *
+     * <p>{@code
+     *  <intent-filter>
+     *      <action android:name="cyanogenmod.externalviews.KeyguardExternalViewProviderService"/>
+     *  </intent-filter>
+     *}</p>
+     */
+    public static final String SERVICE_INTERFACE =
+            "cyanogenmod.externalviews.KeyguardExternalViewProviderService";
+
+    /**
+     * Name under which an external keyguard view publishes information about itself.
+     * This meta-data must reference an XML resource containing
+     * a <code>&lt;lockscreen&gt;</code>
+     * tag.
+     */
+    public static final String META_DATA = "cyanogenmod.externalviews.keyguard";
+
     private WindowManager mWindowManager;
     private final Handler mHandler = new Handler();