Added AppLaunchEventsPlugin which relays app launch/dismiss events to

all connected plugins.
Listener for this plugin is added in PredictionAppTracker which receives
all app events.

Change-Id: Iec53d20272f6a587f78e3d84666efa4f02cf6962

src_plugins/com/android/systemui/plugins/AppLaunchEventsPlugin.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2019 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.systemui.plugins;
+
+import android.content.ComponentName;
+import android.os.UserHandle;
+
+import com.android.systemui.plugins.annotations.ProvidesInterface;
+
+/**
+ * Plugin interface which sends app launch events.
+ */
+@ProvidesInterface(action = AppLaunchEventsPlugin.ACTION, version = AppLaunchEventsPlugin.VERSION)
+public interface AppLaunchEventsPlugin extends Plugin {
+    String ACTION = "com.android.systemui.action.PLUGIN_APP_EVENTS";
+    int VERSION = 1;
+
+    /**
+     * Receives onStartShortcut event from
+     * {@link com.android.launcher3.appprediction.PredictionAppTracker}.
+     */
+    void onStartShortcut(String packageName, String shortcutId, UserHandle user, String container);
+
+    /**
+     * Receives onStartApp event from
+     * {@link com.android.launcher3.appprediction.PredictionAppTracker}.
+     */
+    void onStartApp(ComponentName componentName, UserHandle user, String container);
+
+    /**
+     * Receives onDismissApp event from
+     * {@link com.android.launcher3.appprediction.PredictionAppTracker}.
+     */
+    void onDismissApp(ComponentName componentName, UserHandle user, String container);
+
+    /**
+     * Receives onReturnedToHome event from
+     * {@link com.android.launcher3.appprediction.PredictionAppTracker}.
+     */
+    void onReturnedToHome();
+}