Add context to customization class constructors

Context may be needed to obtain extra information.

Also fix bug where exception is thrown when
MediaKeyDispatcher#getOverriddenKeyEvents is not overridden in the
custom MediaKeyDispatcher class.

Bug: 168579449
Test: build and manually check that custom classes are being
      instantiated through reflection.
Change-Id: I248c5842dc8675d3fbe5699cfc7174d10a4d7188

services/core/java/com/android/server/media/MediaKeyDispatcher.java

@@ -20,6 +20,7 @@ import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.app.PendingIntent;
+import android.content.Context;
 import android.media.session.ISessionManager;
 import android.media.session.MediaSession;
 import android.os.Binder;
@@ -60,7 +61,7 @@ public abstract class MediaKeyDispatcher {
 
     private Map<Integer, Integer> mOverriddenKeyEvents;
 
-    public MediaKeyDispatcher() {
+    public MediaKeyDispatcher(Context context) {
         // Constructor used for reflection
         mOverriddenKeyEvents = new HashMap<>();
         mOverriddenKeyEvents.put(KeyEvent.KEYCODE_MEDIA_PLAY, 0);

services/core/java/com/android/server/media/MediaSessionService.java

@@ -96,7 +96,6 @@ import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 /**
  * System implementation of MediaSessionManager
@@ -152,7 +151,6 @@ public class MediaSessionService extends SystemService implements Monitor {
 
     private SessionPolicyProvider mCustomSessionPolicyProvider;
     private MediaKeyDispatcher mCustomMediaKeyDispatcher;
-    private Map<Integer, Integer> mOverriddenKeyEventsMap;
 
     public MediaSessionService(Context context) {
         super(context);
@@ -771,7 +769,6 @@ public class MediaSessionService extends SystemService implements Monitor {
     private void instantiateCustomDispatcher(String nameFromTesting) {
         synchronized (mLock) {
             mCustomMediaKeyDispatcher = null;
-            mOverriddenKeyEventsMap = null;
 
             String customDispatcherClassName = (nameFromTesting == null)
                     ? mContext.getResources().getString(R.string.config_customMediaKeyDispatcher)
@@ -779,9 +776,10 @@ public class MediaSessionService extends SystemService implements Monitor {
             try {
                 if (!TextUtils.isEmpty(customDispatcherClassName)) {
                     Class customDispatcherClass = Class.forName(customDispatcherClassName);
-                    Constructor constructor = customDispatcherClass.getDeclaredConstructor();
-                    mCustomMediaKeyDispatcher = (MediaKeyDispatcher) constructor.newInstance();
-                    mOverriddenKeyEventsMap = mCustomMediaKeyDispatcher.getOverriddenKeyEvents();
+                    Constructor constructor =
+                            customDispatcherClass.getDeclaredConstructor(Context.class);
+                    mCustomMediaKeyDispatcher =
+                            (MediaKeyDispatcher) constructor.newInstance(mContext);
                 }
             } catch (ClassNotFoundException | InstantiationException | InvocationTargetException
                     | IllegalAccessException | NoSuchMethodException e) {
@@ -801,9 +799,10 @@ public class MediaSessionService extends SystemService implements Monitor {
             try {
                 if (!TextUtils.isEmpty(customProviderClassName)) {
                     Class customProviderClass = Class.forName(customProviderClassName);
-                    Constructor constructor = customProviderClass.getDeclaredConstructor();
+                    Constructor constructor =
+                            customProviderClass.getDeclaredConstructor(Context.class);
                     mCustomSessionPolicyProvider =
-                            (SessionPolicyProvider) constructor.newInstance();
+                            (SessionPolicyProvider) constructor.newInstance(mContext);
                 }
             } catch (ClassNotFoundException | InstantiationException | InvocationTargetException
                     | IllegalAccessException | NoSuchMethodException e) {
@@ -2398,9 +2397,12 @@ public class MediaSessionService extends SystemService implements Monitor {
                     return;
                 }
 
-                int overriddenKeyEvents = (mCustomMediaKeyDispatcher == null) ? 0
-                        : mCustomMediaKeyDispatcher.getOverriddenKeyEvents()
-                                .get(keyEvent.getKeyCode());
+                int overriddenKeyEvents = 0;
+                if (mCustomMediaKeyDispatcher == null
+                        && mCustomMediaKeyDispatcher.getOverriddenKeyEvents() != null) {
+                    overriddenKeyEvents = mCustomMediaKeyDispatcher.getOverriddenKeyEvents()
+                            .get(keyEvent.getKeyCode());
+                }
                 cancelTrackingIfNeeded(packageName, pid, uid, asSystemService, keyEvent,
                         needWakeLock, opPackageName, stream, musicOnly, overriddenKeyEvents);
                 if (!needTracking(keyEvent, overriddenKeyEvents)) {

services/core/java/com/android/server/media/SessionPolicyProvider.java

@@ -18,6 +18,7 @@ package com.android.server.media;
 
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.content.Context;
 import android.media.session.MediaSession;
 
 import java.lang.annotation.Retention;
@@ -54,7 +55,7 @@ public abstract class SessionPolicyProvider {
      */
     static final int SESSION_POLICY_IGNORE_BUTTON_SESSION = 1 << 1;
 
-    public SessionPolicyProvider() {
+    public SessionPolicyProvider(Context context) {
         // Constructor used for reflection
     }