Add workarounds for Honor devices

Audio did not work on Honor devices.

Two workarounds are necessary:
 - a system context must be set as a base context of FakeContext (so
   that a PackageManager is available),
 - the same workaround as for Meizu phones must also be applied (so that
   ActivityThread.currentApplication() return a valid instance).

These workarounds must not be applied for all devices, they cause other
issues.

Fixes #4015 <https://github.com/Genymobile/scrcpy/issues/4015>
Refs #3085 <https://github.com/Genymobile/scrcpy/issues/3805>

Co-authored-by: Simon Chan <1330321+yume-chan@users.noreply.github.com>

server/src/main/java/com/genymobile/scrcpy/FakeContext.java

@@ -1,42 +1,24 @@
 package com.genymobile.scrcpy;
 
-import com.genymobile.scrcpy.wrappers.ActivityThread;
-
 import android.annotation.TargetApi;
 import android.content.AttributionSource;
-import android.content.Context;
-import android.content.ContextWrapper;
+import android.content.MutableContextWrapper;
 import android.os.Build;
 import android.os.Process;
 
-import java.lang.reflect.Method;
-
-public final class FakeContext extends ContextWrapper {
+public final class FakeContext extends MutableContextWrapper {
 
     public static final String PACKAGE_NAME = "com.android.shell";
     public static final int ROOT_UID = 0; // Like android.os.Process.ROOT_UID, but before API 29
 
     private static final FakeContext INSTANCE = new FakeContext();
 
-    private static Context retrieveSystemContext() {
-        try {
-            Class<?> activityThreadClass = ActivityThread.getActivityThreadClass();
-            Object activityThread = ActivityThread.getActivityThread();
-
-            Method getSystemContextMethod = activityThreadClass.getDeclaredMethod("getSystemContext");
-            return (Context) getSystemContextMethod.invoke(activityThread);
-        } catch (Exception e) {
-            Ln.e("Cannot retrieve system context", e);
-            return null;
-        }
-    }
-
     public static FakeContext get() {
         return INSTANCE;
     }
 
     private FakeContext() {
-        super(retrieveSystemContext());
+        super(null);
     }
 
     @Override

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -101,15 +101,23 @@ public final class Server {
 
         Workarounds.prepareMainLooper();
 
-        // Workarounds must be applied for Meizu phones:
-        //  - <https://github.com/Genymobile/scrcpy/issues/240>
-        //  - <https://github.com/Genymobile/scrcpy/issues/365>
-        //  - <https://github.com/Genymobile/scrcpy/issues/2656>
-        //
-        // But only apply when strictly necessary, since workarounds can cause other issues:
-        //  - <https://github.com/Genymobile/scrcpy/issues/940>
-        //  - <https://github.com/Genymobile/scrcpy/issues/994>
-        if (Build.BRAND.equalsIgnoreCase("meizu") || Build.BRAND.equalsIgnoreCase("honor")) {
+        if (Build.BRAND.equalsIgnoreCase("meizu")) {
+            // Workarounds must be applied for Meizu phones:
+            //  - <https://github.com/Genymobile/scrcpy/issues/240>
+            //  - <https://github.com/Genymobile/scrcpy/issues/365>
+            //  - <https://github.com/Genymobile/scrcpy/issues/2656>
+            //
+            // But only apply when strictly necessary, since workarounds can cause other issues:
+            //  - <https://github.com/Genymobile/scrcpy/issues/940>
+            //  - <https://github.com/Genymobile/scrcpy/issues/994>
+            Workarounds.fillAppInfo();
+        } else if (Build.BRAND.equalsIgnoreCase("honor")) {
+            // Honor devices require both a system context (as a base context of FakeContext) and the same workarounds as for Meizu phones:
+            //  - <https://github.com/Genymobile/scrcpy/issues/4015>
+            // The system context must not be set for all devices, it would cause other problems:
+            //  - <https://github.com/Genymobile/scrcpy/issues/4015#issuecomment-1595382142>
+            //  - <https://github.com/Genymobile/scrcpy/issues/3805#issuecomment-1596148031>
+            Workarounds.fillBaseContext();
             Workarounds.fillAppInfo();
         }
 

server/src/main/java/com/genymobile/scrcpy/Workarounds.java

@@ -1,11 +1,10 @@
 package com.genymobile.scrcpy;
 
-import com.genymobile.scrcpy.wrappers.ActivityThread;
-
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.app.Application;
 import android.content.AttributionSource;
+import android.content.Context;
 import android.content.ContextWrapper;
 import android.content.pm.ApplicationInfo;
 import android.media.AudioAttributes;
@@ -22,7 +21,9 @@ import java.lang.reflect.Method;
 
 public final class Workarounds {
 
-    private static boolean activityThreadFilled;
+    private static Class<?> activityThreadClass;
+    private static Object activityThread;
+    private static boolean currentActivityThreadInitialized;
 
     private Workarounds() {
         // not instantiable
@@ -42,17 +43,26 @@ public final class Workarounds {
     }
 
     @SuppressLint("PrivateApi,DiscouragedPrivateApi")
-    private static void fillActivityThread() throws Exception {
-        if (!activityThreadFilled) {
-            Class<?> activityThreadClass = ActivityThread.getActivityThreadClass();
-            Object activityThread = ActivityThread.getActivityThread();
+    private static void initActivityThread() throws Exception {
+        if (activityThread == null) {
+            // ActivityThread activityThread = new ActivityThread();
+            activityThreadClass = Class.forName("android.app.ActivityThread");
+            Constructor<?> activityThreadConstructor = activityThreadClass.getDeclaredConstructor();
+            activityThreadConstructor.setAccessible(true);
+            activityThread = activityThreadConstructor.newInstance();
+        }
+    }
 
+    @SuppressLint("PrivateApi,DiscouragedPrivateApi")
+    private static void fillActivityThread() throws Exception {
+        initActivityThread();
+
+        if (!currentActivityThreadInitialized) {
             // ActivityThread.sCurrentActivityThread = activityThread;
             Field sCurrentActivityThreadField = activityThreadClass.getDeclaredField("sCurrentActivityThread");
             sCurrentActivityThreadField.setAccessible(true);
             sCurrentActivityThreadField.set(null, activityThread);
-
-            activityThreadFilled = true;
+            currentActivityThreadInitialized = true;
         }
     }
 
@@ -75,9 +85,6 @@ public final class Workarounds {
             appInfoField.setAccessible(true);
             appInfoField.set(appBindData, applicationInfo);
 
-            Class<?> activityThreadClass = ActivityThread.getActivityThreadClass();
-            Object activityThread = ActivityThread.getActivityThread();
-
             // activityThread.mBoundApplication = appBindData;
             Field mBoundApplicationField = activityThreadClass.getDeclaredField("mBoundApplication");
             mBoundApplicationField.setAccessible(true);
@@ -98,9 +105,6 @@ public final class Workarounds {
             baseField.setAccessible(true);
             baseField.set(app, FakeContext.get());
 
-            Class<?> activityThreadClass = ActivityThread.getActivityThreadClass();
-            Object activityThread = ActivityThread.getActivityThread();
-
             // activityThread.mInitialApplication = app;
             Field mInitialApplicationField = activityThreadClass.getDeclaredField("mInitialApplication");
             mInitialApplicationField.setAccessible(true);
@@ -111,6 +115,19 @@ public final class Workarounds {
         }
     }
 
+    public static void fillBaseContext() {
+        try {
+            initActivityThread();
+
+            Method getSystemContextMethod = activityThreadClass.getDeclaredMethod("getSystemContext");
+            Context context = (Context) getSystemContextMethod.invoke(activityThread);
+            FakeContext.get().setBaseContext(context);
+        } catch (Throwable throwable) {
+            // this is a workaround, so failing is not an error
+            Ln.d("Could not fill base context: " + throwable.getMessage());
+        }
+    }
+
     @TargetApi(Build.VERSION_CODES.R)
     @SuppressLint("WrongConstant,MissingPermission,BlockedPrivateApi,SoonBlockedPrivateApi,DiscouragedPrivateApi")
     public static AudioRecord createAudioRecord(int source, int sampleRate, int channelConfig, int channels, int channelMask, int encoding) {

server/src/main/java/com/genymobile/scrcpy/wrappers/ActivityThread.java

@@ -1,32 +0,0 @@
-package com.genymobile.scrcpy.wrappers;
-
-import java.lang.reflect.Constructor;
-
-public class ActivityThread {
-
-    private static final Class<?> activityThreadClass;
-    private static final Object activityThread;
-
-    static {
-        try {
-            activityThreadClass = Class.forName("android.app.ActivityThread");
-            Constructor<?> activityThreadConstructor = activityThreadClass.getDeclaredConstructor();
-            activityThreadConstructor.setAccessible(true);
-            activityThread = activityThreadConstructor.newInstance();
-        } catch (Exception e) {
-            throw new AssertionError(e);
-        }
-    }
-
-    private ActivityThread() {
-        // only static methods
-    }
-
-    public static Object getActivityThread() {
-        return activityThread;
-    }
-
-    public static Class<?> getActivityThreadClass() {
-        return activityThreadClass;
-    }
-}