Deconstructed APK prototyping

apk/hijack/org/chromium/deconstructed/ResourceInstaller.java

+package org.chromium.deconstructed;
+
+import android.content.res.AssetManager;
+import android.content.res.Resources;
+import android.util.ArrayMap;
+
+import java.io.File;
+import java.lang.ref.WeakReference;
+import java.lang.reflect.InvocationTargetException;
+
+public class ResourceInstaller {
+    private static final String TAG = "org.chromium.deconstructed.ResourceInstaller";
+
+    public static void install(File resources)
+            throws NoSuchFieldException, NoSuchMethodException, InvocationTargetException,
+                   InstantiationException, ClassNotFoundException, IllegalAccessException {
+        AssetManager assetManager = AssetManager.class.getConstructor().newInstance();
+        if ((int) Reflect.invokeMethod(assetManager, "addAssetPath", resources.getPath()) == 0) {
+            throw new IllegalStateException("Couldn't add assets.");
+        }
+        Object resourcesManager =
+                Reflect.invokeStaticMethod("android.app.ResourcesManager", "getInstance");
+        for (WeakReference<Resources> ref :
+                ((ArrayMap<?, WeakReference<Resources>>) Reflect.getField(
+                        resourcesManager, "mActiveResources")).values()) {
+            Resources res = ref.get();
+            Reflect.setField(res, "mAssets", assetManager);
+            res.updateConfiguration(res.getConfiguration(), res.getDisplayMetrics());
+        }
+    }
+}