Implement access to settings without Context

Expose methods to access the Android settings using private APIs.

This allows to read and write settings values immediately without
starting a new process to call "settings".

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

@@ -1,5 +1,6 @@
 package com.genymobile.scrcpy;
 
+import com.genymobile.scrcpy.wrappers.ContentProvider;
 import com.genymobile.scrcpy.wrappers.InputManager;
 import com.genymobile.scrcpy.wrappers.ServiceManager;
 import com.genymobile.scrcpy.wrappers.SurfaceControl;
@@ -199,4 +200,8 @@ public final class Device {
             wm.thawRotation();
         }
     }
+
+    public ContentProvider createSettingsProvider() {
+        return serviceManager.getActivityManager().createSettingsProvider();
+    }
 }

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

@@ -0,0 +1,87 @@
+package com.genymobile.scrcpy.wrappers;
+
+import com.genymobile.scrcpy.Ln;
+
+import android.os.Binder;
+import android.os.IBinder;
+import android.os.IInterface;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public class ActivityManager {
+
+    private final IInterface manager;
+    private Method getContentProviderExternalMethod;
+    private boolean getContentProviderExternalMethodLegacy;
+    private Method removeContentProviderExternalMethod;
+
+    public ActivityManager(IInterface manager) {
+        this.manager = manager;
+    }
+
+    private Method getGetContentProviderExternalMethod() throws NoSuchMethodException {
+        if (getContentProviderExternalMethod == null) {
+            try {
+                getContentProviderExternalMethod = manager.getClass()
+                        .getMethod("getContentProviderExternal", String.class, int.class, IBinder.class, String.class);
+            } catch (NoSuchMethodException e) {
+                // old version
+                getContentProviderExternalMethod = manager.getClass().getMethod("getContentProviderExternal", String.class, int.class, IBinder.class);
+                getContentProviderExternalMethodLegacy = true;
+            }
+        }
+        return getContentProviderExternalMethod;
+    }
+
+    private Method getRemoveContentProviderExternalMethod() throws NoSuchMethodException {
+        if (removeContentProviderExternalMethod == null) {
+            removeContentProviderExternalMethod = manager.getClass().getMethod("removeContentProviderExternal", String.class, IBinder.class);
+        }
+        return removeContentProviderExternalMethod;
+    }
+
+    private ContentProvider getContentProviderExternal(String name, IBinder token) {
+        try {
+            Method method = getGetContentProviderExternalMethod();
+            Object[] args;
+            if (!getContentProviderExternalMethodLegacy) {
+                // new version
+                args = new Object[]{name, ServiceManager.USER_ID, token, null};
+            } else {
+                // old version
+                args = new Object[]{name, ServiceManager.USER_ID, token};
+            }
+            // ContentProviderHolder providerHolder = getContentProviderExternal(...);
+            Object providerHolder = method.invoke(manager, args);
+            if (providerHolder == null) {
+                return null;
+            }
+            // IContentProvider provider = providerHolder.provider;
+            Field providerField = providerHolder.getClass().getDeclaredField("provider");
+            providerField.setAccessible(true);
+            Object provider = providerField.get(providerHolder);
+            if (provider == null) {
+                return null;
+            }
+            return new ContentProvider(this, provider, name, token);
+        } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException | NoSuchFieldException e) {
+            Ln.e("Could not invoke method", e);
+            return null;
+        }
+    }
+
+    void removeContentProviderExternal(String name, IBinder token) {
+        try {
+            Method method = getRemoveContentProviderExternalMethod();
+            method.invoke(manager, name, token);
+        } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
+            Ln.e("Could not invoke method", e);
+        }
+    }
+
+    public ContentProvider createSettingsProvider() {
+        return getContentProviderExternal("settings", new Binder());
+    }
+}

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

@@ -0,0 +1,132 @@
+package com.genymobile.scrcpy.wrappers;
+
+import com.genymobile.scrcpy.Ln;
+
+import android.os.Bundle;
+import android.os.IBinder;
+
+import java.io.Closeable;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public class ContentProvider implements Closeable {
+
+    public static final String TABLE_SYSTEM = "system";
+    public static final String TABLE_SECURE = "secure";
+    public static final String TABLE_GLOBAL = "global";
+
+    // See android/providerHolder/Settings.java
+    private static final String CALL_METHOD_GET_SYSTEM = "GET_system";
+    private static final String CALL_METHOD_GET_SECURE = "GET_secure";
+    private static final String CALL_METHOD_GET_GLOBAL = "GET_global";
+
+    private static final String CALL_METHOD_PUT_SYSTEM = "PUT_system";
+    private static final String CALL_METHOD_PUT_SECURE = "PUT_secure";
+    private static final String CALL_METHOD_PUT_GLOBAL = "PUT_global";
+
+    private static final String CALL_METHOD_USER_KEY = "_user";
+
+    private static final String NAME_VALUE_TABLE_VALUE = "value";
+
+    private final ActivityManager manager;
+    // android.content.IContentProvider
+    private final Object provider;
+    private final String name;
+    private final IBinder token;
+
+    private Method callMethod;
+    private boolean callMethodLegacy;
+
+    ContentProvider(ActivityManager manager, Object provider, String name, IBinder token) {
+        this.manager = manager;
+        this.provider = provider;
+        this.name = name;
+        this.token = token;
+    }
+
+    private Method getCallMethod() throws NoSuchMethodException {
+        if (callMethod == null) {
+            try {
+                callMethod = provider.getClass().getMethod("call", String.class, String.class, String.class, String.class, Bundle.class);
+            } catch (NoSuchMethodException e) {
+                // old version
+                callMethod = provider.getClass().getMethod("call", String.class, String.class, String.class, Bundle.class);
+                callMethodLegacy = true;
+            }
+        }
+        return callMethod;
+    }
+
+    private Bundle call(String callMethod, String arg, Bundle extras) {
+        try {
+            Method method = getCallMethod();
+            Object[] args;
+            if (!callMethodLegacy) {
+                args = new Object[]{ServiceManager.PACKAGE_NAME, "settings", callMethod, arg, extras};
+            } else {
+                args = new Object[]{ServiceManager.PACKAGE_NAME, callMethod, arg, extras};
+            }
+            return (Bundle) method.invoke(provider, args);
+        } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
+            Ln.e("Could not invoke method", e);
+            return null;
+        }
+    }
+
+    public void close() {
+        manager.removeContentProviderExternal(name, token);
+    }
+
+    private static String getGetMethod(String table) {
+        switch (table) {
+            case TABLE_SECURE:
+                return CALL_METHOD_GET_SECURE;
+            case TABLE_SYSTEM:
+                return CALL_METHOD_GET_SYSTEM;
+            case TABLE_GLOBAL:
+                return CALL_METHOD_GET_GLOBAL;
+            default:
+                throw new IllegalArgumentException("Invalid table: " + table);
+        }
+    }
+
+    private static String getPutMethod(String table) {
+        switch (table) {
+            case TABLE_SECURE:
+                return CALL_METHOD_PUT_SECURE;
+            case TABLE_SYSTEM:
+                return CALL_METHOD_PUT_SYSTEM;
+            case TABLE_GLOBAL:
+                return CALL_METHOD_PUT_GLOBAL;
+            default:
+                throw new IllegalArgumentException("Invalid table: " + table);
+        }
+    }
+
+    public String getValue(String table, String key) {
+        String method = getGetMethod(table);
+        Bundle arg = new Bundle();
+        arg.putInt(CALL_METHOD_USER_KEY, ServiceManager.USER_ID);
+        Bundle bundle = call(method, key, arg);
+        if (bundle == null) {
+            return null;
+        }
+        return bundle.getString("value");
+    }
+
+    public void putValue(String table, String key, String value) {
+        String method = getPutMethod(table);
+        Bundle arg = new Bundle();
+        arg.putInt(CALL_METHOD_USER_KEY, ServiceManager.USER_ID);
+        arg.putString(NAME_VALUE_TABLE_VALUE, value);
+        call(method, key, arg);
+    }
+
+    public String getAndPutValue(String table, String key, String value) {
+        String oldValue = getValue(table, key);
+        if (!value.equals(oldValue)) {
+            putValue(table, key, value);
+        }
+        return oldValue;
+    }
+}

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

@@ -16,6 +16,7 @@ public final class ServiceManager {
     private PowerManager powerManager;
     private StatusBarManager statusBarManager;
     private ClipboardManager clipboardManager;
+    private ActivityManager activityManager;
 
     public ServiceManager() {
         try {
@@ -76,4 +77,21 @@ public final class ServiceManager {
         }
         return clipboardManager;
     }
+
+    public ActivityManager getActivityManager() {
+        if (activityManager == null) {
+            try {
+                // On old Android versions, the ActivityManager is not exposed via AIDL,
+                // so use ActivityManagerNative.getDefault()
+                Class<?> cls = Class.forName("android.app.ActivityManagerNative");
+                Method getDefaultMethod = cls.getDeclaredMethod("getDefault");
+                IInterface am = (IInterface) getDefaultMethod.invoke(null);
+                activityManager = new ActivityManager(am);
+            } catch (Exception e) {
+                throw new AssertionError(e);
+            }
+        }
+
+        return activityManager;
+    }
 }