Improve overlay permission check

app/src/main/java/io/timelimit/android/integration/platform/android/AppOps.kt

@@ -0,0 +1,98 @@
+/*
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package io.timelimit.android.integration.platform.android
+
+import android.annotation.SuppressLint
+import android.app.AppOpsManager
+import android.content.Context
+import android.os.Process
+import java.lang.ClassCastException
+import java.lang.IllegalArgumentException
+import java.lang.reflect.InvocationTargetException
+import java.lang.reflect.Method
+
+@SuppressLint("PrivateApi")
+object AppOps {
+    internal class ReflectionData (
+        val getOpsForPackage: Method,
+        val getOps: Method,
+        val getMode: Method
+    )
+
+    private val reflectionData by lazy {
+        try {
+            val getOpsForPackage = AppOpsManager::class.java.getMethod("getOpsForPackage", Int::class.java, String::class.java, Array<String>::class.java)
+            val packageOpsClass = Class.forName("android.app.AppOpsManager\$PackageOps")
+            val getOps = packageOpsClass.getMethod("getOps")
+            val opEntryClass = Class.forName("android.app.AppOpsManager\$OpEntry")
+            val getMode = opEntryClass.getMethod("getMode")
+
+            ReflectionData(
+                getOpsForPackage = getOpsForPackage,
+                getOps = getOps,
+                getMode = getMode
+            )
+        } catch (ex: ReflectiveOperationException) {
+            null
+        }
+    }
+
+    fun getOpMode(op: String, appOpsManager: AppOpsManager, context: Context): Mode {
+        try {
+            val reflectionData = reflectionData ?: return Mode.Unknown
+
+            val uid: Int = Process.myUid()
+            val pkg: String = context.packageName
+            val ops: Array<String> = arrayOf(op)
+
+            val packageOpsList =
+                reflectionData.getOpsForPackage.invoke(appOpsManager, uid, pkg, ops) as List<*>
+
+            val packageOpsItem = packageOpsList.singleOrNull() ?: return Mode.Unknown
+
+            val opEntryList = reflectionData.getOps.invoke(packageOpsItem) as List<*>
+
+            val opEntryItem = opEntryList.singleOrNull() ?: return Mode.Unknown
+
+            val mode = reflectionData.getMode.invoke(opEntryItem) as Int
+
+            return when (mode) {
+                AppOpsManager.MODE_ALLOWED -> Mode.Allowed
+                AppOpsManager.MODE_DEFAULT -> Mode.Default
+                AppOpsManager.MODE_IGNORED -> Mode.Ignored
+                AppOpsManager.MODE_ERRORED -> Mode.Blocked
+                else -> Mode.Unknown
+            }
+        } catch (ex: ReflectiveOperationException) {
+            return Mode.Unknown
+        } catch (ex: ClassCastException) {
+            return Mode.Unknown
+        } catch (ex: IllegalArgumentException) {
+            return Mode.Unknown
+        } catch (ex: InvocationTargetException) {
+            if (ex.cause is SecurityException) return Mode.Unknown
+            else throw ex
+        }
+    }
+
+    enum class Mode {
+        Unknown,
+        Allowed,
+        Blocked,
+        Default,
+        Ignored
+    }
+}

app/src/main/java/io/timelimit/android/integration/platform/android/OverlayUtil.kt

@@ -1,5 +1,5 @@
 /*
- * TimeLimit Copyright <C> 2019 - 2021 Jonas Lochmann
+ * TimeLimit Copyright <C> 2019 - 2022 Jonas Lochmann
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -100,8 +100,14 @@ class OverlayUtil(private var application: Application) {
     private fun checkAppOp(): Boolean {
         if (systemOverlayOp == null) return false
 
-        val status = appsOpsManager.checkOpNoThrow(systemOverlayOp, Process.myUid(), application.packageName)
+        val mode1 = AppOps.getOpMode(systemOverlayOp, appsOpsManager, application)
 
-        return status == AppOpsManager.MODE_ALLOWED || status == AppOpsManager.MODE_IGNORED
+        if (mode1 != AppOps.Mode.Unknown) {
+            return mode1 == AppOps.Mode.Allowed
+        }
+
+        val mode2 = appsOpsManager.checkOpNoThrow(systemOverlayOp, Process.myUid(), application.packageName)
+
+        return mode2 == AppOpsManager.MODE_ALLOWED || mode2 == AppOpsManager.MODE_IGNORED
     }
 }