Android系统 给第三方应用运行时权限默认开启（不会弹授予权限窗口）

一.对于单个应用
frameworks/base/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java 类是对默认权限管理类

可以查看grantDefaultSystemHandlerPermissions 该方法，里面有就有授予权限类似方法,可以参考系统对Phone, contacts等应用授予默认权限的处理方法

我们可以通过此类来对我们系统中存在的应用进行默认权限设置。

 private void grantDefaultSystemHandlerPermissions(int userId) {
        Log.i(TAG, "Granting permissions to default platform handlers for user " + userId);

       ...

        synchronized (mService.mPackages) {
            // Installer
            PackageParser.Package installerPackage = getSystemPackageLPr(
                    mService.mRequiredInstallerPackage);
            if (installerPackage != null
                    && doesPackageSupportRuntimePermissions(installerPackage)) {
                grantRuntimePermissionsLPw(installerPackage, STORAGE_PERMISSIONS, true, userId);
            }

            // Verifier
            PackageParser.Package verifierPackage = getSystemPackageLPr(
                    mService.mRequiredVerifierPackage);
            if (verifierPackage != null
                    && doesPackageSupportRuntimePermissions(verifierPackage)) {
                grantRuntimePermissionsLPw(verifierPackage, STORAGE_PERMISSIONS, true, userId);
                grantRuntimePermissionsLPw(verifierPackage, PHONE_PERMISSIONS, false, userId);
                grantRuntimePermissionsLPw(verifierPackage, SMS_PERMISSIONS, false, userId);
            }

            // SetupWizard
            PackageParser.Package setupPackage = getSystemPackageLPr(
                    mService.mSetupWizardPackage);
            if (setupPackage != null
                    && doesPackageSupportRuntimePermissions(setupPackage)) {
                grantRuntimePermissionsLPw(setupPackage, PHONE_PERMISSIONS, userId);
                grantRuntimePermissionsLPw(setupPackage, CONTACTS_PERMISSIONS, userId);
                grantRuntimePermissionsLPw(setupPackage, LOCATION_PERMISSIONS, userId);
                grantRuntimePermissionsLPw(setupPackage, CAMERA_PERMISSIONS, userId);
            }

            // Camera
            Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            PackageParser.Package cameraPackage = getDefaultSystemHandlerActivityPackageLPr(
                    cameraIntent, userId);
            if (cameraPackage != null
                    && doesPackageSupportRuntimePermissions(cameraPackage)) {
                grantRuntimePermissionsLPw(cameraPackage, CAMERA_PERMISSIONS, userId);
                grantRuntimePermissionsLPw(cameraPackage, MICROPHONE_PERMISSIONS, userId);
                grantRuntimePermissionsLPw(cameraPackage, STORAGE_PERMISSIONS, userId);
            }

            // Media provider
            PackageParser.Package mediaStorePackage = getDefaultProviderAuthorityPackageLPr(
                    MediaStore.AUTHORITY, userId);
            if (mediaStorePackage != null) {
                grantRuntimePermissionsLPw(mediaStorePackage, STORAGE_PERMISSIONS, true, userId);
            }

            // Downloads provider
            PackageParser.Package downloadsPackage = getDefaultProviderAuthorityPackageLPr(
                    "downloads", userId);
            if (downloadsPackage != null) {
                grantRuntimePermissionsLPw(downloadsPackage, STORAGE_PERMISSIONS, true, userId);
            }
	
		...

二.对于所有应用

可以在循环里面，处理各种权限问题

/frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

private void grantPermissionsLPw(PackageParser.Package pkg, boolean replace,
            String packageOfInterest) {
  ...
case GRANT_RUNTIME: {
                        // Grant previously granted runtime permissions.
                        for (int userId : UserManagerService.getInstance().getUserIds()) {
                            PermissionState permissionState = origPermissions
                                    .getRuntimePermissionState(bp.name, userId);
                            final int flags = permissionState != null
                                    ? permissionState.getFlags() : 0;
                            if (origPermissions.hasRuntimePermission(bp.name, userId)) {
                                if (permissionsState.grantRuntimePermission(bp, userId) ==
                                        PermissionsState.PERMISSION_OPERATION_FAILURE) {
                                    // If we cannot put the permission as it was, we have to write.
                                    changedRuntimePermissionUserIds = ArrayUtils.appendInt(
                                            changedRuntimePermissionUserIds, userId);
                                }
                            }

                           //modify start
                            boolean isGrant = SystemProperties.getBoolean(CustomProperties.RT_PERMISSION, true);
                            if (!isGrant) {
                                permissionsState.grantRuntimePermission(bp, userId);
                            }
                            //end
                            // Propagate the permission flags.
                            permissionsState.updatePermissionFlags(bp, userId, flags, flags);
                        }
  ...