Manage device applications

private void showPackageState(boolean state) {
        // Instantiate the EnterpriseDeviceManager class
        EnterpriseDeviceManager enterpriseDeviceManager = EnterpriseDeviceManager.getInstance(this);
        ApplicationPolicy appPolicy = enterpriseDeviceManager.getApplicationPolicy();
        try {
            // getApplicationStateList() gets the list of enabled or disabled applications based on state.
            String[] packageList = appPolicy.getApplicationStateList(state);
            if (packageList == null) {
                // If an empty/null array returns, no enabled/disabled apps received
                if (state) {
                    mUtils.log(getString(R.string.no_enabled_apps));
                }
                else {
                    mUtils.log(getString(R.string.no_disabled_apps));
                }
            } else {
                // If not an empty array, display the contents whether its enabled or disabled apps
                if (state) {
                    mUtils.log(getString(R.string.showing_enabled_apps));
                } else {
                    mUtils.log(getString(R.string.showing_disabled_apps));
                }
                for (String packageName : packageList) {
                    mUtils.log(packageName);
                }
                mUtils.log(getString(R.string.finished_showing_app_list));
            }
        } catch(SecurityException e) {
            mUtils.processException(e, TAG);
        }
}

private void enableAllDisabledPackages() {
        // Instantiate the EnterpriseDeviceManager class
        EnterpriseDeviceManager enterpriseDeviceManager = EnterpriseDeviceManager.getInstance(this);
        // Get the ApplicationPolicy class where the setApplicationStateList method lives
        ApplicationPolicy appPolicy = enterpriseDeviceManager.getApplicationPolicy();
        try {
            // Get an array of all the disabled packages
            String [] disabledPackages = appPolicy.getApplicationStateList(false);

            // Enable packages in the array received in previous line,
            // get an array of successfully enabled packages
            String [] enabledPackages = appPolicy.setApplicationStateList(disabledPackages, true);
            if (enabledPackages == null) {
                mUtils.log(getString(R.string.failed_enable_all_apps));
            } else {
                for (String enabledPackage : enabledPackages) {
                    mUtils.log(getString(R.string.enabled_package, enabledPackage));
                }
            }
        } catch (SecurityException e) {
            mUtils.processException(e, TAG);
        }
}       

private void promptUserForPackageToEnableOrDisable(final boolean state) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);

        // Set the dialog's title to enable or disable depending on state
        if (state) {
            builder.setTitle(getString(R.string.enable_given_app));
        } else {
            builder.setTitle(getString(R.string.disable_given_app));
        }

        View viewInflated = LayoutInflater.from(this).inflate(R.layout.prompt_user_package_name,
                findViewById(R.id.prompt_user_package_name), false);
        final EditText packageNameTxt = viewInflated.findViewById(R.id.packageNameTxt);

        builder.setView(viewInflated);
        builder.setPositiveButton(getString(R.string.option_confirm), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // Get the user provided package name
                String packageName = packageNameTxt.getText().toString();

                // Enable or disable the given package name depending on state
                if (state) {
                    enablePackage(packageName);
                } else {
                    disablePackage(packageName);
                }
                dialog.dismiss();
            }
        });
        builder.setNegativeButton(getString(R.string.option_cancel), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        builder.show();
}     

private void enablePackage(String packageName) {
        // Instantiate the EnterpriseDeviceManager class
        EnterpriseDeviceManager enterpriseDeviceManager = EnterpriseDeviceManager.getInstance(this);
        // Get the ApplicationPolicy class where the setEnableApplication method lives
        ApplicationPolicy appPolicy = enterpriseDeviceManager.getApplicationPolicy();
        try {
            // Enable the given app package name
            boolean appEnabled = appPolicy.setEnableApplication(packageName);

            mUtils.log(getResources().getString(R.string.enabled_app_result, appEnabled));
        } catch (SecurityException e) {
            mUtils.processException(e, TAG);
        }
}       

private void disablePackage(String packageName) {
        // Instantiate the EnterpriseDeviceManager class
        EnterpriseDeviceManager enterpriseDeviceManager =
                EnterpriseDeviceManager.getInstance(this.getApplicationContext());
        // Get the ApplicationPolicy class where the setDisableApplication method lives
        ApplicationPolicy appPolicy = enterpriseDeviceManager.getApplicationPolicy();
        try {
            // Disable the given app package name
            boolean appDisabled = appPolicy.setDisableApplication(packageName);

            mUtils.log(getResources().getString(R.string.disabled_app_result, appDisabled));
        } catch (SecurityException e) {
            mUtils.processException(e, TAG);
        }
}

private void promptUserPackageForBatteryWhitelist() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle(getString(R.string.add_or_remove_app_battery_optimization_whitelist));

        View viewInflated = LayoutInflater.from(this).inflate(R.layout.prompt_user_package_name,
                findViewById(R.id.prompt_user_package_name), false);
        final EditText packageNameTxt = viewInflated.findViewById(R.id.packageNameTxt);

        builder.setView(viewInflated);
        builder.setPositiveButton(getString(R.string.option_confirm), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // Get the user provided package name
                String packageName = packageNameTxt.getText().toString();
                toggleBatteryOptimizationWhitelist(packageName);
                dialog.dismiss();
            }
        });
        builder.setNegativeButton(getString(R.string.option_cancel), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        builder.show();
}

private void toggleBatteryOptimizationWhitelist(String packageName) {
        EnterpriseDeviceManager enterpriseDeviceManager =
                EnterpriseDeviceManager.getInstance(this.getApplicationContext());
        ApplicationPolicy appPolicy = enterpriseDeviceManager.getApplicationPolicy();
        int result;
        String signature = null;

        try {
            signature = getPackageSignature(packageName);
        } catch (PackageManager.NameNotFoundException e) {
            mUtils.processException(e, TAG);
        }

        AppIdentity appIdentity = new AppIdentity(packageName, signature);
        boolean isInWhitelist;

        try {
            List<String> packageNames = appPolicy.getPackagesFromBatteryOptimizationWhiteList();
            isInWhitelist = packageNames.contains(packageName);

            if(isInWhitelist) {
                result = appPolicy.removePackageFromBatteryOptimizationWhiteList(appIdentity);
            } else {
                result = appPolicy.addPackageToBatteryOptimizationWhiteList(appIdentity);
            }

            if(result != ApplicationPolicy.ERROR_NONE) {
                mUtils.log(getResources().getString(R.string.add_or_remove_app_battery_optimization_whitelist_fail,
                        Integer.toString(result), packageName, isInWhitelist));
            } else {
                mUtils.log(getResources().getString(R.string.add_or_remove_app_battery_optimization_whitelist_success,
                        packageName, !isInWhitelist));
            }
        } catch (SecurityException e) {
            mUtils.processException(e, TAG);
        }
}

private void promptUserPackageForForceStopBlacklist() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle(getString(R.string.add_or_remove_app_force_stop_blacklist));

        View viewInflated = LayoutInflater.from(this).inflate(R.layout.prompt_user_package_name,
                findViewById(R.id.prompt_user_package_name), false);
        final EditText packageNameTxt = viewInflated.findViewById(R.id.packageNameTxt);

        builder.setView(viewInflated);
        builder.setPositiveButton(getString(R.string.option_confirm), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // Get the user provided package name
                String packageName = packageNameTxt.getText().toString();
                toggleForceStopBlacklist(packageName);
                dialog.dismiss();
            }
        });
        builder.setNegativeButton(getString(R.string.option_cancel), new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        builder.show();
}

private void toggleForceStopBlacklist(String packageName) {
        EnterpriseDeviceManager enterpriseDeviceManager =
                EnterpriseDeviceManager.getInstance(this.getApplicationContext());
        ApplicationPolicy appPolicy = enterpriseDeviceManager.getApplicationPolicy();
        List<String> list =new ArrayList<>();
        list.add(packageName);
        boolean result;
        boolean isInBlacklist;

        try {
            List<String> packageNames = appPolicy.getPackagesFromForceStopBlackList();
            isInBlacklist = packageNames.contains(packageName);

            if(isInBlacklist) {
                result = appPolicy.removePackagesFromForceStopBlackList(list);
            } else {
                result = appPolicy.addPackagesToForceStopBlackList(list);
            }

            if(!result) {
                mUtils.log(getResources().getString(R.string.add_or_remove_app_force_stop_blacklist_fail,
                        packageName, isInBlacklist));
            } else {
                mUtils.log(getResources().getString(R.string.add_or_remove_app_force_stop_blacklist_success,
                        packageName, !isInBlacklist));
            }
        } catch (SecurityException e) {
            mUtils.processException(e, TAG);
        }
}

private String getPackageSignature(String packageName) throws PackageManager.NameNotFoundException {
        Signature[] signatures;
        Context context = this;
        PackageManager packageManager = context.getPackageManager();
        PackageInfo packageInfo;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
            packageInfo = packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNING_CERTIFICATES);
            signatures = packageInfo.signingInfo.getSigningCertificateHistory();
        } else {
            packageInfo = packageManager.getPackageInfo(packageName, GET_SIGNATURES);
            signatures = packageInfo.signatures;
        }

        return signatures[0].toCharsString();
}