setPassword method
      
Future<bool> 
setPassword({ 
    
- String? userPassword,
- String? ownerPassword,
- bool allowsPrinting = true,
- bool allowsCopying = true,
- CPDFDocumentEncryptAlgo encryptAlgo = CPDFDocumentEncryptAlgo.rc4,
This method sets the document password, including the user password for access restrictions and the owner password for granting permissions.
- To enable permissions like printing or copying, the owner password must be set; otherwise, the settings will not take effect.
example:
bool result = controller.document.setPassword(
  userPassword : '1234',
  ownerPassword : '4321',
  allowsPrinting : false,
  allowsCopying : false,
  encryptAlgo = CPDFDocumentEncryptAlgo.rc4
);
Implementation
Future<bool> setPassword(
    {String? userPassword,
    String? ownerPassword,
    bool allowsPrinting = true,
    bool allowsCopying = true,
    CPDFDocumentEncryptAlgo encryptAlgo =
        CPDFDocumentEncryptAlgo.rc4}) async {
  try {
    return await _channel.invokeMethod('set_password', {
      'user_password': userPassword,
      'owner_password': ownerPassword,
      'allows_printing': allowsPrinting,
      'allows_copying': allowsCopying,
      'encrypt_algo': encryptAlgo.name
    });
  } on PlatformException catch (e) {
    debugPrint(e.message);
    return false;
  }
}