1

I am working on custom lightweight UI library for my C++ project and I have question about implementing control's behavior.

Currently I have system that create instances of controls from provided files, so graphical representation, text, dimensions and other parameters are defined in external file. Regarding buttons and other interactive controls: I have base button class and for each button I am creating derived class with its own implementation of behavior related methods(onClick() etc.) see pseudo snippet:

class Button
{
public:
   Button();
   virtual void onClick();
};

class newButton : public Button
{
   void onClick()
   {}//specific implementation
};

I am looking for way to describe behavior externally(scripting language possibly) and inserting it to specific instance of base button on compile, so I won't need to create subclasses of button, and buttons/components could be completely described in external file. Any toughts or recommendations will be appreciated.

Thanks

Improve this question

1 Answer 1

Reset to default
1

Well I think you got another XY problem: Using run-time object polymorphism is not able to solve your wish. Although it enables C++ code to not care which specific implementation one uses, and can accept new unknown solutions at run time, these new solution still have to be compiled with an C++ compiler, and be compliant with the base class definition and C++ implementation (your compiler like gcc or MSVC) specific details of runtime polymorphism.

Since I assume you don't want that, which also makes sense and is a pattern getting popular in the C++ world (see QML or Javascript/C++ hybrids), you have some options.

Either you implement all basic behaviour building blocks in C++ (where you can of course use runtime polymorphism or even compile time polymorphism), which you then simply combine according to your UI description language at run time. To parse your so called DSL i.e. UI description language, you can use libraries like boost spirit.

How ever if you really to script the UI logic and not simply describe it, you would have to design and implement a whole programming language, which is also compatible to your C++ implementations runtime object polymorphism. Which I would find a very big and long task.

But don't dispair, that are ready solution like Javescript/C++ in the form of react native and electron using native node modules, or QML/Qt, or lua, a scripting language, specifically designed to be used in other programming languages.

Improve this answer
Sign up to request clarification or add additional context in comments.

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.