Varx – Reactive Extensions (Rx) for JUCE

varx – Reactive Extensions (Rx) for JUCE

Hi everyone! I’ve created a JUCE module called varx that brings Reactive Extensions (Rx) to JUCE. This helps to connect our app’s user interface, parameters and audio processing in a simple, flexible and consistent way. It reduces boilerplate code and errors.

Get it for free on GitHub!

So what does it do?
For example, let’s say we want to update a Label text whenever a Slider is moved.
Normally you have to inherit from Slider::Listener, call slider.addListener(this) in your constructor, override sliderValueChanged, and call label.setText() from there.

With varx however, it’s just one line of code:;

This connects the Label text to the Slider and makes sure it stays up-to-date. (More details in the README on GitHub)

It’s not limited to GUI components: You can connect any value, and things stay in sync. For more examples, please refer to the Getting Started guide.

If you already know Rx: varx has Observables with all the common operators, Observers and Subjects.

varx is released under the MIT license. I appreciate your feedback and any questions.


Brilliant work, look forward to trying this out in my current project.

I’m interested especially in having direct reactive connections to elements in a ValueTree, instead of using the sometimes unwieldy (and verbose) ValueTree::Listener overrides.

This looks fantastic and will come in very handy. :smiley: Thank you for sharing this. :heart:

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That’s interesting…could you please describe how you use the ValueTree: Do you use nested ValueTrees, and what events do you need to be notified about?

Yes, I do use nested ValueTrees, however I think most of the time subscribing to the Value of a ValueTree property would be sufficient. It would also be useful to be able subscribe to the events from ValueTree::Listener for some cases.

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great jobs