Keyboard Controller

Last week I started making the new controller type; KeyboardController. It is already recognized by Mixxx as a legit Controller and listed under Controllers in the Mixxx preferences window. It is not functional yet, though.

KeyboardController

This class subclasses Controller, which it implements all the pure virtual methods from. It's mostly boilerplate code yet. Just enough to make it compile.

Using as EventFilter?

I also started migrating all the methods and fields from KeyboardEventFilter to KeyboardController, with the idea that we could use it as event filter on all the widgets that have currently the KeyboardEventFilter installed on. It turns out though that we couldn't use the KeyboardController as event filter, because it lives in another thread. We could make it thread-save, but that could make Mixxx seem unresponsive.

The new approach is to let the KeyboardEventFilter live, but let it emit signals of what key sequence was pressed instead of setting controls directly. That will be done by the KeyboardController.

KeyboardEnumerator

Every controller type needs a enumerator. This ControllerEnumerator handles discovery and enumeration of controllers. For instance, the MidiController lists all connected MIDI devices, and the HidController does that with HID devices. Since we only support one keyboard, the KeyboardEnumerator returns a list with just one KeyboardController. If we are ever going to support multiple keyboards, this list could be larger.

KeyboardControllerPreset

The KeyboardControllerPreset subclasses ControllerPreset and implements all its pure virtual methods. Just like KeyboardController, this class consists entirely of boilerplate code. It was needed to be able to implement KeyboardController::visit(KeyboardControllerPreset *) : void, which I BTW also implemented in HidController MidiController and BulkController.

Let the coding begin!

Today is the official coding start date for the GSoC. According to the planning I made in the proposal, I will spend the first two weeks making the API for the keyboard controller. As with many other software projects though, the unexpected is the rule rather than the exception. The unforseen, which in this case is supporting the possibility to script the keyboard, is in my opinion too important to postpone. As a consequence to this, the planned two weeks will be stretched a little bit. It would be great to have the keyboard completely migrated to the controller variant before the midterm evaluation, and after the midterm focus on the GUI for the newly created controller. Time will tell if this is realistic or not.

But for this week, I will be making the base for the new controller. That is, making a unfunctional controller that Mixxx can detect.

Keymapping GUI for Mixxx

This year I can proudly say that I have been given a chance to contribute to Mixxx, the most advanced free DJ software available. In the first instance I will be developing from May 23th till August 29th, as part of the GSoC 2016 program. Although the main work will be done this summer, I do not rule out further contributions to Mixxx after the GSoC.

Project

The goal of this project is to make it as easy as possible for the users of Mixxx to customize the keyboard mapping to their taste, without having to modify a *.cfg file and having to restart Mixxx, which is currently a real pain. In order to achieve that, the idea is to make a GUI for the keyboard mapping. There are now two main controller types: MIDI and HID. This project is about developing the third one: Keyboard.

PROJECT PROPOSAL

I will be posting further details this weekend!