Kaleidoscope/NEWS.md

# Kaleidoscope v2.0

> Currently at 1.92-beta, in development!

See [UPGRADING.md](UPGRADING.md) for more detailed instructions about upgrading from earlier versions (even earlier betas). This is just a list of noteworthy changes.

* [New features](#new-features)
* [New hardware support](#new-hardware-support)
* [New plugins](#new-plugins)
* [Breaking changes](#breaking-changes)
* [Bugfixes](#bugfixes)

## New features

### KALEIDOSCOPE_API_VERSION bump

`KALEIDOSCOPE_API_VERSION` has been bumped to **2** due to the plugin API
changes mentioned below. It does not mean that version two of the API is final,
though. The bump is there so plugins can check it, and make compile-time
decisions based on it. Such as whether to compile for the version one, or for
the version two API.

The API version will remain the same, even if we introduce breaking changes -
until a stable release is made from the v2 branch. From that point onwards, the
API version will change with further breaking changes.

### New plugin API

A new plugin API was introduced in May 2018, which replaces the old system. The new system is hopefully easier to use and develop for:

 - It does not require one to register / use hooks anymore. Implementing the interface provided by `kaleidoscope::Plugin` is all that is required.
 - The new system has more hook points, and the method names are much more clear now.

Plugins under Keyboardio control have all been updated to use the new API, and they no longer support the older one.

See [UPGRADING.md](UPGRADING.md#new-plugin-api) for more information.

### Transition to a monorepo

We heard a lot of complaints that while the plugin architecture of Kaleidoscope is great, having so many plugins scattered around in dozens of repositories is a huge barrier of entry for potential contributors, and a significant pain point for end-users to update. For these reasons and more, we merged almost all plugins into the Kaleidoscope repository.

While at first it may seem that this is a move towards a monolithic architecture, rest assured, it is not. The plugin APIs are still a core part of Kaleidoscope, it isn't going anywhere. We merely rearranged the sources, is all. Nothing else changes.

Some headers and names did change, however, see [UPGRADING.md](UPGRADING.md#source-code-and-namespace-rearrangement) for more information.

### Bidirectional communication for plugins

The bi-directional communication protocol formerly implemented by `Kaleidoscope-Focus` has been partially pulled into core, using the new plugin system mentioned above. The new system makes it a lot easier for both end-users and developers to use the feature.

See [UPGRADING.md](UPGRADING.md#bidirectional-communication-for-plugins) for more information.

### Consistent timing

Numerous plugins use timers, most of them directly calling `millis()`. This has the disadvantage that calls within a main loop cycle will be inconsistent, which makes timing synchronization across plugins hard. The newly introduced `Kaleidoscope.millisAtCycleStart()` function helps dealing with this issue.

See [UPGRADING.md](UPGRADING.md#consistent-timing) for more information.

### USB detach / attach

It is now possible to detach, and re-attach the USB link from/to the host, without resetting the device. The intent of this feature (as implemented by the `Kaleidoscope.detachFromHost()` and `Kaleidoscope.attachToHost()` methods) is to allow configuration changes without rebooting.

See the [Kaleidoscope-USB-Quirks][plugin:USB-Quirks] plugin for a use-case.

 [plugin:USB-Quirks]: hAttps://github.com/keyboardio/Kaleidoscope-USB-Quirks

### Finer stickability controls for OneShot

The [OneShot plugin](doc/plugin/OneShot.md) gained finer stickability controls, one can now control whether the double-tap stickiness is enabled on a per-key basis. See [UPGRADING.md](UPGRADING.md#finer-oneshot-stickability-control) for more information.

### A way to slow down Unicode input

In certain cases we need to delay the unicode input sequence, otherwise the host is unable to process the input properly. For this reason, the [Unicode](doc/plugin/Unicode.md) gained an `.input_delay()` method that lets us do just that. It still defaults to no delay.

### Better support for modifiers in the Cycle plugin

The [Cycle](doc/plugin/Cycle.md) plugin has much better support for cycling through keys with modifiers applied to them, such as `LSHIFT(Key_A)`. Please see the documentation and the updated example for more information.

### More control over when to send reports during Macro playback

There are situations where one would like to disable sending a report after each and every step of a macro, and rather have direct control over when reports are sent. The new `WITH_EXPLICIT_REPORT`, `WITH_IMPLICIT_REPORT` and `SEND_REPORT` steps help with that. Please see the [Macros](doc/plugin/Macros.md) documentation for more information.

### Events now trigger on layer changes

Changing layers now triggers the `onLayerChange` event - but only if there was real change (thus, calling `Layer.on(SOME_LAYER)` multiple times in a row will only trigger one event). This event was introduced to help plugins that depend on layer state schedule their work better.

## New hardware support

Kaleidoscope has been ported to the following devices:

- [Atreus](doc/plugin/Hardware-Technomancy-Atreus.md), post-2016 PCB variants with an A* MCU, and the handwired with Teensy from FalbaTech are supported, PCBs prior to 2016 and the legacy teensy2 variants are not.
- [ErgoDox](doc/plugin/Hardware-EZ-ErgoDox.md): Originally developed to support the ErgoDox EZ, but all other compatible hardware is supported, such as the original ErgoDox and anything else wired like it, like some Dactyls.
- [Planck](doc/plugin/Hardware-OLKB-Planck.md): AVR-based Plancks, and anything else wired similarly should be supported, as long as they use a Teensy.

For more information, please see the hardware plugins' documentation.

To make it easier to port Kaleidoscope, we introduced the [ATMegaKeyboard](doc/plugin/ATMegaKeyboard.md) base class. For any board that's based on the ATMega MCU and a simple matrix, this might be a good foundation to develop the hardware plugin upon.

## New plugins

### IdleLEDs

The [IdleLEDs](doc/plugin/IdleLEDs.md) plugin is a simple, yet, useful one: it will turn the keyboard LEDs off after a period of inactivity, and back on upon the next key event.

## Breaking changes

### The `RxCy` macros and peeking into the keyswitch state

The `RxCy` macros changed from being indexes into a per-hand bitmap to being an index across the whole keyboard. This mostly affected the [MagicCombo](doc/plugin/MagicCombo.md) plugin.

Please see the [relevant upgrade notes](UPGRADING.md#the-rxcy-macros-and-peeking-into-the-keyswitch-state) for more information.

## Bugfixes

We fixed way too many issues to list here, so we're going to narrow it down to the most important, most visible ones.

### Support for BIOSes, EFI, login prompts, etc

Keyboards report keys pressed to the host via either of two protocols: the boot protocol, or the report protocol. The boot protocol is the simpler, and it is what older BIOSes, EFI, and certain OS login prompts (or hard disk password prompts and the like) require. Until recently, the firmware wasn't able to provide this protocol, only the more advanced report one, which is required for N-key roll-over.

We now support the boot protocol, and on operating systems that fully conform to the USB specification, this works automatically. For all others, one can implement a way to force one mode or the other. See the [factory firmware][Model01-Firmware] for an example how to achieve this.

 [Model01-Firmware]: https://github.com/keyboardio/Model01-Firmware