Kaleidoscope/UPGRADING.md

Kaleidoscope upgrade notes

Noteworthy features

New plugin API

A new plugin API was introduced in May 2018, which replaces the old system (which still continues to work, but see below). 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.

Bidirectional communication for plugins

Formerly the Kaleidoscope-Focus plugin implemented a way for plugins to register hooks that respond to commands sent from the host. A part of this has been pulled into Kaleidoscope itself, in the form of the new onFocusEvent hook. For most intents and purposes, this hook works similar to how focus hooks worked previously, but has the advantage of not having to explicitly register them: if you use a plugin that supports this feature, and you have the new Kaleidoscope-FocusSerial plugin enabled, the commands will be made available.

This drastically simplifies both the plugins that wish to implement this, and the user sketches, which no longer need to explicitly register the focus hooks.

Kaleidoscope.millisAtCycleStart()

Many plugins use timers, and most of them will call millis(), which isn't wrong, but isn't the most efficient either. While millis() isn't terribly expensive, it's not cheap either. For most cases, we do not need an exact timer, and one updated once per cycle is enough - which is what .millisAtCycleStart() is. Having a timer that is consistent throughout the whole cycle may also be beneficial.

While millis() should continue to work forever, plugins and user code should, as a general rule, use Kaleidoscope.millisAtCycleStart() rather than millis().

Kaleidoscope.detachFromHost() and Kaleidoscope.attachToHost()

These two require changes to the Hardware plugins, as they wrap functionality provided by it. The intent of these methods is to allow one to apply some configuration changes between detach and attach - because we only sever the link between device and host, power remains connected, and the device does not reboot. A quick way to re-initialize the endpoints.

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

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 means they can no longer be or-ed together to check against the keyswitch state of a given hand. Instead, the kaleidoscope::hid::getKeyswitchStateAtPosition() method can be used to check the state of a keyswitch at a given row and column; or at a given index.

KALEIDOSCOPE_API_VERSION bump

KALEIDOSCOPE_API_VERSION has been bumped to 2 due to the plugin API changes. 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.

Deprecated APIs and their replacements

As the firmware evolves, there are - and will be - APIs that we deprecate, and eventually remove. This document is a short guide that lists the deprecations - along with when it happened, and when the functionality will be removed -, suggested upgrade paths, and any other information that may be useful.

If any of this does not make sense to you, or you have trouble updating your .ino sketch, do not hesitate to write us at help@keyboard.io, we can help you fix it.

Deprecated and removed APIs

Removed on 2018-08-20

We aim at making a new release by mid-July, and APIs we deprecate now, will be removed shortly after the major release, before the next point release. We may deprecate further APIs during the next month (until mid-June), and those deprecations will share the same removal date. We will try our best to minimize deprecations, and do them as soon as possible, to give everyone at least a month to prepare and update.

Kaleidoscope.use()

Deprecated in May 2018, this method is part of the old plugin API, replaced by KALEIDOSCOPE_INIT_PLUGINS. To upgrade, you need to modify your .ino sketch file, and replace the text Kaleidoscope.use with KALEIDOSCOPE_INIT_PLUGINS, then remove the & from all of the plugins inside it, and finally, move it outside of setup().

If your current sketch looks like this:

void setup() {
  Kaleidoscope.use(&Plugin1, &Plugin2);
  Kaleidoscope.setup();
}

You should change it so that it looks like this instead:

KALEIDOSCOPE_INIT_PLUGINS(Plugin1, Plugin2);

void setup() {
  Kaleidoscope.setup();
}

The old-style (v1) plugin API

This includes using KaleidoscopePlugin, Kaleidoscope.useEventHandlerHook, Kaleidoscope.replaceEventHandlerHook, Kaleidoscope.appendEventHandlerHook, Kaleidoscope.useLoopHook, Kaleidoscope.replaceLoopHook, Kaleidoscope.appendLoopHook. They were deprecated in May 2017.

Their replacement is the new plugin API:

namespace kaleidoscope {

enum class EventHandlerResult {
  OK,
  EVENT_CONSUMED,
  ERROR,
};

class Plugin {
public:
  EventHandlerResult onSetup();
  EventHandlerResult beforeEachCycle();
  EventHandlerResult onKeyswitchEvent(Key &mapped_key, byte row, byte col, uint8_t key_state);
  EventHandlerResult beforeReportingState();
  EventHandlerResult afterEachCycle();
};

}

Plugins are supposed to implement this new API, and then be initialised via KALEIDOSCOPE_INIT_PLUGINS.

Consumer_SNapshot

A key with a typo in its name, which was left in place after fixing the typo, so as to not break any code that may be using it already, however unlikely.

Removed on 2018-06-10 (originally scheduled for 2018-05-27)

These APIs and functions have been deprecated for a long time, and as far as we can tell, aren't used by any third party or user code anymore. They were removed as of the June 10th, 2018.

Kaleidoscope.setup(KEYMAP_SIZE)

The Kaleidoscope.setup() method is still around, and is not deprecated, but the variant of it that takes a keymap size is, and has been since October 2017.

Instead, one should use the argument-less Kaleidoscope.setup(), and the new KEYMAP() macros to define a keymap.

event_handler_hook_use, loop_hook_use, and USE_PLUGINS

Deprecated in October 2017, these are old aliases that should no longer be in use. They were replaced by Kaleidoscope.useEventHandlerHook, Kaleidoscope.useLoopHook, and Kaleidoscope.use, respectively.

The replacements themselves are also deprecated - see below -, but their removal will come at a later date.

MOMENTARY_OFFSET

Deprecated in October 2017, replaced by LAYER_SHIFT_OFFSET.

This symbol was meant to be used by plugins, not user code, and as far as we know, no third party plugin ever used it.

key_was_pressed, key_is_pressed, key_toggled_on, key_toggled_off

Deprecated in July 2017, replaced by keyWasPressed, keyIsPressed, keyToggledOn, and keyToggledOff, respectively.