Kaleidoscope-SpaceCadet

Space Cadet is a way to make it more convenient to input parens - those ( and ) things -, symbols that a lot of programming languages use frequently. If you are working with Lisp, you are using these all the time.

What it does, is that it turns your left and right Shift keys into parens if you tap and release them, without pressing any other key while holding them. Therefore, to input, say, (print foo), you don't need to press Shift, hold it, and press 9 to get a (, you simply press and release Shift, and continue writing. You use it as if you had a dedicated key for parens!

But if you wish to write capital letters, you hold it, as usual, and you will not see any parens when you release it. You can also hold it for a longer time, and it still would act as a Shift, without the parens inserted on release: this is useful when you want to augment some mouse action with Shift, to select text, for example.

After getting used to the Space Cadet style of typing, you may wish to enable this sort of functionality on other keys, as well. Fortunately, the Space Cadet plugin is configurable and extensible to support adding symbols to other keys.
Along with ( on your left Shift key and ) on your right Shift key, you may wish to add other such programming mainstays as { to your left-side cmd key, } to your right-side alt key, [ to your left Control key, and ] to your right Control key. You can map the keys in whatever way you may wish to do, so feel free to experiment with different combinations and discover what works best for you!

Using the plugin

Using the plugin with its defaults is as simple as including the header, and enabling the plugin:

#include <Kaleidoscope.h>
#include <Kaleidoscope-SpaceCadet.h>

void setup() {
  Kaleidoscope.use(&SpaceCadet);

  Kaleidoscope.setup();
}

This assumes a US QWERTY layout on the host computer, though the plugin sends the correct keymap code for each symbol. Because the mapping is entirely configurable, though, you may switch out keys at your leisure.

If you wish to enable additional modifier keys (or disable the default behavior for the shift and parentheses combinations), configuration is as simple as passing a new keymap into the SpaceCadet object, as shown below:

#include <Kaleidoscope.h>
#include <Kaleidoscope-SpaceCadet.h>

void setup() {
  Kaleidoscope.use(&SpaceCadet);

  //Set the keymap with a 250ms timeout per-key
  //Setting is {KeyThatWasPressed, AlternativeKeyToSend, TimeoutInMS}
  //Note: must end with the SPACECADET_MAP_END delimiter
  static kaleidoscope::SpaceCadet::KeyBinding spacecadetmap[] = {
    {Key_LeftShift, Key_LeftParen, 250}
    , {Key_RightShift, Key_RightParen, 250}
    , {Key_LeftGui, Key_LeftCurlyBracket, 250}
    , {Key_RightAlt, Key_RightCurlyBracket, 250}
    , {Key_LeftAlt, Key_RightCurlyBracket, 250}
    , {Key_LeftControl, Key_LeftBracket, 250}
    , {Key_RightControl, Key_RightBracket, 250}
    , SPACECADET_MAP_END
  };
  //Set the map.
  SpaceCadet.map = spacecadetmap;

  Kaleidoscope.setup();
}

Plugin methods

The plugin provides the SpaceCadet object, with the following methods and properties:

.map

Set the key map. This takes an array of kaleidoscope::SpaceCadet::KeyBinding objects with the special SPACECADET_MAP_END sentinal to mark the end of the map. Each KeyBinding object takes, in order, the key that was pressed, the key that should be sent instead, and an optional per-key timeout override

If not explicitly set, defaults to mapping left shift to ( and right shift to ).

kaleidoscope::SpaceCadet::KeyBinding

An object consisting of the key that is pressed, the key that should be sent in its place, and the timeout (in milliseconds) until the key press is considered to be a "held" key press. The third parameter, the timeout, is optional and may be set per-key or left out entirely (or set to 0) to use the default timeout value.

.time_out

Set this property to the number of milliseconds to wait before considering a held key in isolation as its secondary role. That is, we'd have to hold a Shift key this long, by itself, to trigger the Shift role in itself. This timeout setting can be overridden by an individual key in the keymap, but if it is omitted or set to 0 in the key map, the global timeout will be used.

Defaults to 1000.

Further reading

Starting from the example is the recommended way of getting started with the plugin.