Add PrefixLayer plugin

Signed-off-by: iliana etaoin <iliana@buttslol.net>

examples/Keystrokes/PrefixLayer/PrefixLayer.ino

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+// -*- mode: c++ -*-
+
+/* This example demonstrates the Model 01 / Model 100 butterfly logo key as a
+ * tmux prefix key. When the key is held, Ctrl-B is pressed prior to the key
+ * you pressed.
+ *
+ * This example also demonstrates the purpose of using an entire layer for this
+ * plugin: the h/j/k/l keys in the TMUX layer are swapped for arrow keys to
+ * make switching between panes easier.
+ */
+
+#include <Kaleidoscope.h>
+#include <Kaleidoscope-PrefixLayer.h>
+
+enum {
+  PRIMARY,
+  TMUX,
+};  // layers
+
+/* Used in setup() below. */
+static const kaleidoscope::plugin::PrefixLayer::Entry prefix_layers[] PROGMEM = {
+  kaleidoscope::plugin::PrefixLayer::Entry(TMUX, LCTRL(Key_B)),
+};
+
+// clang-format off
+KEYMAPS(
+  [PRIMARY] = KEYMAP_STACKED
+  (XXX,          Key_1, Key_2, Key_3, Key_4, Key_5, XXX,
+   Key_Backtick, Key_Q, Key_W, Key_E, Key_R, Key_T, Key_Tab,
+   Key_PageUp,   Key_A, Key_S, Key_D, Key_F, Key_G,
+   Key_PageDown, Key_Z, Key_X, Key_C, Key_V, Key_B, Key_Escape,
+   Key_LeftControl, Key_Backspace, Key_LeftGui, Key_LeftShift,
+   XXX,
+
+   XXX,                Key_6, Key_7, Key_8,     Key_9,      Key_0,         XXX,
+   Key_Enter,          Key_Y, Key_U, Key_I,     Key_O,      Key_P,         Key_Equals,
+                       Key_H, Key_J, Key_K,     Key_L,      Key_Semicolon, Key_Quote,
+   ShiftToLayer(TMUX), Key_N, Key_M, Key_Comma, Key_Period, Key_Slash,     Key_Minus,
+   Key_RightShift, Key_RightAlt, Key_Spacebar, Key_RightControl,
+   XXX),
+
+  [TMUX] = KEYMAP_STACKED
+  (___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___,
+   ___,
+
+   ___, ___,           ___,           ___,         ___,            ___, ___,
+   ___, ___,           ___,           ___,         ___,            ___, ___,
+        Key_LeftArrow, Key_DownArrow, Key_UpArrow, Key_RightArrow, ___, ___,
+   ___, ___,           ___,           ___,         ___,            ___, ___,
+   ___, ___, ___, ___,
+   ___),
+)
+// clang-format on
+
+KALEIDOSCOPE_INIT_PLUGINS(PrefixLayer);
+
+void setup() {
+  Kaleidoscope.setup();
+  /* Configure the previously-defined prefix layers. */
+  PrefixLayer.prefix_layers = prefix_layers;
+  PrefixLayer.prefix_layers_length = 1;
+}
+
+void loop() {
+  Kaleidoscope.loop();
+}

examples/Keystrokes/PrefixLayer/sketch.json

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+{
+  "cpu": {
+    "fqbn": "keyboardio:avr:model01",
+    "port": ""
+  }
+}

plugins/Kaleidoscope-PrefixLayer/README.md

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+# PrefixLayer
+
+The `PrefixLayer` plugin allows you to easily create a keyboard layer designed
+for use with programs that use a prefix key, such as tmux or screen. When a key
+in a prefix layer is pressed, the prefix is injected first, then the key in
+that layer is pressed.
+
+## Using the plugin
+
+You will need to define a keymap layer and configure the plugin to use that
+layer with a prefix key. You can then include the plugin's header and set the
+`.prefix_layers` property.
+
+```c++
+#include <Kaleidoscope.h>
+#include <Kaleidoscope-PrefixLayer.h>
+
+enum {
+  PRIMARY,
+  TMUX,
+};  // layers
+
+static const kaleidoscope::plugin::PrefixLayer::Entry prefix_layers[] PROGMEM = {
+  kaleidoscope::plugin::PrefixLayer::Entry(TMUX, LCTRL(Key_B)),
+};
+
+KALEIDOSCOPE_INIT_PLUGINS(LEDControl, PrefixLayer);
+
+void setup() {
+  Kaleidoscope.setup();
+  PrefixLayer.prefix_layers = prefix_layers;
+  PrefixLayer.prefix_layers_length = 1;
+}
+```
+
+## Plugin methods
+
+The plugin provides a `PrefixLayer` object, which has the following methods
+and properties:
+
+### `.prefix_layers`
+
+> A `kaleidoscope::plugin::PrefixLayer::Entry` array that maps layers to prefix
+> keys. The `Entry` constructor accepts `Entry(layer_number, prefix_key)`. This
+> array must be stored in `PROGMEM` as shown above.
+>
+> Defaults to an empty array.
+
+### `.prefix_layers_length`
+
+> Length of the `prefix_layers` array.
+>
+> Defaults to *0*
+
+## Further reading
+
+Starting from the [example][plugin:example] is the recommended way of getting
+started with the plugin.
+
+ [plugin:example]: /examples/Keystrokes/PrefixLayer/PrefixLayer.ino

plugins/Kaleidoscope-PrefixLayer/library.properties

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+name=Kaleidoscope-PrefixLayer
+version=0.0.0
+sentence=Sends a prefix key for every key in a layer.
+maintainer=Kaleidoscope's Developers <jesse@keyboard.io>
+url=https://github.com/keyboardio/Kaleidoscope
+author=iliana etaoin, James Cash
+paragraph=

plugins/Kaleidoscope-PrefixLayer/src/Kaleidoscope-PrefixLayer.h

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+/* -*- mode: c++ -*-
+ * Kaleidoscope-PrefixLayer -- Sends a prefix key for every key in a layer.
+ * Copyright (C) 2017, 2022  iliana etaoin <iliana@buttslol.net>
+ * Copyright (C) 2017  James Cash
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "kaleidoscope/plugin/PrefixLayer.h"  // IWYU pragma: export

plugins/Kaleidoscope-PrefixLayer/src/kaleidoscope/plugin/PrefixLayer.cpp

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+/* -*- mode: c++ -*-
+ * Kaleidoscope-PrefixLayer -- Sends a prefix key for every key in a layer.
+ * Copyright (C) 2017, 2022  iliana etaoin <iliana@buttslol.net>
+ * Copyright (C) 2017  James Cash
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "kaleidoscope/plugin/PrefixLayer.h"
+
+#include <Arduino.h>  // for PROGMEM
+#include <stdint.h>   // for uint8_t
+
+#include "kaleidoscope/KeyEvent.h"              // for KeyEvent
+#include "kaleidoscope/Runtime.h"               // for Runtime
+#include "kaleidoscope/event_handler_result.h"  // for EventHandlerResult, EventHandlerResult::OK
+#include "kaleidoscope/key_defs.h"              // for Key
+#include "kaleidoscope/keyswitch_state.h"       // for keyToggledOn
+#include "kaleidoscope/layers.h"                // for Layer
+
+namespace kaleidoscope {
+namespace plugin {
+
+static const PrefixLayer::Entry prefix_layers_default_[] PROGMEM = {};
+const PrefixLayer::Entry *PrefixLayer::prefix_layers             = prefix_layers_default_;
+uint8_t PrefixLayer::prefix_layers_length                        = 0;
+bool PrefixLayer::clear_modifiers_                               = false;
+
+EventHandlerResult PrefixLayer::onKeyEvent(KeyEvent &event) {
+  if (event.state & INJECTED)
+    return EventHandlerResult::OK;
+  if (!keyToggledOn(event.state))
+    return EventHandlerResult::OK;
+  if (event.key == Key_NoKey)
+    return EventHandlerResult::OK;
+  if (!event.key.isKeyboardKey())
+    return EventHandlerResult::OK;
+  if (event.key.isKeyboardModifier())
+    return EventHandlerResult::OK;
+
+  for (uint8_t i = 0; i < prefix_layers_length; i++) {
+    if (Layer.isActive(prefix_layers[i].layer)) {
+      clear_modifiers_ = true;
+      Runtime.handleKeyEvent(KeyEvent{KeyAddr::none(), IS_PRESSED | INJECTED, prefix_layers[i].prefix});
+      Runtime.handleKeyEvent(KeyEvent{KeyAddr::none(), WAS_PRESSED | INJECTED, prefix_layers[i].prefix});
+      clear_modifiers_ = false;
+    }
+  }
+
+  return EventHandlerResult::OK;
+}
+
+EventHandlerResult PrefixLayer::beforeReportingState(const KeyEvent &event) {
+  if (clear_modifiers_) {
+    for (uint8_t i = HID_KEYBOARD_FIRST_MODIFIER; i <= HID_KEYBOARD_LAST_MODIFIER; i++) {
+      Runtime.hid().keyboard().releaseKey(Key(i, KEY_FLAGS));
+    }
+    Runtime.hid().keyboard().pressModifiers(event.key);
+  }
+
+  return EventHandlerResult::OK;
+}
+
+}  // namespace plugin
+}  // namespace kaleidoscope
+
+kaleidoscope::plugin::PrefixLayer PrefixLayer;

plugins/Kaleidoscope-PrefixLayer/src/kaleidoscope/plugin/PrefixLayer.h

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+/* -*- mode: c++ -*-
+ * Kaleidoscope-PrefixLayer -- Sends a prefix key for every key in a layer.
+ * Copyright (C) 2017, 2022  iliana etaoin <iliana@buttslol.net>
+ * Copyright (C) 2017  James Cash
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>  // for uint8_t
+
+#include "kaleidoscope/KeyEvent.h"              // for KeyEvent
+#include "kaleidoscope/event_handler_result.h"  // for EventHandlerResult
+#include "kaleidoscope/key_defs.h"              // for Key
+#include "kaleidoscope/plugin.h"                // for Plugin
+
+namespace kaleidoscope {
+namespace plugin {
+
+class PrefixLayer : public Plugin {
+ public:
+  EventHandlerResult onKeyEvent(KeyEvent &event);
+  EventHandlerResult beforeReportingState(const KeyEvent &event);
+
+  struct Entry {
+    uint8_t layer;
+    Key prefix;
+
+    constexpr Entry(uint8_t layer, Key prefix)
+      : layer(layer), prefix(prefix) {}
+  };
+
+  static const Entry *prefix_layers;
+  static uint8_t prefix_layers_length;
+
+ private:
+  static bool clear_modifiers_;
+};
+
+}  // namespace plugin
+}  // namespace kaleidoscope
+
+extern kaleidoscope::plugin::PrefixLayer PrefixLayer;

tests/plugins/PrefixLayer/basic/basic.ino

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+/* -*- mode: c++ -*-
+ * Copyright (C) 2022  iliana etaoin <iliana@buttslol.net>
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <Kaleidoscope.h>
+#include <Kaleidoscope-PrefixLayer.h>
+
+// clang-format off
+KEYMAPS(
+  [0] = KEYMAP_STACKED
+  (ShiftToLayer(1), ___, ___, ___, ___, ___, ___,
+   Key_LeftControl, Key_LeftShift, ___, ___, ___, ___, ___,
+   Key_H, Key_J, Key_K, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___,
+   ___,
+
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+        ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___,
+   ___),
+
+  [1] = KEYMAP_STACKED
+  (___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, Key_DownArrow, XXX, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___,
+   ___,
+
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+        ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___, ___, ___, ___,
+   ___, ___, ___, ___,
+   ___),
+)
+// clang-format on
+
+static const kaleidoscope::plugin::PrefixLayer::Entry prefix_layers[] PROGMEM = {
+  kaleidoscope::plugin::PrefixLayer::Entry(1, LCTRL(Key_B)),
+};
+
+KALEIDOSCOPE_INIT_PLUGINS(PrefixLayer);
+
+void setup() {
+  Kaleidoscope.setup();
+  PrefixLayer.prefix_layers = prefix_layers;
+  PrefixLayer.prefix_layers_length = 1;
+}
+
+void loop() {
+  Kaleidoscope.loop();
+}

tests/plugins/PrefixLayer/basic/sketch.json

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+{
+  "cpu": {
+    "fqbn": "keyboardio:virtual:model01",
+    "port": ""
+  }
+}

tests/plugins/PrefixLayer/basic/test.ktest

@@ -0,0 +1,231 @@
+VERSION 1
+
+KEYSWITCH PREFIX_B  0 0
+KEYSWITCH CTRL      1 0
+KEYSWITCH SHIFT     1 1
+KEYSWITCH H         2 0
+KEYSWITCH J         2 1
+KEYSWITCH K         2 2
+
+# ==============================================================================
+NAME Prefix layer passthrough
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS H
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl # press Ctrl
+EXPECT keyboard-report Key_LCtrl Key_B # press B, Ctrl held
+EXPECT keyboard-report Key_LCtrl # release B, Ctrl held
+EXPECT keyboard-report empty # release Ctrl
+EXPECT keyboard-report Key_H # press H
+
+RUN 4 ms
+RELEASE H
+RUN 1 cycle
+EXPECT keyboard-report empty # release H
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B
+
+# ==============================================================================
+NAME Prefix layer explicit
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS J
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl # press Ctrl
+EXPECT keyboard-report Key_LCtrl Key_B # press B, Ctrl held
+EXPECT keyboard-report Key_LCtrl # release B, Ctrl held
+EXPECT keyboard-report empty # release Ctrl
+EXPECT keyboard-report Key_DownArrow # press J
+
+RUN 4 ms
+RELEASE J
+RUN 1 cycle
+EXPECT keyboard-report empty # release J
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B
+
+# ==============================================================================
+NAME Prefix layer masked
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS K
+RUN 1 cycle
+EXPECT no keyboard-report # press K (masked)
+
+RUN 4 ms
+RELEASE K
+RUN 1 cycle
+EXPECT no keyboard-report # release K (masked)
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B
+
+# ==============================================================================
+NAME Prefix layer same modifier first
+
+RUN 4 ms
+PRESS CTRL
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl # press Ctrl
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS H
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl Key_B # press B, Ctrl held
+EXPECT keyboard-report Key_LCtrl # release B, Ctrl held
+EXPECT keyboard-report Key_LCtrl Key_H # press H
+
+RUN 4 ms
+RELEASE H
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl # release H
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B
+
+RUN 4 ms
+RELEASE CTRL
+RUN 1 cycle
+EXPECT keyboard-report empty # release Ctrl
+
+# ==============================================================================
+NAME Prefix layer same modifier second
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS CTRL
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl # press Ctrl
+
+RUN 4 ms
+PRESS H
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl Key_B # press B, Ctrl held
+EXPECT keyboard-report Key_LCtrl # release B, Ctrl held
+EXPECT keyboard-report Key_LCtrl Key_H # press H
+
+RUN 4 ms
+RELEASE H
+RUN 1 cycle
+EXPECT keyboard-report Key_LCtrl # release H
+
+RUN 4 ms
+RELEASE CTRL
+RUN 1 cycle
+EXPECT keyboard-report empty # release Ctrl
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B
+
+# ==============================================================================
+NAME Prefix layer different modifier first
+
+RUN 4 ms
+PRESS SHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LShift # press Shift
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS H
+RUN 1 cycle
+EXPECT keyboard-report Key_LShift Key_LCtrl # press Ctrl
+EXPECT keyboard-report Key_LCtrl # release pressed shift
+EXPECT keyboard-report Key_LCtrl Key_B # press B, Ctrl held
+EXPECT keyboard-report Key_LCtrl # release B, Ctrl held
+EXPECT keyboard-report Key_LShift # restoring pressed Shift
+EXPECT keyboard-report Key_LShift Key_H # press H
+
+RUN 4 ms
+RELEASE H
+RUN 1 cycle
+EXPECT keyboard-report Key_LShift # release H
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B
+
+RUN 4 ms
+RELEASE SHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # release Ctrl
+
+# ==============================================================================
+NAME Prefix layer different modifier second
+
+RUN 4 ms
+PRESS PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after pressing PREFIX_B
+
+RUN 4 ms
+PRESS SHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LShift # press Shift
+
+RUN 4 ms
+PRESS H
+RUN 1 cycle
+EXPECT keyboard-report Key_LShift Key_LCtrl # press Ctrl
+EXPECT keyboard-report Key_LCtrl # release pressed shift
+EXPECT keyboard-report Key_LCtrl Key_B # press B, Ctrl held
+EXPECT keyboard-report Key_LCtrl # release B, Ctrl held
+EXPECT keyboard-report Key_LShift # restoring pressed Shift
+EXPECT keyboard-report Key_LShift Key_H # press H
+
+RUN 4 ms
+RELEASE H
+RUN 1 cycle
+EXPECT keyboard-report Key_LShift # release H
+
+RUN 4 ms
+RELEASE SHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # release Ctrl
+
+RUN 4 ms
+RELEASE PREFIX_B
+RUN 1 cycle
+EXPECT no keyboard-report # no report after releasing PREFIX_B