Implement a way to do simple macros

The main thing here is `Macros_::play`, which takes a list of bytes from
PROGMEM, and plays a macro. The array is always a command, followed by
arguments, and the size of the argument depends on the command: key presses and
releases take a 16-bit argument, and the event is injected into the event
handler flow. Waiting and interval change take a 8-bit time. Helpers are
provided to make it a little bit easier to construct a macro.

Of course, the `macroAction` method may do any other side effects, and is not
restricted to returning a sequence of commands.

Fixes #5.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

examples/KeyboardioFirmware/KeyboardioFirmware.ino

@@ -40,10 +40,17 @@ static LEDChaseEffect chaseEffect;
 
 static LEDNumlock numLockEffect (NUMPAD_KEYMAP);
 
-void macroAction(uint8_t macroIndex, uint8_t keyState) {
+const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState) {
     if (macroIndex == 1 && key_toggled_on(keyState)) {
         Serial.print("Keyboard.IO keyboard driver v0.00");
+        return MACRO(I(25),
+                     D(LShift), T(M), U(LShift), T(O), T(D), T(E), T(L),
+                     T(Space),
+                     W(100),
+                     T(0), T(1),
+                     END);
     }
+    return MACRO_NONE;
 }
 
 void setup() {

libraries/Keyboardio-Macros/src/Keyboardio-Macros.cpp

@@ -1,15 +1,56 @@
 #include "Keyboardio-Macros.h"
 
 __attribute__((weak))
-void
-macroAction(uint8_t macroIndex, uint8_t keyState) {
+const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState) {
+    return MACRO_NONE;
+}
+
+void Macros_::play(const macro_t *macro_p) {
+    macro_t macro = END;
+    uint8_t interval = 0;
+    Key key;
+
+    if (!macro_p)
+        return;
+
+    while (true) {
+        switch (macro = pgm_read_byte(macro_p++)) {
+        case MACRO_ACTION_STEP_INTERVAL:
+            interval = pgm_read_byte(macro_p++);
+            break;
+        case MACRO_ACTION_STEP_WAIT: {
+            uint8_t wait = pgm_read_byte(macro_p++);
+            delay(wait);
+            break;
+        }
+        case MACRO_ACTION_STEP_KEYDOWN:
+            key.flags = pgm_read_byte(macro_p++);
+            key.rawKey = pgm_read_byte(macro_p++);
+            handle_key_event(key, 255, 255, IS_PRESSED | INJECTED);
+            Keyboard.sendReport();
+            break;
+        case MACRO_ACTION_STEP_KEYUP:
+            key.flags = pgm_read_byte(macro_p++);
+            key.rawKey = pgm_read_byte(macro_p++);
+            handle_key_event(key, 255, 255, WAS_PRESSED | INJECTED);
+            Keyboard.sendReport();
+            break;
+        case END:
+        default:
+            return;
+        }
+
+        delay(interval);
+    }
 }
 
 static bool handleMacroEvent(Key mappedKey, byte row, byte col, uint8_t keyState) {
     if (!(mappedKey.flags & (SYNTHETIC|IS_MACRO)))
         return false;
 
-    macroAction(mappedKey.rawKey, keyState);
+    const macro_t *m = macroAction(mappedKey.rawKey, keyState);
+
+    Macros.play(m);
     return true;
 }
 

libraries/Keyboardio-Macros/src/Keyboardio-Macros.h

@@ -2,25 +2,16 @@
 
 #include <KeyboardioFirmware.h>
 
-#define IS_MACRO       B00000001
+#include "MacroKeyDefs.h"
+#include "MacroSteps.h"
 
-#define M(n)           (Key){ KEY_FLAGS|SYNTHETIC|IS_MACRO, n}
-#define Key_macroKey1  M(1)
-#define Key_macroKey2  M(2)
-#define Key_macroKey3  M(3)
-#define Key_macroKey4  M(4)
-#define Key_macroKey5  M(5)
-#define Key_macroKey6  M(6)
-#define Key_macroKey7  M(7)
-#define Key_macroKey8  M(8)
-#define Key_macroKey9  M(9)
-#define Key_macroKey10 M(10)
-
-void macroAction(uint8_t macroIndex, uint8_t keyState);
+const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState);
 
 class Macros_ {
   public:
     Macros_(void);
+
+    void play(const macro_t *macro_p);
 };
 
 extern Macros_ Macros;

libraries/Keyboardio-Macros/src/MacroKeyDefs.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#define IS_MACRO       B00000001
+
+#define M(n)           (Key){ KEY_FLAGS|SYNTHETIC|IS_MACRO, n}
+#define Key_macroKey1  M(1)
+#define Key_macroKey2  M(2)
+#define Key_macroKey3  M(3)
+#define Key_macroKey4  M(4)
+#define Key_macroKey5  M(5)
+#define Key_macroKey6  M(6)
+#define Key_macroKey7  M(7)
+#define Key_macroKey8  M(8)
+#define Key_macroKey9  M(9)
+#define Key_macroKey10 M(10)

libraries/Keyboardio-Macros/src/MacroSteps.h

@@ -0,0 +1,22 @@
+#pragma once
+
+typedef enum {
+    MACRO_ACTION_END,
+
+    MACRO_ACTION_STEP_INTERVAL,
+    MACRO_ACTION_STEP_WAIT,
+    MACRO_ACTION_STEP_KEYDOWN,
+    MACRO_ACTION_STEP_KEYUP,
+} MacroActionStepType;
+
+typedef uint8_t macro_t;
+
+#define MACRO_NONE 0
+#define MACRO(...) ({static const macro_t __m[] PROGMEM = { __VA_ARGS__ }; &__m[0]; })
+
+#define I(n) MACRO_ACTION_STEP_INTERVAL, n
+#define W(n) MACRO_ACTION_STEP_WAIT, n
+#define D(k) MACRO_ACTION_STEP_KEYDOWN, (Key_ ## k).raw
+#define U(k) MACRO_ACTION_STEP_KEYUP, (Key_ ## k).raw
+#define T(k) D(k), U(k)
+#define END  MACRO_ACTION_END