core: Add hook_process_action()

tmk_core/common/action.c

@@ -58,6 +58,8 @@ void action_exec(keyevent_t event)
 
 void process_action(keyrecord_t *record)
 {
+    if (hook_process_action(record)) return;
+
     keyevent_t event = record->event;
 #ifndef NO_ACTION_TAPPING
     uint8_t tap_count = record->tap.count;

tmk_core/common/hook.c

@@ -47,3 +47,8 @@ void hook_keyboard_leds_change(uint8_t led_status) {
 
 __attribute__((weak))
 void hook_bootmagic(void) {}
+
+__attribute__((weak))
+bool hook_process_action(keyrecord_t *record) {
+    return false;
+}

tmk_core/common/hook.h

@@ -20,6 +20,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "keyboard.h"
 #include "led.h"
+#include "action.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -84,6 +85,10 @@ void hook_keyboard_leds_change(uint8_t led_status);
 /* Default behaviour: do nothing. */
 void hook_bootmagic(void);
 
+/* Called on before processing key event */
+/* returns true if the event is consumed and default action is not needed. */
+bool hook_process_action(keyrecord_t *record);
+
 #ifdef __cplusplus
 }
 #endif