[retro-gtk/wip/aplazas/keyboard-configuration] retro-controller-codes: Add converter for JoypadId

[Adrien Plazas <aplazas src gnome org>]

commit f3301edd403f3e6345f20ebe9d84b2ba5bc213e9
Author: theawless <theawless gmail com>
Date:   Mon Apr 16 02:52:50 2018 +0530

    retro-controller-codes: Add converter for JoypadId
    
    This commit adds conversions for linux event codes to/from JoypadId.
    This will help in simplification for client code of retro-gtk.

 retro-gtk/retro-controller-codes.c | 53 ++++++++++++++++++++++++++++++++++++++
 retro-gtk/retro-controller-codes.h |  4 +++
 2 files changed, 57 insertions(+)
---
diff --git a/retro-gtk/retro-controller-codes.c b/retro-gtk/retro-controller-codes.c
index 420a003..cf18c5b 100644
--- a/retro-gtk/retro-controller-codes.c
+++ b/retro-gtk/retro-controller-codes.c
@@ -2,6 +2,8 @@
 
 #include "retro-controller-codes.h"
 
+#include <linux/input-event-codes.h>
+
 GType
 retro_joypad_id_get_type (void)
 {
@@ -26,6 +28,7 @@ retro_joypad_id_get_type (void)
       { RETRO_JOYPAD_ID_L3, "RETRO_JOYPAD_ID_L3", "l3" },
       { RETRO_JOYPAD_ID_R3, "RETRO_JOYPAD_ID_R3", "r3" },
       { RETRO_JOYPAD_ID_COUNT, "RETRO_JOYPAD_ID_COUNT", "count" },
+      { RETRO_JOYPAD_ID_INVALID, "RETRO_JOYPAD_ID_INVALID", "invalid" },
       { 0, NULL, NULL },
     };
     GType type;
@@ -38,6 +41,56 @@ retro_joypad_id_get_type (void)
   return retro_joypad_id_type;
 }
 
+static guint16 RETRO_JOYPAD_ID_EVENT_CODE_MAPPING[RETRO_JOYPAD_ID_COUNT] = {
+  BTN_A,
+  BTN_Y,
+  BTN_SELECT,
+  BTN_START,
+  BTN_DPAD_UP,
+  BTN_DPAD_DOWN,
+  BTN_DPAD_LEFT,
+  BTN_DPAD_RIGHT,
+  BTN_B,
+  BTN_X,
+  BTN_TL,
+  BTN_TR,
+  BTN_TL2,
+  BTN_TR2,
+  BTN_THUMBL,
+  BTN_THUMBR,
+};
+
+/**
+ * retro_joypad_id_to_event_code:
+ * @joypad_id: a #RetroJoypadId
+ *
+ * Returns: the event code for joypad id
+ */
+guint16
+retro_joypad_id_to_event_code (RetroJoypadId joypad_id)
+{
+  g_return_val_if_fail (joypad_id >= 0, EV_MAX);
+  g_return_val_if_fail (joypad_id < RETRO_JOYPAD_ID_COUNT, EV_MAX);
+
+  return RETRO_JOYPAD_ID_EVENT_CODE_MAPPING[joypad_id];
+}
+
+/**
+ * retro_joypad_id_from_event_code:
+ * @event_code: a linux event code
+ *
+ * Returns: the joypad id for event code
+ */
+RetroJoypadId
+retro_joypad_id_from_event_code (guint16 event_code)
+{
+  for (gint i = 0; i < RETRO_JOYPAD_ID_COUNT; ++i)
+    if (event_code == RETRO_JOYPAD_ID_EVENT_CODE_MAPPING[i])
+      return (RetroJoypadId) i;
+
+  return RETRO_JOYPAD_ID_INVALID;
+}
+
 GType
 retro_mouse_id_get_type (void)
 {
diff --git a/retro-gtk/retro-controller-codes.h b/retro-gtk/retro-controller-codes.h
index 39df383..105d032 100644
--- a/retro-gtk/retro-controller-codes.h
+++ b/retro-gtk/retro-controller-codes.h
@@ -61,8 +61,12 @@ typedef enum
   RETRO_JOYPAD_ID_L3,
   RETRO_JOYPAD_ID_R3,
   RETRO_JOYPAD_ID_COUNT,
+  RETRO_JOYPAD_ID_INVALID,
 } RetroJoypadId;
 
+guint16 retro_joypad_id_to_event_code (RetroJoypadId joypad_id);
+RetroJoypadId retro_joypad_id_from_event_code (guint16 event_code);
+
 #define RETRO_TYPE_MOUSE_ID (retro_mouse_id_get_type ())
 
 GType retro_mouse_id_get_type (void) G_GNUC_CONST;