From a8c9931257dcb995960db6e0d815d50f367497d1 Mon Sep 17 00:00:00 2001
From: George Oikonomou <george@contiki-ng.org>
Date: Sun, 18 Mar 2018 12:39:19 +0000
Subject: [PATCH] Add a function to retrieve a button by index

---
 examples/dev/button-hal/button-hal-example.c |  2 +-
 os/dev/button-hal.c                          | 10 ++++++++++
 os/dev/button-hal.h                          |  7 +++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/examples/dev/button-hal/button-hal-example.c b/examples/dev/button-hal/button-hal-example.c
index f4919f19e..b4d584e3e 100644
--- a/examples/dev/button-hal/button-hal-example.c
+++ b/examples/dev/button-hal/button-hal-example.c
@@ -43,7 +43,7 @@ PROCESS_THREAD(button_hal_example, ev, data)
 
   PROCESS_BEGIN();
 
-  btn = button_hal_get_by_id(BUTTON_HAL_ID_BUTTON_ZERO);
+  btn = button_hal_get_by_index(0);
 
   printf("Button HAL example.\n");
   printf("Device button count: %u.\n", button_hal_button_count);
diff --git a/os/dev/button-hal.c b/os/dev/button-hal.c
index 789100324..58cded790 100644
--- a/os/dev/button-hal.c
+++ b/os/dev/button-hal.c
@@ -141,6 +141,16 @@ button_hal_get_by_id(uint8_t unique_id)
   return NULL;
 }
 /*---------------------------------------------------------------------------*/
+button_hal_button_t *
+button_hal_get_by_index(uint8_t index)
+{
+  if(index >= button_hal_button_count) {
+    return NULL;
+  }
+
+  return button_hal_buttons[index];
+}
+/*---------------------------------------------------------------------------*/
 uint8_t
 button_hal_get_state(button_hal_button_t *button)
 {
diff --git a/os/dev/button-hal.h b/os/dev/button-hal.h
index 4f35437ed..c1822ff8e 100644
--- a/os/dev/button-hal.h
+++ b/os/dev/button-hal.h
@@ -247,6 +247,13 @@ void button_hal_init(void);
  */
 button_hal_button_t *button_hal_get_by_id(uint8_t unique_id);
 
+/**
+ * \brief Retrieve a button by its index
+ * \param index The button's index (0, 1, ... button_hal_button_count - 1)
+ * \return A pointer to the button or NULL if not found
+ */
+button_hal_button_t *button_hal_get_by_index(uint8_t index);
+
 /**
  * \brief Get the state of a button (pressed / released)
  * \param button A pointer to the button