# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1609438577 -3600
# Node ID e9f3994b0cb34667ec654b6420aa55a36c6694ea
# Parent  728a78e453bb386c20e5ee269050cfb31d7e065a
Added backlight disable/enable control, adjusting the keys involved.

diff -r 728a78e453bb -r e9f3994b0cb3 pkg/landfall-examples/letux400_backlight/Makefile
--- a/pkg/landfall-examples/letux400_backlight/Makefile	Thu Dec 31 19:15:34 2020 +0100
+++ b/pkg/landfall-examples/letux400_backlight/Makefile	Thu Dec 31 19:16:17 2020 +0100
@@ -14,7 +14,7 @@
 
 # Individual interfaces.
 
-CLIENT_INTERFACES_CC		= backlight
+CLIENT_INTERFACES_CC		= activation backlight
 
 # Generated and plain source files.
 
diff -r 728a78e453bb -r e9f3994b0cb3 pkg/landfall-examples/letux400_backlight/letux400_backlight.cc
--- a/pkg/landfall-examples/letux400_backlight/letux400_backlight.cc	Thu Dec 31 19:15:34 2020 +0100
+++ b/pkg/landfall-examples/letux400_backlight/letux400_backlight.cc	Thu Dec 31 19:16:17 2020 +0100
@@ -1,7 +1,8 @@
 /*
  * Access the keypad to modify the backlight on the Letux 400.
  *
- * Fn+Volume Down/Up adjusts the brightness.
+ * Fn+Down/Up adjusts the brightness.
+ * Zzz+Down/Up disables/enables the backlight.
  *
  * Copyright (C) 2018, 2020 Paul Boddie <paul@boddie.org.uk>
  *
@@ -24,14 +25,12 @@
 #include <l4/devices/input-keypad-client.h>
 #include <l4/devices/keypad-loader.h>
 
-#include <l4/re/env>
-#include <l4/sys/capability>
+#include <l4/re/env.h>
 
 #include <l4/re/event_enums.h>
 #include <l4/util/util.h>
 
-#include <stdio.h>
-
+#include "activation_client.h"
 #include "backlight_client.h"
 
 /* Backlight level. */
@@ -48,9 +47,11 @@
 /* Key state. */
 
 static int modifier_set = 0;
+static int enable_modifier_set = 0;
 
 /* Backlight references. */
 
+Activation *activation_device;
 Backlight *backlight_device;
 
 
@@ -61,12 +62,14 @@
 {
   (void) priv;
 
-  /* Track the state of the modifier key. */
+  /* Track the state of the modifier keys. */
 
-  if (event.code == L4RE_KEY_SLEEP)
+  if (event.code == L4RE_KEY_FN)
     modifier_set = event.value;
+  else if (event.code == L4RE_KEY_SLEEP)
+    enable_modifier_set = event.value;
 
-  if (!event.value || !modifier_set)
+  if (!event.value || !(modifier_set || enable_modifier_set))
     return;
 
   /* Upon keypress events, test controls and update the backlight. */
@@ -74,14 +77,24 @@
   switch (event.code)
   {
     case L4RE_KEY_DOWN:
-      if (backlight_level < Letux400_backlight_min_level + Letux400_backlight_step)
+      if (enable_modifier_set)
+      {
+        activation_device->disable();
+        return;
+      }
+      else if (backlight_level < Letux400_backlight_min_level + Letux400_backlight_step)
         backlight_level = Letux400_backlight_min_level;
       else
         backlight_level -= Letux400_backlight_step;
       break;
 
     case L4RE_KEY_UP:
-      if (backlight_level > Letux400_backlight_max_level - Letux400_backlight_step)
+      if (enable_modifier_set)
+      {
+        activation_device->enable();
+        return;
+      }
+      else if (backlight_level > Letux400_backlight_max_level - Letux400_backlight_step)
         backlight_level = Letux400_backlight_max_level;
       else
         backlight_level += Letux400_backlight_step;
@@ -109,7 +122,11 @@
   l4_cap_idx_t backlight = l4re_env_get_cap("backlight");
   if (!l4_is_valid_cap(backlight)) return 1;
 
-  /* Use only the backlight interface with the backlight. */
+  /* NOTE: The component framework should permit the use of a compound client
+           object. */
+
+  client_Activation activation_obj(backlight);
+  activation_device = &activation_obj;
 
   client_Backlight backlight_obj(backlight);
   backlight_device = &backlight_obj;