Allow shutting down the device on inactivity

This can be enabled by setting the `general.timeout` configuration.
Timeout must be specified in seconds, and the max ceiling is 3600 (one hour).
Specifying 0 (default) will disable this feature.

Signed-off-by: Eugenio Paolantonio (g7) <me@medesimo.eu>

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - feat: Add config option to customise bullet character (#17)
 - fix: Use actual screen DPI value to compute sizes and spaces
+- feat: Allow shutting down the device on inactivity
 
 ## 0.2.0 (2022-05-27)
 

config.c

@@ -22,7 +22,10 @@
 
 #include "log.h"
 
+#include "lvgl/lvgl.h"
+
 #include <ini.h>
+#include <stdlib.h>
 
 #include "squeek2lvgl/sq2lv.h"
 
@@ -74,6 +77,7 @@ static bool parse_bool(const char *value, bool *result);
 static void init_opts(ul_config_opts *opts) {
     opts->general.animations = false;
     opts->general.backend = ul_backends_backends[0] == NULL ? UL_BACKENDS_BACKEND_NONE : 0;
+    opts->general.timeout = 0;
     opts->keyboard.autohide = true;
     opts->keyboard.layout_id = SQ2LV_LAYOUT_US;
     opts->keyboard.popovers = false;
@@ -103,6 +107,10 @@ static int parsing_handler(void* user_data, const char* section, const char* key
                 opts->general.backend = id;
                 return 1;
             }
+        } else if (strcmp(key, "timeout") == 0) {
+            /* Use a max ceiling of 60 minutes (3600 secs) */
+            opts->general.timeout = (uint16_t)LV_MIN(strtoul(value, (char **)NULL, 10), 3600);
+            return 1;
         }
     } else if (strcmp(section, "keyboard") == 0) {
         if (strcmp(key, "autohide") == 0) {

config.h

@@ -28,6 +28,7 @@
 #include "sq2lv_layouts.h"
 
 #include <stdbool.h>
+#include <stdint.h>
 
 /**
  * General options
@@ -37,6 +38,8 @@ typedef struct {
     ul_backends_backend_id_t backend;
     /* If true, use animations */
     bool animations;
+    /* Timeout (in seconds) - once elapsed, the device will shutdown. 0 (default) to disable */
+    uint16_t timeout;
 } ul_config_opts_general;
 
 /**

main.c

@@ -182,6 +182,11 @@ static void textarea_ready_cb(lv_event_t *event);
  */
 static void print_password_and_exit(lv_obj_t *textarea);
 
+/**
+ * Shuts down the device.
+ */
+static void shutdown(void);
+
 /**
  * Handle termination signals sent to the process.
  *
@@ -278,8 +283,7 @@ static void shutdown_btn_clicked_cb(lv_event_t *event) {
 static void shutdown_mbox_value_changed_cb(lv_event_t *event) {
     lv_obj_t *mbox = lv_event_get_current_target(event);
     if (lv_msgbox_get_active_btn(mbox) == 0) {
-        sync();
-        reboot(RB_POWER_OFF);
+        shutdown();
     }
     lv_msgbox_close(mbox);
 }
@@ -313,6 +317,11 @@ static void print_password_and_exit(lv_obj_t *textarea) {
     sigaction_handler(SIGTERM);
 }
 
+static void shutdown(void) {
+    sync();
+    reboot(RB_POWER_OFF);
+}
+
 static void sigaction_handler(int signum) {
     LV_UNUSED(signum);
     ul_terminal_reset_current_terminal();
@@ -558,8 +567,13 @@ int main(int argc, char *argv[]) {
     }
 
     /* Run lvgl in "tickless" mode */
+    uint32_t timeout = conf_opts.general.timeout * 1000; /* ms */
     while(1) {
-        lv_task_handler();
+        if (!timeout || lv_disp_get_inactive_time(NULL) < timeout) {
+            lv_task_handler();
+        } else if (timeout) {
+            shutdown();
+        }
         usleep(5000);
     }