feat(backlight): hide if the display is powered off

include/modules/backlight.hpp

@@ -18,12 +18,14 @@ class Backlight : public AButton {
   class BacklightDev {
    public:
     BacklightDev() = default;
-    BacklightDev(std::string name, int actual, int max);
+    BacklightDev(std::string name, int actual, int max, bool powered);
     std::string_view name() const;
     int get_actual() const;
     void set_actual(int actual);
     int get_max() const;
     void set_max(int max);
+    bool get_powered() const;
+    void set_powered(bool powered);
     friend inline bool operator==(const BacklightDev &lhs, const BacklightDev &rhs) {
       return lhs.name_ == rhs.name_ && lhs.actual_ == rhs.actual_ && lhs.max_ == rhs.max_;
     }
@@ -32,6 +34,7 @@ class Backlight : public AButton {
     std::string name_;
     int actual_ = 1;
     int max_ = 1;
+    bool powered_ = true;
   };
 
  public:

src/modules/backlight.cpp

@@ -73,8 +73,8 @@ void check_nn(const void *ptr, const char *message = "ptr was null") {
 }
 }  // namespace
 
-waybar::modules::Backlight::BacklightDev::BacklightDev(std::string name, int actual, int max)
+waybar::modules::Backlight::BacklightDev::BacklightDev(std::string name, int actual, int max, bool powered)
-    : name_(std::move(name)), actual_(actual), max_(max) {}
+    : name_(std::move(name)), actual_(actual), max_(max), powered_(powered) {}
 
 std::string_view waybar::modules::Backlight::BacklightDev::name() const { return name_; }
 
@@ -86,6 +86,10 @@ int waybar::modules::Backlight::BacklightDev::get_max() const { return max_; }
 
 void waybar::modules::Backlight::BacklightDev::set_max(int max) { max_ = max; }
 
+bool waybar::modules::Backlight::BacklightDev::get_powered() const { return powered_; }
+
+void waybar::modules::Backlight::BacklightDev::set_powered(bool powered) { powered_ = powered; }
+
 waybar::modules::Backlight::Backlight(const std::string &id, const Json::Value &config)
     : AButton(config, "backlight", id, "{percent}%", 2),
       preferred_device_(config["device"].isString() ? config["device"].asString() : "") {
@@ -172,21 +176,15 @@ auto waybar::modules::Backlight::update() -> void {
       return;
     }
 
-    const uint8_t percent =
+    if (best->get_powered()) {
-        best->get_max() == 0 ? 100 : round(best->get_actual() * 100.0f / best->get_max());
-
-    auto format = format_;
-    auto state = getState(percent);
-    if (!state.empty() && config_["format-" + state].isString()) {
-      format = config_["format-" + state].asString();
-    }
-
-    if (format.empty()) {
-      event_box_.hide();
-    } else {
       event_box_.show();
-      label_->set_markup(fmt::format(format, fmt::arg("percent", std::to_string(percent)),
+      const uint8_t percent =
+          best->get_max() == 0 ? 100 : round(best->get_actual() * 100.0f / best->get_max());
+      label_->set_markup(fmt::format(format_, fmt::arg("percent", std::to_string(percent)),
                                      fmt::arg("icon", getIcon(percent))));
+      getState(percent);
+    } else {
+      event_box_.hide();
     }
   } else {
     if (!previous_best_.has_value()) {
@@ -226,6 +224,7 @@ void waybar::modules::Backlight::upsert_device(ForwardIt first, ForwardIt last,
 
   const char *actual = udev_device_get_sysattr_value(dev, actual_brightness_attr);
   const char *max = udev_device_get_sysattr_value(dev, "max_brightness");
+  const char *power = udev_device_get_sysattr_value(dev, "bl_power");
 
   auto found =
       std::find_if(first, last, [name](const auto &device) { return device.name() == name; });
@@ -236,10 +235,14 @@ void waybar::modules::Backlight::upsert_device(ForwardIt first, ForwardIt last,
     if (max != nullptr) {
       found->set_max(std::stoi(max));
     }
+    if (power != nullptr) {
+      found->set_powered(std::stoi(power) == 0);
+    }
   } else {
     const int actual_int = actual == nullptr ? 0 : std::stoi(actual);
     const int max_int = max == nullptr ? 0 : std::stoi(max);
-    *inserter = BacklightDev{name, actual_int, max_int};
+    const bool power_bool = power == nullptr ? true : std::stoi(power) == 0;
+    *inserter = BacklightDev{name, actual_int, max_int, power_bool};
     ++inserter;
   }
 }