Introduce cpu_usage module

src/modules/cpu_usage/common.cpp

@@ -0,0 +1,78 @@
+#include "modules/cpu_usage.hpp"
+
+// In the 80000 version of fmt library authors decided to optimize imports
+// and moved declarations required for fmt::dynamic_format_arg_store in new
+// header fmt/args.h
+#if (FMT_VERSION >= 80000)
+#include <fmt/args.h>
+#else
+#include <fmt/core.h>
+#endif
+
+waybar::modules::CpuUsage::CpuUsage(const std::string& id, const Json::Value& config)
+    : AButton(config, "cpu_usage", id, "{usage}%", 10) {
+  thread_ = [this] {
+    dp.emit();
+    thread_.sleep_for(interval_);
+  };
+}
+
+auto waybar::modules::CpuUsage::update() -> void {
+  // TODO: as creating dynamic fmt::arg arrays is buggy we have to calc both
+  auto [cpu_usage, tooltip] = getCpuUsage();
+  if (tooltipEnabled()) {
+    button_.set_tooltip_text(tooltip);
+  }
+  auto format = format_;
+  auto total_usage = cpu_usage.empty() ? 0 : cpu_usage[0];
+  auto state = getState(total_usage);
+  if (!state.empty() && config_["format-" + state].isString()) {
+    format = config_["format-" + state].asString();
+  }
+
+  if (format.empty()) {
+    event_box_.hide();
+  } else {
+    event_box_.show();
+    auto icons = std::vector<std::string>{state};
+    fmt::dynamic_format_arg_store<fmt::format_context> store;
+    store.push_back(fmt::arg("usage", total_usage));
+    store.push_back(fmt::arg("icon", getIcon(total_usage, icons)));
+    for (size_t i = 1; i < cpu_usage.size(); ++i) {
+      auto core_i = i - 1;
+      auto core_format = fmt::format("usage{}", core_i);
+      store.push_back(fmt::arg(core_format.c_str(), cpu_usage[i]));
+      auto icon_format = fmt::format("icon{}", core_i);
+      store.push_back(fmt::arg(icon_format.c_str(), getIcon(cpu_usage[i], icons)));
+    }
+    label_->set_markup(fmt::vformat(format, store));
+  }
+
+  // Call parent update
+  AButton::update();
+}
+
+std::tuple<std::vector<uint16_t>, std::string> waybar::modules::CpuUsage::getCpuUsage() {
+  if (prev_times_.empty()) {
+    prev_times_ = parseCpuinfo();
+    std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  }
+  std::vector<std::tuple<size_t, size_t>> curr_times = parseCpuinfo();
+  std::string tooltip;
+  std::vector<uint16_t> usage;
+  for (size_t i = 0; i < curr_times.size(); ++i) {
+    auto [curr_idle, curr_total] = curr_times[i];
+    auto [prev_idle, prev_total] = prev_times_[i];
+    const float delta_idle = curr_idle - prev_idle;
+    const float delta_total = curr_total - prev_total;
+    uint16_t tmp = 100 * (1 - delta_idle / delta_total);
+    if (i == 0) {
+      tooltip = fmt::format("Total: {}%", tmp);
+    } else {
+      tooltip = tooltip + fmt::format("\nCore{}: {}%", i - 1, tmp);
+    }
+    usage.push_back(tmp);
+  }
+  prev_times_ = curr_times;
+  return {usage, tooltip};
+}