initial commit

SystemInfo.cpp

@@ -0,0 +1,89 @@
+#include "SystemInfo.h"
+
+#include <QDir>
+#include <QFile>
+#include <QTextStream>
+
+SystemInfo::SystemInfo(QObject *parent)
+    : QObject(parent)
+{
+    m_capacityPath = findBatteryCapacityPath();
+
+    updateBattery();
+
+    connect(&m_batteryTimer,
+            &QTimer::timeout,
+            this,
+            &SystemInfo::updateBattery);
+
+    // Battery percentage doesn't need millisecond precision.
+    m_batteryTimer.start(10000);
+}
+
+int SystemInfo::batteryPercent() const
+{
+    return m_batteryPercent;
+}
+
+QString SystemInfo::findBatteryCapacityPath() const
+{
+    QDir powerSupply("/sys/class/power_supply");
+
+    const QStringList devices =
+        powerSupply.entryList(QDir::Dirs | QDir::NoDotAndDotDot);
+
+    for (const QString &device : devices) {
+        const QString base =
+            powerSupply.absoluteFilePath(device);
+
+        QFile typeFile(base + "/type");
+
+        if (!typeFile.open(QIODevice::ReadOnly | QIODevice::Text))
+            continue;
+
+        const QString type =
+            QString::fromUtf8(typeFile.readAll()).trimmed();
+
+        if (type != "Battery")
+            continue;
+
+        const QString capacityPath = base + "/capacity";
+
+        if (QFile::exists(capacityPath))
+            return capacityPath;
+    }
+
+    return {};
+}
+
+void SystemInfo::updateBattery()
+{
+    if (m_capacityPath.isEmpty())
+        m_capacityPath = findBatteryCapacityPath();
+
+    if (m_capacityPath.isEmpty())
+        return;
+
+    QFile capacityFile(m_capacityPath);
+
+    if (!capacityFile.open(QIODevice::ReadOnly | QIODevice::Text))
+        return;
+
+    bool ok = false;
+
+    int percent =
+        QString::fromUtf8(capacityFile.readAll())
+            .trimmed()
+            .toInt(&ok);
+
+    if (!ok)
+        return;
+
+    percent = qBound(0, percent, 100);
+
+    if (percent == m_batteryPercent)
+        return;
+
+    m_batteryPercent = percent;
+    emit batteryPercentChanged();
+}