Fetch updated gamepad mappings each launch

app/settings/mappingfetcher.cpp

@@ -0,0 +1,52 @@
+#include "mappingfetcher.h"
+#include "path.h"
+
+#include <QNetworkReply>
+
+MappingFetcher::MappingFetcher(QObject *parent) :
+    QObject(parent),
+    m_Nam(this)
+{
+    // Never communicate over HTTP
+    m_Nam.setStrictTransportSecurityEnabled(true);
+
+    // Allow HTTP redirects
+    m_Nam.setRedirectPolicy(QNetworkRequest::NoLessSafeRedirectPolicy);
+
+    connect(&m_Nam, SIGNAL(finished(QNetworkReply*)),
+            this, SLOT(handleMappingListFetched(QNetworkReply*)));
+}
+
+void MappingFetcher::start()
+{
+#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0) && QT_VERSION < QT_VERSION_CHECK(5, 15, 1) && !defined(QT_NO_BEARERMANAGEMENT)
+    // HACK: Set network accessibility to work around QTBUG-80947 (introduced in Qt 5.14.0 and fixed in Qt 5.15.1)
+    QT_WARNING_PUSH
+    QT_WARNING_DISABLE_DEPRECATED
+    m_Nam.setNetworkAccessible(QNetworkAccessManager::Accessible);
+    QT_WARNING_POP
+#endif
+
+    // We'll get a callback when this is finished
+    QUrl url("https://moonlight-stream.org/SDL_GameControllerDB/gamecontrollerdb.txt");
+    m_Nam.get(QNetworkRequest(url));
+}
+
+void MappingFetcher::handleMappingListFetched(QNetworkReply* reply)
+{
+    Q_ASSERT(reply->isFinished());
+
+    if (reply->error() == QNetworkReply::NoError) {
+        // Queue the reply for deletion
+        reply->deleteLater();
+
+        // Update the cached data on disk for next call to applyMappings()
+        Path::writeDataFile("gamecontrollerdb.txt", reply->readAll());
+
+        qInfo() << "Downloaded updated gamepad mappings";
+    }
+    else {
+        qWarning() << "Failed to download updated gamepad mappings:" << reply->error();
+        reply->deleteLater();
+    }
+}

app/settings/mappingfetcher.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <QObject>
+#include <QNetworkAccessManager>
+
+class MappingFetcher : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit MappingFetcher(QObject *parent = nullptr);
+
+    void start();
+
+private slots:
+    void handleMappingListFetched(QNetworkReply* reply);
+
+private:
+    QNetworkAccessManager m_Nam;
+};

app/settings/mappingmanager.cpp

@@ -10,10 +10,18 @@
 #define SER_GUID "guid"
 #define SER_MAPPING "mapping"
 
+MappingFetcher* MappingManager::s_MappingFetcher;
+
 MappingManager::MappingManager()
 {
     QSettings settings;
 
+    // Load updated mappings from the Internet once per Moonlight launch
+    if (s_MappingFetcher == nullptr) {
+        s_MappingFetcher = new MappingFetcher();
+        s_MappingFetcher->start();
+    }
+
     // First load existing saved mappings. This ensures the user's
     // hints can always override the old data.
     int mappingCount = settings.beginReadArray(SER_GAMEPADMAPPING);

app/settings/mappingmanager.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "mappingfetcher.h"
+
 #include <QSettings>
 
 class SdlGamepadMapping
@@ -70,5 +72,7 @@ public:
 
 private:
     QMap<QString, SdlGamepadMapping> m_Mappings;
+
+    static MappingFetcher* s_MappingFetcher;
 };