Add BoxArtManager for loading box art with caching

app/http/boxartmanager.cpp

@@ -0,0 +1,77 @@
+#include "boxartmanager.h"
+
+#include <QStandardPaths>
+#include <QImageReader>
+#include <QImageWriter>
+
+BoxArtManager::BoxArtManager(QObject *parent) :
+    QObject(parent),
+    m_BoxArtDir(
+        QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + "/boxart"),
+    m_PlaceholderImage(":/res/no_app_image.png")
+{
+    if (!m_BoxArtDir.exists()) {
+        m_BoxArtDir.mkpath(".");
+    }
+}
+
+QString
+BoxArtManager::getFilePathForBoxArt(NvComputer* computer, int appId)
+{
+    QDir dir = m_BoxArtDir;
+
+    // Create the cache directory if it did not already exist
+    if (!dir.exists(computer->uuid)) {
+        dir.mkdir(computer->uuid);
+    }
+
+    // Change to this computer's box art cache folder
+    dir.cd(computer->uuid);
+
+    // Try to open the cached file
+    return dir.filePath(QString::number(appId) + ".png");
+}
+
+QImage BoxArtManager::loadBoxArt(NvComputer* computer, NvApp& app)
+{
+    // Try to open the cached file
+    QFile cacheFile(getFilePathForBoxArt(computer, app.id));
+    if (cacheFile.open(QFile::ReadOnly)) {
+        // Return what we have if it's a valid image
+        QImage image = QImageReader(&cacheFile).read();
+        if (!image.isNull()) {
+            return image;
+        }
+    }
+
+    // If we get here, we need to fetch asynchronously.
+    // Kick off a worker on our thread pool to do just that.
+    NetworkBoxArtLoadTask* netLoadTask = new NetworkBoxArtLoadTask(this, computer, app);
+    QThreadPool::globalInstance()->start(netLoadTask);
+
+    // Return the placeholder then we can notify the caller
+    // later when the real image is ready.
+    return m_PlaceholderImage;
+}
+
+void BoxArtManager::handleBoxArtLoadComplete(NvComputer* computer, NvApp app, QImage image)
+{
+    emit boxArtLoadComplete(computer, app, image);
+}
+
+QImage BoxArtManager::loadBoxArtFromNetwork(NvComputer* computer, int appId)
+{
+    NvHTTP http(computer->activeAddress);
+
+    QImage image;
+    try {
+        image = http.getBoxArt(appId);
+    } catch (...) {}
+
+    // Cache the box art on disk if it loaded
+    if (!image.isNull()) {
+        image.save(getFilePathForBoxArt(computer, appId));
+    }
+
+    return image;
+}

app/http/boxartmanager.h

@@ -0,0 +1,73 @@
+#pragma once
+
+#include "computermanager.h"
+#include <QDir>
+#include <QImage>
+#include <QThreadPool>
+#include <QRunnable>
+
+class BoxArtManager : public QObject
+{
+    Q_OBJECT
+
+    friend class NetworkBoxArtLoadTask;
+
+public:
+    explicit BoxArtManager(QObject *parent = nullptr);
+
+    QImage
+    loadBoxArt(NvComputer* computer, NvApp& app);
+
+signals:
+    void
+    boxArtLoadComplete(NvComputer* computer, NvApp app, QImage image);
+
+public slots:
+
+private slots:
+    void
+    handleBoxArtLoadComplete(NvComputer* computer, NvApp app, QImage image);
+
+private:
+    QImage
+    loadBoxArtFromNetwork(NvComputer* computer, int appId);
+
+    QString
+    getFilePathForBoxArt(NvComputer* computer, int appId);
+
+    QDir m_BoxArtDir;
+    QImage m_PlaceholderImage;
+};
+
+class NetworkBoxArtLoadTask : public QObject, public QRunnable
+{
+    Q_OBJECT
+
+public:
+    NetworkBoxArtLoadTask(BoxArtManager* boxArtManager, NvComputer* computer, NvApp& app)
+        : m_Bam(boxArtManager),
+          m_Computer(computer),
+          m_App(app)
+    {
+        connect(this, SIGNAL(boxArtFetchCompleted(NvComputer*,NvApp,QImage)),
+                boxArtManager, SLOT(handleBoxArtLoadComplete(NvComputer*,NvApp,QImage)));
+    }
+
+signals:
+    void boxArtFetchCompleted(NvComputer* computer, NvApp app, QImage image);
+
+private:
+    void run()
+    {
+        QImage image = m_Bam->loadBoxArtFromNetwork(m_Computer, m_App.id);
+        if (image.isNull()) {
+            // Give it another shot if it fails once
+            image = m_Bam->loadBoxArtFromNetwork(m_Computer, m_App.id);
+        }
+        emit boxArtFetchCompleted(m_Computer, m_App, image);
+    }
+
+    BoxArtManager* m_Bam;
+    NvComputer* m_Computer;
+    NvApp m_App;
+};

app/http/nvhttp.h

@@ -25,6 +25,8 @@ public:
     bool hdrSupported;
 };
 
+Q_DECLARE_METATYPE(NvApp)
+
 class GfeHttpResponseException : public std::exception
 {
 public: