1 files changed, 227 insertions, 9 deletions

diff --git a/src/filetree.cpp b/src/filetree.cpp
index d7a61898..0d9a1414 100644
--- a/src/filetree.cpp
+++ b/src/filetree.cpp
@@ -83,6 +83,11 @@ QString FileTreeItem::dataRelativeFilePath() const
   return path += m_file;
 }
 
+const QString& FileTreeItem::realPath() const
+{
+  return m_realPath;
+}
+
 const QString& FileTreeItem::filename() const
 {
   return m_file;
@@ -154,12 +159,209 @@ QString FileTreeItem::debugName() const
 }
 
 
+class FileTreeModel::IconFetcher
+{
+public:
+  IconFetcher()
+    : m_iconSize(GetSystemMetrics(SM_CXSMICON)), m_stop(false)
+  {
+    m_quickCache.file = getPixmapIcon(QFileIconProvider::File);
+    m_quickCache.directory = getPixmapIcon(QFileIconProvider::Folder);
+
+    m_thread = std::thread([&]{ threadFun(); });
+  }
+
+  ~IconFetcher()
+  {
+    stop();
+    m_thread.join();
+  }
+
+  void stop()
+  {
+    m_stop = true;
+    m_waiter.wakeUp();
+  }
+
+  QVariant icon(const QString& path) const
+  {
+    if (hasOwnIcon(path)) {
+      return fileIcon(path);
+    } else {
+      const auto dot = path.lastIndexOf(".");
+
+      if (dot == -1) {
+        // no extension
+        return m_quickCache.file;
+      }
+
+      return extensionIcon(path.midRef(dot));
+    }
+  }
+
+  QPixmap genericFileIcon() const
+  {
+    return m_quickCache.file;
+  }
+
+  QPixmap genericDirectoryIcon() const
+  {
+    return m_quickCache.directory;
+  }
+
+private:
+  struct QuickCache
+  {
+    QPixmap file;
+    QPixmap directory;
+  };
+
+  struct Cache
+  {
+    std::map<QString, QPixmap, std::less<>> map;
+    std::mutex mapMutex;
+
+    std::set<QString> queue;
+    std::mutex queueMutex;
+  };
+
+  struct Waiter
+  {
+    mutable std::mutex m_wakeUpMutex;
+    std::condition_variable m_wakeUp;
+    bool m_queueAvailable = false;
+
+    void wait()
+    {
+      std::unique_lock lock(m_wakeUpMutex);
+      m_wakeUp.wait(lock, [&]{ return m_queueAvailable; });
+      m_queueAvailable = false;
+    }
+
+    void wakeUp()
+    {
+      {
+        std::scoped_lock lock(m_wakeUpMutex);
+        m_queueAvailable = true;
+      }
+
+      m_wakeUp.notify_one();
+    }
+  };
+
+  const int m_iconSize;
+  QFileIconProvider m_provider;
+  std::thread m_thread;
+  std::atomic<bool> m_stop;
+
+  mutable QuickCache m_quickCache;
+  mutable Cache m_extensionCache;
+  mutable Cache m_fileCache;
+  mutable Waiter m_waiter;
+
+
+  bool hasOwnIcon(const QString& path) const
+  {
+    static const QString exe = ".exe";
+    static const QString lnk = ".lnk";
+    static const QString ico = ".ico";
+
+    return
+      path.endsWith(exe, Qt::CaseInsensitive) ||
+      path.endsWith(lnk, Qt::CaseInsensitive) ||
+      path.endsWith(ico, Qt::CaseInsensitive);
+  }
+
+  template <class T>
+  QPixmap getPixmapIcon(T&& t) const
+  {
+    return m_provider.icon(t).pixmap({m_iconSize, m_iconSize});
+  }
+
+  void threadFun()
+  {
+    while (!m_stop) {
+      m_waiter.wait();
+      if (m_stop) {
+        break;
+      }
+
+      checkCache(m_extensionCache);
+      checkCache(m_fileCache);
+    }
+  }
+
+  void checkCache(Cache& cache)
+  {
+    std::set<QString> queue;
+
+    {
+      std::scoped_lock lock(cache.queueMutex);
+      queue = std::move(cache.queue);
+    }
+
+    if (queue.empty()) {
+      return;
+    }
+
+    std::map<QString, QPixmap> map;
+    for (auto&& ext : queue) {
+      map.emplace(std::move(ext), getPixmapIcon(ext));
+    }
+
+    {
+      std::scoped_lock lock(cache.mapMutex);
+      for (auto&& p : map) {
+        cache.map.insert(std::move(p));
+      }
+    }
+  }
+
+  void queue(Cache& cache, QString path) const
+  {
+    {
+      std::scoped_lock lock(cache.queueMutex);
+      cache.queue.insert(std::move(path));
+    }
+
+    m_waiter.wakeUp();
+  }
+
+  QVariant fileIcon(const QString& path) const
+  {
+    {
+      std::scoped_lock lock(m_fileCache.mapMutex);
+      auto itor = m_fileCache.map.find(path);
+      if (itor != m_fileCache.map.end()) {
+        return itor->second;
+      }
+    }
+
+    queue(m_fileCache, path);
+    return {};
+  }
+
+  QVariant extensionIcon(const QStringRef& ext) const
+  {
+    {
+      std::scoped_lock lock(m_extensionCache.mapMutex);
+      auto itor = m_extensionCache.map.find(ext);
+      if (itor != m_extensionCache.map.end()) {
+        return itor->second;
+      }
+    }
+
+    queue(m_extensionCache, ext.toString());
+    return {};
+  }
+};
+
+
 FileTreeModel::FileTreeModel(OrganizerCore& core, QObject* parent)
   : QAbstractItemModel(parent), m_core(core), m_flags(NoFlags)
 {
-  QFileIconProvider provider;
-  m_fileIcon = provider.icon(QFileIconProvider::File);
-  m_directoryIcon = provider.icon(QFileIconProvider::Folder);
+  m_iconFetcher.reset(new IconFetcher);
+  connect(&m_iconPendingTimer, &QTimer::timeout, [&]{ updatePendingIcons(); });
 }
 
 void FileTreeModel::setFlags(Flags f)
@@ -496,12 +698,16 @@ QVariant FileTreeModel::data(const QModelIndex& index, int role) const
     {
       if (index.column() == 0) {
         if (auto* item=itemFromIndex(index)) {
-          const auto iconType = item->icon();
-
-          if (iconType == QFileIconProvider::File) {
-            return m_fileIcon;
-          } else if (iconType == QFileIconProvider::Folder) {
-            return m_directoryIcon;
+          if (item->isDirectory()) {
+            return m_iconFetcher->genericDirectoryIcon();
+          } else {
+            auto v = m_iconFetcher->icon(item->realPath());
+            if (v.isNull()) {
+              m_iconPending.push_back(index);
+              m_iconPendingTimer.start(std::chrono::milliseconds(1));
+              return m_iconFetcher->genericFileIcon();
+            }
+            return v;
           }
         }
       }
@@ -513,6 +719,18 @@ QVariant FileTreeModel::data(const QModelIndex& index, int role) const
   return {};
 }
 
+void FileTreeModel::updatePendingIcons()
+{
+  log::debug("updating {} pending icons", m_iconPending.size());
+
+  for (auto&& index : m_iconPending) {
+    emit dataChanged(index, index, {Qt::DecorationRole});
+  }
+
+  m_iconPending.clear();
+  m_iconPendingTimer.stop();
+}
+
 QVariant FileTreeModel::headerData(int i, Qt::Orientation ori, int role) const
 {
   if (role == Qt::DisplayRole) {