[desktop] Clean up game list code, fix external watcher crash, and fix macOS flickering (#4106)

- Remove unnecessary icon update code (the UI reloads this stuff anyways); test on Windows please
- Cleaned up a bunch of duplicated/unused code within the game list
- Fix the game list constantly reloading on macOS
  * When you reconstruct the entire directory list on the watcher the directoryChanged signal fires on macOS--seems like a behavioral change that occurred somewhere in the 6.8 release cycle--and it would enter an infinite loop very quickly
  * To fix this, only the differences between the current and old watch list are accounted for on both ends.
  * Since this bug is now fixed, macOS uses Qt 6.11.1 now. Should theoretically improve our situation.
- Fix the external content watcher crashing; the worker would attempt to read files that didn't exist without any bounds since its cache was still pointing to that file.

This supersedes and replaces #4099.

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4106
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

4 files changed, 73 insertions, 150 deletions

diff --git a/src/qt_common/game_list/game_list_p.h b/src/qt_common/game_list/game_list_p.h
index 3994887755..a5297d0db3 100644
--- a/src/qt_common/game_list/game_list_p.h
+++ b/src/qt_common/game_list/game_list_p.h
@@ -48,6 +48,14 @@ static QPixmap GetDefaultIcon(u32 size) {
     return icon;
 }
 
+static QPixmap ThemeIcon(const char* name) {
+    const int size = UISettings::values.folder_icon_size.GetValue();
+
+    return QIcon::fromTheme(QLatin1String(name))
+        .pixmap(size, size)
+        .scaled(size, size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
+}
+
 class GameListItem : public QStandardItem {
 
 public:
@@ -296,45 +304,33 @@ public:
         UISettings::GameDir* game_dir = &directory;
         setData(QVariant(UISettings::values.game_dirs.indexOf(directory)), GameDirRole);
 
-        const int icon_size = UISettings::values.folder_icon_size.GetValue();
+        const char* icon_name = nullptr;
+
         switch (dir_type) {
         case GameListItemType::SdmcDir:
-            setData(
-                QIcon::fromTheme(QStringLiteral("sd_card"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
+            icon_name = "sd_card";
             setData(QObject::tr("Installed SD Titles"), Qt::DisplayRole);
             break;
         case GameListItemType::UserNandDir:
-            setData(
-                QIcon::fromTheme(QStringLiteral("chip"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
+            icon_name = "chip";
             setData(QObject::tr("Installed NAND Titles"), Qt::DisplayRole);
             break;
         case GameListItemType::SysNandDir:
-            setData(
-                QIcon::fromTheme(QStringLiteral("chip"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
+            icon_name = "chip";
             setData(QObject::tr("System Titles"), Qt::DisplayRole);
             break;
         case GameListItemType::CustomDir: {
             const QString path = QString::fromStdString(game_dir->path);
-            const QString icon_name =
-                QFileInfo::exists(path) ? QStringLiteral("folder") : QStringLiteral("bad_folder");
-            setData(QIcon::fromTheme(icon_name).pixmap(icon_size).scaled(
-                        icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                    Qt::DecorationRole);
+            icon_name = QFileInfo::exists(path) ? "folder" : "bad_folder";
             setData(path, Qt::DisplayRole);
             break;
         }
         default:
             break;
         }
+
+        if (icon_name != nullptr)
+            setData(ThemeIcon(icon_name), Qt::DecorationRole);
     }
 
     int type() const override {
@@ -357,12 +353,7 @@ public:
     explicit GameListAddDir() {
         setData(type(), TypeRole);
 
-        const int icon_size = UISettings::values.folder_icon_size.GetValue();
-
-        setData(QIcon::fromTheme(QStringLiteral("list-add"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
+        setData(ThemeIcon("list-add"), Qt::DecorationRole);
         setData(QObject::tr("Add New Game Directory"), Qt::DisplayRole);
     }
 
@@ -380,12 +371,7 @@ public:
     explicit GameListFavorites() {
         setData(type(), TypeRole);
 
-        const int icon_size = UISettings::values.folder_icon_size.GetValue();
-
-        setData(QIcon::fromTheme(QStringLiteral("star"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
+        setData(ThemeIcon("star"), Qt::DecorationRole);
         setData(QObject::tr("Favorites"), Qt::DisplayRole);
     }
 
diff --git a/src/qt_common/game_list/model.cpp b/src/qt_common/game_list/model.cpp
index 91ec80c525..5c1042b002 100644
--- a/src/qt_common/game_list/model.cpp
+++ b/src/qt_common/game_list/model.cpp
@@ -19,8 +19,8 @@
 #include "qt_common/util/game.h"
 
 #include "qt_common/game_list/game_list_p.h"
-#include "qt_common/game_list/worker.h"
 #include "qt_common/game_list/model.h"
+#include "qt_common/game_list/worker.h"
 
 GameListModel::GameListModel(std::shared_ptr<FileSys::VfsFilesystem> vfs_,
                              FileSys::ManualContentProvider* provider_,
@@ -36,6 +36,8 @@ GameListModel::GameListModel(std::shared_ptr<FileSys::VfsFilesystem> vfs_,
     connect(external_watcher, &QFileSystemWatcher::directoryChanged, this,
             &GameListModel::RefreshExternalContent);
 
+    ResetExternalWatcher();
+
     insertColumns(0, COLUMN_COUNT);
     RetranslateUI();
 
@@ -45,6 +47,8 @@ GameListModel::GameListModel(std::shared_ptr<FileSys::VfsFilesystem> vfs_,
 GameListModel::~GameListModel() = default;
 
 void GameListModel::PopulateAsync(QVector<UISettings::GameDir>& game_dirs) {
+    emit PopulatingStarted();
+
     current_worker.reset();
     removeRows(0, rowCount());
 
@@ -57,12 +61,6 @@ void GameListModel::PopulateAsync(QVector<UISettings::GameDir>& game_dirs) {
     QThreadPool::globalInstance()->start(current_worker.get());
 }
 
-void GameListModel::StopWorker() {
-    // ~GameListWorker sets stop_requested and blocks until run() finishes, so this returns only
-    // once the worker is no longer touching the content providers.
-    current_worker.reset();
-}
-
 void GameListModel::WorkerEvent() {
     current_worker->ProcessEvents(this);
 }
@@ -203,24 +201,25 @@ void GameListModel::LoadCompatibilityList() {
     }
 }
 
+void GameListModel::Repopulate() {
+    current_worker.reset();
+    QtCommon::system->GetFileSystemController().CreateFactories(*QtCommon::vfs);
+    PopulateAsync(UISettings::values.game_dirs);
+}
+
 void GameListModel::RefreshGameDirectory() {
     ResetExternalWatcher();
-
     if (!UISettings::values.game_dirs.empty() && current_worker != nullptr) {
         LOG_INFO(Frontend, "Change detected in the games directory. Reloading game list.");
-        StopWorker();
-        QtCommon::system->GetFileSystemController().CreateFactories(*QtCommon::vfs);
-        PopulateAsync(UISettings::values.game_dirs);
+        Repopulate();
     }
 }
 
 void GameListModel::RefreshExternalContent() {
     if (!UISettings::values.game_dirs.empty() && current_worker != nullptr) {
         LOG_INFO(Frontend, "External content directory changed. Clearing metadata cache.");
-        StopWorker();
         QtCommon::Game::ResetMetadata(false);
-        QtCommon::system->GetFileSystemController().CreateFactories(*QtCommon::vfs);
-        PopulateAsync(UISettings::values.game_dirs);
+        Repopulate();
     }
 }
 
@@ -235,60 +234,6 @@ void GameListModel::ResetExternalWatcher() {
     }
 }
 
-void GameListModel::OnUpdateThemedIcons() {
-    for (int i = 0; i < invisibleRootItem()->rowCount(); i++) {
-        QStandardItem* child = invisibleRootItem()->child(i);
-
-        const int icon_size = UISettings::values.folder_icon_size.GetValue();
-
-        switch (child->data(GameListItem::TypeRole).value<GameListItemType>()) {
-        case GameListItemType::SdmcDir:
-            child->setData(
-                QIcon::fromTheme(QStringLiteral("sd_card"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
-            break;
-        case GameListItemType::UserNandDir:
-        case GameListItemType::SysNandDir:
-            child->setData(
-                QIcon::fromTheme(QStringLiteral("chip"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
-            break;
-        case GameListItemType::CustomDir: {
-            const UISettings::GameDir& game_dir =
-                UISettings::values.game_dirs[child->data(GameListDir::GameDirRole).toInt()];
-            const QString icon_name = QFileInfo::exists(QString::fromStdString(game_dir.path))
-                                          ? QStringLiteral("folder")
-                                          : QStringLiteral("bad_folder");
-            child->setData(
-                QIcon::fromTheme(icon_name).pixmap(icon_size).scaled(
-                    icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
-            break;
-        }
-        case GameListItemType::AddDir:
-            child->setData(
-                QIcon::fromTheme(QStringLiteral("list-add"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
-            break;
-        case GameListItemType::Favorites:
-            child->setData(
-                QIcon::fromTheme(QStringLiteral("star"))
-                    .pixmap(icon_size)
-                    .scaled(icon_size, icon_size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation),
-                Qt::DecorationRole);
-            break;
-        default:
-            break;
-        }
-    }
-}
-
 void GameListModel::RetranslateUI() {
     setHeaderData(COLUMN_NAME, Qt::Horizontal, tr("Name"));
     setHeaderData(COLUMN_COMPATIBILITY, Qt::Horizontal, tr("Compatibility"));
diff --git a/src/qt_common/game_list/model.h b/src/qt_common/game_list/model.h
index ce1fcc87b7..c8661e2fd1 100644
--- a/src/qt_common/game_list/model.h
+++ b/src/qt_common/game_list/model.h
@@ -3,11 +3,11 @@
 
 #pragma once
 
+#include <memory>
 #include <QFileSystemWatcher>
 #include <QStandardItemModel>
 #include <QStringList>
 #include <QVector>
-#include <memory>
 
 #include "common/common_types.h"
 #include "frontend_common/play_time_manager.h"
@@ -52,10 +52,6 @@ public:
     void DonePopulating(const QStringList& watch_list);
 
     void PopulateAsync(QVector<UISettings::GameDir>& game_dirs);
-    // Stops and joins the running populate worker, if any. Must be called before rebuilding the
-    // content providers (CreateFactories), otherwise the worker keeps scanning a cache that is
-    // being torn down underneath it.
-    void StopWorker();
     void WorkerEvent();
 
     bool IsEmpty() const;
@@ -68,7 +64,6 @@ public:
 
     void LoadCompatibilityList();
 
-    void OnUpdateThemedIcons();
     void RetranslateUI();
 
     QFileSystemWatcher* GetWatcher() const;
@@ -80,6 +75,7 @@ public:
 signals:
     void ShowList(bool show);
     void PopulatingCompleted(const QStringList& watch_list);
+    void PopulatingStarted();
     void SaveConfig();
 
 private:
@@ -87,6 +83,7 @@ private:
 
     void AddFavorite(u64 program_id);
     void RemoveFavorite(u64 program_id);
+    void Repopulate();
 
     bool m_flat = false;
 
diff --git a/src/qt_common/game_list/worker.cpp b/src/qt_common/game_list/worker.cpp
index f1499265c6..5cd68996c5 100644
--- a/src/qt_common/game_list/worker.cpp
+++ b/src/qt_common/game_list/worker.cpp
@@ -32,11 +32,11 @@
 #include "qt_common/config/uisettings.h"
 #include "qt_common/qt_common.h"
 
-#include "yuzu/compatibility_list.h"
 #include "qt_common/game_list/game_list_p.h"
+#include "yuzu/compatibility_list.h"
 
-#include "qt_common/game_list/worker.h"
 #include "qt_common/game_list/model.h"
+#include "qt_common/game_list/worker.h"
 
 namespace {
 
@@ -391,6 +391,25 @@ void GameListWorker::ScanFileSystem(ScanTarget target, const std::string& dir_pa
                 std::vector<u64> program_ids;
                 loader->ReadProgramIds(program_ids);
 
+                const auto addEntry = [this, physical_name,
+                                       parent_dir](std::unique_ptr<Loader::AppLoader>& app_loader,
+                                                   const u64 id) {
+                    std::vector<u8> icon;
+                    [[maybe_unused]] const auto res1 = app_loader->ReadIcon(icon);
+
+                    std::string name = " ";
+                    [[maybe_unused]] const auto res3 = app_loader->ReadTitle(name);
+
+                    const FileSys::PatchManager patch{id, system.GetFileSystemController(),
+                                                      system.GetContentProvider()};
+
+                    auto entry = MakeGameListEntry(
+                        physical_name, name, Common::FS::GetSize(physical_name), icon, *app_loader,
+                        id, compatibility_list, play_time_manager, patch);
+
+                    RecordEvent([=](GameListModel* model) { model->AddEntry(entry, parent_dir); });
+                };
+
                 if (res2 == Loader::ResultStatus::Success && program_ids.size() > 1 &&
                     (file_type == Loader::FileType::XCI || file_type == Loader::FileType::NSP)) {
                     for (const auto id : program_ids) {
@@ -404,38 +423,10 @@ void GameListWorker::ScanFileSystem(ScanTarget target, const std::string& dir_pa
                             continue;
                         }
 
-                        std::vector<u8> icon;
-                        [[maybe_unused]] const auto res1 = loader->ReadIcon(icon);
-
-                        std::string name = " ";
-                        [[maybe_unused]] const auto res3 = loader->ReadTitle(name);
-
-                        const FileSys::PatchManager patch{id, system.GetFileSystemController(),
-                                                          system.GetContentProvider()};
-
-                        auto entry = MakeGameListEntry(
-                            physical_name, name, Common::FS::GetSize(physical_name), icon, *loader,
-                            id, compatibility_list, play_time_manager, patch);
-
-                        RecordEvent(
-                            [=](GameListModel* model) { model->AddEntry(entry, parent_dir); });
+                        addEntry(loader, id);
                     }
                 } else {
-                    std::vector<u8> icon;
-                    [[maybe_unused]] const auto res1 = loader->ReadIcon(icon);
-
-                    std::string name = " ";
-                    [[maybe_unused]] const auto res3 = loader->ReadTitle(name);
-
-                    const FileSys::PatchManager patch{program_id, system.GetFileSystemController(),
-                                                      system.GetContentProvider()};
-
-                    auto entry = MakeGameListEntry(
-                        physical_name, name, Common::FS::GetSize(physical_name), icon, *loader,
-                        program_id, compatibility_list, play_time_manager, patch);
-
-                    RecordEvent(
-                        [=](GameListModel* model) { model->AddEntry(entry, parent_dir); });
+                    addEntry(loader, program_id);
                 }
             }
         } else if (is_dir) {
@@ -466,29 +457,33 @@ void GameListWorker::run() {
             break;
         }
 
+        GameListDir* game_list_dir;
+        bool scan = false;
+
         if (game_dir.path == std::string("SDMC")) {
-            auto* const game_list_dir = new GameListDir(game_dir, GameListItemType::SdmcDir);
-            DirEntryReady(game_list_dir);
-            AddTitlesToGameList(game_list_dir);
+            game_list_dir = new GameListDir(game_dir, GameListItemType::SdmcDir);
         } else if (game_dir.path == std::string("UserNAND")) {
-            auto* const game_list_dir = new GameListDir(game_dir, GameListItemType::UserNandDir);
-            DirEntryReady(game_list_dir);
-            AddTitlesToGameList(game_list_dir);
+            game_list_dir = new GameListDir(game_dir, GameListItemType::UserNandDir);
         } else if (game_dir.path == std::string("SysNAND")) {
-            auto* const game_list_dir = new GameListDir(game_dir, GameListItemType::SysNandDir);
-            DirEntryReady(game_list_dir);
-            AddTitlesToGameList(game_list_dir);
+            game_list_dir = new GameListDir(game_dir, GameListItemType::SysNandDir);
         } else {
             const QString qpath = QString::fromStdString(game_dir.path);
             if (QDir(qpath).exists()) {
                 watch_list.append(qpath);
             }
-            auto* const game_list_dir = new GameListDir(game_dir);
-            DirEntryReady(game_list_dir);
+
+            game_list_dir = new GameListDir(game_dir);
+            scan = true;
+        }
+
+        DirEntryReady(game_list_dir);
+        if (scan) {
             ScanFileSystem(ScanTarget::FillManualContentProvider, game_dir.path, game_dir.deep_scan,
                            game_list_dir);
             ScanFileSystem(ScanTarget::PopulateGameList, game_dir.path, game_dir.deep_scan,
                            game_list_dir);
+        } else {
+            AddTitlesToGameList(game_list_dir);
         }
     }