Various tweaks to improve the QFileSystemModel performance. Also slightly improved the initialization.

etc/Translation/LameXP_DE.ts

@@ -1842,6 +1842,10 @@
         <source>Show Favorites</source>
         <translation>Favoriten anzeigen</translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation>Verzeichnisbaum wird erzeugt, bitte warten...</translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_ES.ts

@@ -1841,6 +1841,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_FR.ts

@@ -1851,6 +1851,10 @@ Ouvrir le dossier récursivement...</translation>
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_IT.ts

@@ -1842,6 +1842,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_KR.ts

@@ -1841,6 +1841,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_RU.ts

@@ -1847,6 +1847,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_TW.ts

@@ -1841,6 +1841,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_UK.ts

@@ -1842,6 +1842,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

etc/Translation/LameXP_ZH.ts

@@ -1841,6 +1841,10 @@
         <source>Show Favorites</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Initializing directory outline, please be patient...</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>MetaInfo</name>

src/Config.h

@@ -30,7 +30,7 @@
 #define VER_LAMEXP_MINOR_LO					4
 #define VER_LAMEXP_TYPE						Beta
 #define VER_LAMEXP_PATCH					10
-#define VER_LAMEXP_BUILD					932
+#define VER_LAMEXP_BUILD					939
 
 ///////////////////////////////////////////////////////////////////////////////
 // Tool versions (minimum expected versions!)

src/Dialog_MainWindow.cpp

@@ -94,7 +94,7 @@ MainWindow::MainWindow(FileListModel *fileListModel, AudioFileModel *metaInfo, S
 	m_qaacEncoderAvailable(lamexp_check_tool("qaac.exe") && lamexp_check_tool("libsoxrate.dll")),
 	m_accepted(false),
 	m_firstTimeShown(true),
-	m_outputFolderViewInitialized(false),
+	m_outputFolderViewInitialized(3),
 	m_outputFolderViewCentering(false)
 {
 	//Init the dialog, from the .ui file
@@ -161,6 +161,7 @@ MainWindow::MainWindow(FileListModel *fileListModel, AudioFileModel *metaInfo, S
 	outputFolderView->setAnimated(false);
 	outputFolderView->setMouseTracking(false);
 	outputFolderView->setContextMenuPolicy(Qt::CustomContextMenu);
+	outputFolderView->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
 	outputFolderView->installEventFilter(this);
 	outputFoldersEditorLabel->installEventFilter(this);
 	outputFoldersFovoritesLabel->installEventFilter(this);
@@ -192,6 +193,11 @@ MainWindow::MainWindow(FileListModel *fileListModel, AudioFileModel *metaInfo, S
 	outputFolderLabel->installEventFilter(this);
 	outputFolderView->setCurrentIndex(m_fileSystemModel->index(m_settings->outputDir()));
 	outputFolderViewClicked(outputFolderView->currentIndex());
+	m_outputFolderNoteBox = new QLabel(outputFolderView);
+	m_outputFolderNoteBox->setAutoFillBackground(true);
+	m_outputFolderNoteBox->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
+	m_outputFolderNoteBox->setFrameShape(QFrame::StyledPanel);
+	SET_FONT_BOLD(m_outputFolderNoteBox, true);
 	refreshFavorites();
 	
 	//Setup "Meta Data" tab
@@ -711,6 +717,7 @@ void MainWindow::changeEvent(QEvent *e)
 
 		//Manually re-translate widgets that UIC doesn't handle
 		m_dropNoteLabel->setText(QString("» %1 «").arg(tr("You can drop in audio files here!")));
+		m_outputFolderNoteBox->setText(tr("Initializing directory outline, please be patient..."));
 		m_showDetailsContextAction->setText(tr("Show Details"));
 		m_previewContextAction->setText(tr("Open File in External Application"));
 		m_findFileContextAction->setText(tr("Browse File Location"));
@@ -826,8 +833,13 @@ void MainWindow::closeEvent(QCloseEvent *event)
  */
 void MainWindow::resizeEvent(QResizeEvent *event)
 {
-	QMainWindow::resizeEvent(event);
+	if(event) QMainWindow::resizeEvent(event);
 	m_dropNoteLabel->setGeometry(0, 0, sourceFileView->width(), sourceFileView->height());
+
+	if(QWidget *port = outputFolderView->viewport())
+	{
+		m_outputFolderNoteBox->setGeometry(16, (port->height() - 64) / 2, port->width() - 32,  64);
+	}
 }
 
 /*
@@ -1390,6 +1402,8 @@ void MainWindow::closeButtonClicked(void)
  */
 void MainWindow::tabPageChanged(int idx)
 {
+	resizeEvent(NULL);
+	
 	QList<QAction*> actions = m_tabActionGroup->actions();
 	for(int i = 0; i < actions.count(); i++)
 	{
@@ -1435,7 +1449,7 @@ void MainWindow::tabPageChanged(int idx)
 	}
 	else if(idx == tabWidget->indexOf(tabOutputDir))
 	{
-		if(!m_outputFolderViewInitialized)
+		if(m_outputFolderViewInitialized > 0)
 		{
 			QTimer::singleShot(125, this, SLOT(initOutputFolderModel()));
 		}
@@ -2517,8 +2531,9 @@ void MainWindow::makeFolderButtonClicked(void)
 				QDir createdDir = basePath;
 				if(createdDir.cd(newFolder))
 				{
-					outputFolderView->setCurrentIndex(m_fileSystemModel->index(createdDir.canonicalPath()));
+					QModelIndex newIndex = m_fileSystemModel->index(createdDir.canonicalPath());
-					outputFolderViewClicked(outputFolderView->currentIndex());
+					outputFolderView->setCurrentIndex(newIndex);
+					outputFolderViewClicked(newIndex);
 					CENTER_CURRENT_OUTPUT_FOLDER_DELAYED;
 				}
 			}
@@ -2661,9 +2676,26 @@ void MainWindow::outputFolderEditFinished(void)
  */
 void MainWindow::initOutputFolderModel(void)
 {
-	m_fileSystemModel->setRootPath("");
+	if(m_fileSystemModel) m_fileSystemModel->setRootPath("");
 	CENTER_CURRENT_OUTPUT_FOLDER_DELAYED;
-	m_outputFolderViewInitialized = true;
+	QTimer::singleShot(125, this, SLOT(initOutputFolderModel_doAsync()));
+}
+
+/*
+ * Initialize file system model (do NOT call this one directly!)
+ */
+void MainWindow::initOutputFolderModel_doAsync(void)
+{
+	if(m_outputFolderViewInitialized > 0)
+	{
+		m_outputFolderViewInitialized--;
+		QTimer::singleShot(125, this, SLOT(initOutputFolderModel_doAsync()));
+	}
+	else
+	{
+		QTimer::singleShot(125, m_outputFolderNoteBox, SLOT(hide()));
+		outputFolderView->setFocus();
+	}
 }
 
 /*

src/Dialog_MainWindow.h

@@ -94,6 +94,7 @@ private slots:
 	void importCueSheetActionTriggered(bool checked);
 	void importCsvContextActionTriggered(void);
 	void initOutputFolderModel(void);
+	void initOutputFolderModel_doAsync(void);
 	void languageActionActivated(QAction *action);
 	void languageFromFileActionActivated(bool checked);
 	void makeFolderButtonClicked(void);
@@ -165,7 +166,7 @@ private:
 	
 	bool m_accepted;
 	bool m_firstTimeShown;
-	bool m_outputFolderViewInitialized;
+	uint m_outputFolderViewInitialized;
 	bool m_outputFolderViewCentering;
 
 	const bool m_neroEncoderAvailable;
@@ -186,6 +187,7 @@ private:
 	SettingsModel *m_settings;
 	QMenu *m_sourceFilesContextMenu;
 	QMenu *m_outputFolderFavoritesMenu;
+	QLabel *m_outputFolderNoteBox;
 
 	QAction *m_findFileContextAction;
 	QAction *m_previewContextAction;

src/Model_FileSystem.cpp

@@ -26,6 +26,9 @@
 #include <QFileIconProvider>
 #include <QDesktopServices>
 
+#define IS_DIR(ATTR) (((ATTR) & FILE_ATTRIBUTE_DIRECTORY) && (!((ATTR) & FILE_ATTRIBUTE_HIDDEN)))
+#define NO_DOT_OR_DOTDOT(STR) (wcscmp((STR), L".") && wcscmp((STR), L".."))
+
 ///////////////////////////////////////////////////////////////////////////////
 // Dummy QFileIconProvider class
 ///////////////////////////////////////////////////////////////////////////////
@@ -154,8 +157,78 @@ bool QFileSystemModelEx::hasChildren(const QModelIndex &parent) const
 {
 	if(parent.isValid())
 	{
-		return (QDir(QFileSystemModel::filePath(parent)).entryList(QDir::Dirs | QDir::NoDotAndDotDot).count() > 0);
+		return (QFileSystemModel::rowCount(parent) > 0) || hasSubfoldersCached(filePath(parent));
 	}
 	
 	return true;
 }
+
+int QFileSystemModelEx::rowCount(const QModelIndex &parent) const
+{
+	if(parent.isValid())
+	{
+		removeFromCache(filePath(parent));
+	}
+
+	return QFileSystemModel::rowCount(parent);
+}
+
+void QFileSystemModelEx::fetchMore(const QModelIndex &parent)
+{
+	if(parent.isValid())
+	{
+		removeFromCache(filePath(parent));
+	}
+
+	QFileSystemModel::fetchMore(parent);
+}
+
+
+/* ------------------------ */
+/*  STATIC FUNCTIONS BELOW  */
+/* ------------------------ */
+
+QHash<const QString, bool> QFileSystemModelEx::s_hasFolderCache;
+QMutex QFileSystemModelEx::s_hasFolderMutex;
+
+bool QFileSystemModelEx::hasSubfoldersCached(const QString &path)
+{
+	QMutexLocker lock(&s_hasFolderMutex);
+	
+	if(s_hasFolderCache.contains(path))
+	{
+		return s_hasFolderCache.value(path);
+	}
+	
+	bool bChildren = hasSubfolders(path);
+	s_hasFolderCache.insert(path, bChildren);
+	return bChildren;
+}
+
+void QFileSystemModelEx::removeFromCache(const QString &path)
+{
+	QMutexLocker lock(&s_hasFolderMutex);
+	s_hasFolderCache.remove(path);
+}
+
+bool QFileSystemModelEx::hasSubfolders(const QString &path)
+{
+	bool bChildren = false; WIN32_FIND_DATAW findData;
+	HANDLE h = FindFirstFileW(QWCHAR(QDir::toNativeSeparators(path + "/*")), &findData);
+	if(h != INVALID_HANDLE_VALUE)
+	{
+		if(NO_DOT_OR_DOTDOT(findData.cFileName))
+		{
+			bChildren = IS_DIR(findData.dwFileAttributes);
+		}
+		while((!bChildren) && FindNextFile(h, &findData))
+		{
+			if(NO_DOT_OR_DOTDOT(findData.cFileName))
+			{
+				bChildren = IS_DIR(findData.dwFileAttributes);
+			}
+		}
+		FindClose(h);
+	}
+	return bChildren;
+}

src/Model_FileSystem.h

@@ -22,6 +22,7 @@
 #pragma once
 
 #include <QFileSystemModel>
+#include <QMutex>
 
 class QFileIconProviderEx;
 
@@ -32,7 +33,16 @@ public:
 	~QFileSystemModelEx();
 
 	virtual bool hasChildren(const QModelIndex &parent = QModelIndex()) const;
+	virtual int rowCount(const QModelIndex &parent = QModelIndex()) const;
+	virtual void fetchMore(const QModelIndex &parent);
 
 private:
 	QFileIconProviderEx *m_myIconProvider;
+	
+	static QHash<const QString, bool> s_hasFolderCache;
+	static QMutex s_hasFolderMutex;
+
+	static bool hasSubfolders(const QString &path);
+	static bool hasSubfoldersCached(const QString &path);
+	static void removeFromCache(const QString &path);
 };