can use right click and file dialog to add extension, also fix segfault when multiple copies of extension are added then removed

GUI/extenwindow.cpp

@@ -2,12 +2,15 @@
 #include "ui_extenwindow.h"
 #include "defs.h"
 #include <concrt.h>
+#include <QMenu>
+#include <QFileDialog>
 #include <QDragEnterEvent>
 #include <QDropEvent>
 #include <QMimeData>
 #include <QUrl>
 
 extern const char* EXTENSIONS;
+extern const char* ADD_EXTENSION;
 extern const char* INVALID_EXTENSION;
 extern const char* CONFIRM_EXTENSION_OVERWRITE;
 extern const char* EXTENSION_WRITE_ERROR;
@@ -30,6 +33,8 @@ namespace
 	{
 		// Extension is dll and exports "OnNewSentence"
 		if (QTextFile(extenName + ".dll", QIODevice::ReadOnly).readAll().contains("OnNewSentence"))
+		{
+			if (HMODULE module = LoadLibraryW(S(extenName).c_str()))
 			{
 				if (auto callback = (decltype(Extension::callback))GetProcAddress(LoadLibraryOnce(S(extenName)), "OnNewSentence"))
 				{
@@ -37,6 +42,8 @@ namespace
 					extensions.push_back({ S(extenName), callback });
 					return true;
 				}
+				FreeLibrary(module);
+			}
 		}
 		return false;
 	}
@@ -73,8 +80,7 @@ bool DispatchSentenceToExtensions(std::wstring& sentence, const InfoForExtension
 void CleanupExtensions()
 {
 	std::scoped_lock writeLock(extenMutex);
-	for (auto extension : extensions)
+	for (auto extension : extensions) FreeLibrary(GetModuleHandleW(extension.name.c_str()));
-		FreeLibrary(GetModuleHandleW(extension.name.c_str()));
 	extensions.clear();
 }
 
@@ -84,6 +90,12 @@ ExtenWindow::ExtenWindow(QWidget* parent) :
 {
 	ui->setupUi(this);
 
+	connect(ui->extenList, &QListWidget::customContextMenuRequested, [this](QPoint point)
+	{
+		if (QMenu(this).exec({ std::make_unique<QAction>(ADD_EXTENSION).get() }, ui->extenList->mapToGlobal(point)))
+			if (QString extenFile = QFileDialog::getOpenFileName(this, ADD_EXTENSION, ".", EXTENSIONS + QString(" (*.dll)")); !extenFile.isEmpty()) Add(extenFile);
+	});
+
 	ui->vboxLayout->addWidget(new QLabel(EXTEN_WINDOW_INSTRUCTIONS, this));
 	setWindowTitle(EXTENSIONS);
 
@@ -99,6 +111,20 @@ ExtenWindow::~ExtenWindow()
 	delete ui;
 }
 
+void ExtenWindow::Add(QFileInfo extenFile)
+{
+	if (extenFile.suffix() == "dll")
+	{
+		if (extenFile.absolutePath() != QDir::currentPath())
+		{
+			if (QFile::exists(extenFile.fileName()) && QMessageBox::question(this, EXTENSIONS, CONFIRM_EXTENSION_OVERWRITE) == QMessageBox::Yes) QFile::remove(extenFile.fileName());
+			if (!QFile::copy(extenFile.absoluteFilePath(), extenFile.fileName())) QMessageBox::warning(this, EXTENSIONS, EXTENSION_WRITE_ERROR);
+		}
+		if (Load(extenFile.completeBaseName())) return Sync();
+	}
+	QMessageBox::information(this, EXTENSIONS, QString(INVALID_EXTENSION).arg(extenFile.fileName()));
+}
+
 void ExtenWindow::Sync()
 {
 	ui->extenList->clear();
@@ -140,16 +166,5 @@ void ExtenWindow::dragEnterEvent(QDragEnterEvent* event)
 
 void ExtenWindow::dropEvent(QDropEvent* event)
 {
-	for (auto file : event->mimeData()->urls())
+	for (auto file : event->mimeData()->urls()) Add(file.toLocalFile());
-	{
-		QFileInfo extenFile = file.toLocalFile();
-		if (extenFile.suffix() != "dll") continue;
-		if (extenFile.absolutePath() != QDir::currentPath())
-		{
-			if (QFile::exists(extenFile.fileName()) && QMessageBox::question(this, EXTENSIONS, CONFIRM_EXTENSION_OVERWRITE) == QMessageBox::Yes) QFile::remove(extenFile.fileName());
-			if (!QFile::copy(extenFile.absoluteFilePath(), extenFile.fileName())) QMessageBox::warning(this, EXTENSIONS, EXTENSION_WRITE_ERROR);
-		}
-		if (Load(extenFile.completeBaseName())) Sync();
-		else QMessageBox::information(this, EXTENSIONS, QString(INVALID_EXTENSION).arg(extenFile.fileName()));
-	}
 }

GUI/extenwindow.h

@@ -25,6 +25,7 @@ public:
 private:
 	inline static constexpr auto EXTEN_SAVE_FILE = u8"SavedExtensions.txt";
 
+	void Add(QFileInfo extenFile);
 	void Sync();
 	bool eventFilter(QObject* target, QEvent* event) override;
 	void keyPressEvent(QKeyEvent* event) override;

GUI/extenwindow.ui

@@ -17,6 +17,9 @@
    <layout class="QVBoxLayout">
     <item>
      <widget class="QListWidget" name="extenList">
+      <property name="contextMenuPolicy">
+       <enum>Qt::CustomContextMenu</enum>
+      </property>
       <property name="dragDropMode">
        <enum>QAbstractItemView::InternalMove</enum>
       </property>

text.cpp

@@ -41,11 +41,12 @@ Negatives for data_offset/split_offset refer to registers
 -C for RAX, -14 for RBX, -1C for RCX, -24 for RDX, and so on for RSP, RBP, RSI, RDI, R8-R15
 * means dereference pointer+deref_offset)";
 const char* SAVE_SETTINGS = u8"Save settings";
-const char* EXTEN_WINDOW_INSTRUCTIONS = u8R"(Drag and drop extension (.dll) files here from your computer to add them
+const char* EXTEN_WINDOW_INSTRUCTIONS = u8R"(To add an extension, right click the extension list
-(Does not work if running as administrator)
+Alternatively, drag and drop the extension file from your computer
-Drag and drop within the list to reorder
+To reorder extensions, drag and drop them within the list
 (Extensions are used from top to bottom: order DOES matter)
-Press delete with an extension selected to remove it)";
+To remove an extension, select it and press delete)";
+const char* ADD_EXTENSION = u8"Add extension";
 const char* INVALID_EXTENSION = u8"%1 is an invalid extension";
 const char* CONFIRM_EXTENSION_OVERWRITE = u8"Another version of this extension already exists, do you want to delete and overwrite it?";
 const char* EXTENSION_WRITE_ERROR = u8"Failed to save extension";