From 821e15f1eeba75f3cdd196d7296f6ea31c9c854c Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Wed, 6 Apr 2022 20:49:00 +1000
Subject: [PATCH] Qt: Add QtHost::RunOnUIThread()

---
 pcsx2-qt/MainWindow.cpp | 5 +++++
 pcsx2-qt/MainWindow.h   | 2 ++
 pcsx2-qt/QtHost.cpp     | 8 ++++++++
 pcsx2-qt/QtHost.h       | 3 +++
 4 files changed, 18 insertions(+)

diff --git a/pcsx2-qt/MainWindow.cpp b/pcsx2-qt/MainWindow.cpp
index df8180e6627f5..406498aca0a24 100644
--- a/pcsx2-qt/MainWindow.cpp
+++ b/pcsx2-qt/MainWindow.cpp
@@ -696,6 +696,11 @@ void MainWindow::reportError(const QString& title, const QString& message)
 	QMessageBox::critical(this, title, message);
 }
 
+void MainWindow::runOnUIThread(const std::function<void()>& func)
+{
+	func();
+}
+
 bool MainWindow::requestShutdown(bool allow_confirm /* = true */, bool allow_save_to_state /* = true */, bool block_until_done /* = false */)
 {
 	if (!VMManager::HasValidVM())
diff --git a/pcsx2-qt/MainWindow.h b/pcsx2-qt/MainWindow.h
index 3ea65740611f2..0ff57c8cafd32 100644
--- a/pcsx2-qt/MainWindow.h
+++ b/pcsx2-qt/MainWindow.h
@@ -17,6 +17,7 @@
 
 #include <QtWidgets/QLabel>
 #include <QtWidgets/QMainWindow>
+#include <functional>
 #include <optional>
 
 #include "Settings/ControllerSettingsDialog.h"
@@ -55,6 +56,7 @@ public Q_SLOTS:
 	void refreshGameList(bool invalidate_cache);
 	void invalidateSaveStateCache();
 	void reportError(const QString& title, const QString& message);
+	void runOnUIThread(const std::function<void()>& func);
 	bool requestShutdown(bool allow_confirm = true, bool allow_save_to_state = true, bool block_until_done = false);
 	void requestExit();
 
diff --git a/pcsx2-qt/QtHost.cpp b/pcsx2-qt/QtHost.cpp
index 446cc9b225936..7faca2e94b5d8 100644
--- a/pcsx2-qt/QtHost.cpp
+++ b/pcsx2-qt/QtHost.cpp
@@ -300,6 +300,14 @@ void QtHost::QueueSettingsSave()
 	s_settings_save_timer->start(SETTINGS_SAVE_DELAY);
 }
 
+void QtHost::RunOnUIThread(const std::function<void()>& func, bool block /*= false*/)
+{
+	// main window always exists, so it's fine to attach it to that.
+	QMetaObject::invokeMethod(g_main_window, "runOnUIThread",
+		block ? Qt::BlockingQueuedConnection : Qt::QueuedConnection,
+		Q_ARG(const std::function<void()>&, func));
+}
+
 std::optional<std::vector<u8>> Host::ReadResourceFile(const char* filename)
 {
 	const std::string path(Path::CombineStdString(EmuFolders::Resources, filename));
diff --git a/pcsx2-qt/QtHost.h b/pcsx2-qt/QtHost.h
index 02e6393dcba29..a84269f61248b 100644
--- a/pcsx2-qt/QtHost.h
+++ b/pcsx2-qt/QtHost.h
@@ -42,6 +42,9 @@ namespace QtHost
 	void UpdateFolders();
 	void UpdateLogging();
 
+	/// Executes a function on the UI thread.
+	void RunOnUIThread(const std::function<void()>& func, bool block = false);
+
 	/// Thread-safe settings access.
 	SettingsInterface* GetBaseSettingsInterface();
 	std::string GetBaseStringSettingValue(const char* section, const char* key, const char* default_value = "");