From 6b9e196bb746ef69c40de97596b8ccbc77f84bdf Mon Sep 17 00:00:00 2001
From: Cacodemon345 <wahil1976@outlook.com>
Date: Wed, 12 Jan 2022 01:09:43 +0600
Subject: [PATCH] Implement fullscreen prompt

(cherry picked from commit 7b69723788dab622652f2f11afc823f5d9cbcd86)
---
 src/qt/qt_mainwindow.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/qt/qt_mainwindow.cpp b/src/qt/qt_mainwindow.cpp
index 2de91a279..7ad3b7dd0 100644
--- a/src/qt/qt_mainwindow.cpp
+++ b/src/qt/qt_mainwindow.cpp
@@ -970,6 +970,19 @@ void MainWindow::on_actionFullscreen_triggered() {
             emit resizeContents(scrnsz_x, scrnsz_y);
         }
     } else {
+        if (video_fullscreen_first)
+        {
+            QMessageBox questionbox(QMessageBox::Icon::Information, tr("Entering fullscreen mode"), tr("Press CTRL+ALT+PAGE DOWN to return to windowed mode."), QMessageBox::Ok, this);
+            QCheckBox *chkbox = new QCheckBox(tr("Don't show this message again"));
+            questionbox.setCheckBox(chkbox);
+            chkbox->setChecked(!video_fullscreen_first);
+            bool confirm_exit_temp = false;
+            QObject::connect(chkbox, &QCheckBox::stateChanged, [](int state) {
+                video_fullscreen_first = (state == Qt::CheckState::Unchecked);
+            });
+            questionbox.exec();
+            config_save();
+        }
         setFixedSize(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX);
         ui->menubar->hide();
         ui->statusbar->hide();