feat: add a fullscreen shortcut

mainwindow.cpp

@@ -125,6 +125,10 @@ MainWindow::MainWindow(QWidget *parent) :
     connect(nextPictureShorucut, &QShortcut::activated,
             this, &MainWindow::galleryNext);
 
+    QShortcut * fullscreenShorucut = new QShortcut(QKeySequence(QKeySequence::FullScreen), this);
+    connect(fullscreenShorucut, &QShortcut::activated,
+            this, &MainWindow::toggleFullscreen);
+
     centerWindow();
 }
 
@@ -561,3 +565,12 @@ void MainWindow::quitAppAction(bool force)
         closeWindow();
     }
 }
+
+void MainWindow::toggleFullscreen()
+{
+    if (isFullScreen()) {
+        showNormal();
+    } else {
+        showFullScreen();
+    }
+}

mainwindow.h

@@ -53,6 +53,7 @@ protected slots:
     void toggleStayOnTop();
     bool stayOnTop();
     void quitAppAction(bool force = false);
+    void toggleFullscreen();
 
 private:
     QPoint m_oldMousePos;