14.7: Canvas Only, Toggle Fullscreen on F and Escape

src/ContentView.h

@@ -79,6 +79,8 @@ private:
     MaskAloneBadge *const m_maskAloneBadge;
     // Swift 1.1.7's rulers: the corner, then the two strips.
     std::vector<QWidget *> m_rulers;
+    // Bars and panels Canvas Only puts away.
+    std::vector<QWidget *> m_panels;
     ProjectWorkspace *m_workspace = nullptr;
     // A document that appears hands the canvas the keys.
     bool m_hadDocument = false;