There no full screen or smth like that. it may be like file-fullscreen or alt+enter why not? 
peppy wrote:
Displaying the menu bar and dialog windows is very troublesome in fullscreen, which is why this feature will not be available.
That's why~mm201 wrote:
This is impossible to support. Windows itself will always shrink the window just a little bit, especially along the Y-axis.
When this was "supported" in older builds, this very thing happened, causing weird aliasing artifacts.
Fullscreen editing won't happen because dialogs/menus can't be displayed in fullscreen mode.