Improve Animations

[ghost]

After you apen a pdf file and click somewhere in the screen, the topbar hides itslef and the app enters almost like a full screen mode.

This happens as the menu bar disappears and the pdf also gives a change in its postion when this happens. It moves above little to accompany the position freed by the disappearance of the top bar.

Whereas in apps like Acrobat PDF Viewer, the Top/Bottom bar also disappears but there position of the pdf file is undisturbed.

Make the Secure PDF Viewer to behave similarly as I think this kind of transition is much better than the present one.

[ghost]

Secure.PDF.Viewer_vs_Aobe.Acrobat.mp4