Changing fullscreen right-click action from drag and page change to a context menu with view, zoom, fullscreen, exit.

Changing fullscreen page change click area to left/right (top/bottom for single page) section to not be triggered on double click (word selection) or single click in text (text deselection).
Related change: Don't disable page change if a text selection exist.
Related change: Allow word selection from double click in fullscreen mode too.

Fix: Remove item instead of showing a disabled Copy context menu item when there is no selection.

Adding option to search online for text selection.
Removing the behavior that the fullscreen state also set the maximized state because the user might want to retain the non-maximized state in the non-fullscreen state.
Disabling auto-scroll because it's relatively frequently accidentally activated by scrolling the mouse wheel and has little use
Adding option to hide scrollbars

because it increase the page area
Adding option to sort naturally