Mari 4.6v4 docs:

Navigation Toolbar

The Navigation toolbar displays a number of options for managing navigation in Mari.

Navigation Toolbar Controls

Control	Type	What it does	Notes
	button	Resets all the options in the Navigation toolbar to the default settings.
	button, dropdown	Provides the following options for panning: • Pan All - allows panning in any direction. • Pan X - allows panning on the x axis only. • Pan Y - allows panning on the y axis only. • Pan Disabled - disables all panning.	The button changes to reflect the selected option.
	button, dropdown	Provides the options to either enable or disable zooming.	The button changes to reflect the selected option.
	button, dropdown	Provides the options to either enable or disable rolling.	The button changes to reflect the selected option.
	button, dropdown	Provides the following options for orbiting: • Orbit All - allows orbiting around the model in any direction. • Orbit X - allows orbiting around the model on the x axis only. • Orbit Y - allows orbiting around the model on the y axis only. • Orbit Disabled - disables all orbiting.	The button changes to reflect the selected option.
	button, dropdown	Provides the following options: • Snap 45 degrees - when rotating the model it snaps at 45 degree angles. • Snap 90 degrees - when rotating the model it snaps at 90 degree angles. • Snap angle disabled - when rotating the model it does not snap to any angle.	The button changes to reflect the selected option.