Settings > 
PreferencesThe Navigation Preferences contain mouse and other navigational settings for Revu. Select Navigation from the Preferences dialog box to view or modify these preferences.
To open the Preferences dialog box:
Settings > Preferences
Single Page Mode: Sets the mouse wheel behavior in single page mode. Choose either Zoom or Scroll.
Continuous Mode: Sets the mouse wheel behavior in continuous mode. Choose Zoom or Scroll. This behavior is independent of the Single Page Mode setting.
Reverse Mouse Wheel when Zooming: When enabled, the direction for when the mouse wheel will zoom in versus zoom out is reversed.
Sensitivity: Controls how much the zoom level changes per mouse wheel click.
Enable Horizontal Mouse Wheel: When enabled, turns on panning for mice that have tilt-able scroll wheels.
Synchronize Views:When enabled, Revu synchronizes the viewing windows when displaying PDFs in side-by-side Split View mode or in a detached window. This is useful when you need to compare two different versions of the same document. Moving the document in one window will automatically adjust the view in the second window. This can also be turned on and off with the Sync button on the Status bar.
Mode: Sets the default Synchronize View mode. Document mode synchronizes document pages by page index, thus viewing page 1 on document A will cause document B to automatically also view page 1. Page mode synchronizes the pages currently being viewed, regardless of page index, allowing the user to synchronize different pages across documents or different pages in the same multi-page document.
Enable Horizontal Scrollbar: When enabled, a horizontal scroll bar appears at the bottom of the document tab for PDFs that are larger than the viewing area.
Show Vertical Scrollbar on Left: When enabled, the vertical scroll bar is shown on the left side of the PDF page instead of the right.
Show Full-Screen Crosshair: When enabled, the cursor is replaced with full-screen crosshairs in the main workspace, drawing vertical and horizontal lines across the document that meet at the mouse pointer. The color of the crosshairs is the same as the Snap Color defined in the Grid & Snap Preferences.
Lock Panning in Fit Width: When enabled, panning is constrained to vertical movement when in Fit Width mode. This prevents the page from sliding sideways if the mouse is moved slightly horizontally.
Enable 3D Mouse: When enabled, 3D navigation with a 3D mouse is available. This option is hidden until there is a 3D mouse plugged in.