In Mac OS X Lion, when you open a single PDF document in Preview, you won’t see the sidebar.
This is the default behavior in Lion, unlike in older versions of Mac OS X where the sidebar is visible, showing the table of contents or thumbnail images representing the individual pages of the document.
To change this default behavior so that you’re always able to see the sidebar whenever you open a PDF, you’ll need to change a preference option.
Call up Preferences by clicking on Preview > Preferences… in the menu or pressing the keyboard shortcut command+,.
In the Preferences window, click on PDF, and check the option On opening documents: Show sidebar when opening single file.
Your PDF documents should now open with the sidebar displayed by default.
You can also control the display of the sidebar with the view control buttons located in the toolbar.
From left to right, the view control buttons are:
- Content Only – no sidebar will be shown.
- Thumbnails – sidebar is visible, showing thumbnail representations of the pages in the PDF.
- Table of Contents – sidebar shows a list of topics which, when clicked on, takes you directly to the relevant page.
- Contact Sheet – no sidebar or content is shown in this mode, but a grid of thumbnails of the document pages is displayed.