How can I change the default font size of the Virtual Book?

Question

How can I change the default font size of the Virtual Book?

Answer 1

In version 10 you can change the font size of the Virtual Book by changing its Magnification but in previous versions of Mathematica the file

FindFile["DocumentationNavigator.nb"]

C:\Program Files\Wolfram Research\Mathematica\8.0\Documentation\English\System\DocumentationNavigator.nb

(which is the Virtual Book Notebook) has the option Editable -> False which prevents it from being changed in any way including changing the Magnification which is set to 1.. For changing this you can (after making a backup copy of the original file) open this file in a text editor, then search for the strings "Editable->False" and "Saveable->False" and replace False with True in both cases, then save the file. After opening the file in Mathematica you will be notified that the file was changed outside of Mathematica. Just ignore it, set the Magnification you like and save the file. Now the Virtual Book will open with the Magnification you like (checked in version 8.0.4).

Answer 2

An alternative to modifying DocumentationNavigator.nb using a text editor is to change the notebook's options programmatically.

Locate and open the notebook:

NotebookOpen[FindFile["DocumentationNavigator.nb"]] 

Get the list of open notebooks using Notebooks[]:

nbks = Notebooks[]

nbks[[2]] is the notebook object we want to modify using SetOptions

using

SetOptions[nbks[[2]], {Editable -> True, Saveable -> True, Magnification -> 1.7}]

Before we hit Shift-Enter, this is how the notebook looks:

and after evaluating SetOptions[...] you get

Change the settings back:

SetOptions[nbks[[2]], {Editable -> True, Saveable -> True, Magnification -> 1.}]