PageViewMode can be one of these PageViewMode constants.
Name
Value
Description
PageViewDefault
0
The Normal tab in Page view for HTML pages and HTML tab in Page view for style sheets or .asp pages if they contain HTML that Office SharePoint Designer cannot safely parse.
PageViewHtml
2
The HTML tab in Page view.
PageViewInBetween
512
PageViewInvalid
-1
The Page view is invalid and cannot be displayed.
PageViewNoFrames
4
The NoFrames tab in Page view. (This tab appears only when frames are present.)
PageViewNormal
1
The Normal tab in Page view.
PageViewNoWindow
128
A windowless environment that prevents a window from opening for the page.