I don't know how is your code or your use cases, but that seems to be a work for the CSS and its media queries.
If you need to detect the page orientation on your Java/Javascript code, a simple way is to register a window size change handler, and check if the width is greater than the height. More about it here: https://davidwalsh.name/orientation-change -- You received this message because you are subscribed to the Google Groups "GWT Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-web-toolkit+unsubscr...@googlegroups.com. To post to this group, send email to google-web-toolkit@googlegroups.com. Visit this group at https://groups.google.com/group/google-web-toolkit. For more options, visit https://groups.google.com/d/optout.