How to force X to re-theme all open windows to current X resources?

Question

I've got a ~/.Xdefaults that has a specific color theme defined for Xorg, and this works. I've got a ~/.XdefaultsNew that specifies an alternate color theme. Xorg starts and loads ~/.Xdefaults which is correct. After running some applications, I run

xrdb ~/.XdefaultsNew

This overrides all my X resources to the new defined values (correctly). If I open a new window, the theme is seen correctly. However, all the previously opened windows retain the original theme.

Is there a way to force X to "re-theme" all windows it is managing with the currently loaded X resources?

Answer 1

It's possible for applications that implement the Editres protocol, and that support SetValues requests (see editres(1) for a user-level description and /usr/include/X11/Xmu/EditresP.h for a programmer-level description).

You can watch the Editres protocol in action by launching the editres program. In the menu, select “Commands / Get Tree” and click on the editres window, then select “Tree / Select Widget in Client” and click somewhere in the editres window again. Select “Commands / Show Resource Box”, click on “background” in the normal resources list, and enter a color name where it says “Enter Resource Value”, then click on “Apply” and watch part of the editres window change color.

Unfortunately, while most applications that use X resources understand the Editres protocol, few implement the SetValues part. It's a good idea that hardly anyone bothered to implement.