Can I detect the display size/resolution in Emacs?

elisp, emacs, screen-resolution, xemacs

Solution

The current display resolution is available using the following functions (both non-interactive).

(x-display-pixel-width)
(x-display-pixel-height)

Problem

I'd like to change the window/frame size of my XEmacs based on the current display resolution. This is useful when I run my laptop either by itself or attached to a docking station with an external monitor. In either situation, I'd like Emacs to detect the primary screen resolution and adjust its main window frame size accordingly when I start it up.

Original source