Frame parameters specify frame sizes in character units. On
graphical displays, the
default face determines the actual
pixel sizes of these character units (see Face Attributes).
frame-pixel-height; see Size and Position.)
frame-pixel-width; see Size and Position.)
user-positionparameter (see user-position) does for the position parameters
fullwidthspecifies that width shall be as wide as possible. The value
fullheightspecifies that height shall be as tall as possible. The value
fullbothspecifies that both the width and the height shall be set to the size of the screen. The value
maximizedspecifies that the frame shall be maximized. The difference between
fullbothis that the former can still be resized by dragging window manager decorations with the mouse, while the latter really covers the whole screen and does not allow resizing by mouse dragging.
With some window managers you may have to customize the variable
frame-resize-pixelwise to a non-
nil value in order to make
a frame appear “maximized” or “fullscreen”.