29.7 Frames and Windows

Each window is part of one and only one frame; you can get the frame with window-frame.

Function: window-frame window

This function returns the frame that window is on.

All the non-minibuffer windows in a frame are arranged in a cyclic order. The order runs from the frame's top window, which is at the upper left corner, down and to the right, until it reaches the window at the lower right corner (always the minibuffer window, if the frame has one), and then it moves back to the top. See section 28.5 Cyclic Ordering of Windows.

Function: frame-first-window frame

This returns the topmost, leftmost window of frame frame.

At any time, exactly one window on any frame is selected within the frame. The significance of this designation is that selecting the frame also selects this window. You can get the frame's current selected window with frame-selected-window.

Function: frame-selected-window frame

This function returns the window on frame that is selected within frame.

Conversely, selecting a window for Emacs with select-window also makes that window selected within its frame. See section 28.4 Selecting Windows.

Another function that (usually) returns one of the windows in a given frame is minibuffer-window. See section 20.9 Minibuffer Miscellany.