21.18 Tooltips

Tooltips are small special frames that display text information at the current mouse position. They activate when there is a pause in mouse movement over some significant piece of text in a window, or the mode line, or some other part of the Emacs frame such as a tool bar button or menu item.

You can toggle the use of tooltips with the command M-x tooltip-mode. When Tooltip mode is disabled, the help text is displayed in the echo area instead. To control the use of tooltips at startup, customize the variable tooltip-mode.

The following variables provide customization options for tooltip display:

tooltip-delay

This variable specifies how long Emacs should wait before displaying the first tooltip. The value is in seconds.

tooltip-short-delay

This variable specifies how long Emacs should wait before displaying subsequent tooltips on different items, having already displayed the first tooltip. The value is in seconds.

tooltip-hide-delay

The number of seconds since displaying a tooltip to hide it, if the mouse doesn’t move.

tooltip-x-offset

tooltip-y-offset

The X and Y offsets, in pixels, of the left top corner of the tooltip from the mouse pointer position. Note that these are ignored if tooltip-frame-parameters was customized to include, respectively, the left and top parameters. The values of the offsets should be chosen so that the tooltip doesn’t cover the mouse pointer’s hot spot, or it might interfere with clicking the mouse.

tooltip-frame-parameters

The frame parameters used for displaying tooltips. See Frame Parameters in The Emacs Lisp Reference Manual, and also Tooltips in The Emacs Lisp Reference Manual.

For additional customization options for displaying tooltips, use M-x customize-group RET tooltip RET.

If Emacs is built with GTK+ support, it displays tooltips via GTK+, using the default appearance of GTK+ tooltips. To disable this, change the variable x-gtk-use-system-tooltips to nil. If you do this, or if Emacs is built without GTK+ support, most attributes of the tooltip text are specified by the tooltip face, and by X resources (see X Resources).

GUD tooltips are special tooltips that show the values of variables when debugging a program with GUD. See Debugger Operation.