path: root/devdocs/elisp/header-lines.html

 <h4 class="subsection">Window Header Lines</h4>   <p>A window can have a <em>header line</em> at the top, just as it can have a mode line at the bottom. The header line feature works just like the mode line feature, except that it’s controlled by <code>header-line-format</code>: </p> <dl> <dt id="header-line-format">Variable: <strong>header-line-format</strong>
</dt> <dd><p>This variable, local in every buffer, specifies how to display the header line, for windows displaying the buffer. The format of the value is the same as for <code>mode-line-format</code> (see <a href="mode-line-data">Mode Line Data</a>). It is normally <code>nil</code>, so that ordinary buffers have no header line. </p></dd>
</dl> <dl> <dt id="window-header-line-height">Function: <strong>window-header-line-height</strong> <em>&amp;optional window</em>
</dt> <dd><p>This function returns the height in pixels of <var>window</var>’s header line. <var>window</var> must be a live window, and defaults to the selected window. </p></dd>
</dl> <p>A window that is just one line tall never displays a header line. A window that is two lines tall cannot display both a mode line and a header line at once; if it has a mode line, then it does not display a header line. </p><div class="_attribution">
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    Copyright &copy; 1990-1996, 1998-2022 Free Software Foundation, Inc. <br>Licensed under the GNU GPL license.<br>
    <a href="https://www.gnu.org/software/emacs/manual/html_node/elisp/Header-Lines.html" class="_attribution-link">https://www.gnu.org/software/emacs/manual/html_node/elisp/Header-Lines.html</a>
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