Appendix B HTML Help Browser Tips

There are a wide variety of possible browsers to use for displaying the online HTML help available with IDLWAVE (starting with version 5.0). Since IDL v6.2, a single cross-platform HTML help browser, the IDL Assistant is distributed with IDL. If this help browser is available, it is the preferred choice, and the default. The variable idlwave-help-use-assistant, enabled by default, controls whether this help browser is used. If you use the IDL Assistant, the tips here are not relevant.

Since IDLWAVE runs on a many different system types, a single browser configuration is not possible, but choices abound. On many systems, the default browser configured in browse-url-browser-function, and hence inherited by default by idlwave-help-browser-function, is Netscape. Unfortunately, the HTML manuals decompiled from the original source contain formatting structures which Netscape 4.x does not handle well, though they are still readable. A much better choice is Mozilla, or one of the Mozilla-derived browsers such as Galeon (GNU/Linux), Camino (MacOSX), or Firebird (all platforms). Newer versions of Emacs provide a browser-function choice browse-url-gnome-moz which uses the Gnome-configured browser.

Note that the HTML files decompiled from the help sources contain specific references to the ‘Symbol’ font, which by default is not permitted in normal encodings (it's invalid, technically). Though it only impacts a few symbols, you can trick Mozilla-based browsers into recognizing ‘Symbol’ by following the directions here. With this fix in place, HTML help pages look almost identical to their PDF equivalents (yet can be bookmarked, browsed as history, searched, etc.).

Individual platform recommendations:

• Unix/MacOSX: The w3m browser and its associated emacs-w3m emacs mode provide in-buffer browsing with image display, and excellent speed and formatting. Both the Emacs mode and the browser itself must be downloaded separately. To use this browser, include

            (setq idlwave-help-browser-function 'w3m-browse-url)
  

  in your .emacs. Setting a few other nice w3m options cuts down on screen clutter:

            (setq w3m-use-tab nil
                  w3m-use-header-line nil
                  w3m-use-toolbar nil)
  

  If you use a dedicated frame for help, you might want to add the following, to get consistent behavior with the q key:

            ;; Close my help window when w3m closes.
            (defadvice w3m-close-window (after idlwave-close activate)
              (if (boundp 'idlwave-help-frame)
                  (idlwave-help-quit)))
  

  Note that you can open the file in an external browser from within w3m using M.