Pango tab stops

["Ian Puleston" <ipuleston SonicWALL com>]

Hi,

I want to use a PangoTabArray to pass tab stop settings to a print
function along with text to be sent to a printer. The idea is that the
caller passes the pre-set PangoTabArray, and the print function then
calls pango_layout_set_tabs to add it to the PangoLayout created via
gtk_print_context_create_pango_layout.

But there seems to be a problem with setting the tabs correctly for the
resolution (dpi) of the printer. With a PangoTabArray the tabs are
specified in either pixels or Pango units, and to use either to set tag
stops at fixed distances requires knowledge of the resolution of the
device, but the code requesting the print cannot know that (the user has
not even selected a printer yet).

Two solutions that I can see are 1) define the API to accept tabs set
for a 300 dpi printer and have it internally multiple them up or down if
necessary once the print device has been selected, or 2) pass the tab
settings in an array or list and create the PangoTabArray internally
once the print device has been selected.

Neither is particularly neat, so I'm wondering if there may be some
existing structure or API somewhere in GTK or the other components for
passing tab stops in units such as inches, mm, etc.?

Ian