Re: Gtk+ print support - request for feedback

["John (J5) Palmieri" <johnp redhat com>]

On Fri, 2006-03-03 at 09:45 -0800, Alex Graveley wrote:
> Thought it would be vauable to get some non-gtk eyes on this great work. 
>   I've cc'd Till Kamppeter, who leads linuxprinting.org, and Michael 
> Sweet, the CUPS dude.
> 
> -Alex

That would be great.  I would say eggcupsutils.c should be looked at
closely and perhaps can be reworked to become part of the CUPS library
itself.  It provides a generic async framework for POST and GET. 

> Alexander Larsson wrote:
> > Its no secret that John Palmieri and I have been working on print
> > support for Gtk+ a while now. We're moving forward, and while its not
> > yet finished we now at least have something that is mostly
> > working. So, we think the time has now come to get some feedback from
> > the community.
> > 
> > The code is availible in libegg/libegg/print-operation. You need to
> > use the autogen.sh inside that directory, because the toplevel libegg
> > configure doesn't work on win32.
> > 
> > The code consists of several parts. First we have the highlevel
> > portable print API that most apps are supposed to use, plus
> > implementations for win32 and unix. Then we have the code for the Unix
> > print dialog which is used for the unix implementation of the
> > highlevel code, but is also availible on unix only for apps like OOo
> > and Firefox to use as a "native" print dialog. The dialog is split
> > into common code and code implementing cups support. The cups support
> > is hidden behind a backend interface, and the long term plan is to
> > make it a module (like immodules or pixbuf loaders). However at the
> > moment its just linked in.
> > 
> > Here is a highlevel walktrough of the sources:
> > 
> > Highlevel API
> > =============
> > * eggprint.h
> > 
> > General include file which is meant to pull in all interesting headers
> > for printing.
> > 
> > * eggprintoperation.[ch]
> > * eggprintoperation-private.h
> > 
> > This defines the main object you interact with when printing. When the
> > user selects print you allocate an EggPrintOperation, set some data
> > like page size, old print settings, nr of pages, current page, etc and
> > kick it off. It will then show a dialog, let the user select a printer
> > and options. When the user finished the dialog various signals will be
> > emited on the EggPrintOperation, the main one being draw_page() which
> > you are supposed to catch and render the page using cairo.
> > 
> > * eggprintcontext.[ch]
> > * eggprintcontext-private.h
> > 
> > This is an object that gets passed to the begin_print,
> > request_page_setup, draw_page and end_print signals on the print
> > operation. It lets you get the cairo context and important rendering
> > information like page size and resolution. It also lets you easily
> > create pango layoungs/contexts that match the font metrics of the
> > cairo surface.
> > 
> > * eggprintersettings.[ch]
> > 
> > This object represents the settings of a print dialog in a
> > system-independent way. Its basically a key-string = value-string
> > hashtable with some predefined keys that you can use for conveniency
> > (although an implementation can use more keys than the predefined
> > ones). The main use for this object is that once you've printed you
> > can get a settings object that represents the settings the user chose,
> > and the next time you print you can pass that in so that the user
> > doesn't have to re-set all his settings. Its also possible to
> > enumerate the settings so that you can easily save the settings for
> > the next time your app runs, or even in a document. The predefined
> > keys try to use shared values as much as possible so that moving such
> > a document between systems still works.
> > 
> > * eggpapersize.[ch]
> > * paper_names.c
> > 
> > Object that handles paper sizes. We use a standard called "PWG
> > 5101.1-2002 PWG: Standard for Media Standardized Names" to name the
> > page sizes (and to get the data for the page sizes).
> > 
> > * eggpagesetup.[ch]
> > This object stored the page size, orientation and margins. The idea is
> > that you can pass/get one of these from the page setup dialog and then
> > send it to the print object when printing.
> > 
> > * eggprintenums.h
> > Various enums needed for printing
> > 
> > * eggprintoperation-win32.c
> > * eggprint-win32.[ch]
> > Win32 implementation of the highlevel API
> > 
> > * eggprintoperation-unix.c
> > Unix implementation of the highlevel API
> > 
> > Unix Print Dialog
> > =================
> > * eggprintunixdialog.[ch]
> > The print dialog code. The header is availible only on unix systems. I
> > think it will be put in a separate include directory and have its own
> > pkg-config module that you can use to get the headers.
> > 
> > * eggprintbackend.[ch]
> > * eggprinter.[ch]
> > * eggprinter-private.h
> > A printer backend implements the EggPrintBackend interface, which
> > hands out EggPrinter objects to the dialog.
> > 
> > * eggprintbackendsetting.[ch]
> > * eggprintbackendsettingset.[ch]
> > The backend hands the dialog code a set of EggPrintBackendSettings
> > that describe the possible settings that a printer has. For instance,
> > the cups implementation generates these from the ppd file for the
> > printer. 
> > 
> > * eggprintsettingwidget.[ch]
> > Widget that can display an EggPrintBackendSetting
> > 
> > *eggprintjob.[ch]
> > *eggprintjob-private.h
> > Code to handle sending a print job to the printer
> > 
> > * eggcupsutils.[ch]
> > * eggprintbackendcups.[ch]
> > * eggprintercups.[ch]
> > * eggprintercups-private.h
> > Cups backend.
> > 
> > Test Code
> > =========
> > 
> > * printedit.c
> > A simple editor that lets you print
> > 
> > * testprintfileoperation.[ch]
> > And example of how you can derive from EggPrintOperation to implement
> > printing.
> > 
> > * testprint.c
> > A small test app that shows how you print using the high level api,
> > using both g_signal_connect and using TestPrintFileOperation.
> > 
> > * testshowdialog.c
> > Just shows a print dialog
> > 
> > 
> > The current status of the code is that on both win32 and unix (using
> > cups) you can select a printer and print to it, and most options in
> > the dialog work. However there is still lots of work to do. Here are
> > some of the things we're planning:
> > 
> > Highlevel API:
> > ==============
> > 
> > We want to add an API for showing a page setup dialog. This is
> > something that most other platforms has, and makes sense for
> > page-oriented applications. It's used to allow the user to set the page
> > size and orientation before the print dialog, which is important in
> > e.g. a DTP application.
> > 
> > Add some form of simple feedback of the job progress after
> > printing. This would be in the form of some sort of callbacks on the
> > print operation object so that you can know when the print job
> > finished so you can display some form of progress icon/bar/whatever.
> > 
> > Add API that allows you to add per-application specific settings to
> > the print dialog. Given the support in the various platforms this is
> > best done by allowing you to add a custom tab to the dialog. 
> > 
> > Unix/Cups implementation:
> > =========================
> > 
> > Need to figure out the details of exactly how to handle page sizes,
> > page orientation and margins. We're currently mostly ignoring this
> > because I'm not yet sure what the best way to handle it is.
> > 
> > The settings in the "Job" tab aren't sent to the printer.
> > 
> > We need to add more custom translations for wellknown PPD options so
> > that we can get known good and sane texts in the UI.
> > 
> > The dialog needs some general UI review and polish, including HIGified
> > padding.
> > 
> > Win32:
> > ======
> > 
> > The dialogs currently block the mainloop. We need to use threads or
> > something like that, so that the other windows in the app repaint
> > while the print dialog is up.
> > 
> > 
> > It would be nice if some people could take a look at this and give us
> > feedback on it. The earlier we get feedback, the easier it is to
> > incorporate it.
> > 
> > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> >  Alexander Larsson                                            Red Hat, Inc 
> >                    alexl redhat com    alla lysator liu se 
> > He's a gun-slinging hunchbacked cat burglar on his last day in the job. She's 
> > a cynical Buddhist vampire in the wrong place at the wrong time. They fight 
> > crime! 
> > 
> > _______________________________________________
> > gtk-devel-list mailing list
> > gtk-devel-list gnome org
> > http://mail.gnome.org/mailman/listinfo/gtk-devel-list
> _______________________________________________
> gtk-devel-list mailing list
> gtk-devel-list gnome org
> http://mail.gnome.org/mailman/listinfo/gtk-devel-list
-- 
John (J5) Palmieri <johnp redhat com>