[GRASS-dev] Re: [GRASS GIS] #205: warnings and errors when trying to print the display

[Michael Barton]

In the wxPython/wxWidget docs, I found the following.

Printing under Unix (GTK+)

Printing under Unix has always been a cause of problems as Unix does  
not provide a standard way to display text and graphics on screen and  
print it to a printer using the same application programming interface  
- instead, displaying on screen is done via the X11 library while  
printing has to be done with using PostScript commands. This was  
particularly difficult to handle for the case of fonts with the result  
that only a selected number of application could offer WYSIWYG under  
Unix. Equally, wxWidgets offered its own printing implementation using  
PostScript which never really matched the screen display.

Starting with version 2.8.X, the GNOME project provides printing  
support through the libgnomeprint and libgnomeprintui libraries by  
which especially the font problem is mostly solved. Beginning with  
version 2.5.4, the GTK+ port of wxWidgets can make use of these  
libraries if wxWidgets is configured accordingly and if the libraries  
are present. You need to configure wxWidgets with the configure --with- 
gnomeprint switch and your application will then search for the GNOME  
print libraries at runtime. If they are found, printing will be done  
through these, otherwise the application will fall back to the old  
PostScript printing code. Note that the application will not require  
the GNOME print libraries to be installed in order to run (there will  
be no dependency on these libraries).

In version GTK+ 2.10, support for printing has been added to GTK+  
itself. Support for this has been added to wxWidgets in the  
development branch and it will be available for wxWidgets 3.0.

Perhaps this is helpful.

Michael

On Jan 10, 2009, at 3:23 AM, GRASS GIS wrote:

> #205: warnings and errors when trying to print the display
> ----------------------- 
> +----------------------------------------------------
>  Reporter:  msieczka  |       Owner:  grass-dev at lists.osgeo.org
>      Type:  defect    |      Status:  reopened
>  Priority:  major     |   Milestone:  6.4.0
> Component:  wxGUI     |     Version:  svn-develbranch6
> Resolution:            |    Keywords:
>  Platform:  Linux     |         Cpu:  x86-64
> ----------------------- 
> +----------------------------------------------------
> Changes (by msieczka):
>
>  * status:  closed => reopened
>  * resolution:  worksforme =>
>
> Comment:
>
> In opposite to Mac, print preview works on Debian testing. But  
> WARNINGS
> still crop out when I press the "Print" button in the print-preview
> dialog:
>
> {{{
> (shoofi:8312): GnomePrint-WARNING **: Could not create filter from
> description 'GnomePrintFilterSelect': filter  
> 'GnomePrintFilterSelect' is
> unknown
>
> (shoofi:8312): GLib-GObject-WARNING **: invalid (NULL) pointer  
> instance
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_signal_connect_data:  
> assertion
> `G_TYPE_CHECK_INSTANCE (instance)' failed
>
> (shoofi:8312): GnomePrint-WARNING **: Could not create filter from
> description 'GnomePrintFilterClip [ GnomePrintFilterMultipage ]':  
> filter
> 'GnomePrintFilterClip' is unknown
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_object_unref: assertion
> `G_IS_OBJECT (object)' failed
>
> (shoofi:8312): libgnomeprintui-CRITICAL **:
> gnome_print_layout_selector_load_filter: assertion  
> `GNOME_IS_PRINT_FILTER
> (f)' failed
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_object_set: assertion
> `G_IS_OBJECT (object)' failed
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_object_set: assertion
> `G_IS_OBJECT (object)' failed
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_object_set: assertion
> `G_IS_OBJECT (object)' failed
>
> (shoofi:8312): libgnomeprintui-CRITICAL **:
> gnome_paper_selector_load_paper_size: assertion  
> `GNOME_IS_PAPER_SELECTOR
> (ps)' failed
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_object_set: assertion
> `G_IS_OBJECT (object)' failed
>
> (shoofi:8312): GLib-GObject-CRITICAL **: g_object_set: assertion
> `G_IS_OBJECT (object)' failed
>
> (shoofi:8312): GnomePrint-CRITICAL **: gnome_print_filter_reset:  
> assertion
> `GNOME_IS_PRINT_FILTER (f)' failed
>
> (shoofi:8312): GnomePrint-CRITICAL **: gnome_print_filter_flush:  
> assertion
> `GNOME_IS_PRINT_FILTER (f)' failed
> }}}
>
> Then, switching between the PDF and PS output options yields another  
> set
> of warnings:
>
> {{{
> (shoofi:8312): libgnomeprintui-CRITICAL **:
> gnome_paper_selector_load_paper_size: assertion  
> `GNOME_IS_PAPER_SELECTOR
> (ps)' failed
>
> (shoofi:8312): libgnomeprintui-CRITICAL **:
> gnome_paper_selector_load_paper_size: assertion  
> `GNOME_IS_PAPER_SELECTOR
> (ps)' failed
>
> ** (shoofi:8312): WARNING **: could not set the value of
> Settings.Document.Filter, node not found
> }}}
>
> Finally, when printing to PS the following pops up:
>
> {{{
> (shoofi:8312): GnomePrint-WARNING **: Could not create filter from
> description 'frgba': filter 'frgba' is unknown
> }}}
>
> And the output PS takes forever to render in Evince (never completes).
> Interestingly, there are 2 pages instead of 1.
>
> The PDF output renders fine. However, also 2 pages instead of 1  
> (both with
> the same content).
>
> Also, scale&arrow overlay brings a solid black polygon covering all  
> the
> map content below the scale&arrow, in the ouput PDF.
>
> -- 
> Ticket URL: <http://trac.osgeo.org/grass/ticket/205#comment:4>
> GRASS GIS <http://grass.osgeo.org>