2004-11-13 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.[ch]
* app/file/file-open.c
* app/file/file-save.c: pass the MIME type from the save procedure
to gimp_imagefile_save_thumbnail() so that it can be stored with
the thumbnail.
* tools/pdbgen/pdb/fileops.pdb
* app/pdb/fileops_cmds.c: changed accordingly.
2004-10-23 Sven Neumann <sven@gimp.org>
* libgimpthumb/gimpthumb-utils.[ch]
* libgimpthumb/gimpthumbnail.[ch]
* libgimpthumb/gimpthumb.def: added missing API, mainly for deleting
thumbnails.
* app/core/gimpimagefile.[ch]: when saving a thumbnail, delete a
failure thumbnail if one exists. Unless the thumbnail was created
explicitely, remove all other thumbnails for this image.
* app/actions/documents-commands.c: changed accordingly.
* app/file/file-open.c: only save a thumbnail if there isn't a
valid thumbnail already.
* app/widgets/gimpthumbbox.c: before attempting to create a new
thumbnail, check if there's an uptodate failure thumbnail.
2004-10-13 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.c (gimp_imagefile_create_thumbnail): ref
the imagefile while creating the thumbnail.
* app/core/gimpimagefile.[ch]
* app/widgets/gimpthumbbox.c (gimp_thumb_box_auto_thumbnail): moved
the tricky part about thumbnail creation into the new function
gimp_imagefile_create_thumbnail_weak().
2004-10-08 Sven Neumann <sven@gimp.org>
* app/config/gimpcoreconfig.[ch]
* app/config/gimprc-blurbs.h: added new gimprc option
"thumbnail-filesize-limit" that allows to control the maximum
filesize for automatic thumbnail creation.
* app/dialogs/preferences-dialog.c: added a GUI for it, needs
review.
* app/core/gimpimagefile.[ch]: minor cleanups. Moved call to
gimp_thumbnail_peek_image() from gimp_imagefile_save_thumb() to
gimp_imagefile_save_thumbnail() to avoid it being called twice.
* app/file/file-utils.[ch]: export utility function
file_utils_find_proc_by_extension() that allows to check for a
file plug-in by looking at the filename extension only.
* app/widgets/gimpthumbbox.[ch]: automatically create or update
thumbnails for image files with a known extension that are smaller
than "thumbnail-filesize-limit". Fixes bug #137176.
2004-08-10 Michael Natterer <mitch@gimp.org>
Redid the whole internal progress stuff: don't pass around
progress_callback and progress_data; instead, provide a
pointer to a GimpProgressInterface which can be implemented
by a variety of backends.
Addresses (but not yet fixes) bugs #6010, #97266 and #135185.
* app/display/Makefile.am
* app/display/gimpprogress.[ch]: removed the old progress hack.
* app/core/Makefile.am
* app/core/core-types.h
* app/core/gimpprogress.[ch]: implement GimpProgressInterface.
* app/widgets/Makefile.am
* app/widgets/widgets-types.h
* app/widgets/gimpprogressdialog.[ch]: the standalone progress
dialog as widget implementing GimpProgressInterface.
* app/display/gimpdisplay.c
* app/display/gimpstatusbar.[ch]
* app/widgets/gimpfiledialog.[ch]
* app/widgets/gimpthumbbox.[ch]: added GimpProgressInterface
implementation to these classes.
* app/core/gimp-gui.[ch]
* app/gui/gui-vtable.c: replaced the old progress vtable entries
by two new to create and destroy a GimpProgressDialog in case
no other progress is available.
* app/pdb/procedural_db.[ch]
* app/plug-in/plug-in-run.[ch]
* tools/pdbgen/app.pl: pass a GimpProgress to all PDB wrappers and
all plug-ins.
* app/plug-in/plug-in.[ch]
* app/plug-in/plug-ins.c
* app/plug-in/plug-in-message.c
* app/plug-in/plug-in-progress.c: handle the case there the
plug-in was crated with a progress as well as the case where it
wasn't.
* app/app_procs.c
* app/batch.c
* app/xcf/xcf.c
* app/file/file-open.[ch]
* app/file/file-save.[ch]
* app/widgets/gimphelp.c
* app/widgets/gimpbrushselect.c
* app/widgets/gimpfontselect.c
* app/widgets/gimpgradientselect.c
* app/widgets/gimppaletteselect.c
* app/widgets/gimppatternselect.c: changed accordingly.
* app/core/gimpimagefile.[ch]
* app/display/gimpdisplayshell-dnd.c
* app/gui/file-open-dialog.c
* app/gui/file-open-location-dialog.c
* app/gui/file-save-dialog.c
* app/widgets/gimplayertreeview.c
* app/widgets/gimptoolbox-dnd.c: pass a GimpProgress to all file
related functions. Embed the progress in the file dialog where
possible.
* app/core/gimpdrawable-blend.[ch]
* app/core/gimpdrawable-transform.[ch]
* app/core/gimpimage-convert.[ch]
* app/core/gimpimage-flip.[ch]
* app/core/gimpimage-resize.[ch]
* app/core/gimpimage-rotate.[ch]
* app/core/gimpimage-scale.[ch]
* app/core/gimpitem-linked.[ch]
* app/core/gimpitem.[ch]
* app/core/gimpchannel.c
* app/core/gimpdrawable.c
* app/core/gimplayer.c
* app/core/gimpselection.c
* app/vectors/gimpvectors.c: replaced callback/data by GimpProgress.
* app/tools/gimpblendtool.c
* app/tools/gimptransformtool.c
* app/gui/convert-dialog.c
* app/actions/documents-commands.c
* app/actions/file-commands.c
* app/actions/image-commands.c
* app/actions/layers-commands.c
* app/actions/plug-in-commands.c
* app/actions/vectors-commands.c
* tools/pdbgen/pdb/convert.pdb
* tools/pdbgen/pdb/edit.pdb
* tools/pdbgen/pdb/image.pdb
* tools/pdbgen/pdb/layer.pdb: changed callers accordingly.
* app/pdb/*_cmds.c: regenerated.
2004-05-14 Sven Neumann <sven@gimp.org>
* tools/pdbgen/pdb/fileops.pdb: added new PDB function
gimp_register_file_handler_mime() that allows to associate a MIME
type with a file procecdurre.
* app/pdb/fileops_cmds.c
* app/pdb/internal_procs.c
* libgimp/gimpfileops_pdb.[ch]: regenerated.
* app/plug-in/plug-in-proc.[ch]
* app/plug-in/plug-in-rc.c
* app/plug-in/plug-ins.[ch]: store a mimetype with file procedures.
* app/actions/file-commands.c
* app/core/gimpdocumentlist.[ch]
* app/core/gimpimagefile.[ch]
* app/file/file-open.[ch]
* app/file/file-save.c: set the thumbnail's mimetype from the file
procedure used to load/save the image.
* app/xcf/xcf.c
* plug-ins/bmp/bmp.c
* plug-ins/common/csource.c
* plug-ins/common/dicom.c
* plug-ins/common/gif.c
* plug-ins/common/gifload.c
* plug-ins/common/jpeg.c
* plug-ins/common/mng.c
* plug-ins/common/png.c
* plug-ins/common/postscript.c
* plug-ins/common/psd.c
* plug-ins/common/psd_save.c
* plug-ins/common/sunras.c
* plug-ins/common/svg.c
* plug-ins/common/tga.c
* plug-ins/common/tiff.c
* plug-ins/common/wmf.c
* plug-ins/common/xbm.c
* plug-ins/common/xpm.c
* plug-ins/common/xwd.c
* plug-ins/faxg3/faxg3.c
* plug-ins/winicon/main.c: register a mimetype, set a translatable
action name (taken from shared-mime-info) and register to the <Load>
and <Save> menus using gimp_plugin_menu_register().
2004-01-10 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.[ch] (gimp_imagefile_update): removed the
size parameter and do nothing but invalidating the preview.
* app/gui/file-open-dialog.c
* app/widgets/gimpdocumentview.c: changed accordingly.
* app/core/gimpdocumentlist.c (gimp_document_list_deserialize):
no need for calling gimp_imagefile_update() from here.
* tools/pdbgen/pdb/fileops.pdb
* app/pdb/fileops_cmds.c (file_load_thumbnail): rewritten using the
GimpThumbnail API.
* app/core/gimp.c: cosmetics.
2003-12-08 Sven Neumann <sven@gimp.org>
* Makefile.am (SUBDIRS): added libgimpthumb.
* libgimpthumb/gimpthumb-utils.c
* libgimpthumb/gimpthumbnail.c: basic functionality is implemented
and seems to be working.
* app/Makefile.am: link the application against libgimpthumb.
* app/core/core-types.h: include libgimpthumb/gimpthumb-types.h.
* app/core/gimpimagefile.[ch]: removed thumbnail handling routines
and use libgimpthumb instead. Fixes bug #127914.
* app/gui/file-open-dialog.c
* app/widgets/gimpdocumentview.c: changed accordingly.
2003-04-08 Michael Natterer <mitch@gimp.org>
* app/core/gimpviewable.[ch]: added vitrual function
GimpViewable::get_description() which returns the string that
should be presented to the user plus an optional tooltip with more
information. The default implementation just returns the object's
name and no tooltip.
* app/core/gimpbrush.c
* app/core/gimpbuffer.c
* app/core/gimpimage.c
* app/core/gimppalette.c
* app/core/gimppattern.c
* app/core/gimptoolinfo.c: implement get_description().
* app/core/gimpimagefile.[ch]: ditto. Renamed
gimp_imagefile_get_description() to
gimp_imagefile_get_desc_string(). Well, um, gimme a better name...
* app/gui/file-open-dialog.c: changed accordingly.
* app/file/file-utils.[ch]: renamed readXVThumb() to
file_utils_readXVThumb().
* tools/pdbgen/pdb/fileops.pdb: changed accordingly.
* app/widgets/widgets-types.h: removed GimpItemGetNameFunc typedef.
* app/widgets/gimpcontainerview-utils.[ch]: removed the the actual
get_name_funcs. They now live in the core as
GimpViewable::get_description() implementations.
* app/widgets/gimpcontainermenu.[ch]
* app/widgets/gimpcontainergridview.c
* app/widgets/gimpcontainermenuimpl.c
* app/widgets/gimpcontainertreeview.c
* app/widgets/gimpcontainerview.[ch]
* app/widgets/gimpmenuitem.[ch]
* app/widgets/gimpviewabledialog.c: removed get_name_func stuff
and use gimp_viewable_get_description().
* app/widgets/gimpcontainermenu.[ch]: added "preview_border_width"
to gimp_container_menu_set_preview_size().
* app/widgets/gimpimagedock.c: changed accordingly.
* app/pdb/fileops_cmds.c: regenerated.
2003-01-24 Michael Natterer <mitch@gimp.org>
* app/core/gimpdocumentlist.[ch]
* app/core/gimpimagefile.[ch]: added "Gimp" pointers so we don't
need to use "the_gimp" from "app_procs.h".
* app/core/core-types.h
* app/core/gimp.c
* app/gui/file-open-dialog.c
* tools/pdbgen/pdb/fileops.pdb: changed accordingly.
* app/pdb/fileops_cmds.c: regenerated.
2002-04-29 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.[ch]: added some assertions, cleaned up
internals.
* app/widgets/gimpdocumentview.c: use the preview size instead of a
hardcoded thumbnail size. Should we use the prefs value instead?
2002-04-29 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.[ch]: accept any size so we don't depend on
the values of GimpThumbnailSize. We might want to allow other thumbnail
sizes than only 0, 128 or 256.
2002-04-29 Sven Neumann <sven@gimp.org>
* app/core/core-enums.[ch]: added new enum GimpThumbnailSize.
* app/gimprc.c
* app/config/gimpcoreconfig.[ch]
* app/core/gimpcoreconfig.[ch]: replaced old gimprc value
write_thumbnails with thumbnail_size.
* app/core/gimpimagefile.[ch]: allow to specify a thumbnail size.
* app/core/gimpdocuments.c
* app/file/file-open.c
* app/file/file-save.c
* app/gui/preferences-dialog.c
* app/widgets/gimpdocumentview.c: changed accordingly.
* app/gui/file-open-dialog.c: create the preview according to the
users choice of thumbnail size. Doesn't update on changes yet.
2002-04-29 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.[ch]: save empty thumbnails to
~/.thumbnails/fail/gimp-1.3 if we cannot create a thumbnail. Added
new state GIMP_IMAGEFILE_STATE_THUMBNAIL_EXISTS to indicate that a
thumbnail was found but is not yet loaded. Removed unused thumb_mtime
from GimpImagefile struct and simplified some parts of the code.
* app/gui/file-open-dialog.c: cosmetic changes.
2002-04-29 Michael Natterer <mitch@gimp.org>
* app/core/gimpviewable.[ch]: added "gchar *name_changed_signal"
to GimpViewableClass which defaults to "name_changed".
* app/widgets/gimplistitem.c
* app/widgets/gimpmenuitem.c: connect to
viewable_class->name_changed_signal instead of just
"name_changed". Fixed possible UI inconsistency where the previous
viewable's tooltip would have been displayed.
* app/core/gimpimagefile.[ch]: set name_changed_signal to
"info_changed" so views can update their tooltips correctly.
Merged the separate image_state and thumb_state states into one
state variable and extended the state enum. Added description
strings for all states. Show the file size for all files, not only
for those with a thumbnail. Enabled display of outdated
thumbnails.
* app/gui/file-open-dialog.c: some changes because
gimp_imagefile_get_description() returns 3 instead of 2 lines of
text now.
* app/widgets/gimpcontainerview-utils.c: show the imagefile's
description in the tooltip.
* app/gui/menus.c
* app/gui/documents-commands.[ch]
* app/widgets/gimpdocumentview.c: added functions to remove
"dangling" document history entries. Updated the context menu so
all functions can be accessed through it.
2002-04-19 Michael Natterer <mitch@gimp.org>
* app/core/gimpimagefile.[ch]: made gimp_imagefile_save_thumbnail()
return a gboolean indicating success.
* app/file/file-save.c
* tools/pdbgen/pdb/fileops.pdb: use gimp_imagefile_save_thumbnail()
to save thumbnails.
* app/file/file-utils.[ch]: removed the .xvpics thumbnail saving code.
* app/pdb/fileops_cmds.c: regenerated.
2002-04-19 Michael Natterer <mitch@gimp.org>
* app/core/gimpdocuments.[ch] (gimp_documents_add): speak in terms
of "uri", not "filename". Return the created imagefile.
* app/core/gimpimagefile.[ch]: factored out private function
gimp_imagefile_save_png_thumb() and call it from
gimp_imagefile_create_thumbnail().
Added public function gimp_imagefile_save_thumbnail() which takes
an imagefile and an image.
* app/file/file-open.c: create thumbnails for all images opened
interactively using gimp_imagefile_save_thumbnail().
* app/xcf/xcf-load.c (xcf_load_image): set the filename with
gimp_image_set_filename() so it gets converted to an URI as for
external plug-ins.
2002-04-18 Michael Natterer <mitch@gimp.org>
* app/core/gimpimagefile.[ch]: create the thumbnail subdir strings
only once in class_init, minor stuff.
* app/widgets/gimppreview.c: set widget_class->activate_signal to
the preview's "clicked" id so we can create mnemonics for it.
* app/gui/file-open-dialog.c: make the whole preview area clickable,
block some signals of the "Preview" button so it behaves like
the tree view headers.
2002-04-18 Michael Natterer <mitch@gimp.org>
* app/core/gimpimagefile.[ch]: save the number of layers in the
thumbnail and show it in the description.
* app/gui/file-dialog-utils.[ch]: added file_dialog_new() which
contains a lot of factored out code from file-open and file-save.
* app/gui/file-open-dialog.c
* app/gui/file-save-dialog.c: use file_dialog_new(), reduce use of
global variables, added utility functions to reduce code
duplication, cleanup.
* app/gui/file-open-dialog.c: use a temporary imagefile to create
previews so the dialog's preview can show the progress when
creating many thumbnails.
2002-04-18 Michael Natterer <mitch@gimp.org>
* POTFILES.in: added app/gui/file-dialog-utils.c
2002-04-17 Sven Neumann <sven@gimp.org>
* app/core/gimpimagefile.[ch]
* app/gui/file-open-dialog.c: moved code to generate a literate
description of the image to the GimpImagefile object.
2002-04-17 Michael Natterer <mitch@gimp.org>
* app/core/core-enums.[ch]: register GimpImageType.
* app/core/gimpimagefile.[ch]: read and write more image properties
in thumbnails.
* app/gui/file-open-dialog.c: changed accordingly.
* app/widgets/gimpdialogfactory.c: disabled debugging output.
* app/widgets/gimpdocumentview.c: changed the "Refresh" button to
regenerate the preview on click and reload all previews on
shift+click.
* tools/pdbgen/enums.pl: regenerated.
2002-04-16 Michael Natterer <mitch@gimp.org>
* app/base/temp-buf.c: fixed temp_buf_copy() and
temp_buf_to_[color|gray]() to (1) not crash and (2) to assume the
correct pixelformat. Bugs were never noticed because the code was
never used until today...
* app/core/gimpviewable.c (gimp_viewable_get_new_preview_pixbuf):
use temp_buf_copy() to convert GRAY* TempBufs to RGB* before
creating the pixbuf.
* app/app_procs.c: don't try to open command line images if the
filename could not be converted to an URI.
* app/file/file-open.c
* app/file/file-save.c: use g_file_test() instead of stat().
* app/file/file-utils.[ch]: cleanup, changed
file_utils_filename_to_uri() to take a list of procs, not a Gimp
pointer.
* app/core/gimpimage.c: changed accordingly.
* app/core/gimpimagefile.[ch]: implemented thumbnail saving
following the thumbnail standard v0.5 (the implementation is not
yet fully standard compliant).
* app/gui/file-open-dialog.c: use the new thubmnail functions and
removed all .xvpics code. Not finished yet...
* app/core/gimpdocuments.c
* app/widgets/gimpdocumentview.c: changed accordingly.
* tools/pdbgen/pdb/fileops.pdb (file_save_thumbnail): set "success"
correctly.
* app/pdb/fileops_cmds.c: regenerated.
2001-12-03 Sven Neumann <sven@gimp.org>
Michael Natterer <mitch@gimp.org>
* app/paint-funcs/paint-funcs-mmx.h: removed redefiniton of HAS_ALPHA
macro.
* app/core/gimp.c: reverted Daniel's change; it doesn't make the code
simpler, only more error-prone.
* app/gui/info-dialog.h
* app/gui/resize-dialog.h
* app/core/gimp.h
* app/core/gimpbrushgenerated.h
* app/core/gimpbrushpipe.h
* app/core/gimpchannel.[ch]
* app/core/gimpcontainer.h
* app/core/gimpcoreconfig.h
* app/core/gimpdata.h
* app/core/gimpdatafactory.[ch]
* app/core/gimpdrawable-blend.c
* app/core/gimpdrawable.[ch]
* app/core/gimpimage.h
* app/core/gimpimagefile.h
* app/core/gimplayer.h
* app/core/gimplayermask.h
* app/core/gimpmoduleinfo.h
* app/core/gimppalette.h
* app/core/gimpundo.h
* app/widgets/gimpbrushfactoryview.h
* app/widgets/gimpconstrainedhwrapbox.h
* app/widgets/gimpcontainermenu.h
* app/widgets/gimpcontainerview.h
* app/widgets/gimpdialogfactory.h
* app/widgets/gimpimagedock.h
* app/widgets/gimplistitem.h
* app/widgets/gimpmenuitem.h
* app/widgets/gimpnavigationpreview.h
* app/widgets/gimppreview.h
* app/gimprc.h
* app/pathP.h
* app/tools/gimpbezierselecttool.h
* app/tools/gimpcolorbalancetool.h
* app/tools/gimpcurvestool.h
* app/tools/gimpdodgeburntool.c
* app/tools/gimpfreeselecttool.h
* app/tools/gimphuesaturationtool.h
* app/tools/gimpinktool-blob.h
* app/tools/gimpinktool.h
* app/tools/gimpiscissorstool.h
* app/tools/gimpmagnifytool.h
* app/tools/gimpmeasuretool.h
* app/tools/gimppainttool.h
* app/tools/gimppathtool.h
* app/tools/gimprectselecttool.h
* app/tools/gimpthresholdtool.h
* app/tools/gimptool.h
* app/tools/gimptransformtool.h
* app/base/base-config.h
* app/base/gimplut.[ch]
* app/base/pixel-region.h
* app/base/pixel-surround.[ch]
* app/base/temp-buf.[ch]
* app/base/tile-manager-private.h
* app/base/tile-manager.[ch]
* app/base/tile-private.h
* app/base/tile.[ch]
* app/display/gimpdisplay.h
* app/display/gimpdisplayshell-selection.h
* app/display/gimpdisplayshell.h
* app/gui/brush-select.h
* app/gui/gradient-editor.h
* app/gui/gradient-select.h: reverted most of Daniel's changes.
There's no reason to use unsigned integers here and in lots of places
it is even wrong.
Then it's way too early to convert gbooleans into bitfields. This
change may make sense in a few places but can happen later when the
API has settled and the code is more stable.
* app/gimprc.c: reverted Daniel's change. This is a GCC-ism and this
code is about to die soon anyway.
2001-11-23 Sven Neumann <sven@gimp.org>
* configure.in: bumped version number to 1.3.1.
Require Glib/GTK+-1.3.11 and Pango-0.22. Removed GDK_DISABLE_COMPAT_H
and GTK_DISABLE_COMPAT_H from our default CFLAGS since they don't
exist any longer.
* RELEASE-TO-CVS.patch: removed since the glib/gtk+ API is supposed to
be frozen now.
* HACKING: removed reference to RELEASE-TO-CVS.patch
* app/gui/menus.c
* app/tools/gimptexttool.c: applied RELEASE-TO-CVS.patch to conform
to the new GTK+/Pango API.
* app/core/Makefile.am: generate marshallers with gimp_marshal prefix.
* app/core/gimpmarshal.list: added all marshallers we use.
* app/core/gimpmarshal.[ch]: regenerated.
* app/[lots of .c files]: use gimp_marshal_* for all marshallers.
* data/images/
* app/app_procs.c
* app/gui/splash.c:
* libgimpbase/Makefile.am
* libgimpbase/gimpbase.h
* libgimpbase/gimputils.[ch]: removed since they are no longer needed.
* app/gimprc.c
* plug-ins/common/ps.c
* plug-ins/gdyntext/gdyntext.c
* plug-ins/gdyntext/gdyntextcompat.c
* plug-ins/gfig/gfig.c
* plug-ins/gflare/gflare.c
* plug-ins/script-fu/script-fu-scripts.c: use glib functions instead
of gimp_strescape() and gimpstrcompress().
* cleaned up all header files: use G_BEGIN_DECLS/G_END_DECLS, declared
all _get_type function as G_GNUC_CONST.
* tools/pdbgen/enumcode.pl
* tools/pdbgen/lib.pl: make them generate header files using
G_BEGIN_DECLS/G_END_DECLS.
* pixmaps/Makefile.am
* pixmaps/wilber3.xpm: removed ...
* data/images/tips_wilber.png: ... and added here as PNG
* app/gui/tips-dialog.c: load the Wilber on demand using GdkPixbuf.
* data/images/gimp_splash.ppm: removed ...
* data/images/gimp_splash.png: ... and added as PNG
* app/app_procs.c
* app/gui/splash.[ch]: load the splash image using GdkPixbuf.
* app/gui/about-dialog.c: sink the GtkPreview.
2001-08-11 Michael Natterer <mitch@gimp.org>
* app/core/Makefile.am
* app/core/gimpdocuments.[ch]: new file implementing the
docindex.* replacement.
* app/gimprc.c: added TT_XDOCUMENT to parse the new document
history.
* app/file-save.c
* app/gui/file-open-dialog.c: add opened & saved images to the
document history.
* app/core/gimp.c: call gimp_documents_init/exit() instead of
doing it here.
* app/core/gimpimagefile.[ch]: removed the "filename" attribute
and use GimpObject's "name" instead.
* app/gui/dialogs-constructors.[ch]
* app/gui/dialogs.c
* app/gui/menus.c: added a menu entry/dockable for the document
history.
* app/widgets/gimpdnd.[ch]: make it DND-able.
* app/widgets/gimppreview.c: fix preview rendering correctly this
itme.
2001-08-09 Sven Neumann <sven@gimp.org>
* app/core/Makefile.am
* app/core/core-types.h
* app/core/gimpimagefile.[ch]: added first draft of a GimpImagefile
object that will handle image files on disk, in particular their
thumbnails.