The default interpolation routine can be choosen in the Preferences dialog.

I just thought it would be easier if it just remembered the last setting, that
way a newbie does not have to search trough the preferences, and it is handy if
you want to scale a set of images in a different way as normally

Jaap is right. I didn't know about the preferences setting until I saw
this bug report.

This applies in general to options that the user can set without
going into the preferences dialog: just remember the last setting,
and there is no need for an entry in the preferences dialog.

We would need an entry whether to save the last used setting, for the users who
don't want this.

Michael, I don't agree with having an extra entry whether to save the setting
yes or no. This would clutter the interface even more. Because you then still
need an entry in preferences and you need an extra entry in the scale dialog
whether to save the last used setting. 

Just always remembering the last setting is conceptually by far the easiest for
new users. Furthermore I think it's not really a problem if you have to change
the setting now and then (In your case you also have to click once more to not
save the setting). And most of the times you will not change this setting.

I agree that it is convenient to be able to set a default value from the place
it is used (e.g., the Image->Scale dialog) instead of having to open the
Preferences and find the corresponding option.  This is very useful for those
who are not familiar with all options available in the Preferences.

However, I disagree with the proposal that the last setting should automatically
become the default: I have set the default to Cubic (I might change it to
Lanczos soon) and I expect it to be used all the time.  But from time to time, I
scale up a bitmap image without interpolation.  I don't want this to become the
new default and give me bad results when I scale up another image two days
later.

So if there is a way to change the default from the Scale dialog (which is
probably a good idea), then it should require an explicit action from the user.
This could be a button like "set default" or a checkbox "remember this setting"
next to the "Interpolation type" dropdown list.

>>Jaap is right. I didn't know about the preferences setting until I saw
>>this bug report.

LOL, me too.

I think the suggestion for a "set as defaults" button here is a good all-round solution that satisfies both camps.

See this bug for request to deal with scaling units (percent/pixel) in the same way.
http://bugzilla.gnome.org/show_bug.cgi?id=357424

I think a "set as defaults" button would clutter the UI. This change
remember the settings across dialog invocations. Closing as FIXED.
(Please reopen if you strongly disagree, but please not without a
non-ugly suggestion for a GUI)

2006-10-14  Michael Natterer  <mitch@gimp.org>

	Remember the settings in the scale and resize dialogs for images
	and layers. Fixes bug #164995, bug #316392, and bug #357424.

	* app/dialogs/scale-dialog.h: removed GimpScaleCallback typedef.

	* app/dialogs/dialogs-types.h: added it here.

	* app/dialogs/image-scale-dialog.[ch]: made the ImageScaleDialog
	struct private, return a GtkWidget* from image_scale_dialog_new()
	and use a GimpScaleCallback in the public API.

	* app/actions/actions-types.h: #include "dialogs/dialogs-types.h"

	* app/actions/image-commands.c: changed according to image scale
	dialog changes. Remember the scale dialog's unit (if it is
	"percent") and interpolation type across dialog invocations. Also
	remember the resize dialog's unit (if it is "percent").

	* app/actions/layers-commands.c: remember scale and resize dialog
	stuff as in image-commands.c