2004-08-05  Michael Natterer  <mitch@gimp.org>

	Enabled previewing items without selecting them in all list and
	grid views using mouse button 2. Implicitly enables previewing of
	items in container popups and thus fixes bug #121011:

	* app/widgets/gimppreview.c (gimp_preview_button_press_event)
	* app/widgets/gimpcellrendererviewable.c
	(gimp_cell_renderer_viewable_clicked): show the preview also on
	mouse button 2 click.

	* app/widgets/gimpcontainertreeview.c
	(gimp_container_tree_view_button_press): dispatch mouse button 2
	clicks to GimpCellRendererViewable, but don't select or change
	anything in the tree_view.

	Unrelated cleanup:

	* app/widgets/gimppreview.c (gimp_preview_button_press_event):
	don't offset bevent->x,y by widget->allocation.x,y before calling
	gimp_preview_popup_show() ...

	* app/widgets/gimppreview-popup.c (gimp_preview_popup_show):
	... instead, do it here generically (check if the parent widget is
	GTK_WIDGET_NO_WINDOW()).