2008-08-03  Martin Nordholts  <martinn@svn.gnome.org>

	Further work for completing bug #362915 that makes changes to the
	image size (e.g when cropping) be much more nicely handled by
	display shell.

	* app/core/gimpimage.[ch]: Add new signal
	GimpImage::size-changed-detailed that is emited whenever
	GimpViewable::size-changed is. The new signal provides additional
	information, namely the previous origin relative to the current
	origin. Cliens choose what specific signal to listen to depending
	on how much info they need.

	* app/display/gimpdisplayshell-handlers.c: Connect to
	GimpImage::size-changed-detailed instead of
	GimpViewable::size-changed since the shell wants information about
	the previous image origin.
	(gimp_display_shell_resolution_changed_handler): Use
	gimp_display_shell_scale_resize() instead to avoid display
	garbage.

	* app/display/gimpdisplayshell-scale.[ch]: Add new utility
	function gimp_display_shell_center_image_on_next_size_allocate().

	* app/display/gimpdisplayshell-scroll.[ch]
	(gimp_display_shell_handle_size_changed_detailed): New function
	that replaces logic in gimp_display_shell_handle_size_changed and
	that takes previous-origin of the image into account and adjusts
	the offset so that the image content that remains doesn't move. If
	the window is resized on image resize, just center the image
	afterwards.

	* app/core/gimpimage-undo-push.[ch]
	(gimp_image_undo_push_image_size): Add previous-origin paremeters.

	* app/core/gimpimageundo.[ch]: Add and manage previous-origin
	properties so that the display shell offset can be appropriately
	adjusted also when undoing.

	* app/core/gimpundo.h
	* app/core/gimpimage-undo.c: Add previous_origin members to the
	undo accumulator and emit that information when the size of the
	image changes due to the undo.

	* app/core/gimpimage-crop.c (gimp_image_crop)
	* app/core/gimpimage-scale.c (gimp_image_scale)
	* app/core/gimpimage-rotate.c (gimp_image_rotate)
	* app/core/gimpimage-resize.c (gimp_image_resize_with_layers):
	Supply information about the previous-origin of the image to the
	size-changed signals and the undo system.

svn path=/trunk/; revision=26354