Remove gimp_item_tree_clear(), added in last commit, and move its
code to gimp_item_tree_dispose(). Likewise, in
gimp_image_dispose(), use g_object_run_dispose() on the image item-
trees, instead of gimp_item_tree_clear().
(cherry picked from commit b0de51b6bf)
Add gimp_item_tree_clear(), which removes all the items of a
GimpItemTree, and clear the layers/channels/vectors item trees in
gimp_image_dispose(), *before* finalizing the image, so that the
corresponding items' desctructors are called while the image is
still alive. In particular, this allows the destructors to safely
call gimp_item_is_attached(), which happens when the image has a
floating selection, since commit
8d4e5e0ff7.
(cherry picked from commit d7e3a1e226)
and use them from gimp_image_add,remove_layer,channel,vectors().
Removes quite some code duplication from the remove() functions but
almost none from add() because of the ongoing floating selection
madness. We need the calls to the item tree anyway because it's
going to ensure unique names of its items.
- get rid of the individual undo types and add GIMP_UNDO_ITEM_REORDER.
- replace the pushing functions by a single one.
- merge all the actual undo code into gimpitempropundo.[ch].
- use gimp_item_tree_reorder_item() to do the actual reordering.
- fix gimp_item_tree_reorder_item() to use an ordinary "push_undo"
boolean again instead of a pointer to an undo function.
GimpVectorsPropUndo is now a completely empty skeleton. Keep it around
anyway, maybe we'll get vectors properties to undo soon.
and remove the code duplication in gimp_image_reorder_layer(),
_channel() and _vectors(), which now consist of a single call to
gimp_item_tree_reorder_item().
