clonecanvas.py

#!/usr/bin/env python3

#import argparse
import xml.etree.ElementTree as ET
import gzip
from zipfile import ZipFile

def load_xml(fname):
  dot = fname.find('.')
  if dot < 0:
    ext = 'sif'
  else:
    ext = fname[dot+1:]
  if ext == 'sifz':
    with gzip.open(fname, 'r') as file_obj:
      return ET.parse(file_obj)
  elif ext == 'sfg':
    with ZipFile(fname, 'r') as arc:
      with arc.open('project.sifz', 'r') as file_obj0:
        with gzip.open(file_obj0) as file_obj:
          return ET.parse(file_obj)
  else:
    return ET.parse(fname)
def save_xml(fname, tree):
  dot = fname.find('.')
  if dot < 0:
    ext = 'sif'
  else:
    ext = fname[dot+1:]
  if ext == 'sifz':
    with gzip.open(fname, 'w') as file_obj:
      tree.write(file_obj, 'utf-8', True)
  elif ext == 'sfg':
    files = {}
    with ZipFile(fname, 'r') as arc:
      for name in arc.namelist():
        if name != 'project.sifz':
          files[name] = arc.read(name)
    with ZipFile(fname, 'w') as arc:
      for name, data in files.items():
        arc.writestr(name, data)
      arc.writestr('project.sifz', gzip.compress(b'<?xml version="1.0" encoding="UTF-8"?>\n'+ET.tostring(tree.getroot(), 'utf-8')))
  else:
    tree.write(fname, 'utf-8', True)

class Canvas:
  def __init__(self, fname, tree=None, element=None, parent=None, name=''):
    if tree is None:
      tree = load_xml(fname)
    if element is None:
      element = tree.getroot()
    self.fname = fname
    self.tree = tree
    self.element = element
    self.parent = parent
    self.name = name
  @classmethod
  def named(cls, name, prev=None):
    pound = name.find('#')
    if pound >= 0:
      fname = name[:pound]
      name = name[pound+1:]
    elif prev is None:
      fname = name
      name = ''
    else:
      pound = prev.find('#')
      if pound < 0:
        fname = prev
      else:
        fname = prev[:pound]
    canv = cls(fname)
    return canv.relative(name)
  def relative(self, name):
    canv = self
    tree = name.split(':')
    if len(tree[0]) == 0:
      canv = canv.root()
      tree = tree[1:]
    for branch in tree:
      canv = canv.child(branch)
    return canv
  def child(self, child_id):
    elem = self.element.find("./defs/canvas[@id='%s']" % child_id)
    if elem is None:
      defs = self.element.find("./defs")
      if defs is None:
        defs = ET.SubElement(self.element, 'defs')
      elem = ET.SubElement(defs, 'canvas', {'id': child_id})
    return Canvas(self.fname, self.tree, elem, self, self.name+':'+child_id)
  def root(self):
    return self if self.parent is None else self.parent.root()
  def copy_to(self, other, mine=None, others=None):
    if mine is None:
      mine = self.element
    if others is None:
      others = other.element
    others.text = mine.text
    others.tail = mine.tail
    for name, value in mine.items():
      if others.get(name) is not None:
        continue
      if name == 'use' and value[0] == ':':
        if value.startswith(self.name):
          value = other.name+value[len(self.name):]
        elif other.fname != self.fname:
          value = self.fname+'#'+value
      others.set(name, value)
    for el in mine:
      self.copy_to(other, el, ET.SubElement(others, el.tag))

import sys

src = Canvas.named(sys.argv[1])
dest = Canvas.named(sys.argv[2], sys.argv[1])
src.copy_to(dest)
save_xml(dest.fname, dest.tree)