Implement serialization/deserialization

chat/richtext.py

@@ -4,6 +4,7 @@ import pygtk
 pygtk.require('2.0')
 import gtk
 import pango
+import xml.sax
 
 class RichTextBuffer(gtk.TextBuffer):
 	def __init__(self):
@@ -32,12 +33,6 @@ class RichTextBuffer(gtk.TextBuffer):
 				pos_end = pos.copy()
 				pos_end.backward_chars(length)
 				self.apply_tag_by_name(tag, pos, pos_end)
-				
-	def to_xml():
-		next_iter = buffer.get_start_iter()
-		while not next_iter.is_end():
-			
-
 		
 class RichTextToolbar(gtk.Toolbar):
 	def __init__(self, buf):
@@ -60,9 +55,100 @@ class RichTextToolbar(gtk.Toolbar):
 			self.buf.apply_tag(tag_name)
 		else:
 			self.buf.unapply_tag(tag_name)
+ 
+class RichTextHandler(xml.sax.handler.ContentHandler):
+	def __init__(self, buf):
+		self.buf = buf
+		self.tags = []
+
+	def _deserialize_element(self, el_name):
+		if el_name == "bold":
+			return "bold"
+		elif el_name == "italic":
+			return "italic"
+		else:
+			return None
+ 
+	def startElement(self, name, attributes):
+		tag = self._deserialize_element(name)
+		if tag:
+			self.tags.append(tag)
+ 
+	def characters(self, data):
+		start_it = it = self.buf.get_end_iter()
+		mark = self.buf.create_mark(None, start_it, True)
+		self.buf.insert(it, data)
+		start_it = self.buf.get_iter_at_mark(mark)
+
+		for tag in self.tags:
+			self.buf.apply_tag_by_name(tag, start_it, it)
+ 
+	def endElement(self, name):
+		tag = self._deserialize_element(name)
+		if tag:
+			self.tags.remove(tag)
+
+class RichTextSerializer:
+	def __init__(self):
+		self._open_xml_tags = []
+	
+	def _get_xml_tag(self, tag):
+		if tag.get_property("name") == "bold":
+			return "bold"
+		elif tag.get_property("name") == "italic":
+			return "italic"
+		else:
+			return "unknown_tag"
+			
+	def serialize(self, buf):
+		xml = "<richtext>"
+
+		next_it = buf.get_start_iter()
+		while not next_it.is_end():
+			it = next_it.copy()
+			if not next_it.forward_to_tag_toggle(None):
+				next_it = buf.get_end_iter()
+
+			reopen_xml_tags = []
+			for tag in it.get_toggled_tags(False):
+				xml_tag = self._get_xml_tag(tag)
+				while 1:
+					open_xml_tag = self._open_xml_tags.pop()
+					if open_xml_tag != xml_tag:
+						xml += "</" + open_xml_tag + ">"
+						reopen_xml_tags.append(open_xml_tag)
+					else:
+						xml += "</" + xml_tag + ">"
+						break
+				
+			for xml_tag in reopen_xml_tags:
+				self._open_xml_tags.append(xml_tag)
+				xml += "<" + xml_tag + ">"
+			
+			for tag in it.get_toggled_tags(True):
+				xml_tag = self._get_xml_tag(tag)
+				self._open_xml_tags.append(xml_tag)
+				xml += "<" + xml_tag + ">"
+			
+			xml += buf.get_text(it, next_it)
+
+		if next_it.is_end():
+			for xml_tag in self._open_xml_tags:
+				xml += "</" + xml_tag + ">"
+		
+		xml += "</richtext>"
+		
+		return xml
+
+	def deserialize(self, xml_string, buf):
+		parser = xml.sax.make_parser()
+		handler = RichTextHandler(buf)
+		parser.setContentHandler(handler)
+		parser.feed(xml_string)
+		parser.close()
 
 def test_quit(window, rich_buf):
-	print rich_buf.to_xml()
+	print RichTextSerializer().serialize(rich_buf)
 	gtk.main_quit()
 
 if __name__ == "__main__":
@@ -73,6 +159,9 @@ if __name__ == "__main__":
 	
 	rich_buf = RichTextBuffer()
 	
+	xml_string = "<richtext><bold><italic>Hello</italic>World</bold></richtext>"
+	RichTextSerializer().deserialize(xml_string, rich_buf)
+	
 	view = gtk.TextView(rich_buf)
 	vbox.pack_start(view)
 	view.show()