feat: add paper_size in SceneInfo

Closes ricklupton#39

README.md

@@ -10,6 +10,10 @@ To convert rm files to other formats, you can use [rmc](https://github.com/rickl
 
 ### Unreleased
 
+New feature:
+
+- Add support for `paper_size` field on some SceneInfo
+
 ### v0.6.1
 
 Fixes:

src/rmscene/scene_stream.py

@@ -143,21 +143,26 @@ def version_info(self, _) -> tuple[int, int]:
     current_layer: LwwValue[CrdtId]
     background_visible: LwwValue[bool]
     root_document_visible: LwwValue[bool]
+    paper_size: tp.Optional[tuple[int, int]]
 
     @classmethod
     def from_stream(cls, stream: TaggedBlockReader) -> SceneInfo:
         current_layer = stream.read_lww_id(1)
         background_visible = stream.read_lww_bool(2)
         root_document_visible = stream.read_lww_bool(3)
+        paper_size = stream.read_int_pair(5) if stream.bytes_remaining_in_block() > 0 else None
 
         return SceneInfo(current_layer=current_layer,
                          background_visible=background_visible,
-                         root_document_visible=root_document_visible)
+                         root_document_visible=root_document_visible,
+                         paper_size=paper_size)
 
     def to_stream(self, writer: TaggedBlockWriter):
         writer.write_lww_id(1, self.current_layer)
         writer.write_lww_bool(2, self.background_visible)
         writer.write_lww_bool(3, self.root_document_visible)
+        if self.paper_size:
+            writer.write_int_pair(5, self.paper_size)
 
 
 @dataclass

src/rmscene/tagged_block_reader.py

@@ -347,3 +347,10 @@ def read_string_with_format(self, index: int) -> tuple[str, tp.Optional[int]]:
                 fmt = None
 
             return string, fmt
+
+    def read_int_pair(self, index: int) -> tp.Optional[tuple[int, int]]:
+        """Read a sub block containing two uint32"""
+        with self.read_subblock(index):
+            first = self.data.read_uint32()
+            second = self.data.read_uint32()
+            return first, second

src/rmscene/tagged_block_writer.py

@@ -186,3 +186,9 @@ def write_string_with_format(self, index: int, text: str, fmt: int):
             self.data.write_bool(is_ascii)
             self.data.write_bytes(b)
             self.write_int(2, fmt)
+
+    def write_int_pair(self, index: int, value: tuple[int, int]):
+        """Read a sub block containing two uint32"""
+        with self.write_subblock(index):
+            self.data.write_uint32(value[0])
+            self.data.write_uint32(value[1])

tests/test_scene_stream.py

@@ -280,18 +280,20 @@ def test_write_blocks():
 
 
 def test_blocks_keep_unknown_data_in_main_block():
-    # The "E1 FF" is represents new, unknown data -- note that this might need
+    # The "E1 FF" represents new, unknown data -- note that this might need
     # to be changed in future if the next id starts to actually be used in a
     # future update!
     data_hex = """
-    21000000 0000010D
+    2E000000 0000010D
     1C 06000000
        1F 0000
        2F 0000
     2C 05000000
        1F 0000 21 01
     3C 05000000
        1F 0000 21 01
+    5C 08000000
+       7C050000 50070000
     E1 FF
     """
     buf = BytesIO(HEADER_V6 + bytes.fromhex(data_hex))