fix(layout): count objects set as characters in a cell paragraph without a layout cache

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 ### 고침
 
+- 쪽 수 추정(실험, `estimate_pages`)이 줄 캐시 없는 표 칸 문단에서 글자처럼 둔 개체(그림·도형·수식 등)를 세지 않던
+  것을 고친다. 전에는 칸 문단에 혼자 든 표만 그 높이로 셌고, 다른 개체는 없는 것처럼 줄을 세어 행이 한/글보다
+  낮았다. 이제 개체 하나만 든 문단은 개체 높이의 한 줄이고 줄 간격은 글자 크기로 센다. 글 사이에 있거나 여럿이면
+  본문처럼 개체의 폭과 높이로 줄 안에 놓는다.
 - 쪽 수 추정(실험, `estimate_pages`)이 `hp:t` 글 안에 글자로 든 전각 공백(U+3000)을 고정폭 빈칸(`hp:fwSpace`)으로
   보던 것을 고친다(python-hwpx는 둘을 모두 U+3000으로 읽는다). 글자 전각 공백은 글꼴의 폭(대개 글자 크기만큼)을
   차지하고, 그 뒤에서 줄이 나뉘며, 줄 끝에서는 몇 개가 이어져도 모두 매달린다. 전에는 1/4 폭의 고정폭 빈칸으로

src/hwpx/layout/pages.py

@@ -89,7 +89,9 @@
   cells' rest (a cell declared taller than its text, whose first line fits, is cut like such a row,
   below). A table set as a character alone in a paragraph of a cell is one line as tall as it
   there, spaced like the text, and a row holding one splits between its cell's lines, each as tall
-  as it is; a nested table among text, placed top and bottom or wrapped square is followed through
+  as it is; so is another object set as a character alone in a cell paragraph without a layout
+  cache, and such objects among its text, or several of them, take their place in its lines as in
+  the body; a nested table among text, placed top and bottom or wrapped square is followed through
   the layout caches of its cell, as tall as Hancom drew it (down to such a table's foot; one placed
   up from its paragraph's top stands at that top; the caches of a row Hancom split over a page end
   start over at the next page's top, and are read as one run of lines, each line that goes back up
@@ -527,9 +529,13 @@ def stack(self, paragraphs: list[Any], width: int, caches: bool) -> tuple[int, i
             shape = self.shape(paragraph.get("paraPrIDRef"))
             pitch = _pitch(shape.kind, shape.value, size)
             table = _table_alone(runs)
+            alone = None if table is not None or caches and _cached_metrics(paragraph) else _object_alone(runs)
             if table is not None:  # one line as tall as the table, spaced like the text
                 tall = _inline_table_height(self, table) + _extent_margins(table)
                 count, size, pitch = 1, tall, tall + pitch - size
+            elif alone is not None:  # so with another object set as a character
+                tall = _object_extent(alone, self)[1]
+                count, size, pitch = 1, tall, tall + pitch - size
             else:
                 cached = _cached_metrics(paragraph) if caches else ()
                 cached = cached or self.marked_lines(paragraph, runs, width) \
@@ -595,10 +601,11 @@ def stack_lines(self, paragraphs: list[Any], width: int, caches: bool) -> tuple[
         return tuple(metrics)
 
     def marked_lines(self, paragraph: Any, runs: list[Any], width: int) -> tuple[tuple[int, int], ...]:
-        """(height, advance) of each line of a paragraph holding composed characters or ruby text, laid
-        out at *width* as in the body; empty for a paragraph holding neither."""
+        """(height, advance) of each line of a paragraph holding composed characters, ruby text, or objects
+        set as characters among its text or several of them, laid out at *width* as in the body; empty for
+        a paragraph holding none of them."""
 
-        if not _marks(runs):
+        if not _marks(runs) and not _objects_among(runs):
             return ()
         shape = self.shape(paragraph.get("paraPrIDRef"))
         _check_ruby_spacing(runs, shape)
@@ -712,6 +719,24 @@ def _row_span(cell: Any) -> int:
     return 1 if span is None else int(span.get("rowSpan", 1))
 
 
+def _object_alone(runs: list[Any]) -> Any:
+    """The object set as a character, not a table, that is all a paragraph holds (but objects in front of or
+    behind the text), or ``None``."""
+
+    objects = _placed_objects(runs)
+    if len(objects) != 1 or _local(objects[0]) == "tbl" or _run_text(runs).strip():
+        return None
+    return objects[0] if objects[0].find(f"{HP}pos").get("treatAsChar") == "1" else None
+
+
+def _objects_among(runs: list[Any]) -> bool:
+    """Whether the runs hold objects set as characters, and nothing else placed, among text or several."""
+
+    objects = _placed_objects(runs)
+    return bool(objects) and (len(objects) > 1 or bool(_run_text(runs).strip())) and all(
+        obj.find(f"{HP}pos").get("treatAsChar") == "1" for obj in objects)
+
+
 def _table_alone(runs: list[Any]) -> Any:
     """The table set as a character that is all a paragraph holds, or ``None``."""
 

tests/test_layout_page_estimate.py

@@ -59,6 +59,18 @@
                                                   # line goes below it, as a line of text would
     "pages_object_pushing_characters_off1398": 1,  # the same 1398 down
     "pages_object_pushing_characters_off1398_char3000": 1,  # with a rectangle 3000 tall set as a character
+    # Objects set as characters in a paragraph of a cell of a flowing table, 10 pt text spaced 160%:
+    "pages_cell_picture_as_character_alone": 1,  # a picture 3000 x 4000 alone: one line 4000 tall
+    "pages_cell_rectangle_as_character_alone": 1,  # a rectangle 3000 x 2000
+    "pages_cell_equation_alone": 1,  # an equation
+    "pages_cell_picture_before_text": 1,  # the picture before two lines of text: the first line as tall
+    "pages_cell_picture_among_text": 1,  # among them
+    "pages_cell_picture_after_text": 1,  # after them: the second line as tall
+    "pages_cell_two_pictures_on_one_line": 1,  # two that fit side by side
+    "pages_cell_two_pictures_on_two_lines": 1,  # two that do not: a line each
+    "pages_cell_picture_alone_fixed_spacing": 1,  # alone, line spacing fixed at 1600
+    "pages_cell_picture_in_a_table_as_character": 1,  # alone, in a table set as a character
+    "pages_cell_picture_then_a_line": 1,  # alone, then a paragraph of a line: spaced from the text size
     # A section hiding a page's first empty lines (hp:visibility@hideFirstEmptyLine), its first page full:
     "pages_hide_empty_lines_one": 2,  # an empty paragraph past the foot stays there, the text after it
                                       # starts the next page