fix(layout): place a square-wrapped object after text on its first line from the paragraph's top

CHANGELOG.md

@@ -16,6 +16,11 @@
 
 ### 고침
 
+- 쪽 수 추정(실험, `estimate_pages`)이 문단 글 뒤에 놓인 어울림(SQUARE) 개체를 지원 밖
+  (`... wrapped square after text`)으로 두던 것을, 그 개체의 조판 부호가 문단 첫 줄에 있을 때 고친다.
+  - 한/글은 개체의 문단 기준 세로 자리를 부호가 놓인 줄(문단을 단 전체 폭으로 놓았을 때)의 윗선에서 잰다.
+    부호가 첫 줄에 있으면 문단 윗선이라, 글 앞에 놓인 개체와 같다. 띠에 닿는 줄은 그 문단의 줄도 곁으로 간다.
+  - 첫 줄은 FormFit으로 문단을 단 전체 폭에서 나누어 가린다. 부호가 뒤 줄에 있으면 전처럼 지원 밖이다.
 - 쪽 수 추정(실험, `estimate_pages`)이 글과 함께 움직이고 나뉠 수 있는 어울림(SQUARE) 표가 본문 바닥을 넘을 때,
   줄 캐시가 없으면 지원 밖으로 두던 것을 고친다.
   - 한/글은 그런 표를 흐르는 표처럼 쪽 끝에서 행 사이나 칸 줄 사이로 나눈다. 표가 걸친 쪽마다 곁 줄은 그 쪽

src/hwpx/layout/pages.py

@@ -170,7 +170,7 @@
 
 import copy
 import os
-from collections.abc import Collection
+from collections.abc import Callable, Collection
 from dataclasses import dataclass, field, replace
 from typing import TYPE_CHECKING, Any
 
@@ -2007,9 +2007,12 @@ def _wraps_top_and_bottom(obj: Any, column: int) -> bool:
     return start < _MIN_SIDE and column - start - width < _MIN_SIDE
 
 
-def _square_object(objects: list[Any], runs: list[Any], column: int) -> Any:
+def _square_object(objects: list[Any], runs: list[Any], column: int,
+                   on_first_line: Callable[[Any], bool] | None = None) -> Any:
     """The one object of a paragraph wrapped square across the column from the paragraph's top, before
-    any text, or ``None`` (:func:`_square_sides` says where the text goes beside it)."""
+    any text or after text that *on_first_line* says ends on the paragraph's first line (Hancom places it from
+    the top of the line its control falls on, the paragraph laid out the column's whole width), or ``None``
+    (:func:`_square_sides` says where the text goes beside it)."""
 
     if len(objects) != 1:
         return None
@@ -2025,10 +2028,29 @@ def _square_object(objects: list[Any], runs: list[Any], column: int) -> Any:
         if child is obj:
             break
         if _local(child) == "t" and _t_text(child):
-            raise _Unsupported(f"{_local(obj)} wrapped square after text")
+            if on_first_line is None or not on_first_line(obj):
+                raise _Unsupported(f"{_local(obj)} wrapped square after text")
+            break
     return obj
 
 
+def _on_first_line(measure: _Measure, page: _Page, paragraph: Any, runs: list[Any], obj: Any) -> bool:
+    """Whether *obj*'s control falls on the paragraph's first line laid out the column's whole width (FormFit's
+    lines, the object taking no room in them)."""
+
+    place = 0
+    for child in (child for run in runs for child in run):
+        if child is obj:
+            break
+        if _local(child) == "t":
+            place += len(_t_text(child))
+    size, refs, _ = _text_size(measure, runs)
+    style = measure.style(paragraph.get("paraPrIDRef"), refs, paragraph)
+    shape = measure.shape(paragraph.get("paraPrIDRef"))
+    starts = measure.line_starts(_run_text(runs), _line_widths(shape, page.column_width, style), size, style)
+    return all(start > place for start in starts[1:])
+
+
 def _square_sides(obj: Any, page: _Page) -> tuple[int, int]:
     """How wide the text beside a square-wrapped object is on its left and on its right in the column: a
     side narrower than 1440, or one its text flow leaves out, takes none (0). Placed from the column,
@@ -2082,7 +2104,8 @@ def _wrapped_paragraph(measure: _Measure, page: _Page, paragraph: Any, wrap: _Wr
         para = _paragraph(measure, page, paragraph, stacked=tuple(stacked))
         shape = measure.shape(paragraph.get("paraPrIDRef"))
         return replace(para, stack=_stack(measure, stacked, page.column_width, shape)), None
-    square = _square_object(objects, runs, page.column_width)
+    square = _square_object(objects, runs, page.column_width,
+                            lambda obj: _on_first_line(measure, page, paragraph, runs, obj))
     pusher = _pushing_object(objects, _run_text(runs), page.column_width)
     if moved:  # the object went on to the next page's top: the paragraph's lines as if it were not there
         # the object: wrapped square, pushing the lines below it, or alone below the empty line (a table that

tests/test_layout_page_estimate.py

@@ -62,6 +62,13 @@
     "pages_square_table_split_text_on_both_sides": 3,  # in the middle: the lines in two pieces
     "pages_square_table_wide_split_text_beside_it": 2,  # 45626 wide, 2562 left beside it: two characters a
                                                         # line there
+    # A table 30000 x 20000 wrapped square at the column's left from its paragraph 8000 down (10 pt text spaced
+    # 160%), its control after 16 characters, on the paragraph's first line laid out the column's whole width:
+    # Hancom places it from the paragraph's top as one before the text, the lines reaching it beside it:
+    "pages_square_table_after_text": 1,  # the paragraph's own lines beside it, 12 characters a line
+    "pages_square_table_after_text_2383_down": 1,  # placed 2383 down: the paragraph's line above it the
+                                                   # whole width, the paragraphs after beside it
+    "pages_square_table_before_text": 1,  # its control before the text: the same
     "pages_picture_1319_down_moved_to_the_next_page": 3,  # a picture 8000 tall placed top and bottom 1319
                                                           # below its empty paragraph's line: alone at the
                                                           # next page's top, the line staying, the lines
@@ -1264,6 +1271,16 @@ def test_a_table_whose_row_addresses_skip_is_estimated_without_the_missing_rows(
     assert estimate.pages == 1
 
 
+def test_a_square_object_after_text_past_the_first_line_is_not_followed() -> None:
+    # The same table, its control after 60 characters: on the paragraph's second line laid out the column's
+    # whole width. Hancom places it from that line's top (9600), the lines from there on beside it. Not
+    # followed.
+    data = (FIXTURES / "pages_square_table_after_text_on_the_second_line.hwpx").read_bytes()
+
+    assert estimate_pages(data).unsupported == ("section 0: tbl wrapped square after text",)
+    assert estimate_pages(_without_caches(data)).unsupported == ("section 0: tbl wrapped square after text",)
+
+
 def test_a_page_break_in_a_row_holding_a_table_beside_a_taller_cell_is_unsupported() -> None:
     # Row 1's cell (1, 0) holds more lines than the cell beside it holding a table; the page end falls
     # among them.