fix(layout): lay an empty line below a top-and-bottom object beside floating ones

CHANGELOG.md

@@ -53,8 +53,14 @@
 - 쪽 수 추정(실험, `estimate_pages`)이 줄 캐시 없는 표 칸에서 글자처럼 둔 표 옆에 글 앞·뒤로 둔 개체가 있는
   문단을 지원 밖(`a nested table`)으로 두던 것을 고친다.
   - 그런 개체는 자리를 차지하지 않으므로, 그 문단은 표 혼자인 문단처럼 표 높이의 한 줄이다.
-  - 위아래로 둔 표 옆에 그런 개체가 있으면 한/글은 빈 줄을 표 아래에 둔다(표 둘일 때처럼). 이것은 전처럼 캐시
-    없이는 지원 밖이다.
+  - 위아래로 둔 표 옆에 그런 개체가 있으면 한/글은 빈 줄을 표 아래에 둔다(표 둘일 때처럼). 이제 캐시 없이도
+    따른다(아래 항목).
+- 쪽 수 추정(실험, `estimate_pages`)이 글 없는 문단에 문단 위에서 위아래로 둔 개체(표·그림)와 글 앞·뒤로 둔
+  개체가 함께 있을 때, 빈 줄을 위아래 개체의 윗선에 두던 것을 고친다.
+  - 한/글은 공백이나 머리표가 있을 때처럼 빈 줄을 그 개체 아래에 전체 폭으로 둔다. 뜬 개체가 종이 기준이든 문단
+    기준이든, 글 앞이든 뒤든 같다.
+  - 위아래 개체만 있으면 전처럼 윗선에 폭 0이다.
+  - 본문과 표 칸 모두 그렇다. 표 칸에서는 전에 캐시 없이 지원 밖(`a nested table`)이었다.
 - 쪽 수 추정(실험, `estimate_pages`)이 글자처럼 둔 개체 하나와 공백·줄 바꿈만 있는 문단을 언제나 한 줄로 세던
   것을 고친다.
   - 한/글은 개체 바로 뒤 공백 둘을 여백을 넘어도 그 줄에 두고, 그다음 공백이 여백이나 그 너머에서 시작하면

src/hwpx/layout/pages.py

@@ -1419,11 +1419,12 @@ def _placed_from(paragraph: Any) -> bool:
 
 def _object_before_text(runs: list[Any], headed: bool = False) -> Any:
     """The object placed top and bottom from its paragraph's top (a table, picture or drawing) that is all the
-    runs hold but text after it -- a space is text, and so is the bullet or number of a *headed* paragraph --
-    or ``None``."""
+    runs hold but text after it -- a space is text, and so is the bullet or number of a *headed* paragraph or
+    an object in front of or behind the text beside it (see :func:`_beside_floating`) -- or ``None``."""
 
-    objects = [child for run in runs for child in run if _local(child) in _OBJECTS]
-    if len(objects) != 1 or not _placed_top_and_bottom(objects[0]) or not (_run_text(runs) or headed):
+    objects = [child for run in runs for child in run if _local(child) in _OBJECTS and not _floating(child)]
+    if len(objects) != 1 or not _placed_top_and_bottom(objects[0]) \
+            or not (_run_text(runs) or headed or _beside_floating(runs)):
         return None
     for child in (child for run in runs for child in run):
         if child is objects[0]:
@@ -1433,6 +1434,14 @@ def _object_before_text(runs: list[Any], headed: bool = False) -> Any:
     return None
 
 
+def _beside_floating(runs: list[Any]) -> bool:
+    """Whether the runs hold an object in front of or behind the text: beside an object placed top and bottom
+    from the paragraph's top in a paragraph of no text, it sends the paragraph's empty line below that object,
+    as the whole width, as a space or a label does."""
+
+    return any(_local(child) in _OBJECTS and _floating(child) for run in runs for child in run)
+
+
 def _table_on_its_own(paragraph: Any) -> bool:
     """Whether a cell paragraph holds no text, not even a space, and nothing but one table placed top and
     bottom from its top (Hancom sets the empty line below two of them, not beside them, and so with an object
@@ -1446,11 +1455,11 @@ def _table_on_its_own(paragraph: Any) -> bool:
 
 def _table_before_text(runs: list[Any]) -> Any:
     """The table placed top and bottom from its paragraph's top that is all the runs hold but text after it
-    (text, a space being enough), or ``None``."""
+    (text, a space being enough, or an object in front of or behind the text beside it), or ``None``."""
 
-    objects = [child for run in runs for child in run if _local(child) in _OBJECTS]
+    objects = [child for run in runs for child in run if _local(child) in _OBJECTS and not _floating(child)]
     if len(objects) != 1 or _local(objects[0]) != "tbl" or not _placed_top_and_bottom(objects[0]) \
-            or not _run_text(runs):
+            or not (_run_text(runs) or _beside_floating(runs)):
         return None
     for child in (child for run in runs for child in run):
         if child is objects[0]:
@@ -1748,8 +1757,10 @@ def _inline_content(measure: _Measure, paragraph: Any, runs: list[Any], anchored
 
 def _anchored_object(objects: list[Any], text: str, column: int, headed: bool = False) -> Any:
     """The one object not set as a character of a paragraph of text (a space is text, and so is the bullet or
-    number label of a *headed* paragraph: its line goes below the object) or of objects set as characters that
-    is placed top and bottom from the paragraph's top (offset 0), or ``None``."""
+    number label of a *headed* paragraph: its line goes below the object; *headed* is also set for an empty
+    paragraph holding an object in front of or behind the text beside it, its empty line going below the object
+    as the whole width) or of objects set as characters that is placed top and bottom from the paragraph's top
+    (offset 0), or ``None``."""
 
     placed = [obj for obj in objects if obj.find(f"{HP}pos").get("treatAsChar") != "1"]
     if len(placed) != 1 or not (text or headed or len(objects) > 1):
@@ -1875,7 +1886,8 @@ def _paragraph(measure: _Measure, page: _Page, paragraph: Any, wrap: _Wrap | Non
     text = _run_text(runs)
     shape = measure.shape(paragraph.get("paraPrIDRef"))
     headed = bool(objects) and not text and measure.headed(paragraph)  # its label is text too
-    anchored = _anchored_object(objects, text, page.column_width, headed)
+    beside = bool(objects) and not text and _beside_floating(runs)  # its empty line goes below the object
+    anchored = _anchored_object(objects, text, page.column_width, headed or beside)
     marks = _marks(runs) and not _cached_metrics(paragraph)  # to lay out like characters
     if marks:
         if anchored is not None or wrap is not None or square is not None:

tests/test_layout_page_estimate.py

@@ -218,6 +218,18 @@
     "pages_table_cell_picture_up_second_far": 1,  # 30000 up: at its top too
     "pages_table_cell_picture_in_a_bulleted_paragraph": 1,  # alone in a bulleted paragraph: the bullet under it
     "pages_picture_alone_after_a_line": 1,  # in the body: the line on its top, the text after under it
+    # An empty paragraph 8000 down holding a table 6659 tall (outer margins 283 above and 1417 below) or a
+    # picture as tall placed top and bottom from its top, and a picture 10000 x 5000 in front of or behind the
+    # text: Hancom sets the empty line below the object (16359), as the whole width, as for a space or a label;
+    # without the floating picture on the object's top, taking no room (8000).
+    "pages_empty_paragraph_table_and_a_picture_behind_on_the_paper": 1,  # the picture placed on the paper
+    "pages_empty_paragraph_table_and_a_picture_behind_from_it": 1,  # placed from the paragraph, over the table
+    "pages_empty_paragraph_table_and_a_picture_in_front": 1,
+    "pages_empty_paragraph_picture_and_a_picture_behind": 1,  # a picture placed top and bottom
+    "pages_empty_paragraph_table_alone": 1,
+    "pages_cell_table_top_and_bottom_and_a_drawing_behind_the_text": 1,  # in a cell, a rectangle behind the
+                                                                         # text: the cell's line under the
+                                                                         # table too
     # A table set as a character (a row 1282 tall) 200 to 2000 narrower than the column (42520; 10 pt text spaced
     # 160%, a space 500 wide), spaces after it: the two right after it stay on its line wherever they start, a
     # further one starting at or past the margin goes on to the next line, the paragraph after below them:
@@ -875,16 +887,6 @@ def test_an_empty_run_before_a_cells_text_takes_no_room(name: str) -> None:
     _assert_like_hancom(estimate_pages(_with_empty_runs_in_cells(data)), data, HANCOM_PAGES[name])
 
 
-def test_a_cell_table_placed_top_and_bottom_beside_a_floating_object_is_not_followed_without_caches() -> None:
-    # A cell paragraph holding a table placed top and bottom from its top and a rectangle behind the text:
-    # Hancom sets the paragraph's empty line below the table (as below two such tables), not beside it. With
-    # the caches the estimate follows the cell's lines; without them it does not.
-    data = (FIXTURES / "pages_cell_table_top_and_bottom_and_a_drawing_behind_the_text.hwpx").read_bytes()
-
-    _assert_like_hancom(estimate_pages(data), data, 1)
-    assert estimate_pages(_without_caches(data)).unsupported == ("section 0: a nested table",)
-
-
 @pytest.mark.parametrize(
     ("fixture", "pages"),
     [