fix(pages): follow empty lines beside a cell object with text on both sides

CHANGELOG.md

@@ -6,6 +6,9 @@
 
 ### 고침
 
+- 쪽 수 추정이 표 칸 안에서 양쪽에 글 자리가 있는 어울림 개체 곁에 빈 줄만 오는 칸도 추정한다. 한/글처럼 빈 줄은 개체 곁에
+  한 높이 두 조각으로 둔다(곁에 글이 오면 지금처럼 지원 밖). 한/글이 저장한 줄 캐시가 있는 칸에서 그런 두 조각을 줄 둘로
+  세어 칸을 조각 수만큼 높게 잡던 것도 바로잡았다.
 - 쪽 수 추정과 FormFit이 줄 바꿈 뒤 빈 run으로 끝나는 문단의 빈 마지막 줄을 한/글처럼 그 run의 크기로 잡는다(글자보다 작아도).
   전에는 작은 run은 무시하고 큰 run은 줄 바꿈 앞 줄까지 키웠다. 끝 run이 더 크면 그 문단의 줄 캐시는 쓰지 않는다.
 - 쪽 수 추정이 첫 줄에 붙은 어울림 개체의 세로 위치를 한/글처럼 위 간격 위 문단 맨 위에서 잰다. 전에는 첫 줄 맨 위에서

src/hwpx/layout/pages.py

@@ -1014,6 +1014,7 @@ def wrapped_lines(self, paragraphs: list[Any], width: int, tables: bool = False
                     raise _Unsupported("an object placed top and bottom or square after the text of a paragraph "
                                        "with a layout cache in a cell")
                 lines, narrow, own = _clear_of(self, fixed, top, shape.prev, anchor, obj, bands, empty, width)
+                _beside_one_side(narrow, empty)
                 if narrow and not _cache_lines(paragraph):
                     raise _Unsupported("text laid out otherwise beside a square-wrapped object in a cell")
             else:
@@ -1035,6 +1036,7 @@ def wrapped_lines(self, paragraphs: list[Any], width: int, tables: bool = False
                     narrow = found
                 else:
                     raise _Unsupported("lines beside a square-wrapped object in a cell that do not settle")
+                _beside_one_side(narrow, empty)
                 if narrow and ("\n" in text or style.head):
                     raise _Unsupported("a paragraph with margins, a label or line breaks beside a square-wrapped "
                                        "object in a cell")
@@ -1405,6 +1407,12 @@ def _drawn_lines(measure: _Measure, paragraphs: list[Any], width: int | None = N
         below = top  # where the paragraph's next line would stand
         for index, segment in enumerate(segments):
             vertpos = int(segment.get("vertpos", 0))
+            if index and vertpos == int(segments[index - 1].get("vertpos", 0)) \
+                    and int(segment.get("horzpos", 0)) > int(segments[index - 1].get("horzpos", 0)):
+                follows.append(follows[-1])  # a line's second piece beside an object with text on both sides: at
+                tops.append(tops[-1])  # the first's height
+                heights.append(int(segment.get("textheight", segment.get("vertsize", 0))))
+                continue
             follows.append(below)
             table = pushing.get(index)
             if table is not None and vertpos == _cell_extent(measure, table) + _down(table.find(f"{HP}pos")) \
@@ -2456,10 +2464,23 @@ def _cell_band(measure: _Measure, obj: Any, top: int, width: int) -> tuple[int,
     left = left if left >= _MIN_SIDE and flow != "RIGHT_ONLY" else 0
     right = right if right >= _MIN_SIDE and flow != "LEFT_ONLY" else 0
     if left and right:
-        raise _Unsupported(f"text on both sides of {_local(obj)} wrapped square in a cell")
+        return up, foot, _BothSides(min(left, right))
     return up, foot, (left or right) or None
 
 
+class _BothSides(int):
+    """The room beside an object wrapped square in a cell with text on both sides of it (the narrower side's): an
+    empty line goes beside it, two empty pieces at one height as tall as the line; text there is not followed."""
+
+
+def _beside_one_side(narrow: dict[int, int], empty: bool) -> None:
+    """Text on lines *narrow* beside an object wrapped square in a cell with text on both sides of it (unless
+    the paragraph is *empty*) is not followed."""
+
+    if not empty and any(isinstance(room, _BothSides) for room in narrow.values()):
+        raise _Unsupported("text on both sides of an object wrapped square in a cell")
+
+
 def _clear_of(measure: _Measure, metrics: list[tuple[int, int]], top: int, prev: int, anchor: int, obj: Any,
               bands: list[tuple[int, int, int | None]], empty: bool, width: int
               ) -> tuple[list[tuple[int, int, int]], dict[int, int], tuple[int, int, int | None] | None]:
@@ -2488,7 +2509,7 @@ def _clear_of(measure: _Measure, metrics: list[tuple[int, int]], top: int, prev:
                     y, moved = band[1], True
         beside = [band[2] for band in around if band[2] is not None and y < band[1] and y + height > band[0]]
         if beside:
-            narrow[index] = min(beside)
+            narrow[index] = _BothSides(min(beside)) if any(isinstance(room, _BothSides) for room in beside)                 else min(beside)
         placed.append((y, height, advance))
     return placed, narrow, own
 

tests/test_layout_page_estimate.py

@@ -115,6 +115,11 @@
     # table placed top and bottom 1958 down from it, then three paragraphs: Hancom places the inner table from the
     # paragraph's top above its spacing, as in the body, the cell's next paragraph below it from there
     "pages_cell_table_down_from_spacing": 4,
+    # Four times on a page of its own: a table whose cell's empty first paragraph holds a 15000 x 8000 rectangle
+    # wrapped square 12000 from its left, text on both sides of it, 0 or 2000 down, overlapping the text or not,
+    # then six empty paragraphs and two of text: the empty lines reaching it go beside it (two empty pieces at one
+    # height), the table as tall as with room on one side only
+    "pages_cell_object_on_both_sides_beside_empty_lines": 5,
     "pages_square_band_table_as_character_alone": 1,  # 47058 wide: beside it all the same, reaching past the room
     "pages_square_band_narrow_table_as_character_alone": 1,  # 5000 wide: beside it, and the lines after
     # ... or text whose lines in the room beside the picture are as wide as it, and an object set as a