feat(api): add nvim_win_text_height (#24236)

It uses the same code as "scroll_delta" of "win_viewport" UI event to
calculate text height, but is more flexible.

1 files changed, 18 insertions, 18 deletions

diff --git a/src/nvim/plines.c b/src/nvim/plines.c
index 476e5b2b7d..df1414bc8f 100644
--- a/src/nvim/plines.c
+++ b/src/nvim/plines.c
@@ -600,14 +600,14 @@ static int win_nolbr_chartabsize(chartabsize_T *cts, int *headp)
 
 /// Get the number of screen lines a range of text will take in window "wp".
 ///
-/// @param start_lnum  first line number
-/// @param start_vcol  >= 0: virtual column on "start_lnum" where counting starts,
-///                          rounded down to full screen lines
-///                    < 0:  count a full "start_lnum", including filler lines above
-/// @param end_lnum    last line number
-/// @param end_vcol    >= 0: virtual column on "end_lnum" where counting ends,
-///                          rounded up to full screen lines
-///                    < 0:  count a full "end_lnum", not including fillers lines below
+/// @param start_lnum  Starting line number, 1-based inclusive.
+/// @param start_vcol  >= 0: Starting virtual column index on "start_lnum",
+///                          0-based inclusive, rounded down to full screen lines.
+///                    < 0:  Count a full "start_lnum", including filler lines above.
+/// @param end_lnum    Ending line number, 1-based inclusive.
+/// @param end_vcol    >= 0: Ending virtual column index on "end_lnum",
+///                          0-based exclusive, rounded up to full screen lines.
+///                    < 0:  Count a full "end_lnum", not including fillers lines below.
 int64_t win_text_height(win_T *const wp, const linenr_T start_lnum, const int64_t start_vcol,
                         const linenr_T end_lnum, const int64_t end_vcol)
 {
@@ -620,39 +620,39 @@ int64_t win_text_height(win_T *const wp, const linenr_T start_lnum, const int64_
     width2 = MAX(width2, 0);
   }
 
-  int64_t size = 0;
-  int64_t height_nofill = 0;
+  int64_t height_sum = 0;
+  int64_t height_cur_nofill = 0;
   linenr_T lnum = start_lnum;
 
   if (start_vcol >= 0) {
     linenr_T lnum_next = lnum;
     const bool folded = hasFoldingWin(wp, lnum, &lnum, &lnum_next, true, NULL);
-    height_nofill = folded ? 1 : plines_win_nofill(wp, lnum, false);
-    size += height_nofill;
+    height_cur_nofill = folded ? 1 : plines_win_nofill(wp, lnum, false);
+    height_sum += height_cur_nofill;
     const int64_t row_off = (start_vcol < width1 || width2 <= 0)
                             ? 0
                             : 1 + (start_vcol - width1) / width2;
-    size -= MIN(row_off, height_nofill);
+    height_sum -= MIN(row_off, height_cur_nofill);
     lnum = lnum_next + 1;
   }
 
   while (lnum <= end_lnum) {
     linenr_T lnum_next = lnum;
     const bool folded = hasFoldingWin(wp, lnum, &lnum, &lnum_next, true, NULL);
-    height_nofill = folded ? 1 : plines_win_nofill(wp, lnum, false);
-    size += win_get_fill(wp, lnum) + height_nofill;
+    height_cur_nofill = folded ? 1 : plines_win_nofill(wp, lnum, false);
+    height_sum += win_get_fill(wp, lnum) + height_cur_nofill;
     lnum = lnum_next + 1;
   }
 
   if (end_vcol >= 0) {
-    size -= height_nofill;
+    height_sum -= height_cur_nofill;
     const int64_t row_off = end_vcol == 0
                             ? 0
                             : (end_vcol <= width1 || width2 <= 0)
                               ? 1
                               : 1 + (end_vcol - width1 + width2 - 1) / width2;
-    size += MIN(row_off, height_nofill);
+    height_sum += MIN(row_off, height_cur_nofill);
   }
 
-  return size;
+  return height_sum;
 }