optimize ScTabView::SkipCursorVertical() for many hidden rows

The code skips all hidden rows, and it does so one by one, until
it encounters the last row, and then it reverses and goes back.
With a huge sheet it may spend a noticeable time doing this.
Since the RowHidden() function gives a range, use that to skip
hidden rows faster.

Change-Id: I14a990d288d28e9cab69d7dcc7f0dc9210434859
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/129643
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

1 files changed, 20 insertions, 4 deletions

diff --git a/sc/source/ui/view/tabview2.cxx b/sc/source/ui/view/tabview2.cxx
index bf2f1603815b..b5ca9b40d521 100644
--- a/sc/source/ui/view/tabview2.cxx
+++ b/sc/source/ui/view/tabview2.cxx
@@ -840,8 +840,14 @@ void ScTabView::SkipCursorVertical(SCCOL& rCurX, SCROW& rCurY, SCROW nOldY, SCRO
     bool bVFlip = false;
     do
     {
-        SCROW nLastRow = -1;
-        bSkipCell = rDoc.RowHidden(rCurY, nTab, nullptr, &nLastRow) || rDoc.IsVerOverlapped( rCurX, rCurY, nTab );
+        SCROW nFirstHiddenRow = -1;
+        SCROW nLastHiddenRow = -1;
+        bSkipCell = rDoc.RowHidden(rCurY, nTab, &nFirstHiddenRow, &nLastHiddenRow);
+        if (!bSkipCell)
+        {
+            nFirstHiddenRow = nLastHiddenRow = -1;
+            bSkipCell = rDoc.IsVerOverlapped( rCurX, rCurY, nTab );
+        }
         if (bSkipProtected && !bSkipCell)
             bSkipCell = rDoc.HasAttrib(rCurX, rCurY, nTab, rCurX, rCurY, nTab, HasAttrFlags::Protected);
         if (bSkipUnprotected && !bSkipCell)
@@ -867,10 +873,20 @@ void ScTabView::SkipCursorVertical(SCCOL& rCurX, SCROW& rCurY, SCROW nOldY, SCRO
                 }
             }
             else
+            {
+                // nFirstRow/nLastRow are set only if the row is hidden, in which case we always skip,
+                // so as an optimization skip to the first row after the hidden range
                 if (nMovY > 0)
-                    ++rCurY;
+                    if (nLastHiddenRow >= 0)
+                        rCurY = std::min<SCROW>(nLastHiddenRow + 1, rDoc.MaxRow());
+                    else
+                        ++rCurY;
                 else
-                    --rCurY;
+                    if (nFirstHiddenRow >= 0)
+                        rCurY = std::max<SCROW>(nFirstHiddenRow - 1, 0);
+                    else
+                        --rCurY;
+            }
         }
     }
     while (bSkipCell);