From 1c8c6a48af625e901ef9658298becbf99db3336e Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Sun, 12 Jun 2022 17:19:28 +0800
Subject: [PATCH] Spreadsheet: fix range selection

---
 src/Mod/Spreadsheet/App/PropertySheet.cpp  |  5 +++
 src/Mod/Spreadsheet/App/PropertySheet.h    |  2 +
 src/Mod/Spreadsheet/Gui/SheetTableView.cpp | 51 +++++++++++++++++++++-
 3 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/src/Mod/Spreadsheet/App/PropertySheet.cpp b/src/Mod/Spreadsheet/App/PropertySheet.cpp
index 7a793cfbd7..3be4fe1c65 100644
--- a/src/Mod/Spreadsheet/App/PropertySheet.cpp
+++ b/src/Mod/Spreadsheet/App/PropertySheet.cpp
@@ -1975,3 +1975,8 @@ const boost::any PropertySheet::getPathValue(const App::ObjectIdentifier & path)
         return boost::any();
     return path.getValue();
 }
+
+bool PropertySheet::hasSpan() const
+{
+    return !mergedCells.empty();
+}
diff --git a/src/Mod/Spreadsheet/App/PropertySheet.h b/src/Mod/Spreadsheet/App/PropertySheet.h
index 6138d8753e..c1f2f1eed6 100644
--- a/src/Mod/Spreadsheet/App/PropertySheet.h
+++ b/src/Mod/Spreadsheet/App/PropertySheet.h
@@ -153,6 +153,8 @@ public:
 
     void getSpans(App::CellAddress address, int &rows, int &cols) const;
 
+    bool hasSpan() const;
+
     App::CellAddress getAnchor(App::CellAddress address) const;
 
     bool isMergedCell(App::CellAddress address) const;
diff --git a/src/Mod/Spreadsheet/Gui/SheetTableView.cpp b/src/Mod/Spreadsheet/Gui/SheetTableView.cpp
index ca1d6bdf7a..a6b3d73baa 100644
--- a/src/Mod/Spreadsheet/Gui/SheetTableView.cpp
+++ b/src/Mod/Spreadsheet/Gui/SheetTableView.cpp
@@ -250,8 +250,55 @@ void SheetTableView::cellProperties()
 std::vector<Range> SheetTableView::selectedRanges() const
 {
     std::vector<Range> result;
-    for (const auto &sel : selectionModel()->selection())
-        result.emplace_back(sel.top(), sel.left(), sel.bottom(), sel.right());
+
+    if (!sheet->getCells()->hasSpan()) {
+        for (const auto &sel : selectionModel()->selection())
+            result.emplace_back(sel.top(), sel.left(), sel.bottom(), sel.right());
+    } else {
+        // If there is spanning cell, QItemSelection returned by
+        // QTableView::selection() does not merge selected indices into ranges.
+        // So we have to do it by ourselves. Qt records selection in the order
+        // of column first and then row.
+        //
+        // Note that there will always be ambiguous cases with the available
+        // information, where multiple user selected ranges are merged
+        // together. For example, consecutive single column selections that
+        // form a rectangle will be merged together, but single row selections
+        // will not be merged.
+        for (const auto &sel : selectionModel()->selection()) {
+            if (!result.empty() && sel.bottom() == sel.top() && sel.right() == sel.left()) {
+                auto &last = result.back();
+                if (last.colCount() == 1
+                        && last.from().col() == sel.left()
+                        && sel.top() == last.to().row() + 1)
+                {
+                    // This is the case of rectangle selection. We keep
+                    // accumulating the last column, and try to merge the
+                    // column to previous range whenever possible.
+                    last = Range(last.from(), CellAddress(sel.top(), sel.left()));
+                    if (result.size() > 1) {
+                        auto &secondLast = result[result.size()-2];
+                        if (secondLast.to().col() + 1 == last.to().col()
+                                && secondLast.from().row() == last.from().row()
+                                && secondLast.rowCount() == last.rowCount()) {
+                            secondLast = Range(secondLast.from(), last.to());
+                            result.pop_back();
+                        }
+                    }
+                    continue;
+                }
+                else if (last.rowCount() == 1
+                        && last.from().row() == sel.top()
+                        && last.to().col() + 1 == sel.left())
+                {
+                    // This is the case of single row selection
+                    last = Range(last.from(), CellAddress(sel.top(), sel.left()));
+                    continue;
+                }
+            }
+            result.emplace_back(sel.top(), sel.left(), sel.bottom(), sel.right());
+        }
+    }
     return result;
 }