From 356eca7e339f87177fc0b3bb5f0066bd120f3753 Mon Sep 17 00:00:00 2001
From: martinfalisse <martinmotteditfalisse@gmail.com>
Date: Mon, 11 Apr 2022 17:05:23 +0200
Subject: [PATCH] Spreadsheet: Implement undo functionality where missing

Implement undo/redo functionality in the Spreadsheet application
for the "extend" function, the drag-and-drop function, and when
copying and pasting.
---
 .../Applications/Spreadsheet/Spreadsheet.cpp    | 17 ++++++++++++-----
 Userland/Applications/Spreadsheet/Spreadsheet.h |  2 +-
 .../Applications/Spreadsheet/SpreadsheetModel.h |  1 +
 .../Spreadsheet/SpreadsheetView.cpp             | 10 ++++++++--
 .../Spreadsheet/SpreadsheetWidget.cpp           |  7 ++++++-
 5 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/Userland/Applications/Spreadsheet/Spreadsheet.cpp b/Userland/Applications/Spreadsheet/Spreadsheet.cpp
index bf474d370f..995a1be233 100644
--- a/Userland/Applications/Spreadsheet/Spreadsheet.cpp
+++ b/Userland/Applications/Spreadsheet/Spreadsheet.cpp
@@ -292,12 +292,13 @@ Position Sheet::offset_relative_to(Position const& base, Position const& offset,
     return { new_column, new_row };
 }
 
-void Sheet::copy_cells(Vector<Position> from, Vector<Position> to, Optional<Position> resolve_relative_to, CopyOperation copy_operation)
+Vector<CellChange> Sheet::copy_cells(Vector<Position> from, Vector<Position> to, Optional<Position> resolve_relative_to, CopyOperation copy_operation)
 {
+    Vector<CellChange> cell_changes;
     // Disallow misaligned copies.
     if (to.size() > 1 && from.size() != to.size()) {
         dbgln("Cannot copy {} cells to {} cells", from.size(), to.size());
-        return;
+        return cell_changes;
     }
 
     Vector<Position> target_cells;
@@ -307,16 +308,20 @@ void Sheet::copy_cells(Vector<Position> from, Vector<Position> to, Optional<Posi
     auto copy_to = [&](auto& source_position, Position target_position) {
         auto& target_cell = ensure(target_position);
         auto* source_cell = at(source_position);
+        auto previous_data = target_cell.data();
 
         if (!source_cell) {
             target_cell.set_data("");
+            cell_changes.append(CellChange(target_cell, previous_data));
             return;
         }
 
         target_cell.copy_from(*source_cell);
-        if (copy_operation == CopyOperation::Cut)
-            if (!target_cells.contains_slow(source_position))
-                source_cell->set_data("");
+        cell_changes.append(CellChange(target_cell, previous_data));
+        if (copy_operation == CopyOperation::Cut && !target_cells.contains_slow(source_position)) {
+            cell_changes.append(CellChange(*source_cell, source_cell->data()));
+            source_cell->set_data("");
+        }
     };
 
     // Resolve each index as relative to the first index offset from the selection.
@@ -359,6 +364,8 @@ void Sheet::copy_cells(Vector<Position> from, Vector<Position> to, Optional<Posi
         dbgln_if(COPY_DEBUG, "Paste from '{}' to '{}'", position.to_url(*this), target.to_url(*this));
         copy_to(position, resolve_relative_to.has_value() ? offset_relative_to(target, position, resolve_relative_to.value()) : target);
     }
+
+    return cell_changes;
 }
 
 RefPtr<Sheet> Sheet::from_json(JsonObject const& object, Workbook& workbook)
diff --git a/Userland/Applications/Spreadsheet/Spreadsheet.h b/Userland/Applications/Spreadsheet/Spreadsheet.h
index 9bab004df0..1e17886582 100644
--- a/Userland/Applications/Spreadsheet/Spreadsheet.h
+++ b/Userland/Applications/Spreadsheet/Spreadsheet.h
@@ -135,7 +135,7 @@ public:
         Cut
     };
 
-    void copy_cells(Vector<Position> from, Vector<Position> to, Optional<Position> resolve_relative_to = {}, CopyOperation copy_operation = CopyOperation::Copy);
+    Vector<CellChange> copy_cells(Vector<Position> from, Vector<Position> to, Optional<Position> resolve_relative_to = {}, CopyOperation copy_operation = CopyOperation::Copy);
 
     /// Gives the bottom-right corner of the smallest bounding box containing all the written data, optionally limited to the given column.
     Position written_data_bounds(Optional<size_t> column_index = {}) const;
diff --git a/Userland/Applications/Spreadsheet/SpreadsheetModel.h b/Userland/Applications/Spreadsheet/SpreadsheetModel.h
index 708097e5df..1177e480b2 100644
--- a/Userland/Applications/Spreadsheet/SpreadsheetModel.h
+++ b/Userland/Applications/Spreadsheet/SpreadsheetModel.h
@@ -30,6 +30,7 @@ public:
     void update();
 
     Function<void(Cell&, String&)> on_cell_data_change;
+    Function<void(Vector<CellChange>)> on_cells_data_change;
 
 private:
     explicit SheetModel(Sheet& sheet)
diff --git a/Userland/Applications/Spreadsheet/SpreadsheetView.cpp b/Userland/Applications/Spreadsheet/SpreadsheetView.cpp
index 0f2ce5765e..105fdf0036 100644
--- a/Userland/Applications/Spreadsheet/SpreadsheetView.cpp
+++ b/Userland/Applications/Spreadsheet/SpreadsheetView.cpp
@@ -220,6 +220,7 @@ void InfinitelyScrollableTableView::mouseup_event(GUI::MouseEvent& event)
         Vector<Position> from;
         Position position { (size_t)m_target_cell.column(), (size_t)m_target_cell.row() };
         from.append(position);
+        Vector<CellChange> cell_changes;
         selection().for_each_index([&](auto& index) {
             if (index == m_starting_selection_index)
                 return;
@@ -227,8 +228,11 @@ void InfinitelyScrollableTableView::mouseup_event(GUI::MouseEvent& event)
             Vector<Position> to;
             Position position { (size_t)index.column(), (size_t)index.row() };
             to.append(position);
-            sheet.copy_cells(from, to);
+            auto cell_change = sheet.copy_cells(from, to);
+            cell_changes.extend(cell_change);
         });
+        if (static_cast<SheetModel&>(*this->model()).on_cells_data_change)
+            static_cast<SheetModel&>(*this->model()).on_cells_data_change(cell_changes);
         update();
     }
 
@@ -425,7 +429,9 @@ SpreadsheetView::SpreadsheetView(Sheet& sheet)
                 return;
 
             auto first_position = source_positions.take_first();
-            m_sheet->copy_cells(move(source_positions), move(target_positions), first_position, Spreadsheet::Sheet::CopyOperation::Cut);
+            auto cell_changes = m_sheet->copy_cells(move(source_positions), move(target_positions), first_position, Spreadsheet::Sheet::CopyOperation::Cut);
+            if (model()->on_cells_data_change)
+                model()->on_cells_data_change(cell_changes);
 
             return;
         }
diff --git a/Userland/Applications/Spreadsheet/SpreadsheetWidget.cpp b/Userland/Applications/Spreadsheet/SpreadsheetWidget.cpp
index bf99c09810..d67897ef0d 100644
--- a/Userland/Applications/Spreadsheet/SpreadsheetWidget.cpp
+++ b/Userland/Applications/Spreadsheet/SpreadsheetWidget.cpp
@@ -193,7 +193,8 @@ SpreadsheetWidget::SpreadsheetWidget(GUI::Window& parent_window, NonnullRefPtrVe
                 return;
 
             auto first_position = source_positions.take_first();
-            sheet.copy_cells(move(source_positions), move(target_positions), first_position, action == "cut" ? Spreadsheet::Sheet::CopyOperation::Cut : Spreadsheet::Sheet::CopyOperation::Copy);
+            auto cell_changes = sheet.copy_cells(move(source_positions), move(target_positions), first_position, action == "cut" ? Spreadsheet::Sheet::CopyOperation::Cut : Spreadsheet::Sheet::CopyOperation::Copy);
+            undo_stack().push(make<CellsUndoCommand>(cell_changes));
         } else {
             for (auto& cell : sheet.selected_cells())
                 sheet.ensure(cell).set_data(StringView { data.data.data(), data.data.size() });
@@ -284,6 +285,10 @@ void SpreadsheetWidget::setup_tabs(NonnullRefPtrVector<Sheet> new_sheets)
             undo_stack().push(make<CellsUndoCommand>(cell, previous_data));
             window()->set_modified(true);
         };
+        new_view.model()->on_cells_data_change = [&](Vector<CellChange> cell_changes) {
+            undo_stack().push(make<CellsUndoCommand>(cell_changes));
+            window()->set_modified(true);
+        };
         new_view.on_selection_changed = [&](Vector<Position>&& selection) {
             auto* sheet_ptr = current_worksheet_if_available();
             // How did this even happen?