Spreadsheet: Add states for cursor hovering

Add states for the cutting and extending icons that are to be shown
depending on where the user's cursor is with respect to the target
cell.

Userland/Applications/Spreadsheet/SpreadsheetView.cpp

@@ -77,6 +77,52 @@ void InfinitelyScrollableTableView::mousemove_event(GUI::MouseEvent& event)
         sheet.disable_updates();
         ScopeGuard sheet_update_enabler { [&] { sheet.enable_updates(); } };
 
+        m_is_hovering_cut_zone = false;
+        m_is_hovering_extend_zone = false;
+        if (selection().size() > 0) {
+            // Get top-left and bottom-right most cells of selection
+            auto bottom_right_most_index = selection().first();
+            auto top_left_most_index = selection().first();
+            selection().for_each_index([&](auto& index) {
+                if (index.row() > bottom_right_most_index.row())
+                    bottom_right_most_index = index;
+                else if (index.column() > bottom_right_most_index.column())
+                    bottom_right_most_index = index;
+                if (index.row() < top_left_most_index.row())
+                    top_left_most_index = index;
+                else if (index.column() < top_left_most_index.column())
+                    top_left_most_index = index;
+            });
+
+            auto top_left_rect = content_rect(top_left_most_index);
+            auto bottom_right_rect = content_rect(bottom_right_most_index);
+            auto distance_tl = top_left_rect.center() - event.position();
+            auto distance_br = bottom_right_rect.center() - event.position();
+            auto is_over_top_line = false;
+            auto is_over_bottom_line = false;
+            auto is_over_left_line = false;
+            auto is_over_right_line = false;
+
+            // If cursor is within the bounds of the selection
+            auto select_padding = 2;
+            if ((distance_br.y() >= -(bottom_right_rect.height() / 2 + select_padding)) && (distance_tl.y() <= (top_left_rect.height() / 2 + select_padding)) && (distance_br.x() >= -(bottom_right_rect.width() / 2 + select_padding)) && (distance_tl.x() <= (top_left_rect.width() / 2 + select_padding))) {
+                if (distance_tl.y() >= (top_left_rect.height() / 2 - select_padding))
+                    is_over_top_line = true;
+                else if (distance_br.y() <= -(bottom_right_rect.height() / 2 - select_padding))
+                    is_over_bottom_line = true;
+
+                if (distance_tl.x() >= (top_left_rect.width() / 2 - select_padding))
+                    is_over_left_line = true;
+                else if (distance_br.x() <= -(bottom_right_rect.width() / 2 - select_padding))
+                    is_over_right_line = true;
+            }
+
+            if (is_over_bottom_line && is_over_right_line)
+                m_is_hovering_extend_zone = true;
+            else if (is_over_top_line || is_over_bottom_line || is_over_left_line || is_over_right_line)
+                m_is_hovering_cut_zone = true;
+        }
+
         auto holding_left_button = !!(event.buttons() & GUI::MouseButton::Primary);
         if (m_is_dragging_for_copy) {
             set_override_cursor(Gfx::StandardCursor::Crosshair);

Userland/Applications/Spreadsheet/SpreadsheetView.h

@@ -80,6 +80,8 @@ private:
     bool m_should_intercept_drag { false };
     bool m_has_committed_to_dragging { false };
     bool m_is_dragging_for_copy { false };
+    bool m_is_hovering_extend_zone { false };
+    bool m_is_hovering_cut_zone { false };
     GUI::ModelIndex m_starting_selection_index;
     RefPtr<Core::Timer> m_horizontal_scroll_end_timer;
     RefPtr<Core::Timer> m_vertical_scroll_end_timer;