perf(datagrid): cache column index lookup in selection drawing

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Drag-selecting many columns in a wide result set scrolls smoothly instead of lagging; the selection overlay and row highlight now look up column positions from a cache that refreshes when columns are added, removed, or reordered.
 - The connection Export Options dialog keeps a steady size when you turn on Include Credentials, and saves through the standard macOS save dialog.
 - Data grid now serves the row count from its existing cache instead of recomputing it on every layout pass, reducing CPU churn while scrolling large result sets.
 - Typing in the sidebar table search stays responsive on databases with thousands of tables; filtering runs after a short pause instead of on every keystroke.

TablePro/Views/Results/DataGridCoordinator.swift

@@ -38,6 +38,27 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
     private(set) var identitySchema: ColumnIdentitySchema = .empty
     var currentSortState = SortState()
 
+    private var columnIndexByDataIndex: [Int: Int] = [:]
+    private static let selectionCacheLogger = Logger(subsystem: "com.TablePro", category: "DataGrid.ColumnIndexCache")
+
+    func tableColumnIndex(for dataIndex: Int) -> Int? {
+        if let cached = columnIndexByDataIndex[dataIndex] {
+            return cached
+        }
+        guard let tableView,
+              let identifier = identitySchema.identifier(for: dataIndex) else { return nil }
+        let resolved = tableView.column(withIdentifier: identifier)
+        guard resolved >= 0 else { return nil }
+        columnIndexByDataIndex[dataIndex] = resolved
+        return resolved
+    }
+
+    func invalidateColumnIndexCache() {
+        guard !columnIndexByDataIndex.isEmpty else { return }
+        Self.selectionCacheLogger.debug("invalidate column index cache (had \(self.columnIndexByDataIndex.count))")
+        columnIndexByDataIndex.removeAll()
+    }
+
     func columnIdentifier(for dataIndex: Int) -> NSUserInterfaceItemIdentifier? {
         identitySchema.identifier(for: dataIndex)
     }
@@ -224,6 +245,7 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
         columnDisplayFormats = []
         cachedRowCount = 0
         cachedColumnCount = 0
+        invalidateColumnIndexCache()
         sortedIDs = nil
         lastUpdateSnapshot = nil
         columnPool.detachFromTableView()
@@ -477,7 +499,7 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
         switch delta {
         case .cellChanged(let row, let column):
             guard let tableView,
-                  let tableColumn = DataGridView.tableColumnIndex(for: column, in: tableView, schema: identitySchema)
+                  let tableColumn = tableColumnIndex(for: column)
             else { return }
             guard row >= 0, row < tableView.numberOfRows else { return }
             invalidateDisplayCache(forDisplayRow: row, column: column)
@@ -494,11 +516,7 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
                 if position.row >= 0, position.row < tableView.numberOfRows {
                     rowSet.insert(position.row)
                 }
-                if let tableColumn = DataGridView.tableColumnIndex(
-                    for: position.column,
-                    in: tableView,
-                    schema: identitySchema
-                ) {
+                if let tableColumn = tableColumnIndex(for: position.column) {
                     colSet.insert(tableColumn)
                 }
                 invalidateDisplayCache(forDisplayRow: position.row, column: position.column)
@@ -620,7 +638,7 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
 
     func beginEditing(displayRow: Int, column: Int) {
         guard let tableView,
-              let displayCol = DataGridView.tableColumnIndex(for: column, in: tableView, schema: identitySchema)
+              let displayCol = tableColumnIndex(for: column)
         else { return }
         guard displayRow >= 0, displayRow < tableView.numberOfRows else { return }
         tableView.scrollRowToVisible(displayRow)
@@ -666,6 +684,7 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
         guard schemaChanged else { return false }
         identitySchema = nextSchema
         displayCache.removeAll()
+        invalidateColumnIndexCache()
         return true
     }
 
@@ -728,11 +747,7 @@ extension TableViewCoordinator: DataGridCellAccessoryDelegate {
 
     func dataGridCellDidDoubleClick(row: Int, columnIndex: Int) {
         guard row >= 0, columnIndex >= 0, let tableView else { return }
-        guard let tableColumn = DataGridView.tableColumnIndex(
-            for: columnIndex,
-            in: tableView,
-            schema: identitySchema
-        ) else { return }
+        guard let tableColumn = tableColumnIndex(for: columnIndex) else { return }
         handleCellInteraction(row: row, tableColumn: tableColumn, columnIndex: columnIndex, tableView: tableView)
     }
 }

TablePro/Views/Results/DataGridRowView.swift

@@ -99,9 +99,10 @@ class DataGridRowView: NSTableRowView {
     }
 
     private func drawCellSelectionFill(in dirtyRect: NSRect) {
-        guard let selection = coordinator?.selectionController.selection,
-              !selection.isEmpty,
-              let tableView = coordinator?.tableView else { return }
+        guard let coordinator,
+              let tableView = coordinator.tableView else { return }
+        let selection = coordinator.selectionController.selection
+        guard !selection.isEmpty else { return }
         let columns = selection.columns(in: rowIndex)
         guard !columns.isEmpty else { return }
 
@@ -110,10 +111,8 @@ class DataGridRowView: NSTableRowView {
             : NSColor.selectedContentBackgroundColor.withAlphaComponent(0.28)
         fillColor.setFill()
 
-        let schema = coordinator?.identitySchema
         for dataColumn in columns {
-            guard let schema,
-                  let tableColumnIndex = DataGridView.tableColumnIndex(for: dataColumn, in: tableView, schema: schema) else { continue }
+            guard let tableColumnIndex = coordinator.tableColumnIndex(for: dataColumn) else { continue }
             let columnRect = tableView.rect(ofColumn: tableColumnIndex)
             let localRect = NSRect(x: columnRect.minX, y: 0, width: columnRect.width, height: bounds.height)
             guard localRect.intersects(dirtyRect) else { continue }
@@ -531,11 +530,7 @@ class DataGridRowView: NSTableRowView {
     @objc private func previewForeignKey(_ sender: NSMenuItem) {
         guard let columnIndex = sender.representedObject as? Int,
               let coordinator, let tableView = coordinator.tableView,
-              let column = DataGridView.tableColumnIndex(
-                for: columnIndex,
-                in: tableView,
-                schema: coordinator.identitySchema
-              ) else { return }
+              let column = coordinator.tableColumnIndex(for: columnIndex) else { return }
         coordinator.showForeignKeyPreview(
             tableView: tableView, row: rowIndex, column: column, columnIndex: columnIndex
         )

TablePro/Views/Results/DataGridView.swift

@@ -271,6 +271,7 @@ struct DataGridView: NSViewRepresentable {
                 savedLayout: savedLayout
             )
             coordinator.isRebuildingColumns = false
+            coordinator.invalidateColumnIndexCache()
 
             if savedLayout == nil {
                 coordinator.scheduleLayoutPersist()
@@ -400,16 +401,6 @@ struct DataGridView: NSViewRepresentable {
         tableColumnIndex >= firstDataTableColumnIndex
     }
 
-    static func tableColumnIndex(
-        for dataIndex: Int,
-        in tableView: NSTableView,
-        schema: ColumnIdentitySchema
-    ) -> Int? {
-        guard let identifier = schema.identifier(for: dataIndex) else { return nil }
-        let index = tableView.column(withIdentifier: identifier)
-        return index >= 0 ? index : nil
-    }
-
     static func dataColumnIndex(
         for tableColumnIndex: Int,
         in tableView: NSTableView,

TablePro/Views/Results/Extensions/DataGridView+CellCommit.swift

@@ -21,11 +21,7 @@ extension TableViewCoordinator {
         invalidateDisplayCache()
         visualIndex.updateRow(row, from: changeManager, sortedIDs: sortedIDs)
 
-        guard let tableColumnIndex = DataGridView.tableColumnIndex(
-            for: columnIndex,
-            in: tableView,
-            schema: identitySchema
-        ) else { return }
+        guard let tableColumnIndex = tableColumnIndex(for: columnIndex) else { return }
         tableView.reloadData(
             forRowIndexes: IndexSet(integer: row),
             columnIndexes: IndexSet(integer: tableColumnIndex)

TablePro/Views/Results/Extensions/DataGridView+Click.swift

@@ -65,11 +65,7 @@ extension TableViewCoordinator {
         guard row >= 0, columnIndex >= 0 else { return }
         guard !changeManager.isRowDeleted(row) else { return }
         guard let tableView else { return }
-        guard let column = DataGridView.tableColumnIndex(
-            for: columnIndex,
-            in: tableView,
-            schema: identitySchema
-        ) else { return }
+        guard let column = tableColumnIndex(for: columnIndex) else { return }
 
         if let dropdownCols = dropdownColumns, dropdownCols.contains(columnIndex) {
             showDropdownMenu(tableView: tableView, row: row, column: column, columnIndex: columnIndex)

TablePro/Views/Results/Extensions/DataGridView+Columns.swift

@@ -56,11 +56,7 @@ extension TableViewCoordinator {
         let isFocused: Bool = {
             guard let keyTableView = tableView as? KeyHandlingTableView,
                   keyTableView.focusedRow == row,
-                  let tableColumnIndex = DataGridView.tableColumnIndex(
-                    for: columnIndex,
-                    in: tableView,
-                    schema: identitySchema
-                  ),
+                  let tableColumnIndex = tableColumnIndex(for: columnIndex),
                   keyTableView.focusedColumn == tableColumnIndex else { return false }
             return true
         }()

TablePro/Views/Results/Extensions/DataGridView+Popovers.swift

@@ -82,11 +82,7 @@ extension TableViewCoordinator {
         let focusedRow = (tableView as? KeyHandlingTableView)?.focusedRow ?? -1
         let newRow = focusedRow >= 0 ? focusedRow : (tableView.selectedRowIndexes.max() ?? -1)
         guard newRow >= 0,
-              let tableColumnIndex = DataGridView.tableColumnIndex(
-                for: columnIndex,
-                in: tableView,
-                schema: identitySchema
-              ) else {
+              let tableColumnIndex = tableColumnIndex(for: columnIndex) else {
             popover.close()
             clearFKPreviewState()
             return

TablePro/Views/Results/Extensions/DataGridView+Selection.swift

@@ -14,6 +14,7 @@ extension TableViewCoordinator {
 
     func tableViewColumnDidMove(_ notification: Notification) {
         guard !isRebuildingColumns else { return }
+        invalidateColumnIndexCache()
         layoutPersistTask?.cancel()
         persistColumnLayoutToStorage()
     }

TablePro/Views/Results/KeyHandlingTableView.swift

@@ -162,7 +162,7 @@ final class KeyHandlingTableView: NSTableView {
                 selectRowIndexes(IndexSet(integer: activeCoord.row), byExtendingSelection: false)
             }
             focusedRow = activeCoord.row
-            focusedColumn = DataGridView.tableColumnIndex(for: activeCoord.column, in: self, schema: schema) ?? clickedColumn
+            focusedColumn = coordinator?.tableColumnIndex(for: activeCoord.column) ?? clickedColumn
         case .clearFocus:
             deselectAll(nil)
             focusedRow = -1

TablePro/Views/Results/Selection/GridSelectionOverlay.swift

@@ -34,13 +34,12 @@ final class GridSelectionOverlay: NSView {
 
     override func draw(_ dirtyRect: NSRect) {
         guard let tableView, let coordinator else { return }
-        let schema = coordinator.identitySchema
         let totalRows = tableView.numberOfRows
         let editingCell = activeOverlayCell(in: coordinator)
 
         NSColor.selectedContentBackgroundColor.withAlphaComponent(Self.borderAlpha).setStroke()
         for rect in selection.rectangles {
-            guard let frame = frame(for: rect, in: tableView, schema: schema) else { continue }
+            guard let frame = frame(for: rect, in: tableView, coordinator: coordinator) else { continue }
             guard frame.intersects(dirtyRect) else { continue }
             if isFullHeight(rect, totalRows: totalRows) { continue }
             if let editingCell, rect.contains(editingCell) { continue }
@@ -53,7 +52,7 @@ final class GridSelectionOverlay: NSView {
         if let active = selection.activeCell,
            editingCell != active,
            selection.rectangles.count > 1 || (selection.rectangles.first?.rows.count ?? 0) > 1 || (selection.rectangles.first?.columns.count ?? 0) > 1,
-           let frame = frame(for: GridRect(cell: active), in: tableView, schema: schema),
+           let frame = frame(for: GridRect(cell: active), in: tableView, coordinator: coordinator),
            frame.intersects(dirtyRect) {
             NSColor.controlAccentColor.setStroke()
             let inset = frame.insetBy(dx: Self.activeCellBorderWidth / 2, dy: Self.activeCellBorderWidth / 2)
@@ -78,7 +77,7 @@ final class GridSelectionOverlay: NSView {
         return rect.rows.lowerBound <= 0 && rect.rows.upperBound >= totalRows - 1
     }
 
-    private func frame(for rect: GridRect, in tableView: NSTableView, schema: ColumnIdentitySchema) -> NSRect? {
+    private func frame(for rect: GridRect, in tableView: NSTableView, coordinator: TableViewCoordinator) -> NSRect? {
         guard tableView.numberOfRows > 0, tableView.numberOfColumns > 0 else { return nil }
         let firstRow = max(0, rect.rows.lowerBound)
         let lastRow = min(tableView.numberOfRows - 1, rect.rows.upperBound)
@@ -92,7 +91,7 @@ final class GridSelectionOverlay: NSView {
         var leadingX = CGFloat.infinity
         var trailingX = -CGFloat.infinity
         for dataColumn in rect.columns.lowerBound...rect.columns.upperBound {
-            guard let tableColumnIndex = DataGridView.tableColumnIndex(for: dataColumn, in: tableView, schema: schema) else { continue }
+            guard let tableColumnIndex = coordinator.tableColumnIndex(for: dataColumn) else { continue }
             let columnRect = tableView.rect(ofColumn: tableColumnIndex)
             leadingX = min(leadingX, columnRect.minX)
             trailingX = max(trailingX, columnRect.maxX)