> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/Steema/TeeGrid-VCL-FMX-Samples/llms.txt
> Use this file to discover all available pages before exploring further.

# Cell Editing

> Edit cell values with customizable editors and events

TeeGrid provides powerful cell editing capabilities with support for custom editor controls, automatic text selection, and flexible event handling.

## Basic Editing Setup

Enable cell editing through the `Editing` property:

```delphi theme={null}
TeeGrid1.Editing.AutoEdit := True;          // Start editing on key press
TeeGrid1.Editing.DoubleClick := True;       // Start editing on double-click
TeeGrid1.Editing.AlwaysVisible := False;    // Hide editor when moving cells
```

## Editing Properties

### AutoEdit

When `True`, pressing any key automatically shows the cell editor. When `False`, only F2 or double-clicking starts editing.

```delphi theme={null}
TeeGrid1.Editing.AutoEdit := True;
```

### AlwaysVisible

Keeps the editor visible when moving from one cell to another:

```delphi theme={null}
TeeGrid1.Editing.AlwaysVisible := True;
```

### EnterKey Behavior

Control what happens when pressing Enter while editing:

```delphi theme={null}
// TEditingEnter options:
// - NextCell: Move to next cell
// - NextRow: Move to next row
// - SameCell: Stay in same cell

TeeGrid1.Editing.EnterKey := TEditingEnter.NextCell;
```

### Text Selection

Control whether text is selected when editing begins:

```delphi theme={null}
TeeGrid1.Editing.Text.Selected := True;  // Select all text when editing starts
```

## Custom Cell Editors

Assign different editor controls to each column using `EditorClass`:

```delphi theme={null}
// TrackBar for numeric values
TeeGrid1.Columns['Height'].EditorClass := TTrackBar;

// DateTimePicker for dates
TeeGrid1.Columns['BirthDate'].EditorClass := TDateTimePicker;

// ComboBox for selections
TeeGrid1.Columns['Vehicle'].EditorClass := TComboBox;
TeeGrid1.Columns['EyeColor'].EditorClass := TComboBox;

// CheckBox for boolean values
TeeGrid1.Columns['Holidays'].EditorClass := TCheckBox;

// SpinEdit for integers
TeeGrid1.Columns['Happiness'].EditorClass := TSpinEdit;
```

## OnCellEditing Event

Called when a cell editor is displayed. Use this to customize the editor:

```delphi theme={null}
procedure TForm1.TeeGrid1CellEditing(const Sender: TObject;
  const AEditor: TControl; const AColumn: TColumn; const ARow: Integer);
var
  tmpValue: String;
begin
  // Setup ComboBox items
  if AEditor is TComboBox then
  begin
    tmpValue := TeeGrid1.Data.AsString(AColumn, ARow);
    TComboBox(AEditor).Style := csDropDown;

    if AColumn = TeeGrid1.Columns['Vehicle'] then
      FillCombo(TComboBox(AEditor),
                ['None','Bicycle','MotorBike','Car','Caravan','Truck','Boat','Plane'],
                tmpValue)
    else if AColumn = TeeGrid1.Columns['EyeColor'] then
      FillCombo(TComboBox(AEditor),
                ['Black','Brown','Green','Blue'],
                tmpValue);
  end;

  // Setup TrackBar range
  if AColumn = TeeGrid1.Columns['Height'] then
    if AEditor is TTrackBar then
    begin
      TTrackBar(AEditor).Min := 400;
      TTrackBar(AEditor).Max := 700;
      TTrackBar(AEditor).Frequency := 50;
      TTrackBar(AEditor).Position := Round(100 * TeeGrid1.Data.AsFloat(AColumn, ARow));
    end;
end;
```

## OnCellEdited Event

Called when editing is finished. Retrieve the new value and update data:

```delphi theme={null}
procedure TForm1.TeeGrid1CellEdited(const Sender: TObject;
  const AEditor: TControl; const AColumn: TColumn; const ARow: Integer;
  var ChangeData: Boolean; var NewData: String);
var
  tmp: Single;
  tmpValue: String;
begin
  // Handle TrackBar value
  if AColumn = TeeGrid1.Columns['Height'] then
  begin
    if AEditor is TTrackBar then
    begin
      tmp := 0.01 * TTrackBar(AEditor).Position;
      TeeGrid1.Data.SetValue(AColumn, ARow, FloatToStr(tmp));
      ChangeData := False;  // We handled the data change
    end;
  end
  // Handle ComboBox value
  else if AEditor is TComboBox then
  begin
    tmpValue := TComboBox(AEditor).Text;
    
    if tmpValue = '' then
      tmpValue := 'none';
      
    TeeGrid1.Data.SetValue(AColumn, ARow, tmpValue);
    ChangeData := False;  // We handled the data change
  end;
end;
```

## Read-Only Columns

Prevent editing specific columns:

```delphi theme={null}
TeeGrid1.Columns['ID'].ReadOnly := True;
```

Or make the entire grid read-only:

```delphi theme={null}
TeeGrid1.ReadOnly := True;
```

## Programmatic Editing

Start or stop editing programmatically:

```delphi theme={null}
// Start editing current cell
TeeGrid1.StartEditor;

// Stop editing and save changes
TeeGrid1.StopEditor;

// Cancel editing without saving
TeeGrid1.CancelEditor;
```

## Cell Format During Editing

Customize individual cells with formatting:

```delphi theme={null}
var
  cell: TCell;
  fontstyles: TFontStyles;
begin
  fontstyles := [TFontStyle.fsBold, TFontStyle.fsStrikeOut];
  
  cell := TeeGrid1.CellFormat.AddCell(1, TeeGrid1.Columns[1].Index);
  cell.Format.Font.Style := fontstyles;
  cell.Format.Brush.Color := clYellow;
  cell.Format.Font.Color := TColors.Red;
  cell.Format.Brush.Show;
  
  TeeGrid1.Invalidate;
end;
```

## Best Practices

* Use `OnCellEditing` to initialize editor controls (fill ComboBox items, set TrackBar ranges, etc.)
* Use `OnCellEdited` to retrieve editor values and update your data
* Set `ChangeData := False` when manually updating data to prevent duplicate updates
* Use column-specific `ReadOnly` for fields that shouldn't be edited (like IDs)
* Consider `AlwaysVisible := True` for spreadsheet-like data entry workflows