> ## 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.

# Selection

> Select cells, rows, and ranges with keyboard and mouse

TeeGrid provides flexible cell and range selection with visual feedback, keyboard navigation, and customizable appearance.

## Basic Selection

Access the current selection:

```delphi theme={null}
// Get selected column and row
var
  Col: TColumn;
  Row: Integer;
begin
  Col := TeeGrid1.Selected.Column;
  Row := TeeGrid1.Selected.Row;
  
  if (Col <> nil) and (Row >= 0) then
    ShowMessage('Selected: ' + Col.Header.Text + ', Row ' + IntToStr(Row));
end;
```

## Programmatic Selection

Set selection programmatically:

```delphi theme={null}
// Select specific cell
TeeGrid1.Selected.Column := TeeGrid1.Columns[3];
TeeGrid1.Selected.Row := 42;

// Or use Change method
TeeGrid1.Selected.Change(TeeGrid1.Columns[3], 42);

// Clear selection
TeeGrid1.Selected.Clear;
```

## Selection Events

### OnSelect

Fired when selection changes:

```delphi theme={null}
TeeGrid1.OnSelect := GridSelectionChanged;

procedure TForm1.GridSelectionChanged(Sender: TObject);
begin
  if TeeGrid1.Selected.Row >= 0 then
    Label1.Caption := 'Row: ' + IntToStr(TeeGrid1.Selected.Row)
  else
    Label1.Caption := 'No selection';
end;
```

## Selection Appearance

Customize how selection looks:

```delphi theme={null}
// Selected cell/row colors
TeeGrid1.Selected.Format.Brush.Color := clHighlight;
TeeGrid1.Selected.Format.Brush.Visible := True;
TeeGrid1.Selected.Format.Font.Color := clHighlightText;
TeeGrid1.Selected.Format.Font.Style := [fsBold];

// Selection when grid doesn't have focus
TeeGrid1.Selected.UnFocused.Visible := True;
TeeGrid1.Selected.UnFocused.Format.Brush.Color := clSilver;
TeeGrid1.Selected.UnFocused.Format.Font.Color := clBlack;
```

## Full Row Selection

Select entire rows instead of individual cells:

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

// Now clicking any cell selects the whole row
```

## Range Selection

Select multiple cells:

```delphi theme={null}
// Enable range selection
TeeGrid1.Selected.Range.Enabled := True;

// Set range programmatically
TeeGrid1.Selected.Range.FromRow := 10;
TeeGrid1.Selected.Range.ToRow := 20;
TeeGrid1.Selected.Range.FromColumn := TeeGrid1.Columns[3];
TeeGrid1.Selected.Range.ToColumn := TeeGrid1.Columns[6];
```

## Mouse Range Selection

Users can select ranges by dragging:

```delphi theme={null}
// Enable range selection
TeeGrid1.Selected.Range.Enabled := True;

// User can now:
// 1. Click and drag to select range
// 2. Shift+Click to extend selection
// 3. Shift+Arrow keys to extend selection
```

## Checking Range Selection

```delphi theme={null}
if TeeGrid1.Selected.Range.Enabled then
begin
  ShowMessage('Range from row ' + 
              IntToStr(TeeGrid1.Selected.Range.FromRow) + 
              ' to ' + 
              IntToStr(TeeGrid1.Selected.Range.ToRow));
end;
```

## Keyboard Navigation

Control Enter key behavior:

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

TeeGrid1.Selected.EnterKey := TSelectingEnter.NextRow;
```

## Scroll to View

Automatically scroll to show selection:

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

// Now when selection changes, grid scrolls to show it
TeeGrid1.Selected.Row := 1000;  // Scrolls to row 1000
```

## Selectable Columns

Control which columns can be selected:

```delphi theme={null}
// Disable selection for specific column
TeeGrid1.Columns['Actions'].Selectable := False;

// User can't select cells in this column
```

## Selection Hover

Highlight cells on mouse hover:

```delphi theme={null}
// Enable hover highlighting
TeeGrid1.Selected.Hover.Brush.Color := clYellow;
TeeGrid1.Selected.Hover.Brush.Visible := True;
```

## Parent Font

Inherit selection font from parent:

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

// Selection now uses grid's font
// Override with custom font:
TeeGrid1.Selected.ParentFont := False;
TeeGrid1.Selected.Format.Font.Size := 12;
```

## Copy Selection

Copy selected data to clipboard:

```delphi theme={null}
// Copy current selection
TeeGrid1.Copy;

// Copy specific range
var
  Range: TGridSelection;
begin
  Range := TGridSelection.Create(nil);
  try
    Range.Range.Enabled := True;
    Range.Range.FromRow := 0;
    Range.Range.ToRow := 10;
    Range.Range.FromColumn := TeeGrid1.Columns[0];
    Range.Range.ToColumn := TeeGrid1.Columns[2];
    
    TeeGrid1.Copy(Range);
  finally
    Range.Free;
  end;
end;
```

## Paste to Selection

Paste clipboard data:

```delphi theme={null}
// Paste at current selection
TeeGrid1.PasteSelected;

// Data from clipboard is pasted starting at selected cell
```

## Multi-Selection

For advanced multi-selection scenarios:

```delphi theme={null}
// Range selection supports rectangular regions
TeeGrid1.Selected.Range.Enabled := True;

// Users can:
// - Click cell (start selection)
// - Shift+Click another cell (select range)
// - Ctrl+C to copy range
// - Ctrl+V to paste
```

## Selection with Master-Detail

Each row group has independent selection:

```delphi theme={null}
procedure TForm1.DetailGroupCreated(const Sender, NewGroup: TRowGroup);
begin
  // Detail group has its own selection
  NewGroup.Selected.Format.Brush.Color := TAlphaColors.Lightblue;
  NewGroup.Selected.Format.Brush.Visible := True;
  
  // Handle detail selection
  NewGroup.OnChangedSelected := DetailSelectionChanged;
end;

procedure TForm1.DetailSelectionChanged(Sender: TObject);
var
  Group: TRowGroup;
begin
  Group := TRowGroup(Sender);
  
  if Group.Selected.Row >= 0 then
    ShowMessage('Detail row ' + IntToStr(Group.Selected.Row) + ' selected');
end;
```

## Getting Selected Data

Retrieve data from selected cell:

```delphi theme={null}
var
  Value: String;
begin
  if (TeeGrid1.Selected.Column <> nil) and (TeeGrid1.Selected.Row >= 0) then
  begin
    Value := TeeGrid1.Data.AsString(TeeGrid1.Selected.Column, 
                                     TeeGrid1.Selected.Row);
    ShowMessage('Selected value: ' + Value);
  end;
end;
```

## Selection Hit Testing

Check if a point is in selection:

```delphi theme={null}
var
  X, Y: Single;
begin
  X := Mouse.CursorPos.X;
  Y := Mouse.CursorPos.Y;
  
  if TeeGrid1.Grid.Current.SelectedContains(X, Y) then
    ShowMessage('Mouse is over selection');
end;
```

## Empty Selection

Check if there's a selection:

```delphi theme={null}
if TeeGrid1.Selected.IsEmpty then
  ShowMessage('Nothing selected')
else
  ShowMessage('Cell is selected');
```

## Column Selection

Select entire columns (combined with FullRow):

```delphi theme={null}
procedure TForm1.SelectColumn(AColumn: TColumn);
begin
  TeeGrid1.Selected.Column := AColumn;
  TeeGrid1.Selected.Row := 0;
  TeeGrid1.Selected.Range.Enabled := True;
  TeeGrid1.Selected.Range.FromRow := 0;
  TeeGrid1.Selected.Range.ToRow := TeeGrid1.Data.Count - 1;
  TeeGrid1.Selected.Range.FromColumn := AColumn;
  TeeGrid1.Selected.Range.ToColumn := AColumn;
end;
```

## Selection Context Menu

Show context menu on selection:

```delphi theme={null}
procedure TForm1.TeeGrid1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button = mbRight then
  begin
    if TeeGrid1.Grid.Current.SelectedContains(X, Y) then
      PopupMenu1.Popup(Mouse.CursorPos.X, Mouse.CursorPos.Y);
  end;
end;
```

## Previous Selection

Track previous selection:

```delphi theme={null}
var
  PreviousRow: Integer;

procedure TForm1.TeeGrid1Select(Sender: TObject);
begin
  ShowMessage('Changed from row ' + IntToStr(PreviousRow) + 
              ' to row ' + IntToStr(TeeGrid1.Selected.Row));
  
  PreviousRow := TeeGrid1.Selected.Row;
end;
```

## Validate Selection

Prevent selection of certain cells:

```delphi theme={null}
procedure TForm1.TeeGrid1Select(Sender: TObject);
begin
  // Don't allow selecting first row
  if TeeGrid1.Selected.Row = 0 then
  begin
    TeeGrid1.Selected.Row := 1;  // Move to row 1
  end;
end;
```

## Best Practices

* Use `OnSelect` to respond to selection changes
* Enable `ScrollToView` for better user experience
* Use `FullRow := True` for record-based data
* Use `Range.Enabled := True` for spreadsheet-like grids
* Customize `UnFocused` appearance so users can see selection when grid loses focus
* Make important columns non-selectable with `Selectable := False`
* Combine selection with Copy/Paste for data entry workflows
* Use `IsEmpty` to check for selection before accessing `Column` or `Row`
* Remember that each row group has its own selection in master-detail grids