GridX Cell Editors

Overview

The GridX cell editor system uses a factory-based registry that maps column types (BeepColumnType) to editor implementations. Seven default editors are pre-registered, covering all standard data types. The factory supports custom editor registration and a fallback mechanism for unknown column types.

Each editor wraps a native WinForms control (TextBox, ComboBox, CheckBox, etc.) and manages the full lifecycle: control creation, setup, value binding, event attachment, and cleanup. Editors communicate back to the grid via the IGridEditorEvents callback interface.

The system is managed by GridEditHelper (orchestrates edit mode enter/exit) and GridEditorFactory (69 lines, creates/resolves editor instances).

GridEditorFactory (69 lines)

GridEditorFactory maintains an internal Dictionary<BeepColumnType, Type> registry and provides three methods:

The factory is a singleton per grid instance. Resolve() uses Activator.CreateInstance() to instantiate editors, then calls editor.Setup() before returning. If no matching editor is found for a column type, the fallback editor is returned (defaults to BeepGridTextEditor).

Default Editor Registry

IGridEditor Interface

Every editor implements IGridEditor. This contract defines the full editing lifecycle.

public interface IGridEditor
{
    Control CreateControl(BeepColumnConfig column, object currentValue);
    void Setup(BeepColumnConfig column, IGridEditorEvents editorEvents, Theme theme);
    void SetValue(object value);
    object GetValue();
    void AttachEvents();
    void DetachEvents();
    void OnBeginEdit(Rectangle cellBounds);
    bool IsPopupOpen { get; }
    bool IsEditing { get; }
    Control EditingControl { get; }
}

IGridEditorEvents

Editors communicate with the grid host via the IGridEditorEvents callback interface. The grid passes itself as this interface during Setup().

public interface IGridEditorEvents
{
    void RequestEndEdit(bool commit);
    void RequestCancelEdit();
    void OnEditorValueChanged(object newValue);
}

Editor Details

BeepGridTextEditor

Wraps a TextBox control. Enter key commits the edit (RequestEndEdit(true)). Escape cancels (RequestCancelEdit()). Supports MaxLength and CharacterCasing from column config. On LostFocus, auto-commits.

BeepGridComboBoxEditor

Wraps a ComboBox with DropDownStyle = DropDownList. Fills items from the column's DataSource or Items collection. Supports AutoCompleteMode = SuggestAppend when configured. Dropdown opens automatically on OnBeginEdit. Enter commits; Escape cancels.

BeepGridDateDropDownEditor

Wraps a DateTimePicker with ShowUpDown = false (calendar popup). Format from Format property (Short, Long, or custom). Popup opens on Focus. Enter or click-away commits; Escape cancels.

BeepGridNumericEditor

Wraps a NumericUpDown control. Reads Minimum, Maximum, Increment, and DecimalPlaces from column config. Supports ThousandsSeparator. Enter commits; Escape cancels. Up/down arrow keys adjust value within bounds.

BeepGridCheckBoxEditor

Wraps a CheckBox control supporting three data type mappings: bool (Checked/Unchecked), char (Y/N mapping), string (True/False mapping). On toggle, immediately fires RequestEndEdit(true) — no separate commit step needed. Space bar toggles the checkbox.

BeepGridMaskedEditor

Wraps a MaskedTextBox control. The mask is read from the column's Mask property (e.g., "(999) 000-0000"). PromptChar and TextMaskFormat configurable. Enter commits (must pass validation); Escape cancels.

BeepGridGenericEditor

Fallback editor for complex column types (ListBox, LOV, Image, Button, ProgressBar, Radio). Wraps a simple TextBox for string editing. Displays the cell's ToString() representation. Used when no specialized editor is registered.

Editor Lifecycle

The editing lifecycle is managed by GridEditHelper and follows this sequence:

1. User double-clicks cell or presses F2
2. GridEditHelper calls GridEditorFactory.Resolve(column.ColumnType)
3. Editor.CreateControl(column, currentValue) → instantiates native control
4. Editor.Setup(column, gridAsEvents, theme) → stores references
5. Editor.SetValue(currentValue) → populates control
6. Editor.AttachEvents() → wires KeyDown/LostFocus
7. Editor.OnBeginEdit(cellBounds) → positions & shows control
8. [User edits value]
9a. Enter pressed / focus lost → Editor calls events.RequestEndEdit(true)
9b. Escape pressed → Editor calls events.RequestCancelEdit()
10. Editor.GetValue() → grid writes back to data source
11. Editor.DetachEvents() → unwires handlers
12. Editor.EditingControl.Dispose() → cleanup

Examples

Custom Editor Registration

var factory = grid.EditorFactory;

factory.Register(BeepColumnType.DateTime, typeof(MyCustomDateEditor));

public class MyCustomDateEditor : IGridEditor
{
    private DateTimePicker _control;
    private IGridEditorEvents _events;

    public Control CreateControl(BeepColumnConfig column, object currentValue)
    {
        _control = new DateTimePicker
        {
            Format = DateTimePickerFormat.Custom,
            CustomFormat = "ddd, MMM dd yyyy",
            Width = 200
        };
        return _control;
    }

    public void Setup(BeepColumnConfig column, IGridEditorEvents editorEvents, Theme theme)
    {
        _events = editorEvents;
    }

    public void SetValue(object value) => _control.Value = (DateTime)value;
    public object GetValue() => _control.Value;
    public void AttachEvents()
    {
        _control.KeyDown += (s, e) =>
        {
            if (e.KeyCode == Keys.Enter) _events.RequestEndEdit(true);
            if (e.KeyCode == Keys.Escape) _events.RequestCancelEdit();
        };
    }
    public void DetachEvents() { }
    public void OnBeginEdit(Rectangle cellBounds)
    {
        _control.Bounds = cellBounds;
        _control.Focus();
        _control.Select();
    }
    public bool IsPopupOpen => false;
    public bool IsEditing => _control != null;
    public Control EditingControl => _control;
}

Set Fallback Editor

grid.EditorFactory.SetFallback(typeof(BeepGridMaskedEditor));