Creating SpinComboBoxEdit control

I saw a question about how to extend [DevEx]’ ComboBoxEdit control to include spin down and up buttons in their forums. The buttons should cycle through available items. I thought I could easily create such a control and here it is in all its glory:

Note the two added spin buttons at the right side.

Now, let’s test it. Here is my test data:

Clicking on left spin button will set the first value:

Next click on the same button will move the selection forward:

and so on.

And here is the required code

using System;
using System.Collections.Generic;
using System.Text;
using DevExpress.XtraEditors.Repository;
using System.Drawing;
using DevExpress.XtraEditors.Registrator;
using DevExpress.XtraEditors;
using System.ComponentModel;
using DevExpress.XtraEditors.Controls;
using System.Collections;

namespace Righthand.Editors
{
    public class RepositoryItemSpinComboEdit : RepositoryItemComboBox
    {
        static RepositoryItemSpinComboEdit() { }

        public const string SpinComboEditName = "SpinComboEdit";

        public override string EditorTypeName { get { return SpinComboEditName; } }

        public override void CreateDefaultButton()
        {
            base.CreateDefaultButton();
            Buttons.Clear();
            Buttons.Add(new EditorButton(ButtonPredefines.Combo));
            Buttons.Add(new EditorButton(ButtonPredefines.SpinLeft));
            Buttons.Add(new EditorButton(ButtonPredefines.SpinRight));
        }

        public static void RegisterSpinComboEdit()
        {
            //Icon representing the editor within a container editor's Designer
            Image img = null;
            try
            {
                img = null; // your image;
            }
            catch
            {
            }
            EditorRegistrationInfo.Default.Editors.Add(new EditorClassInfo(SpinComboEditName,
                typeof(SpinComboEdit), typeof(RepositoryItemSpinComboEdit),
                typeof(DevExpress.XtraEditors.ViewInfo.ComboBoxViewInfo),
                new DevExpress.XtraEditors.Drawing.ButtonEditPainter(), true, img));
        }
    }

    public class SpinComboEdit: ComboBoxEdit
    {
        static SpinComboEdit() { RepositoryItemSpinComboEdit.RegisterSpinComboEdit(); }

        public SpinComboEdit()
        {
            Properties.ButtonClick += new ButtonPressedEventHandler(Properties_ButtonClick);
        }

        void Properties_ButtonClick(object sender, ButtonPressedEventArgs e)
        {
            if (e.Button.Index == 1)
                MoveSelection(1);
            else if (e.Button.Index == 2)
                MoveSelection(-1);
        }

        private void MoveSelection(int index)
        {
            int? indexOfItem = null;
            if (EditValue != null)
            {
                indexOfItem = Properties.Items.IndexOf(EditValue);
            }
            int newIndex = -1;
            if (indexOfItem.HasValue)
                newIndex = Math.Max(Math.Min(indexOfItem.Value+index, Properties.Items.Count - 1), 0);
            else if (index > 0 && Properties.Items.Count > 0)
                newIndex = 0;
            EditValue = Properties.Items[newIndex];
        }

        public override string EditorTypeName
        {
            get { return RepositoryItemSpinComboEdit.SpinComboEditName; }
        }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public new RepositoryItemSpinComboEdit Properties
        {
            get { return base.Properties as RepositoryItemSpinComboEdit; }
        }

    }
}

Most of the code is required to derive my SpinComboEdit control out of [DevEx]’ provided ComboBoxEdit control (see 7.2 help file topic Editor Features/01.Editor Structure/Custom Editors – or previous version help file, just this link won’t work).

Points of interests are CreateDefaultButton() method where I create default buttons, SpinComboEdit() constructor where I attach to Properties.ButtonClick event and MoveSelection(int index) method where I actually move the selection forth and back. It should be pretty straightforward to understand.

I hope you’ll find this sample useful and take note that this code can and should be further improved as it was a quickly built with demo purposes in mind.

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