WinForms Data Grid - How to display a custom button within a column header

C#
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using DevExpress.Skins;
using DevExpress.XtraGrid.Views.Grid;
using System.Drawing;
using DevExpress.XtraEditors.Drawing;
using DevExpress.XtraEditors.Controls;
using DevExpress.XtraGrid.Views.Grid.ViewInfo;
using DevExpress.XtraGrid.Drawing;
using DevExpress.Utils.Drawing;
using DevExpress.XtraEditors;
using DevExpress.XtraGrid.Columns;
using DevExpress.Utils;

namespace DXSample {
    public class ColumnHeaderExtender {
        GridView view;
        SkinEditorButtonPainter customButtonPainter;
        EditorButtonObjectInfoArgs args;
        Size buttonSize;

        public ColumnHeaderExtender(GridView view) {
            this.view = view;
            buttonSize = new Size(14, 14);
            
        }

        public void AddCustomButton() {
            CreateButtonPainter();
            CreateButtonInfoArgs();
            SubscribeToEvents();
        }

        private void CreateButtonInfoArgs() {
            EditorButton btn = new EditorButton(ButtonPredefines.Glyph);
            args = new EditorButtonObjectInfoArgs(btn, new DevExpress.Utils.AppearanceObject());
        }

        private void CreateButtonPainter() {
            customButtonPainter = new SkinEditorButtonPainter(DevExpress.LookAndFeel.UserLookAndFeel.Default.ActiveLookAndFeel);
        }

        private void SubscribeToEvents() {
            view.CustomDrawColumnHeader += OnCustomDrawColumnHeader;
            view.MouseDown += OnMouseDown;
            view.MouseUp += OnMouseUp;
            view.MouseMove += OnMouseMove;
        }

        void OnMouseUp(object sender, MouseEventArgs e) {
            GridHitInfo hitInfo = view.CalcHitInfo(e.Location);
            if(hitInfo.HitTest != GridHitTest.Column) return;
            GridColumn column = hitInfo.Column;
            if(IsButtonRect(e.Location, column)) {
                SetButtonState(column, ObjectState.Normal);
                XtraMessageBox.Show(string.Format("Custom Button in {0}", column.FieldName));
                // your code here
                DXMouseEventArgs.GetMouseArgs(e).Handled = true;
            }
        }

        void OnMouseMove(object sender, MouseEventArgs e) {
            GridHitInfo hitInfo = view.CalcHitInfo(e.Location);
            if(hitInfo.HitTest != GridHitTest.Column) return;
            GridColumn column = hitInfo.Column;
            if(IsButtonRect(e.Location, column))
                SetButtonState(column, ObjectState.Hot);
            else
                SetButtonState(column, ObjectState.Normal);
        }

        void OnMouseDown(object sender, MouseEventArgs e) {
            GridHitInfo hitInfo = view.CalcHitInfo(e.Location);
            if(hitInfo.HitTest != GridHitTest.Column) return;
            GridColumn column = hitInfo.Column;
            if(IsButtonRect(e.Location, column)) {
                SetButtonState(column, ObjectState.Pressed);
                DXMouseEventArgs.GetMouseArgs(e).Handled = true;
            }
        }

        private void SetButtonState(GridColumn column, ObjectState state) {
            column.Tag = state;
            view.InvalidateColumnHeader(column);
        }

        private bool IsButtonRect(Point point, GridColumn column) {
            GraphicsInfo info = new GraphicsInfo();
            info.AddGraphics(null);
            GridViewInfo viewInfo = view.GetViewInfo() as GridViewInfo;
            GridColumnInfoArgs columnArgs = viewInfo.ColumnsInfo[column];
            Rectangle buttonRect = CalcButtonRect(columnArgs, info.Graphics);
            info.ReleaseGraphics();
            return buttonRect.Contains(point);
        }

        private Rectangle CalcButtonRect(GridColumnInfoArgs columnArgs, Graphics gr) {
            Rectangle columnRect = columnArgs.Bounds;
            int innerElementsWidth = CalcInnerElementsMinWidth(columnArgs, gr);
            Rectangle buttonRect = new Rectangle(columnRect.Right - innerElementsWidth - buttonSize.Width - 2,
                columnRect.Y + columnRect.Height / 2 - buttonSize.Height / 2, buttonSize.Width, buttonSize.Height);
            return buttonRect;
        }

        private int CalcInnerElementsMinWidth(GridColumnInfoArgs columnArgs, Graphics gr) {
            bool canDrawMode = true;
            return columnArgs.InnerElements.CalcMinSize(gr, ref canDrawMode).Width;
        }

        void OnCustomDrawColumnHeader(object sender, ColumnHeaderCustomDrawEventArgs e) {
            if(e.Column == null) return;
            DefaultDrawColumnHeader(e);
            DrawCustomButton(e);
            e.Handled = true;
        }

        private void DrawCustomButton(ColumnHeaderCustomDrawEventArgs e) {
            SetUpButtonInfoArgs(e);
            customButtonPainter.DrawObject(args);
        }

        private void SetUpButtonInfoArgs(ColumnHeaderCustomDrawEventArgs e) {
            args.Cache = e.Cache;
            args.Bounds = CalcButtonRect(e.Info, e.Cache.Graphics);
            ObjectState state = ObjectState.Normal;
            if(e.Column.Tag is ObjectState)
                state = (ObjectState)e.Column.Tag;
            args.State = state;
        }

        private static void DefaultDrawColumnHeader(ColumnHeaderCustomDrawEventArgs e) {
            e.Painter.DrawObject(e.Info);
        }

        private void UnsubscribeFromEvents() {
            view.CustomDrawColumnHeader -= OnCustomDrawColumnHeader;
            view.MouseDown -= OnMouseDown;
            view.MouseUp -= OnMouseUp;
            view.MouseMove -= OnMouseMove;
        }

        public void RemoveCustomButton() {
            UnsubscribeFromEvents();

        }
    }
}

Visual Basic
Imports System
Imports System.Collections.Generic
Imports System.Windows.Forms
Imports DevExpress.Skins
Imports DevExpress.XtraGrid.Views.Grid
Imports System.Drawing
Imports DevExpress.XtraEditors.Drawing
Imports DevExpress.XtraEditors.Controls
Imports DevExpress.XtraGrid.Views.Grid.ViewInfo
Imports DevExpress.XtraGrid.Drawing
Imports DevExpress.Utils.Drawing
Imports DevExpress.XtraEditors
Imports DevExpress.XtraGrid.Columns
Imports DevExpress.Utils

Namespace DXSample
    Public Class ColumnHeaderExtender
        Private view As GridView
        Private customButtonPainter As SkinEditorButtonPainter
        Private args As EditorButtonObjectInfoArgs
        Private buttonSize As Size

        Public Sub New(ByVal view As GridView)
            Me.view = view
            buttonSize = New Size(14, 14)

        End Sub

        Public Sub AddCustomButton()
            CreateButtonPainter()
            CreateButtonInfoArgs()
            SubscribeToEvents()
        End Sub

        Private Sub CreateButtonInfoArgs()
            Dim btn As New EditorButton(ButtonPredefines.Glyph)
            args = New EditorButtonObjectInfoArgs(btn, New DevExpress.Utils.AppearanceObject())
        End Sub

        Private Sub CreateButtonPainter()
            customButtonPainter = New SkinEditorButtonPainter(DevExpress.LookAndFeel.UserLookAndFeel.Default.ActiveLookAndFeel)
        End Sub

        Private Sub SubscribeToEvents()
            AddHandler view.CustomDrawColumnHeader, AddressOf OnCustomDrawColumnHeader
            AddHandler view.MouseDown, AddressOf OnMouseDown
            AddHandler view.MouseUp, AddressOf OnMouseUp
            AddHandler view.MouseMove, AddressOf OnMouseMove
        End Sub

        Private Sub OnMouseUp(ByVal sender As Object, ByVal e As MouseEventArgs)
            Dim hitInfo As GridHitInfo = view.CalcHitInfo(e.Location)
            If hitInfo.HitTest <> GridHitTest.Column Then
                Return
            End If
            Dim column As GridColumn = hitInfo.Column
            If IsButtonRect(e.Location, column) Then
                SetButtonState(column, ObjectState.Normal)
                XtraMessageBox.Show(String.Format("Custom Button in {0}", column.FieldName))
                ' your code here
                DXMouseEventArgs.GetMouseArgs(e).Handled = True
            End If
        End Sub

        Private Sub OnMouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
            Dim hitInfo As GridHitInfo = view.CalcHitInfo(e.Location)
            If hitInfo.HitTest <> GridHitTest.Column Then
                Return
            End If
            Dim column As GridColumn = hitInfo.Column
            If IsButtonRect(e.Location, column) Then
                SetButtonState(column, ObjectState.Hot)
            Else
                SetButtonState(column, ObjectState.Normal)
            End If
        End Sub

        Private Sub OnMouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
            Dim hitInfo As GridHitInfo = view.CalcHitInfo(e.Location)
            If hitInfo.HitTest <> GridHitTest.Column Then
                Return
            End If
            Dim column As GridColumn = hitInfo.Column
            If IsButtonRect(e.Location, column) Then
                SetButtonState(column, ObjectState.Pressed)
                DXMouseEventArgs.GetMouseArgs(e).Handled = True
            End If
        End Sub

        Private Sub SetButtonState(ByVal column As GridColumn, ByVal state As ObjectState)
            column.Tag = state
            view.InvalidateColumnHeader(column)
        End Sub

        Private Function IsButtonRect(ByVal point As Point, ByVal column As GridColumn) As Boolean
            Dim info As New GraphicsInfo()
            info.AddGraphics(Nothing)
            Dim viewInfo As GridViewInfo = TryCast(view.GetViewInfo(), GridViewInfo)
            Dim columnArgs As GridColumnInfoArgs = viewInfo.ColumnsInfo(column)
            Dim buttonRect As Rectangle = CalcButtonRect(columnArgs, info.Graphics)
            info.ReleaseGraphics()
            Return buttonRect.Contains(point)
        End Function

        Private Function CalcButtonRect(ByVal columnArgs As GridColumnInfoArgs, ByVal gr As Graphics) As Rectangle
            Dim columnRect As Rectangle = columnArgs.Bounds
            Dim innerElementsWidth As Integer = CalcInnerElementsMinWidth(columnArgs, gr)
            Dim buttonRect As New Rectangle(columnRect.Right - innerElementsWidth - buttonSize.Width - 2, columnRect.Y + columnRect.Height \ 2 - buttonSize.Height \ 2, buttonSize.Width, buttonSize.Height)
            Return buttonRect
        End Function

        Private Function CalcInnerElementsMinWidth(ByVal columnArgs As GridColumnInfoArgs, ByVal gr As Graphics) As Integer
            Dim canDrawMode As Boolean = True
            Return columnArgs.InnerElements.CalcMinSize(gr, canDrawMode).Width
        End Function

        Private Sub OnCustomDrawColumnHeader(ByVal sender As Object, ByVal e As ColumnHeaderCustomDrawEventArgs)
            If e.Column Is Nothing Then
                Return
            End If
            DefaultDrawColumnHeader(e)
            DrawCustomButton(e)
            e.Handled = True
        End Sub

        Private Sub DrawCustomButton(ByVal e As ColumnHeaderCustomDrawEventArgs)
            SetUpButtonInfoArgs(e)
            customButtonPainter.DrawObject(args)
        End Sub

        Private Sub SetUpButtonInfoArgs(ByVal e As ColumnHeaderCustomDrawEventArgs)
            args.Cache = e.Cache
            args.Bounds = CalcButtonRect(e.Info, e.Cache.Graphics)
            Dim state As ObjectState = ObjectState.Normal
            If TypeOf e.Column.Tag Is ObjectState Then
                state = DirectCast(e.Column.Tag, ObjectState)
            End If
            args.State = state
        End Sub

        Private Shared Sub DefaultDrawColumnHeader(ByVal e As ColumnHeaderCustomDrawEventArgs)
            e.Painter.DrawObject(e.Info)
        End Sub

        Private Sub UnsubscribeFromEvents()
            RemoveHandler view.CustomDrawColumnHeader, AddressOf OnCustomDrawColumnHeader
            RemoveHandler view.MouseDown, AddressOf OnMouseDown
            RemoveHandler view.MouseUp, AddressOf OnMouseUp
            RemoveHandler view.MouseMove, AddressOf OnMouseMove
        End Sub

        Public Sub RemoveCustomButton()
            UnsubscribeFromEvents()

        End Sub
    End Class
End Namespace