A Float Tree Control like the Parameter List Control in Visual Studio

// vs_treectrlView.cpp : implementation of the CVs_treectrlView class
//

#include "stdafx.h"
#include "vs_treectrl.h"

#include "vs_treectrlDoc.h"
#include "vs_treectrlView.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CVs_treectrlView

IMPLEMENT_DYNCREATE(CVs_treectrlView, CView)

BEGIN_MESSAGE_MAP(CVs_treectrlView, CView)
	//{{AFX_MSG_MAP(CVs_treectrlView)
	ON_WM_LBUTTONUP()
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
	ON_MESSAGE(WM_FLOAT_CTRL,OnFloatCtrl)

END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CVs_treectrlView construction/destruction

CVs_treectrlView::CVs_treectrlView()
{
	// TODO: add construction code here

}

CVs_treectrlView::~CVs_treectrlView()
{
}

BOOL CVs_treectrlView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CVs_treectrlView drawing

void CVs_treectrlView::OnDraw(CDC* pDC)
{
	CVs_treectrlDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
}

/////////////////////////////////////////////////////////////////////////////
// CVs_treectrlView printing

BOOL CVs_treectrlView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}

void CVs_treectrlView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}

void CVs_treectrlView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}

/////////////////////////////////////////////////////////////////////////////
// CVs_treectrlView diagnostics

#ifdef _DEBUG
void CVs_treectrlView::AssertValid() const
{
	CView::AssertValid();
}

void CVs_treectrlView::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CVs_treectrlDoc* CVs_treectrlView::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CVs_treectrlDoc)));
	return (CVs_treectrlDoc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CVs_treectrlView message handlers

void CVs_treectrlView::OnLButtonUp(UINT nFlags, CPoint point) 
{
	m_Tree.ShowMe (point);
	CView::OnLButtonUp(nFlags, point);
}

void CVs_treectrlView::OnInitialUpdate() 
{
	CView::OnInitialUpdate();
		CRect rect(0,0,200,300);
	m_Tree.CreateTree (rect,this,IDB_BITMAP_TREE_ICONS);
	m_Tree.loadXML  ("catalog.xml",TRUE);
	// TODO: Add your specialized code here and/or call the base class
	
}
LRESULT CVs_treectrlView::OnFloatCtrl(WPARAM wParam, LPARAM lParam)
{
	CString str = (BSTR)wParam;
	MessageBox(str);
	m_Tree.ShowWindow (SW_HIDE);
	return 0;
}