Understanding CDockablePane

#include "stdafx.h"
#include "resource.h"
#include "PhoneBook.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

#define IDC_OUTLOOK 100
#define IDC_TABCTRL 101

IMPLEMENT_DYNAMIC(PhoneBook, CDialog)
BEGIN_MESSAGE_MAP(PhoneBook, CDialog)
	ON_WM_CREATE()
	ON_WM_SIZE()
END_MESSAGE_MAP()

PhoneBook::PhoneBook(CWnd* pParent /*=NULL*/)
	: CDialog(PhoneBook::IDD, pParent)
{
}

PhoneBook::~PhoneBook()
{
}

int PhoneBook::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
	if (CDialog::OnCreate(lpCreateStruct) == -1)
		return -1;

	CRect rect;
	GetClientRect(&rect);
	rect.bottom = int(rect.Height() * 0.9);
	m_wndOutlook.Create(rect,this,IDC_OUTLOOK);
	m_dlgSimple.Create(IDD_SIMPLE,this);
	m_wndTabCtrl.Create(CMFCTabCtrl::STYLE_3D_ONENOTE,rect,this,IDC_TABCTRL,CMFCBaseTabCtrl::LOCATION_TOP);
	m_dlgSimple.SetOwner(&m_wndOutlook);
	m_wndTabCtrl.SetOwner(&m_wndOutlook);
	m_wndOutlook.AddTab(&m_dlgSimple,_T("Simple"));
	m_wndOutlook.AddTab(&m_wndTabCtrl,_T("Advanced"));
	m_dlgMain.Create(IDD_MAIN,&m_wndTabCtrl);
	m_wndTabCtrl.AddTab(&m_dlgMain,_T("Main"));
	m_dlgWork.Create(IDD_WORK,&m_wndTabCtrl);
	m_wndTabCtrl.AddTab(&m_dlgWork,_T("Work"));
	m_dlgHome.Create(IDD_HOME,&m_wndTabCtrl);
	m_wndTabCtrl.AddTab(&m_dlgHome,_T("Home"));
	m_dlgGeneral.Create(IDD_GENERAL,&m_wndTabCtrl);
	m_wndTabCtrl.AddTab(&m_dlgGeneral,_T("General"));
	return 0;
}

void PhoneBook::OnSize(UINT nType, int cx, int cy)
{
	CDialog::OnSize(nType, cx, cy);
	int Height = int(cy * 0.9);//take 90% of parent dialog height
	m_wndOutlook.MoveWindow(0,0,cx,Height);
}