The Spring Computing Windows Controls

#ifndef __ATLSPCTLW_H__
#define __ATLSPCTLW_H__

#pragma once

#ifndef __cplusplus
	#error atlspctlw.h requires C++ compilation (use a .cpp suffix)
#endif

#ifndef __ATLSPCTL_H__
	#error atlspctlw.h requires atlspctl.h to be included first
#endif

/////////////////////////////////////////////////////////////////////////////
// Forward declarations

template <class T, class TBase = CWindow, class TWinTraits = CControlWinTraits> class CCaptionBarWindowImpl;
template <class T> class CCaptionBarWindow;

/////////////////////////////////////////////////////////////////////////////
// CCaptionBarWindowImpl

template <class T, class TBase = CWindow, class TWinTraits = CControlWinTraits>
class ATL_NO_VTABLE CCaptionBarWindowImpl : public CWindowImpl<T, TBase, TWinTraits>
{
public:
	DECLARE_WND_CLASS(NULL)

// Constants
	enum {
		m_cySpacing = 5,
		m_cchTitle = 128
	};

// Data members
	CCaptionBarCtrl	m_captionBar;
	HWND			m_hWndClient;
	TCHAR			m_pszTitle[m_cchTitle];

// Constructor
	CCaptionBarWindowImpl() : m_hWndClient(0)
	{
		m_pszTitle[0] = 0;
	}

// Attributes
	CCaptionBarCtrl& GetCaptionBarCtrl()
	{
		ATLASSERT(::IsWindow(m_hWnd));
		ATLASSERT(::IsWindow(m_captionBar.m_hWnd));
		return m_captionBar;
	}

	HWND SetClient(HWND hWnd)
	{
		HWND hWndOldClient = m_hWndClient;
		m_hWndClient = hWnd;
		if(m_hWnd != NULL) {
			T* pT = static_cast<T*>(this);
			pT->RecalcLayout();
		}
		return hWndOldClient;
	}

// Implementation
	HWND Create(HWND hWndParent, _U_RECT rect = NULL, LPCTSTR pszTitle = NULL, DWORD dwStyle = 0, DWORD dwExStyle = 0, UINT nID = 0U)
	{
		ATLASSERT(m_hWnd == NULL);

		if (pszTitle != 0)
			lstrcpyn(m_pszTitle, pszTitle, m_cchTitle);

		if (rect.m_lpRect == NULL || rect.m_lpRect == &TBase::rcDefault)
			::GetClientRect(hWndParent, rect.m_lpRect);

		return CWindowImpl<T, TBase, TWinTraits>::Create(hWndParent, *rect.m_lpRect, NULL, dwStyle, dwExStyle, nID);
	}

// Message Handlers
	LRESULT OnCreate(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
	{
		m_captionBar.Create(m_hWnd, NULL, m_pszTitle, WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS);
		return 0L;
	}

	LRESULT OnSize(UINT /*uMsg*/, WPARAM wParam, LPARAM /*lParam*/, BOOL& /*bHandled*/)
	{
		if(wParam != SIZE_MINIMIZED) {
			T* pT = static_cast<T*>(this);
			pT->RecalcLayout();
		}
		return 0L;
	}

	LRESULT OnEraseBackground(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& bHandled)
	{
		return 1L;	// no further processing
	}

	LRESULT OnSetFocus(UINT, WPARAM, LPARAM, BOOL& bHandled)
	{
		if(m_hWndClient != NULL && ::IsWindowVisible(m_hWndClient))
			::SetFocus(m_hWndClient);

		bHandled = FALSE;
		return 1L;
	}

	LRESULT OnPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
	{
		CPaintDC hDC(m_hWnd);

		RECT rect;
		GetClientRect(&rect);

		// Offset client dimensions

		RECT rectCB;
		m_captionBar.GetClientRect(&rectCB);
		rect.top += rectCB.bottom - rectCB.top;

		// Draw gap

		CRect rectSpacing = rect;
		rectSpacing.bottom = rectSpacing.top + m_cySpacing;
		rect.top += m_cySpacing;
		
		hDC.FillRect(&rectSpacing, (HBRUSH)LongToPtr(COLOR_BTNFACE + 1));

		// Draw pane

		if (m_hWndClient == NULL) {
			T* pT = static_cast<T*>(this);
			pT->DrawPane(hDC.m_hDC, rect);
		}

		return 0L;
	}

	LRESULT OnCaptionBarAutoSize(int /*idCtrl*/, LPNMHDR /*pnmh*/, BOOL& /*bHandled*/)
	{
		T* pT = static_cast<T*>(this);
		pT->RecalcLayout();
		return 0L;
	}

// Message Map
	BEGIN_MSG_MAP(CCaptionBarWindow)
		MESSAGE_HANDLER(WM_CREATE, OnCreate)
		MESSAGE_HANDLER(WM_SIZE, OnSize)
		MESSAGE_HANDLER(WM_ERASEBKGND, OnEraseBackground)
		MESSAGE_HANDLER(WM_SETFOCUS, OnSetFocus)
		MESSAGE_HANDLER(WM_PAINT, OnPaint)
		NOTIFY_CODE_HANDLER(CBN_AUTOSIZE, OnCaptionBarAutoSize)
		FORWARD_NOTIFICATIONS()
	END_MSG_MAP()

// Overridables
public:
	void RecalcLayout()
	{
		RECT rect;
		GetClientRect(&rect);

		// position bar and offset client dimensions

		m_captionBar.SendMessage(WM_SIZE, 0, 0);

		RECT rectCB;
		m_captionBar.GetWindowRect(&rectCB);
		rect.top += rectCB.bottom - rectCB.top;
		rect.top += m_cySpacing;

		// resize client window

		if(m_hWndClient != NULL) {
			::SetWindowPos(m_hWndClient, NULL, rect.left, rect.top,
				rect.right - rect.left, rect.bottom - rect.top,
				SWP_NOZORDER | SWP_NOACTIVATE);
		}
	}

	// called only if pane is empty
	void DrawPane(CDCHandle hDC, const CRect& rect)
	{
		CRect rcPane = rect;
		if((GetExStyle() & WS_EX_CLIENTEDGE) == 0)
			hDC.DrawEdge(&rcPane, EDGE_SUNKEN, BF_RECT | BF_ADJUST);
		hDC.FillRect(&rcPane, (HBRUSH)LongToPtr(COLOR_APPWORKSPACE + 1));
	}
};

template <class T>
class CCaptionBarWindow : public CCaptionBarWindowImpl<T>
{
public:
	DECLARE_WND_CLASS(NULL)
};

#endif // __ATLSPCTLW_H__