WTL self drawn control library (cqscheckcomboxbox)

summary ：

CQsCheckComboxBox Inherit and CComboBox, Draw the background by self drawing , And the drawing of various selected states .

The code implementation is as follows ：

****/
#pragma once;
#include "QsInclude.h"

#pragma warning(disable: 4312)
#pragma warning(disable: 4311)

extern WNDPROC m_pWndProc;
LRESULT ComboBoxListBoxProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam);

class CQsCheckComboxBox :
    public CWindowImpl< CQsCheckComboxBox, CComboBox >, public COwnerDraw< CQsCheckComboxBox >
{
    
    typedef CWindowImpl< CQsCheckComboxBox, CComboBox > theBaseClass;
public:

    BEGIN_MSG_MAP(CQsCheckComboxBox)
        MESSAGE_HANDLER( CB_ADDSTRING, OnAddString )
        MESSAGE_HANDLER( CB_INSERTSTRING, OnInsertString )
        MESSAGE_HANDLER( CB_DELETESTRING, OnDeleteString )
        MESSAGE_HANDLER( WM_CTLCOLORLISTBOX, OnCtlColorListBox )
        MESSAGE_HANDLER( CBN_DROPDOWN, OnCbnDropdown )
        MESSAGE_HANDLER( WM_GETTEXT, OnGetText )
        MESSAGE_HANDLER( WM_GETTEXTLENGTH, OnGetTextLength )
        CHAIN_MSG_MAP_ALT( COwnerDraw< CQsCheckComboxBox >, 1 )
        DEFAULT_REFLECTION_HANDLER()
    END_MSG_MAP()

	/** *@method CQsCheckComboxBox *@brief  Constructors  * *@param void *@return */
	CQsCheckComboxBox( void )
	{
    
		m_hListBox = NULL;
		m_bTextUpdated = FALSE;
		m_strText = _T("");
		m_strbkText = _T("");
	}

	/** *@method ~CQsCheckComboxBox *@brief  Destructor  * *@param void *@return */
    ~CQsCheckComboxBox( void )
	{
    

	}

	/** *@method Create *@brief  adopt Create To create a window . * *@param HWND hWndParent parent window *@param _U_RECT rect = NULL create window rect *@param LPCTSTR szWindowName = NULL the window name *@param DWORD dwStyle = 0 base window style *@param DWORD dwExStyle = 0 extended window style *@param _U_MENUorID MenuOrID = 0U menu or ID *@param LPVOID lpCreateParam = NULL create param *@return HWND  Not NULL success return TRUE, failed return NULL */
    HWND Create(HWND hWndParent, _U_RECT rect = NULL, LPCTSTR szWindowName = NULL,
        DWORD dwStyle = 0, DWORD dwExStyle = 0,
        _U_MENUorID MenuOrID = 0U, LPVOID lpCreateParam = NULL)
	{
    
		// Remove the CBS_SIMPLE and CBS_DROPDOWN styles and add the one I'm designed for
		dwStyle &= ~0xF;
		dwStyle |= CBS_DROPDOWNLIST;

		// Make sure to use the CBS_OWNERDRAWVARIABLE style
		dwStyle |= CBS_OWNERDRAWVARIABLE;

		// Use default strings. We need the itemdata to store checkmarks
		dwStyle |= CBS_HASSTRINGS;

		return theBaseClass::Create(hWndParent, rect, szWindowName, dwStyle, dwExStyle, MenuOrID, lpCreateParam);
	}
	
    /** *@method SubclassWindow *@brief  Class object association  * *@param HWND hWnd  Object handle  *@return BOOL  Successfully returns TRUE, Failure to return FALSE */
	BOOL SubclassWindow(HWND hWnd)
	{
    
		DWORD dwStyle = CBS_DROPDOWNLIST|CBS_OWNERDRAWVARIABLE|CBS_HASSTRINGS;
		BOOL bRet = theBaseClass::SubclassWindow( hWnd );
		ModifyStyle(0,dwStyle);

		return bRet;
	}
	/** *@method SetBkText *@brief  Set the background Text * *@param CString & strBkText *@return void */
	void SetBkText(CString& strBkText)
	{
    
		m_strbkText = strBkText;
	}
	/** *@method DrawItem *@brief  Button redraw function  * *@param LPDRAWITEMSTRUCT lpDrawItemStruct  See MSN *@return void */
	void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct )
	{
    
		HDC dc = lpDrawItemStruct->hDC;

		CRect rcBitmap = lpDrawItemStruct->rcItem;
		CRect rcText   = lpDrawItemStruct->rcItem;

		CString strText;

		// 0 - No check, 1 - Empty check, 2 - Checked
		bool bCheck = false;

		// Check if we are drawing the static portion of the combobox
		if ((LONG)lpDrawItemStruct->itemID < 0) 
		{
    
			// Make sure the m_strText member is updated
			RecalcText();

			// Get the text
			strText = m_strText;
		}
		// Otherwise it is one of the items
		else 
		{
    
			int nLen = GetLBTextLen( lpDrawItemStruct->itemID );
			TCHAR *str = new TCHAR[nLen+1];
			GetLBText(lpDrawItemStruct->itemID, str);
			strText = str;
			bCheck = m_vtChekcList[lpDrawItemStruct->itemID];

			TEXTMETRIC metrics;
			GetTextMetrics(dc, &metrics);

			rcBitmap.left    = 0;
			rcBitmap.right   = rcBitmap.left + metrics.tmHeight + metrics.tmExternalLeading + 6;
			rcBitmap.top    += 1;
			rcBitmap.bottom -= 1;

			rcText.left = rcBitmap.right;

			UINT nState = DFCS_BUTTONCHECK;

			if (bCheck)
			{
    
				nState |= DFCS_CHECKED;
			}

			// Draw the checkmark using DrawFrameControl
			DrawFrameControl(dc, rcBitmap, DFC_BUTTON, nState);
			delete [] str;
		}

		if (lpDrawItemStruct->itemState & ODS_SELECTED) 
		{
    
			SetBkColor(dc, GetSysColor(COLOR_HIGHLIGHT));
			SetTextColor(dc, GetSysColor(COLOR_HIGHLIGHTTEXT));
		}
		else 
		{
    
			SetBkColor(dc, GetSysColor(COLOR_WINDOW));
			SetTextColor(dc, GetSysColor(COLOR_WINDOWTEXT));
		}
		if(strText.GetLength()>0)
		{
    
		  // Erase and draw
		  ExtTextOut(dc, 0, 0, ETO_OPAQUE, &rcText, 0, 0, 0);
		  DrawText(dc, ' ' + strText, strText.GetLength() + 1, &rcText, DT_SINGLELINE|DT_VCENTER|DT_END_ELLIPSIS);
	   }
	   else
	   {
    
		   HWND hwnd = GetFocus();
		   if(hwnd!=m_hWnd)
		   {
    
			   CRect rectBk;
			   GetClientRect(&rectBk);
			   rectBk.left = rectBk.left+5;
			   DrawText(dc, m_strbkText, m_strbkText.GetLength() + 1, &rectBk, DT_SINGLELINE|DT_VCENTER|DT_END_ELLIPSIS);
		   }
	   }
		if ((lpDrawItemStruct->itemState & (ODS_FOCUS|ODS_SELECTED)) == (ODS_FOCUS|ODS_SELECTED))
		{
    
			DrawFocusRect(dc, &rcText);

		}
	}

	/** *@method SetCheck *@brief  Used to set item The state of  * *@param int nIndex  Set the status of ID *@param bool bFlag  The status value , Checked or unchecked  *@return int */
	int SetCheck( int nIndex, bool bFlag )
	{
    
		m_vtChekcList[(UINT)nIndex] = bFlag;
		m_bTextUpdated = FALSE;
		Invalidate(FALSE);
		return 0;
	}
	
    /** *@method GetCheck *@brief  obtain item The state of  * *@param int nIndex item Mark (Id) *@return bool */
	bool GetCheck( int nIndex )
	{
    
		return m_vtChekcList[(UINT)nIndex];
	}

	/** *@method SelectAll *@brief CQsCheckComboxBox Control Item All check Or all Uncheck * *@param bool bFlag item Of check state ,true For the selection ,false For unselected  *@return void */
	void SelectAll( bool bFlag )
	{
    
		int nCount = GetCount();

		for (int i = 0; i < nCount; i++)
		{
    
			SetCheck(i, bFlag);
		}
	}
	/** *@method OnAddString *@brief CB_ADDSTRING Message response function , See MSDN * *@param UINT uMsg  news ID, by CB_ADDSTRING *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnAddString(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& bHandled)
	{
    
		m_vtChekcList.push_back( false );
		bHandled = FALSE;
		return 0;
	}
	
    /** *@method OnInsertString *@brief CB_INSERTSTRING Message response function , See MSDN * *@param UINT uMsg  news ID, by CB_ADDSTRING *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnInsertString(UINT /*uMsg*/, WPARAM wParam, LPARAM /*lParam*/, BOOL& bHandled)
	{
    
		int nIndex = (int)wParam;
		if ( -1 == nIndex )
		{
    
			m_vtChekcList.push_back( false );
		}
		else
		{
    
			std::vector<bool>::iterator it;
			for ( int i = 0; i < nIndex; i++, it++ );
			m_vtChekcList.insert( it, false );
		}
		bHandled = FALSE;
		return 0;
	}
	
    /** *@method OnDeleteString *@brief CB_DELETESTRING Message response function , See MSDN * *@param UINT uMsg  news ID, by CB_DELETESTRING *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnDeleteString(UINT /*uMsg*/, WPARAM wParam, LPARAM /*lParam*/, BOOL& bHandled)
	{
    
		int nIndex = (int)wParam;
		std::vector<bool>::iterator it;
		for ( int i = 0; i < nIndex; i++, it++ );
		m_vtChekcList.erase( it );
		bHandled = FALSE;
		return 0;
	}
	
    /** *@method OnCtlColorListBox *@brief WM_CTLCOLORLISTBOX Message response function , See MSDN * *@param UINT uMsg  news ID, by WM_CTLCOLORLISTBOX *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnCtlColorListBox(UINT /*uMsg*/, WPARAM wParam, LPARAM lParam, BOOL& /*bHandled*/ ) 
	{
    
		// If the listbox hasn't been subclassed yet, do so...
		if (m_hListBox == 0) 
		{
    
			HWND hWnd = (HWND)lParam;

			if (hWnd != 0 && hWnd != m_hWnd) 
			{
    
				// Save the listbox handle
				m_hListBox = hWnd;

				// Do the subclassing
				m_pWndProc = (WNDPROC)(::GetWindowLong(m_hListBox, GWL_WNDPROC));
				::SetWindowLong(m_hListBox, GWL_WNDPROC, (LONG)ComboBoxListBoxProc);
				::SetWindowLong(m_hListBox, GWL_USERDATA, (LONG)this);
			}
		}

		return DefWindowProc(WM_CTLCOLORLISTBOX, wParam, lParam);
	}
	
    /** *@method RecalcText *@brief CQSCheckComboxBox Control recalculates Text function  * *@return void */
	void RecalcText()
	{
    
		if (!m_bTextUpdated) 
		{
    
			CString strText;

			// Get the list count
			UINT nCount    = (UINT)GetCount();

			// Get the list separator
			TCHAR szBuffer[10] = {
    0};
			GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_SLIST, szBuffer, sizeof(szBuffer));

			CString strSeparator = szBuffer;

			// If none found, the the ';'
			if (strSeparator.GetLength() == 0)
			{
    
				strSeparator = ';';
			}

			// Trim extra spaces
			strSeparator.TrimRight();

			// And one...
			strSeparator += ' ';

			for (UINT i = 0; i < nCount; i++) 
			{
    
				if (m_vtChekcList[i]) 
				{
    
					//CString strItem;
					int nLen = GetLBTextLen( i );
					TCHAR *str = new TCHAR[nLen + 1];
					GetLBText(i, str);

					CString strItem( str );

					if (!strText.IsEmpty())
					{
    
						strText += strSeparator;
					}

					strText += strItem;
					delete [] str;
				}
			}

			// Set the text
			m_strText = strText;

			m_bTextUpdated = TRUE;
		}
	}

	/** *@method OnCbnDropdown *@brief CBN_DROPDOWN Message response function , See MSDN * *@param UINT uMsg  news ID, by WM_CTLCOLORLISTBOX *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnCbnDropdown(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& bHandled)
	{
    		
		bHandled = FALSE;
		
		return 0;
	}
	
    /** *@method OnGetText *@brief WM_GETTEXT Message response function , See MSDN * *@param UINT uMsg  news ID, by WM_GETTEXT *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnGetText(UINT /*uMsg*/, WPARAM wParam, LPARAM lParam, BOOL& /*bHandled*/)
	{
    
		// TODO:  Add control notification handler code here 
		// Make sure the text is updated
		RecalcText();

		if (lParam == 0)
			return 0;

		// Copy the 'fake' window text
		lstrcpyn((TCHAR *)lParam, m_strText, (INT)wParam);
		return m_strText.GetLength();
	}

	/** *@method OnGetTextLength *@brief WM_GETTEXTLENGTH Message response function , See MSDN * *@param UINT uMsg  news ID, by WM_GETTEXTLENGTH *@param WPARAM wParam  Not used  *@param LPARAM lParam  See MSDN *@param BOOL& bHandled  See MSDN *@return LRESULT */
	LRESULT OnGetTextLength(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
	{
    
		// Make sure the text is updated
		RecalcText();
		return m_strText.GetLength();
	}

    CString m_strText;			
    BOOL m_bTextUpdated;
    HWND m_hListBox;
	CString m_strbkText;
private:
    std::vector<bool> m_vtChekcList;           // list Of item Of checkbox Check flag vector  
};