Hyperlink Text View Control

Magomed Abdurakhmanov
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4.50/5 (4 votes)
20 Jun 20021 min read
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Control that shows text and automatically finds and highlights hyperlinks (like http://, www. etc.) so that user can click on them.
htcdemo.zip
- HTSample
  - AboutDlg.h
  - HTSample.cpp
  - HTSample.exe
  - HTSample.h
  - HTSample.rc
  - HTSample.sln
  - HTSample.vcproj
  - HyperTextCtrl.h
  - MainFrm.h
  - res
    - hand.cur
    - HTSample.ico
    - toolbar.bmp
  - resource.h
  - stdafx.cpp
  - stdafx.h
htcsrc.zip
- HyperTextCtrl.h
hlinkview_demo.zip
- HView
  - aboutdlg.h
  - HView.cpp
  - HView.dsp
  - HView.dsw
  - HView.exe
  - HView.h
  - HView.rc
  - HViewview.h
  - HyperTextCtrl.cpp
  - HyperTextCtrl.h
  - mainfrm.h
  - RegSettings.cpp
  - RegSettings.h
  - res
    - hand.cur
    - HView.ico
    - toolbar.bmp
  - resource.h
  - stdafx.cpp
  - stdafx.h
hlinkview_src.zip
- HyperTextCtrl.cpp
- HyperTextCtrl.h
// HyperTextCtrl.cpp: implementation of the CHyperTextCtrl class.
//
// Copyright (c) 2001 Magomed Abdurakhmanov
// maq@hotbox.ru, http://mickels.iwt.ru/en
//
//
//
// No warranties are given. Use at your own risk.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "HyperTextCtrl.h"

//////////////////////////////////////////////////////////////////////
// CHyperLink

namespace HyperTextControl{

	inline bool check_bits(DWORD Value, DWORD Mask)
	{
		return (Value & Mask) == Mask;
	}

CHyperLink::CHyperLink(int iBegin, int iEnd, const CString& sTitle, const CString& sCommand, const CString& sDirectory)
{
	m_Type = lt_Shell;
	m_iBegin = iBegin;
	m_iEnd = iEnd;
	m_sTitle = sTitle;
	m_sCommand = sCommand;
	m_sDirectory = sDirectory;
}

CHyperLink::CHyperLink(int iBegin, int iEnd, const CString& sTitle, HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	m_Type = lt_Message;
	m_iBegin = iBegin;
	m_iEnd = iEnd;
	m_sTitle = sTitle;
	m_hWnd = hWnd;
	m_uMsg = uMsg;
	m_wParam = wParam;
	m_lParam = lParam;
}

CHyperLink::CHyperLink(const CHyperLink& Src)
{
	m_Type = Src.m_Type;
	m_iBegin = Src.m_iBegin;
	m_iEnd = Src.m_iEnd;
	m_sTitle = Src.m_sTitle;
	m_sCommand = Src.m_sCommand;
	m_sDirectory = Src.m_sDirectory;
	m_hWnd = Src.m_hWnd;
	m_uMsg = Src.m_uMsg;
	m_wParam = Src.m_wParam;
	m_lParam = Src.m_lParam;
}

CHyperLink::~CHyperLink()
{
	;
}

void CHyperLink::Execute()
{
	switch(m_Type)
	{
	case lt_Shell:
		ShellExecute(NULL, NULL, m_sCommand, NULL, m_sDirectory, SW_SHOWDEFAULT);
		break;

	case lt_Message:
		PostMessage(m_hWnd, m_uMsg, m_wParam, m_lParam);
		break;
	}
}

//////////////////////////////////////////////////////////////////////
// CPreparedHyperText

bool tspace(TCHAR c)
{
	return _istspace(c) || c < _T(' ') || c == _T(';') || c == _T(',') || c == _T('!');
}

CPreparedHyperText::CPreparedHyperText()
{
}

CPreparedHyperText::CPreparedHyperText(const CString& sText)
{
	PrepareText(sText);
}

CPreparedHyperText::CPreparedHyperText(const CPreparedHyperText& src)
{
	m_sText = src.m_sText;
	m_Links.assign(src.m_Links.begin(), src.m_Links.end());
}

CPreparedHyperText::~CPreparedHyperText()
{
	;
}

void CPreparedHyperText::PrepareText(const CString& sText)
{
	m_sText = sText;
	m_Links.clear();
	
	enum {
		unknown,
		space,
		http0,		/* http://		*/
			http1, http2, http3, http4, http5, http6,
		ftp0,		/* ftp://		*/
			ftp1, ftp2, ftp3, ftp4, ftp5,
		ftp,		/* ftp.			*/
		www0,		/* www.			*/
			www1, www2, www3,
		mailto0, 	/* mailto:		*/
			mailto1, mailto2, mailto3, mailto4, mailto5, mailto6,
		mail		/* xxx@yyy		*/
	} state = space;
	
	int WordPos = 0;
	TCHAR sz[2];
	TCHAR& c = sz[0];
	sz[1] = 0;
	int last = m_sText.GetLength() -1;
	for(int i = 0; i <= last; i++)
	{
		c = m_sText[i];
		_tcslwr(sz);

		switch(state)
		{
		case unknown:
			if(tspace(c))
				state = space;
			else
			if(c == _T('@') && WordPos != i)
				state = mail;		
			break;

		case space:
			WordPos = i;
			switch(c)
			{
			case _T('h'): state = http0; break;
			case _T('f'): state = ftp0; break;
			case _T('w'): state = www0; break;
			case _T('m'): state = mailto0; break;
			default:
				if(!tspace(c))
					state = unknown;
			}
			break;

		/*----------------- http -----------------*/
		case http0:
			if(c == _T('t'))
				state = http1;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case http1:
			if(c == _T('t'))
				state = http2;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case http2:
			if(c == _T('p'))
				state = http3;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case http3:
			if(c == _T(':'))
				state = http4;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case http4:
			if(c == _T('/'))
				state = http5;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case http5:
			if(c == _T('/'))
				state = http6;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case http6:
			if(tspace(c) || i == last)
			{
				int len = i == last ? i - WordPos + 1 : i - WordPos;
				CString s = m_sText.Mid(WordPos, len);
				m_Links.push_back(CHyperLink(WordPos, WordPos + len - 1, s, s, (LPCTSTR)NULL));
				state = space;
			}
			break;

		/*----------------- ftp -----------------*/
		case ftp0:
			if(c == _T('t'))
				state = ftp1;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case ftp1:
			if(c == _T('p'))
				state = ftp2;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case ftp2:
			if(c == _T(':'))
				state = ftp3;
			else
			if(c == _T('.'))
				state = ftp;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case ftp3:
			if(c == _T('/'))
				state = ftp4;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case ftp4:
			if(c == _T('/'))
				state = ftp5;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case ftp:
			if(tspace(c) || i == last)
			{
				int len = i == last ? i - WordPos + 1 : i - WordPos;
				CString s = CString(_T("ftp://")) + m_sText.Mid(WordPos, len);
				m_Links.push_back(CHyperLink(WordPos, WordPos + len - 1, s, s, (LPCTSTR)NULL));
				state = space;
			}
			break;

		case ftp5:
			if(tspace(c) || i == last)
			{
				int len = i == last ? i - WordPos + 1 : i - WordPos;
				CString s = m_sText.Mid(WordPos, len);
				m_Links.push_back(CHyperLink(WordPos, WordPos + len - 1, s, s, (LPCTSTR)NULL));
				state = space;
			}
			break;

		/*----------------- www -----------------*/
		case www0:
			if(c == _T('w'))
				state = www1;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case www1:
			if(c == _T('w'))
				state = www2;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case www2:
			if(c == _T('.'))
				state = www3;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case www3:
			if(tspace(c) || i == last)
			{
				int len = i == last ? i - WordPos + 1 : i - WordPos;
				CString s = CString(_T("http://")) + m_sText.Mid(WordPos, len);
				m_Links.push_back(CHyperLink(WordPos, WordPos + len - 1, s, s, (LPCTSTR)NULL));
				state = space;
			}
			break;

		/*----------------- mailto -----------------*/
		case mailto0:
			if(c == _T('a'))
				state = mailto1;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case mailto1:
			if(c == _T('i'))
				state = mailto2;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case mailto2:
			if(c == _T('l'))
				state = mailto3;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case mailto3:
			if(c == _T('t'))
				state = mailto4;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case mailto4:
			if(c == _T('o'))
				state = mailto5;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case mailto5:
			if(c == _T(':'))
				state = mailto6;
			else
			if(tspace(c))
				state = space;
			else
				state = unknown;
			break;

		case mailto6:
			if(tspace(c) || i == last)
			{
				int len = i == last ? i - WordPos + 1 : i - WordPos;
				CString s = m_sText.Mid(WordPos, len);
				m_Links.push_back(CHyperLink(WordPos, WordPos + len - 1, s, s, (LPCTSTR)NULL));
				state = space;
			}
			break;

		/*----------------- mailto -----------------*/
		case mail:
			if(tspace(c) || i == last)
			{
				int len = i == last ? i - WordPos + 1 : i - WordPos;
				CString s = CString(_T("mailto:")) + m_sText.Mid(WordPos, len);
				m_Links.push_back(CHyperLink(WordPos, WordPos + len - 1, s, s, (LPCTSTR)NULL));
				state = space;
			}
			break;
		}
	}

	m_Links.sort();
}

void CPreparedHyperText::Clear()
{
	m_sText.Empty();
	m_Links.erase(m_Links.begin(), m_Links.end());
}

void CPreparedHyperText::SetText(const CString& sText)
{
	Clear();
	PrepareText(sText);
}

void CPreparedHyperText::AppendText(const CString& sText)
{
	int len = m_sText.GetLength();
	CPreparedHyperText ht(sText);
	m_sText+=sText;
	for(std::list<CHyperLink>::iterator it = ht.m_Links.begin(); it != ht.m_Links.end(); it++)
	{
		CHyperLink hl = *it;
		hl.m_iBegin += len;
		hl.m_iEnd += len;
		m_Links.push_back(hl);
	}
}

void CPreparedHyperText::AppendHyperLink(const CString& sText, const CString& sTitle, const CString& sCommand, const CString& sDirectory)
{
	ATLASSERT(sText.GetLength()>0);
	ATLASSERT(sCommand.GetLength()>0);

	int len = m_sText.GetLength();
	m_sText+=sText;
	m_Links.push_back(CHyperLink(len, len + sText.GetLength() - 1, sTitle, sCommand, sDirectory));
}

void CPreparedHyperText::AppendHyperLink(const CString& sText, const CString& sTitle, HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	ATLASSERT(sText.GetLength()>0);
	ATLASSERT(hWnd != 0);

	int len = m_sText.GetLength();
	m_sText+=sText;
	m_Links.push_back(CHyperLink(len, len + sText.GetLength() - 1, sTitle, hWnd, uMsg, wParam, lParam));
}

//////////////////////////////////////////////////////////////////////
// CHyperTextCtrl

CHyperTextCtrl::CHyperTextCtrl()
{
}

CHyperTextCtrl::~CHyperTextCtrl()
{

}

BOOL CHyperTextCtrl::PreTranslateMessage(MSG* pMsg)
{
	return FALSE;
}

LRESULT CHyperTextCtrl::OnCreate(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{    
	LPCREATESTRUCT lpCreateStruct = (LPCREATESTRUCT)lParam;
	m_iMaxWidth = 0;
	m_iLinesHeight = 0;
	m_bDontUpdateSizeInfo = false;
	m_iHorzPos = 0;
	m_iVertPos = 0;
	m_DefaultFont.CreatePointFont(100,_T("Times New Roman"));
	m_Font = m_DefaultFont;
	m_LinkColor = RGB(0,0,255);
	m_HoverColor = RGB(255,0,0);
	m_LinkCursor = LoadCursor(NULL,IDC_ARROW);
	m_DefaultCursor = LoadCursor(NULL,IDC_ARROW);
	m_pActivePart = NULL;
	m_iWheelDelta = 0;

	// create a tool tip
	m_tip.Create(*this);
	ATLASSERT(m_tip.IsWindow());
	if(m_tip.IsWindow())
		m_tip.Activate(TRUE);

	UpdateFonts();
	return 0;
}

LRESULT CHyperTextCtrl::OnPaint(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	CPaintDC dc(m_hWnd); // device context for painting

	CFontHandle hOldFont = dc.SelectFont(m_Font);
	
	COLORREF clText = GetSysColor(COLOR_WINDOWTEXT);
	COLORREF clWindow = GetSysColor(COLOR_WINDOW);
	dc.SetBkColor(clWindow);

	int ypos = 0;
	LPCTSTR s = m_Text.m_sText;

	CRect rc;
	CRect rcClient;
	GetClientRect(rcClient);
	rc.left = dc.m_ps.rcPaint.left;
	rc.right = 2;
	rc.top = dc.m_ps.rcPaint.top;
	rc.bottom = dc.m_ps.rcPaint.bottom;
	dc.FillRect(rc, (HBRUSH) (COLOR_WINDOW+1));

	for(std::vector<CVisLine>::iterator it = m_VisLines.begin(); it != m_VisLines.end(); it++)
	{
		int iLastX = dc.m_ps.rcPaint.left;
		for(CVisLine::iterator jt = it->begin(); jt != it->end(); jt++)
		{
			if(jt->m_pHyperLink == NULL)
				dc.SetTextColor(clText);
			else
			{
				if(m_pActivePart != NULL && m_pActivePart->m_pHyperLink == jt->m_pHyperLink)
				{
					dc.SetTextColor(m_HoverColor);
					dc.SelectFont(m_HoverFont);
				}
				else
				{
					dc.SetTextColor(m_LinkColor);
					dc.SelectFont(m_LinksFont);
				}
			}
			
			TextOut(dc, jt->m_rcBounds.left, jt->m_rcBounds.top, s + jt->m_iRealBegin, jt->m_iRealLen);

			if(jt->m_pHyperLink != NULL)
				dc.SelectFont(m_Font);

			iLastX = jt->m_rcBounds.right;
		}

		rc.left = iLastX;
		rc.right = dc.m_ps.rcPaint.right;
		rc.top = ypos;
		rc.bottom = ypos + m_iLineHeight;

		dc.FillRect(rc, (HBRUSH) (COLOR_WINDOW+1));

		ypos+=m_iLineHeight;
	}

	rc.left = dc.m_ps.rcPaint.left;
	rc.right = dc.m_ps.rcPaint.right;
	rc.top = ypos;
	rc.bottom = dc.m_ps.rcPaint.bottom;
	dc.FillRect(rc, (HBRUSH) (COLOR_WINDOW+1));

	dc.SelectFont(hOldFont);
	return 0;
}

LRESULT CHyperTextCtrl::OnSize(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	WORD cx, cy;
	cx = LOWORD(lParam);
	cy = HIWORD(lParam);

	UpdateSize(true);
	return 0;
}

LRESULT CHyperTextCtrl::OnSetText(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	m_Text.PrepareText((LPTSTR)lParam);
	UpdateSize(true);
	return TRUE;
}

LRESULT CHyperTextCtrl::OnGetText(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	int bufsize = wParam;
	LPTSTR buf = (LPTSTR)lParam;
	if(lParam == NULL || bufsize == 0 || m_Text.m_sText.IsEmpty())
		return 0;
	int cpy = m_Text.m_sText.GetLength() > (bufsize-1) ? (bufsize-1) : m_Text.m_sText.GetLength();
	_tcsncpy(buf, m_Text.m_sText, cpy);
	return cpy;
}

LRESULT CHyperTextCtrl::OnSetFont(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	m_Font = (HFONT)wParam;
	UpdateFonts();
	UpdateSize(LOWORD(lParam) != 0);
	return 0;
}

LRESULT CHyperTextCtrl::OnGetFont(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	return (LRESULT)m_Font.m_hFont;
}

LRESULT CHyperTextCtrl::OnHScroll(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	SCROLLINFO si;
	si.cbSize = sizeof(si);
	si.fMask = SIF_ALL;
	GetScrollInfo(SB_HORZ, &si);

	switch(LOWORD(wParam))
	{
	case SB_LEFT:
		si.nPos=si.nMin;
		break;

	case SB_RIGHT:
		si.nPos=si.nMax;
		break;

	case SB_LINELEFT:
		if(si.nPos > si.nMin)
			si.nPos-=1;
		break;

	case SB_LINERIGHT:
		if(si.nPos < si.nMax)
			si.nPos+=1;
		break;

	case SB_PAGELEFT:
		if(si.nPos > si.nMin)
			si.nPos-=si.nPage;
		if(si.nPos < si.nMin)
			si.nPos = si.nMin;
		break;

	case SB_PAGERIGHT:
		if(si.nPos < si.nMax)
			si.nPos+=si.nPage;
		if(si.nPos > si.nMax)
			si.nPos = si.nMax;
		break;

	case SB_THUMBTRACK:
		si.nPos=si.nTrackPos;
		break;
	}
	 
	if(si.nMax != si.nMin)
		m_iHorzPos = si.nPos * 100 / (si.nMax - si.nMin);
	SetScrollInfo(SB_HORZ, &si);
	UpdateVisLines();
	InvalidateRect(NULL,FALSE);
	return TRUE;
}

LRESULT CHyperTextCtrl::OnVScroll(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
	SCROLLINFO si;
	si.cbSize = sizeof(si);
	si.fMask = SIF_ALL;
	GetScrollInfo(SB_VERT, &si);

	switch(LOWORD(wParam))
	{
	case SB_TOP:
		si.nPos=si.nMin;
		break;

	case SB_BOTTOM:
		si.nPos=si.nMax;
		break;

	case SB_LINEUP:
		if(si.nPos > si.nMin)
			si.nPos-=1;
		break;

	case SB_LINEDOWN:
		if(si.nPos < si.nMax)
			si.nPos+=1;
		break;

	case SB_PAGEUP:
		if(si.nPos > si.nMin)
			si.nPos-=si.nPage;
		if(si.nPos < si.nMin)
			si.nPos = si.nMin;
		break;

	case SB_PAGEDOWN:
		if(si.nPos < si.nMax)
			si.nPos+=si.nPage;
		if(si.nPos > si.nMax)
			si.nPos = si.nMax;
		break;

	case SB_THUMBTRACK:
		si.nPos=si.nTrackPos;
		break;
	}
	 
	if(si.nMax != si.nMin)
		m_iVertPos = si.nPos * 100 / (si.nMax - si.nMin);
	SetScrollInfo(SB_VERT, &si);
	UpdateVisLines();
	InvalidateRect(NULL,FALSE);
	return TRUE;
}

LRESULT CHyperTextCtrl::OnMouseMessage(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{   
	if(Msg == WM_MOUSEMOVE)
	{
		CPoint pt(LOWORD(lParam),HIWORD(lParam));
		CRect rcClient;
		GetClientRect(rcClient);
		if(PtInRect(rcClient, pt))
		{
			bool bFound = false;
			if(GetCapture() != m_hWnd)
				SetCapture();

			int i = pt.y / m_iLineHeight;
			if(i < m_VisLines.size())
			{
				std::vector<CVisLine>::iterator it = m_VisLines.begin() + i;
				for(CVisLine::iterator jt = it->begin(); jt != it->end(); jt++)
					if(pt.x >= jt->m_rcBounds.left && pt.x <= jt->m_rcBounds.right)
					{
						if(jt->m_pHyperLink != NULL)
						{
							HighlightLink(jt, pt);
							bFound = true;
						}
						break;
					}
			}
			if(!bFound)
				RestoreLink();
		}
		else
			ReleaseCapture();
	}
	else
	if(Msg == WM_LBUTTONDOWN)
	{
		CPoint pt(LOWORD(lParam),HIWORD(lParam));
		CRect rcClient;
		GetClientRect(rcClient);
		if(PtInRect(rcClient, pt))
		{
			bool bFound = false;
			int i = pt.y / m_iLineHeight;
			if(i < m_VisLines.size())
			{
				std::vector<CVisLine>::iterator it = m_VisLines.begin() + i;
				for(CVisLine::iterator jt = it->begin(); jt != it->end(); jt++)
					if(pt.x >= jt->m_rcBounds.left && pt.x <= jt->m_rcBounds.right)
					{
						if(jt->m_pHyperLink != NULL)
							jt->m_pHyperLink->Execute();
						break;
					}
			}
		}
	}
	else
	if(Msg == WM_MOUSEWHEEL)
	{
		CPoint pt(LOWORD(lParam),HIWORD(lParam));
		CRect rc;
		GetWindowRect(rc);
		if(PtInRect(rc, pt))
		{
			int iScrollLines;
			SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 
								 0, 
								 &iScrollLines, 
								 0);

			m_iWheelDelta -= (short)HIWORD(wParam);
			if(abs(m_iWheelDelta) >= WHEEL_DELTA)
			{
				if(m_iWheelDelta > 0)
				{
					for(int i = 0; i<iScrollLines; i++)
						PostMessage(WM_VSCROLL, SB_LINEDOWN, 0);
				}
				else
				{
					for(int i = 0; i<iScrollLines; i++)
						PostMessage(WM_VSCROLL, SB_LINEUP, 0);
				}

				m_iWheelDelta %= WHEEL_DELTA;
			}
		}
	}

	MSG msg = { m_hWnd, Msg, wParam, lParam };
	if(m_tip.IsWindow())
		m_tip.RelayEvent(&msg);
	return 0;
}

LRESULT CHyperTextCtrl::OnCaptureChanged(UINT Msg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{    
	RestoreLink();
	return 0;
}

void CHyperTextCtrl::UpdateSize(bool bRepaint/* = false*/)
{
	if(m_bDontUpdateSizeInfo)
		return;
	m_bDontUpdateSizeInfo = true;
	DWORD dwStyle = GetWindowLongPtr(GWL_STYLE);
	bool bFirstPhase = false;
	if(check_bits(dwStyle, HTC_AUTO_SCROLL_BARS))
	{
		ShowScrollBar(SB_BOTH, FALSE);
		bFirstPhase = true;
	}
	
	CClientDC dc(*this);
	CFontHandle hOldFont = dc.SelectFont(m_Font);

	int iScrollHeight = GetSystemMetrics(SM_CYHSCROLL);

second_phase:
	m_Lines.clear();
	CRect rc;
	GetClientRect(rc);
	rc.DeflateRect(2,0);
	m_iMaxWidth = 0;
	m_iLinesHeight = 0;
	long iMaxWidthChars = 0;
	SIZE sz;

	if(rc.Width() > 5 && rc.Height() > 5)
	{
		std::list<CHyperLink>::iterator it = m_Text.m_Links.begin();
		LPCTSTR s = m_Text.m_sText;
		int len = m_Text.m_sText.GetLength();
		int width = rc.Width();
		
		int npos, /* new position */
			pos = 0, /* current position */
			ll, /* line length */
			rll; /* line length with wordwrap (if used)*/

		while(len>0)
		{
			ll = len;
			npos = ll;
			for(int i = 0; i < len; i++)
			{
				if(s[i] == _T('\r') || s[i] == _T('\n'))
				{
					if(s[i] == _T('\r') && ((i+1) < len) && s[i+1] == _T('\n'))
						npos = i + 2;
					else
						npos = i + 1;

					ll = i;
					break;
				}
			}

			if(!::GetTextExtentExPoint(dc, s , (ll > 512) ? 512 : ll, width, &rll, NULL, &sz))
			{
				::GetTextExtentExPoint(dc, _T(" ") , 1, 0, NULL, NULL, &sz);
				sz.cx = 0;
				rll = ll;
			}


			if(rll>ll)
				rll = ll;

			if(!check_bits(dwStyle, HTC_WORDWRAP))
				rll = ll;
			else
				if(rll < ll)
					npos = rll;

			if(rll>0)
			{
				if((rll < len) && !_istspace(s[rll]))
					for(int i = rll - 1; i >= 0; i--)
						if(_istspace(s[i]))
						{
							rll = i;
							npos = i + 1;
							break;
						}
			}

			CLineInfo li(pos, pos + rll - 1);
			CLinePartInfo pl(pos, pos + rll - 1);

			while(it != m_Text.m_Links.end() && it->End() < pos)
				it++;

			while(it != m_Text.m_Links.end() && (it->Begin() >= pl.Begin() && it->Begin() <= pl.End()) || 
				(it->End() >= pl.Begin() && it->End() <= pl.End()) ||
				(pl.Begin()>=it->Begin() && pl.End() <= it->End()))
			{
				int b = it->Begin();
				int e = it->End();
				if(b<pl.Begin())
					b = pl.Begin();
				if(e>pl.End())
					e = pl.End();

				if(b>pl.Begin())
				{
					CLinePartInfo pln(pl.Begin(), b - 1);
					li.push_back(pln);
					pl.m_iBegin = e + 1;
				}

				CLinePartInfo pln(b, e, &*it);
				li.push_back(pln);
				pl.m_iBegin = e + 1;	

				if(e < pl.End())
					it++;
				else
					break;
			}

			if(pl.Len()>0)
				li.push_back(pl);

			m_iLineHeight = sz.cy;
			m_iLinesHeight+=m_iLineHeight;
			if(sz.cx > m_iMaxWidth)
				m_iMaxWidth = sz.cx;
			if(iMaxWidthChars < li.Len())
				iMaxWidthChars = li.Len();

			m_Lines.push_back(li);

			pos+=npos;
			s+=npos;
			len-=npos;

			if(bFirstPhase && ((m_iLinesHeight + iScrollHeight) > rc.Height()))
			{
				bFirstPhase = false;
				ShowScrollBar(SB_VERT,TRUE);
				dwStyle|=WS_VSCROLL;
				goto second_phase;
			}
		}
		if(bRepaint)
			InvalidateRect(rc);
	}

	dc.SelectFont(hOldFont);
	
	// Update scroll bars
	dwStyle = GetWindowLongPtr(GWL_STYLE);
	if(check_bits(dwStyle, HTC_AUTO_SCROLL_BARS) && !check_bits(dwStyle, HTC_WORDWRAP))
	{
		if(m_iMaxWidth > rc.Width())
		{
			ShowScrollBar(SB_HORZ,TRUE);
			dwStyle|=WS_HSCROLL;
		};
	}

	SCROLLINFO si;
	si.cbSize = sizeof(si);
	si.fMask = SIF_PAGE | SIF_POS | SIF_RANGE;

	if(check_bits(dwStyle,WS_HSCROLL))
	{
		si.nMin = 0;
		si.nMax = iMaxWidthChars + iMaxWidthChars/2;
		int i = m_Text.m_sText.GetLength();
		si.nPos = double(si.nMax) * m_iHorzPos / 100;
		si.nPage = (rc.Width() * si.nMax)/m_iMaxWidth;
		SetScrollInfo(SB_HORZ, &si, FALSE);
	}

	if(check_bits(dwStyle,WS_VSCROLL))
	{
		si.nMin = 0;
		si.nMax = m_Lines.size();
		si.nPos = double(si.nMax) * m_iVertPos / 100;
		si.nPage = (rc.Height() * si.nMax)/m_iLinesHeight;
		SetScrollInfo(SB_VERT, &si, FALSE);
	}

	m_bDontUpdateSizeInfo = false;
	UpdateVisLines();
}

void CHyperTextCtrl::UpdateFonts()
{
	DWORD dwStyle = GetWindowLongPtr(GWL_STYLE);

	if(!m_LinksFont.IsNull())
		m_LinksFont.DeleteObject();

	if(!m_HoverFont.IsNull())
		m_HoverFont.DeleteObject();

	LOGFONT lf;
	m_Font.GetLogFont(&lf);
	if(check_bits(dwStyle, HTC_UNDERLINE_LINKS))
		lf.lfUnderline = TRUE;
	m_LinksFont.CreateFontIndirect(&lf);

	m_Font.GetLogFont(&lf);
	if(check_bits(dwStyle, HTC_UNDERLINE_HOVER))
		lf.lfUnderline = TRUE;
	m_HoverFont.CreateFontIndirect(&lf);
}

void CHyperTextCtrl::UpdateVisLines()
{
	RestoreLink();
	DWORD dwStyle = GetWindowLongPtr(GWL_STYLE);

	int id = 1;
	if(check_bits(dwStyle, HTC_ENABLE_TOOLTIPS))
	{
		for(std::vector<CVisLine>::iterator itv = m_VisLines.begin(); itv != m_VisLines.end(); itv++)
			for(CVisLine::iterator jt = itv->begin(); jt != itv->end(); jt++)
			{
				if(jt->m_pHyperLink != NULL)
					m_tip.DelTool(*this, id++);
			}
	}

	m_VisLines.clear();

	CClientDC dc(m_hWnd); // device context for painting

	std::vector<CLineInfo>::iterator it = m_Lines.begin();
	int iVertPos = 0;
	int iHorzPos = 0;
	if(check_bits(dwStyle,WS_VSCROLL))
		iVertPos = GetScrollPos(SB_VERT);
	if(check_bits(dwStyle,WS_HSCROLL))
		iHorzPos = GetScrollPos(SB_HORZ);

	if(iVertPos >= m_Lines.size())
		return;

	it+=iVertPos;

	CFontHandle hOldFont = dc.SelectFont(m_Font);
	
	int ypos = 0;
	LPCTSTR s = m_Text.m_sText;

	CRect rcClient;
	GetClientRect(rcClient);

	for(; it != m_Lines.end(); it++)
	{
		int XPos = 2;
		int LinePos = it->Begin();
		int Offset = 0;
		int Len = 0;

		CVisLine vl;
		CRect rcBounds;

		std::vector<CLinePartInfo>::iterator jt;

		for(jt = it->begin(); jt != it->end(); jt++)
		{
			if(jt->Begin() <= (LinePos + iHorzPos) && jt->End() >= (LinePos + iHorzPos))
			{
				Offset = LinePos + iHorzPos;
				Len = jt->Len() - ((LinePos + iHorzPos) - jt->Begin());
				break;
			}
		}

		while(jt != it->end())
		{
			if(Len > 0)
			{
				SIZE sz;
				::GetTextExtentExPoint(dc, s + Offset, Len, 0, NULL, NULL, &sz);

				rcBounds.left = XPos;
				XPos+=sz.cx;
				rcBounds.right = XPos;
				rcBounds.top = ypos;
				rcBounds.bottom = ypos+m_iLineHeight;

				vl.push_back(CVisPart(*jt, rcBounds, Offset, Len, NULL, NULL));
			}

			if(XPos > rcClient.Width())
				break;

			jt++;
			Offset = jt->Begin();
			Len = jt->Len();
		}

		m_VisLines.push_back(vl);
		ypos+=m_iLineHeight;
		if(ypos>rcClient.bottom)
			break;
	}

	CVisPart *pPrev = NULL, *pNext;
	
	id = 1;
	for(std::vector<CVisLine>::iterator it2 = m_VisLines.begin(); it2 != m_VisLines.end(); it2++)
		for(CVisLine::iterator jt = it2->begin(); jt != it2->end(); jt++)
		{
			pNext = &*jt;
			if(pPrev != NULL && 
				pPrev->m_pHyperLink != NULL && 
				pPrev->m_pHyperLink == pNext->m_pHyperLink &&
				pPrev != pNext)
			{
				pPrev->m_pNext = pNext;
				pNext->m_pPrev = pPrev;
			}
			pPrev = pNext;

			if(check_bits(dwStyle, HTC_ENABLE_TOOLTIPS) && jt->m_pHyperLink != NULL)
				m_tip.AddTool(*this, (LPCTSTR)jt->m_pHyperLink->Title(), jt->m_rcBounds, id++);
		}

	dc.SelectFont(hOldFont);
}

void CHyperTextCtrl::HighlightLink(CVisPart* Part, const CPoint& MouseCoords)
{
	if(m_pActivePart == Part)
		return;

	if(m_pActivePart != Part && m_pActivePart != NULL && Part != NULL && m_pActivePart->m_pHyperLink != Part->m_pHyperLink)
		RestoreLink();

	m_pActivePart = Part;
	while(m_pActivePart->m_pPrev != NULL)
		m_pActivePart = m_pActivePart->m_pPrev;

	CClientDC dc(*this);
	CFontHandle hOldFont = dc.SelectFont(m_HoverFont);
	COLORREF clWindow = GetSysColor(COLOR_WINDOW);
	dc.SetBkColor(clWindow);
	dc.SetTextColor(m_HoverColor);
	LPCTSTR s = m_Text.m_sText;

	CVisPart* p = m_pActivePart;
	while(p != NULL)
	{
		TextOut(dc, p->m_rcBounds.left, p->m_rcBounds.top, 
			s + p->m_iRealBegin, p->m_iRealLen);
		p = p->m_pNext;
	}

	dc.SelectFont(hOldFont);

	SetCursor(m_LinkCursor);
}

void CHyperTextCtrl::RestoreLink()
{
	if(m_pActivePart == NULL)
		return;

	CClientDC dc(*this);
	CFontHandle hOldFont = dc.SelectFont(m_LinksFont);
	COLORREF clWindow = GetSysColor(COLOR_WINDOW);
	dc.SetBkColor(clWindow);
	dc.SetTextColor(m_LinkColor);
	LPCTSTR s = m_Text.m_sText;

	CVisPart* p = m_pActivePart;
	while(p != NULL)
	{
		TextOut(dc, p->m_rcBounds.left, p->m_rcBounds.top, 
			s + p->m_iRealBegin, p->m_iRealLen);
		p = p->m_pNext;
	}

	dc.SelectFont(hOldFont);

	m_pActivePart = NULL;
	SetCursor(m_DefaultCursor);
}

LRESULT CHyperTextCtrl::OnEraseBkgnd(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
	return TRUE;
}

//
}; //namespace HyperTextControl
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Written By
Magomed Abdurakhmanov
Web Developer
Russian Federation
This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.
Hyperlink Text View Control

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