StatLink.cpp

////////////////////////////////////////////////////////////////
// 1997 Microsoft Systems Journal
// If this code works, it was written by Paul DiLascia.
// If not, I don't know who wrote it.
//
// CStaticLink implements a static control that's a hyperlink
// to any file on your desktop or web. You can use it in dialog boxes
// to create hyperlinks to web sites. When clicked, opens the file/URL
//
#include "StdAfx.h"
#include "StatLink.h"

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

COLORREF CStaticLink::g_colorUnvisited = RGB(0,0,255);		 // blue
COLORREF CStaticLink::g_colorVisited   = RGB(128,0,128);		 // purple

HCURSOR	CStaticLink::g_hCursorLink = NULL;

IMPLEMENT_DYNAMIC(CStaticLink, CStatic)

BEGIN_MESSAGE_MAP(CStaticLink, CStatic)
	ON_WM_NCHITTEST()
	ON_WM_CTLCOLOR_REFLECT()
	ON_WM_LBUTTONDOWN()
	ON_WM_SETCURSOR()
END_MESSAGE_MAP()

///////////////////
// Constructor sets default colors = blue/purple.
// bDeleteOnDestroy is used internally by PixieLib in CPixieDlg.
//
CStaticLink::CStaticLink(LPCTSTR lpText, BOOL bDeleteOnDestroy)
{
	m_link = lpText;								// link text (NULL ==> window text)
	m_color = g_colorUnvisited;				// not visited yet
	m_bDeleteOnDestroy = bDeleteOnDestroy;	// delete object with window?
}

//////////////////
// Normally,	a static control does not get mouse events unless it has
// SS_NOTIFY. This achieves the same effect as SS_NOTIFY, but it's fewer
// lines of code and more reliable than turning on SS_NOTIFY in OnCtlColor
// because Windows doesn't send WM_CTLCOLOR to bitmap static controls.
//
LRESULT CStaticLink::OnNcHitTest(CPoint point)
{
	return (LRESULT)HTCLIENT;
}

//////////////////
// Handle reflected WM_CTLCOLOR to set custom control color.
// For a text control, use visited/unvisited colors and underline font.
// For non-text controls, do nothing. Also ensures SS_NOTIFY is on.
//
HBRUSH CStaticLink::CtlColor(CDC* pDC, UINT nCtlColor)
{
	ASSERT(nCtlColor == CTLCOLOR_STATIC);
	DWORD dwStyle = GetStyle();
	
	HBRUSH hbr = NULL;
	if ((dwStyle & 0xFF) <= SS_RIGHT) {

		// this is a text control: set up font and colors
		if (!(HFONT)m_font) {
			// first time init: create font
			LOGFONT lf;
			GetFont()->GetObject(sizeof(lf), &lf);
			lf.lfUnderline = TRUE;
			m_font.CreateFontIndirect(&lf);
		}

		// use underline font and visited/unvisited colors
		pDC->SelectObject(&m_font);
		pDC->SetTextColor(m_color);
		pDC->SetBkMode(TRANSPARENT);

		// return hollow brush to preserve parent background color
		hbr = (HBRUSH)::GetStockObject(HOLLOW_BRUSH);
	}
	return hbr;
}

/////////////////
// Handle mouse click: navigate link
//
void CStaticLink::OnLButtonDown(UINT nFlags, CPoint point)
{
	if (m_link.IsEmpty()) {		// if URL/filename not set..
		GetWindowText(m_link);	// ..get it from window text
		if (m_link.IsEmpty())
			return;
	}

	// Call ShellExecute to run the file.
	// For an URL, this means opening it in the browser.
	//
	HINSTANCE h = m_link.Navigate();
	if ((UINT)h > 32) {						 // success!
		m_color = g_colorVisited;			 // change color
		Invalidate();							 // repaint 
	} else {
		CString msg = TFormat ("Unable to execute: %s", (LPCTSTR) m_link);
    ::TMessageBox (msg, MB_ICONEXCLAMATION);
		TRACE(_T("*** WARNING: CStaticLink: unable to navigate link %s\n"),
			(LPCTSTR)m_link);
	}
}

//////////////////
// Set "hand" cursor to cue user that this is a link. If app has not set
// g_hCursorLink, then try to get the cursor from winhlp32.exe,
// resource 106, which is a pointing finger. This is a bit of a kludge,
// but it works.
//
BOOL CStaticLink::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
	if (g_hCursorLink == NULL) {
		static BOOL bTriedOnce = FALSE;
		if (!bTriedOnce) {
			CString windir;
			GetWindowsDirectory(windir.GetBuffer(MAX_PATH), MAX_PATH);
			windir.ReleaseBuffer();
			windir += _T("\\winhlp32.exe");
			HMODULE hModule = LoadLibrary(windir);
			if (hModule) {
				g_hCursorLink =
					CopyCursor(::LoadCursor(hModule, MAKEINTRESOURCE(106)));
			}
			FreeLibrary(hModule);
			bTriedOnce = TRUE;
		}
	}
	if (g_hCursorLink) {
		::SetCursor(g_hCursorLink);
		return TRUE;
	}
	return FALSE;
}

//////////////////
// Normally, a control class is not destoyed when the window is;
// however, CPixieDlg creates static controls with "new" instead of
// as class members, so it's convenient to allow the option of destroying
// object with window. In applications where you want the object to be
// destoyed along with the window, you can call constructor with
// bDeleteOnDestroy=TRUE.
//
void CStaticLink::PostNcDestroy()
{
	if (m_bDeleteOnDestroy)
		delete this;
}