The Windows Access Control Model Part 4

/**
*	This code is by OShah. all code will have the following licence.
*	Copyright Shexec32. All code bears the following licence:
**/

/**
*	Copyright Shexec32 2004-2005. All rights reserved.
*
*	THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
*	ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED
*	TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
*	PARTICULAR PURPOSE.
**/



/** This file is the URL control presented at www.catch22.net that
*	turns a static text label into a url link. The code has been
*	slightly altered to work with FilePermsBox. The code is apparently
*	public domain and comes with the following introductory notice:
*
*	urlctrl - altered static text ctrl - bittmann 2004
*
*  based upon "urlctrl" by jbrown
*  please visit: http://www.catch22.net/tuts/
**/

#include "SecurityCore.h"
#include "UrlCtrl.h"

typedef struct tagURLCTRL
{
	sized_array<TCHAR> szURL;//url!=display
	WNDPROC oldproc;//old window proc
	HCURSOR hcur;//cursor
	HFONT hfont;//underlined font
	COLORREF crUnvisited;//color unvisited
	COLORREF crVisited;//color visited
	BOOL fClicking;//internal state
	DWORD dwFlags;//combination of UCF_xxx values
} URLCTRL;


BOOL util_url_draw(HWND, HDC, RECT*); //draw (LPRECT==NULL) OR calc (LPRECT!=NULL)
BOOL util_url_fit(HWND, BOOL); //resize window
BOOL util_url_open(HWND );//open url
LRESULT CALLBACK urlctrl_proc(HWND, UINT, WPARAM, LPARAM);




BOOL util_url_draw(HWND hwnd,HDC hdc,RECT *calcrect)
{/* calc OR draw */
	if(::GetWindowLongPtr(hwnd, GWLP_WNDPROC) == reinterpret_cast<LONG_PTR>(urlctrl_proc) && hdc)
	{/* is urlctrl and hdc? */
		URLCTRL *url = reinterpret_cast<URLCTRL *>(::GetProp(hwnd, _T("UrlCtrl")));
		if(url != NULL)
		{
			HANDLE hOld = NULL;
			DWORD style = DT_SINGLELINE | DT_NOPREFIX;
			RECT rc = {0};

			int len = 2 + ::GetWindowTextLength(hwnd);
			sized_array<TCHAR> szText(len);
			::GetWindowText(hwnd, szText.get(), len);

			if(url->dwFlags & UCF_TXT_RIGHT)
				style |= DT_RIGHT;
			else if(url->dwFlags & UCF_TXT_HCENTER)
				style |= DT_CENTER;

			if (url->dwFlags & UCF_TXT_BOTTOM)
				style |= DT_BOTTOM;
			else if(url->dwFlags & UCF_TXT_VCENTER)
				style |= DT_VCENTER;

			if(calcrect == NULL)
			{/* draw! */
				COLORREF crOldText = {0};
				int iOldBkMode = 0;

				::GetClientRect(hwnd, &rc);
				::FillRect( hdc, &rc, reinterpret_cast<HBRUSH>(COLOR_3DFACE + 1) );
				if(url->dwFlags & UCF_KBD)
				{/* protect focus rect */
					if(::GetFocus() == hwnd)
						::DrawFocusRect(hdc, &rc);
					++rc.left;
					--rc.right;
					++rc.top;
					--rc.bottom;
				}
				crOldText = ::SetTextColor(hdc, (url->dwFlags & UCF_LNK_VISITED) ? (url->crVisited) : (url->crUnvisited));
				iOldBkMode = ::SetBkMode(hdc, TRANSPARENT);
				hOld = ::SelectObject(hdc, url->hfont);
				::DrawText(hdc, szText.get(), -1, &rc, style);
				::SelectObject(hdc, hOld);
				::SetBkMode(hdc, iOldBkMode);
				::SetTextColor(hdc, crOldText);
			}
			else
			{/* just calc */
				calcrect->left = calcrect->top = 0;
				hOld = ::SelectObject(hdc, url->hfont);
				calcrect->right = calcrect->bottom = 0x00007FFF;
				/* some big value */

				::DrawText(hdc, szText.get(), -1, calcrect, style | DT_CALCRECT);
				hOld = ::SelectObject(hdc, hOld);

				if(url->dwFlags & UCF_KBD)
				{/* for focus rect */
					calcrect->right += 2;
					calcrect->bottom += 2;
				}
			}
			return TRUE;
		}
	}
	return FALSE;
}



BOOL util_url_fit(HWND hwnd, BOOL fRedraw /*= TRUE*/)
{
	BOOL fResult = FALSE;
	if( ::GetWindowLongPtr(hwnd, GWLP_WNDPROC) == reinterpret_cast<LONG_PTR>(urlctrl_proc) )
	{/* is urlctrl? */
		HDC hdc = ::GetDC(hwnd);
		if(hdc != NULL)
		{
			RECT rc = {0};
			fResult = util_url_draw(hwnd, hdc, &rc);
			/* calc rect (does NOT draw) */
			::ReleaseDC(hwnd, hdc); hdc = NULL;
			if(fResult)
			{/* apply rect */
				UINT flags = SWP_NOZORDER | SWP_NOACTIVATE | SWP_NOMOVE;
				if(fRedraw == FALSE)
					flags |= SWP_NOREDRAW;
				fResult = ::SetWindowPos(hwnd, NULL, 0, 0, rc.right, rc.bottom, flags);
			}
		}
	}
	return fResult;
}



BOOL util_url_open(HWND hwnd)
{	
	BOOL fResult = FALSE;
	if( ::GetWindowLongPtr(hwnd, GWLP_WNDPROC)== reinterpret_cast<LONG_PTR>(urlctrl_proc) )
	{/* is urlctrl? */
		URLCTRL *url = reinterpret_cast<URLCTRL *>(::GetProp(hwnd, _T("UrlCtrl")));
		if(url)
		{
			::ShellExecute(NULL,_T("open"), url->szURL.get(), NULL, NULL, SW_SHOWNORMAL);
			/* open browser */
			url->dwFlags |= UCF_LNK_VISITED;
			/* set visited */
			::InvalidateRect(hwnd, NULL, TRUE);
			::UpdateWindow(hwnd);
			fResult = TRUE;
		}
	}
	return fResult;
}



LRESULT CALLBACK urlctrl_proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	URLCTRL *url = reinterpret_cast<URLCTRL *>(::GetProp(hwnd, _T("UrlCtrl")));
	WNDPROC oldproc = url->oldproc;
	switch(uMsg)
	{
		case WM_NCDESTROY:
		{
			::SetWindowLongPtr(hwnd, GWLP_WNDPROC, LONG_PTR2(reinterpret_cast<void *>(oldproc)));
			if(url->hcur) ::DestroyCursor(url->hcur);
			if(url->hfont) ::DeleteObject(url->hfont);
			delete [] url; url = NULL;
			::RemoveProp(hwnd, _T("UrlCtrl"));
			break;
		}

		case WM_PAINT:
		{
			PAINTSTRUCT ps = {0};
			HDC hdc = reinterpret_cast<HDC>(wParam);
			if(wParam == 0)
				hdc = ::BeginPaint(hwnd, &ps);
			if(hdc)
			{
				util_url_draw(hwnd, hdc, NULL);
				if(wParam==0) ::EndPaint(hwnd, &ps);
			}
			return 0;
		}

		case WM_SETTEXT:
		{
			LRESULT result = ::CallWindowProc(oldproc, hwnd, uMsg, wParam, lParam);
			if(url->dwFlags & UCF_FIT)
				util_url_fit(hwnd, FALSE);
			::InvalidateRect(hwnd, NULL, TRUE);
			::UpdateWindow(hwnd);
			return result;
		}


		case WM_SETCURSOR:
		{
			HCURSOR hcur = url->hcur;
			if(hcur == NULL) hcur = ::LoadCursor(NULL, IDC_ARROW);
			/* fall back */
			::SetCursor(hcur);
			return 1;
		}

		case WM_NCHITTEST:
		{/* static returns HTTRANSPARENT (prevents receiving mouse msgs) */
			return HTCLIENT;
		}


		case WM_SETFONT: //we always modify the font!
		{
			LOGFONT lf = {0};
			HFONT hfont = reinterpret_cast<HFONT> (wParam);
			if(hfont == NULL)
				hfont = reinterpret_cast<HFONT>(::GetStockObject(SYSTEM_FONT));
			::GetObject(hfont, sizeof(LOGFONT), &lf);
			lf.lfUnderline = TRUE;
			/* add underline */
			if(url->hfont)
			{/* delete old font */
				::DeleteObject(url->hfont);
			}
			url->hfont = ::CreateFontIndirect(&lf);
			/* create new font */
			::CallWindowProc(oldproc, hwnd, uMsg, wParam, 0);
			/* block redraw */
			if(url->dwFlags & UCF_FIT)
				util_url_fit(hwnd, FALSE);
			if(LOWORD(lParam))
			{/* redraw? */
				::InvalidateRect(hwnd, NULL, TRUE);
				::UpdateWindow(hwnd);
			}
			return 0;
		}

		case WM_LBUTTONDOWN:
		{
			if(url->dwFlags & UCF_KBD) ::SetFocus(hwnd);
			::SetCapture(hwnd);
			url->fClicking = TRUE;
			break;
		}

		case WM_LBUTTONUP:
		{
			::ReleaseCapture();
			if(url->fClicking)
			{
				POINT pt = {0};
				RECT rc = {0};
				url->fClicking = FALSE;
				pt.x=static_cast<short>(LOWORD(lParam));
				pt.y=static_cast<short>(HIWORD(lParam));
				::ClientToScreen(hwnd, &pt);
				::GetWindowRect(hwnd, &rc);
				if(::PtInRect(&rc,pt))/* inside? */
					util_url_open(hwnd);
			}
			break;
		}

		case WM_KEYDOWN:
		{
			if(url->dwFlags & UCF_KBD)
			{
				if(wParam == VK_SPACE)
				{
					util_url_open(hwnd);
					return 0;
				}
			}
			break;
		}
		case WM_KEYUP:
		{
			if(url->dwFlags & UCF_KBD)
			{
				if(wParam == VK_SPACE)
				{
					return 0;
				}
			}
			break;
		}

		case WM_GETDLGCODE:
		{
			if(url->dwFlags & UCF_KBD)
				return DLGC_WANTCHARS;
			break;
		}

		case WM_SETFOCUS:
		case WM_KILLFOCUS:
		{
			if(url->dwFlags & UCF_KBD)
			{
				::InvalidateRect(hwnd, NULL, TRUE);
				::UpdateWindow(hwnd);
				return 0;
			}
			break;
		}
	}
	return ::CallWindowProc(oldproc, hwnd, uMsg, wParam, lParam);
}



BOOL urlctrl_set(HWND hwnd, const std::basic_string<TCHAR> &szURL,
	COLORREF unvisited /*= RGB(0,0,255)*/, COLORREF visited /*= RGB(128,0,128)*/, DWORD dwFlags /*= UCF_KBD*/)
{
	if(::IsWindow(hwnd))
	{
		URLCTRL *url = NULL;
		if(::GetWindowLongPtr(hwnd, GWLP_WNDPROC) == LONG_PTR2(reinterpret_cast<void *>(urlctrl_proc)))
		{/* update old */
			throw STD(_T("Inited a URL control more than once"));
		}
		else
		{/* create new */
			url = new URLCTRL[1];
			/* init once */

			HFONT hfont = reinterpret_cast<HFONT>(::SendMessage(hwnd, WM_GETFONT, 0, 0));
			url->oldproc = reinterpret_cast<WNDPROC>(static_cast<LONG_PTR>
				(::SetWindowLongPtr(hwnd, GWLP_WNDPROC, LONG_PTR2(reinterpret_cast<void *>(urlctrl_proc)))));
			::SetProp(hwnd, _T("UrlCtrl"), url);
			/* store in control */
			url->fClicking = FALSE;
			url->hcur = ::LoadCursor(NULL, IDC_HAND);
			/* modify current font */
			::SendMessage(hwnd, WM_SETFONT, reinterpret_cast<WPARAM>(hfont), 0);
		}

		/* init always */
		LONG style = ::GetWindowLong(hwnd, GWL_STYLE);
		url->szURL.reset(szURL.size() + 2);
		url->szURL = szURL;
		//szURL.copy(url->szURL.get(), szURL.size(), 0);

		url->crUnvisited = (unvisited);
		url->crVisited = (visited);

		url->dwFlags = dwFlags;
		style &= ~(WS_BORDER | WS_TABSTOP);//remove
		style |= SS_NOTIFY;//add

		if(url->dwFlags & UCF_KBD)
			style |= WS_TABSTOP;//add?

		::SetWindowLong(hwnd, GWL_STYLE, style);

		if(url->dwFlags & UCF_FIT)
			util_url_fit(hwnd, FALSE);

		::InvalidateRect(hwnd, NULL, TRUE);
		::UpdateWindow(hwnd);
	}
	return TRUE;
}