/*
 * Module ID: hyperlink.cpp
 * Title    : CHyperLink definition.
 *
 * Author   : Olivier Langlois <olivier@olivierlanglois.net>
 * Date     : November 15, 2005
 *
 * To read the article describing this class, visit
 * http://www.olivierlanglois.net/hyperlinkdemo.htm
 *
 * Note: Strongly inspired by Neal Stublen code
 *       Minor ideas come from Chris Maunder and Paul DiLascia code
 *
 * Revision :
 *
 * 001        26-Nov-2005 - Olivier Langlois
 *            - Added changes to make CHyperLink compatible with UNICODE
 *            - Use dynamic memory allocation for the URL string
 *            - Use of the MAKEINTATOM macro
 */
#include "stdafx.h"
#include "hyperlink.h"
#include <shellapi.h>

/*
 * If you do not wish to link with the windebug module,
 * comment out the next include directive and uncomment the
 * define directive.
 */
//#include "win/windebug.h"
#define LASTERRORDISPLAYR(a) (a)

/*
 * Defines
 */
#ifndef IDC_HAND
#define IDC_HAND MAKEINTRESOURCE(32649)
#endif

#define PROP_OBJECT_PTR         MAKEINTATOM(ga.atom)
#define PROP_ORIGINAL_PROC      MAKEINTATOM(ga.atom)

/*
 * typedefs
 */
class CGlobalAtom
{
public:
    CGlobalAtom(void)
#ifdef _WIN64
    { atom = GlobalAddAtom(TEXT("_Hyperlink_Object_Pointer64_")
             TEXT("\\{AFEED740-CC6D-47c5-831D-9848FD916EEF}")); }
#else
    { atom = GlobalAddAtom(TEXT("_Hyperlink_Object_Pointer_")
             TEXT("\\{AFEED740-CC6D-47c5-831D-9848FD916EEF}")); }
#endif
    ~CGlobalAtom(void)
    { DeleteAtom(atom); }

    ATOM atom;
};

/*
 * Local variables
 */
static CGlobalAtom ga;

/*
 * Static members initializations
 */
COLORREF CHyperLink::g_crLinkColor     = RGB(  0,   0, 255);   // Blue;
COLORREF CHyperLink::g_crVisitedColor  = RGB( 128,  0, 128);   // Purple;
HCURSOR  CHyperLink::g_hLinkCursor     = nullptr;
HFONT    CHyperLink::g_UnderlineFont   = nullptr;
int      CHyperLink::g_counter         = 0;

/*
 * Macros and inline functions
 */
inline bool PTINRECT( LPCRECT r, const POINT &pt )
{ return  ( pt.x >= r->left && pt.x < r->right && pt.y >= r->top && pt.y < r->bottom ); }
inline void INFLATERECT( PRECT r, int dx, int dy )
{ r->left -= dx; r->right += dx; r->top -= dy; r->bottom += dy; }

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

CHyperLink::CHyperLink(void)
{
    m_bOverControl      = FALSE;                // Cursor not yet over control
    m_bVisited          = FALSE;                // Hasn't been visited yet.
    m_StdFont           = nullptr;
    m_pfnOrigCtlProc    = nullptr;
    m_strURL            = nullptr;
}

CHyperLink::~CHyperLink(void)
{
    delete [] m_strURL;
}

/*-----------------------------------------------------------------------------
 * Public functions
 */

/*
 * Function CHyperLink::ConvertStaticToHyperlink
 */
BOOL CHyperLink::ConvertStaticToHyperlink(HWND hwndCtl, LPCTSTR strURL)
{
    if( !(setURL(strURL)) )
        return FALSE;

    // Subclass the parent so we can color the controls as we desire.

    HWND hwndParent = GetParent(hwndCtl);
    if (nullptr != hwndParent)
    {
        WNDPROC pfnOrigProc = (WNDPROC) GetWindowLongPtr(hwndParent, GWLP_WNDPROC);
        if (pfnOrigProc != _HyperlinkParentProc)
        {
            SetProp( hwndParent, PROP_ORIGINAL_PROC, (HANDLE)pfnOrigProc );
            SetWindowLongPtr( hwndParent, GWLP_WNDPROC,
                           (LONG_PTR) (WNDPROC) _HyperlinkParentProc );
        }
    }

    // Make sure the control will send notifications.

    LONG_PTR Style = GetWindowLongPtr(hwndCtl, GWL_STYLE);
    SetWindowLongPtr(hwndCtl, GWL_STYLE, Style | SS_NOTIFY);

    // Create an updated font by adding an underline.

    m_StdFont = (HFONT) SendMessage(hwndCtl, WM_GETFONT, 0, 0);

    if( g_counter++ == 0 )
    {
        createGlobalResources();
    }

    // Subclass the existing control.

    m_pfnOrigCtlProc = (WNDPROC) GetWindowLongPtr(hwndCtl, GWLP_WNDPROC);
    SetProp(hwndCtl, PROP_OBJECT_PTR, (HANDLE) this);
    SetWindowLongPtr(hwndCtl, GWLP_WNDPROC, (LONG_PTR) (WNDPROC) _HyperlinkProc);

    return TRUE;
}

/*
 * Function CHyperLink::ConvertStaticToHyperlink
 */
BOOL CHyperLink::ConvertStaticToHyperlink(HWND hwndParent, UINT uiCtlId,
                                          LPCTSTR strURL)
{
    return ConvertStaticToHyperlink(GetDlgItem(hwndParent, uiCtlId), strURL);
}

/*
 * Function CHyperLink::setURL
 */
BOOL CHyperLink::setURL(LPCTSTR strURL)
{
    delete [] m_strURL;
    if( (m_strURL = new (std::nothrow) TCHAR[lstrlen(strURL)+1])==0 )
    {
        return FALSE;
    }

    lstrcpy(m_strURL, strURL);

    return TRUE;
}

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 * Private functions
 */

/*
 * Function CHyperLink::_HyperlinkParentProc
 */
LRESULT CALLBACK CHyperLink::_HyperlinkParentProc(HWND hwnd, UINT message,
                                                 WPARAM wParam, LPARAM lParam)
{
    WNDPROC pfnOrigProc = (WNDPROC) GetProp(hwnd, PROP_ORIGINAL_PROC);

    switch (message)
    {
    case WM_CTLCOLORSTATIC:
        {
            HDC hdc = (HDC) wParam;
            HWND hwndCtl = (HWND) lParam;
            CHyperLink *pHyperLink = (CHyperLink *)GetProp(hwndCtl,
                                                           PROP_OBJECT_PTR);

            if(pHyperLink)
            {
                LRESULT lr = CallWindowProc(pfnOrigProc, hwnd, message,
                                            wParam, lParam);
                if (!pHyperLink->m_bVisited)
                {
                    // This is the most common case for static branch prediction
                    // optimization
                    SetTextColor(hdc, CHyperLink::g_crLinkColor);
                }
                else
                {
                    SetTextColor(hdc, CHyperLink::g_crVisitedColor);
                }
                return lr;
            }
            break;
        }
    case WM_DESTROY:
        {
            SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR) pfnOrigProc);
            RemoveProp(hwnd, PROP_ORIGINAL_PROC);
            break;
        }
    }
    return CallWindowProc(pfnOrigProc, hwnd, message, wParam, lParam);
}

/*
 * Function CHyperLink::Navigate
 */
inline void CHyperLink::Navigate(void)
{
    SHELLEXECUTEINFO sei;
    ::SecureZeroMemory(&sei,sizeof(SHELLEXECUTEINFO));
    sei.cbSize = sizeof( SHELLEXECUTEINFO );        // Set Size
    sei.lpVerb = TEXT( "open" );                    // Set Verb
    sei.lpFile = m_strURL;                          // Set Target To Open
    sei.nShow = SW_SHOWNORMAL;                      // Show Normal

    LASTERRORDISPLAYR(ShellExecuteEx(&sei));
    m_bVisited = TRUE;
}

/*
 * Function CHyperLink::DrawFocusRect
 */
inline void CHyperLink::DrawFocusRect(HWND hwnd)
{
    HWND hwndParent = ::GetParent(hwnd);

    if( hwndParent )
    {
        // calculate where to draw focus rectangle, in screen coords
        RECT rc;
        GetWindowRect(hwnd, &rc);

        INFLATERECT(&rc,1,1);                    // add one pixel all around
                                                 // convert to parent window client coords
        ::ScreenToClient(hwndParent, (LPPOINT)&rc);
        ::ScreenToClient(hwndParent, ((LPPOINT)&rc)+1);
        HDC dcParent = GetDC(hwndParent);        // parent window's DC
        ::DrawFocusRect(dcParent, &rc);          // draw it!
        ReleaseDC(hwndParent,dcParent);
    }
}

/*
 * Function CHyperLink::_HyperlinkProc
 *
 * Note: Processed messages are not passed back to the static control
 *       procedure. It does work fine but be aware that it could cause
 *       some problems if the static control is already subclassed.
 *       Consider the example where the static control would be already
 *       subclassed with the ToolTip control that needs to process mouse
 *       messages. In that situation, the ToolTip control would not work
 *       as expected.
 */
LRESULT CALLBACK CHyperLink::_HyperlinkProc(HWND hwnd, UINT message,
                                           WPARAM wParam, LPARAM lParam)
{
    CHyperLink *pHyperLink = (CHyperLink *)GetProp(hwnd, PROP_OBJECT_PTR);

    switch (message)
    {
    case WM_MOUSEMOVE:
        {
            if ( pHyperLink->m_bOverControl )
            {
                // This is the most common case for static branch prediction
                // optimization
                RECT rect;
                GetClientRect(hwnd,&rect);

                POINT pt = { LOWORD(lParam), HIWORD(lParam) };

                if (!PTINRECT(&rect,pt))
                {
                    ReleaseCapture();
                }
            }
            else
            {
                pHyperLink->m_bOverControl = TRUE;
                SendMessage(hwnd, WM_SETFONT,
                            (WPARAM)CHyperLink::g_UnderlineFont, FALSE);
                InvalidateRect(hwnd, nullptr, FALSE);
                pHyperLink->OnSelect();
                SetCapture(hwnd);
            }
            return 0;
        }
    case WM_SETCURSOR:
        {
            SetCursor(CHyperLink::g_hLinkCursor);
            return TRUE;
        }
    case WM_CAPTURECHANGED:
        {
            pHyperLink->m_bOverControl = FALSE;
            pHyperLink->OnDeselect();
            SendMessage(hwnd, WM_SETFONT,
                        (WPARAM)pHyperLink->m_StdFont, FALSE);
            InvalidateRect(hwnd, nullptr, FALSE);
            return 0;
        }
    case WM_KEYUP:
        {
            if( wParam != VK_SPACE )
            {
                break;
            }
        }
                        // Fall through
    case WM_LBUTTONUP:
        {
            if (pHyperLink->m_strURL && _tcslen(pHyperLink->m_strURL))
            {
                pHyperLink->Navigate();
                InvalidateRect(hwnd, nullptr, FALSE);
                return 0;
            }
        }
    case WM_SETFOCUS:   // Fall through
    case WM_KILLFOCUS:
        {
            if( message == WM_SETFOCUS )
            {
                pHyperLink->OnSelect();
            }
            else        // WM_KILLFOCUS
            {
                pHyperLink->OnDeselect();
            }
            CHyperLink::DrawFocusRect(hwnd);
            return 0;
        }
    case WM_DESTROY:
        {
            SetWindowLongPtr(hwnd, GWLP_WNDPROC,
                          (LONG_PTR) pHyperLink->m_pfnOrigCtlProc);

            SendMessage(hwnd, WM_SETFONT, (WPARAM) pHyperLink->m_StdFont, 0);

            if( --CHyperLink::g_counter <= 0 )
            {
                destroyGlobalResources();
            }

            RemoveProp(hwnd, PROP_OBJECT_PTR);
            break;
        }
    }

    return CallWindowProc(pHyperLink->m_pfnOrigCtlProc, hwnd, message,
                          wParam, lParam);
}

/*
 * Function CHyperLink::createUnderlineFont
 */
void CHyperLink::createUnderlineFont(void)
{
    LOGFONT lf;
    GetObject(m_StdFont, sizeof(lf), &lf);
    lf.lfUnderline = TRUE;

    g_UnderlineFont = CreateFontIndirect(&lf);
}

/*
 * Function CHyperLink::createLinkCursor
 */
void CHyperLink::createLinkCursor(void)
{
    g_hLinkCursor = ::LoadCursor(nullptr, IDC_HAND); // Load Windows' hand cursor
    if( !g_hLinkCursor )    // if not available, use the standard Arrow cursor
    {
        /*
         * There exist an alternative way to get the IDC_HAND by loading winhlp32.exe but I
         * estimated that it didn't worth the trouble as IDC_HAND is supported since Win98.
         * I consider that if a user is happy with 10 years old OS, he won't bother to have
         * an arrow cursor.
         */
        g_hLinkCursor = ::LoadCursor(nullptr, IDC_ARROW);
    }
}
