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

    ATOM atom;
};

/*
 * Local variables
 */
static CGlobalAtom ga;

/*
 * Static members initializations
 */
COLORREF CHyperLink::m_gCrLinkColor    = RGB(0, 0, 255);   // Blue;
COLORREF CHyperLink::m_gCrVisitedColor = RGB(128, 0, 128); // Purple;
HCURSOR  CHyperLink::m_gHLinkCursor    = nullptr;
HFONT    CHyperLink::m_gUnderlineFont  = nullptr;
int      CHyperLink::m_gCounter        = 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()
{
    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()
{
}

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

/*
 * Function CHyperLink::ConvertStaticToHyperlink
 */
BOOL CHyperLink::ConvertStaticToHyperlink(HWND hwndCtl, LPCWSTR 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 = reinterpret_cast<WNDPROC>(GetWindowLongPtr(hwndParent, GWLP_WNDPROC));
        if (pfnOrigProc != _HyperlinkParentProc)
        {
            SetProp(hwndParent, PROP_ORIGINAL_PROC, static_cast<HANDLE>(pfnOrigProc));
            SetWindowLongPtr(hwndParent, GWLP_WNDPROC,
                             reinterpret_cast<LONG_PTR>(static_cast<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 = reinterpret_cast<HFONT>(SendMessage(hwndCtl, WM_GETFONT, 0, 0));

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

    // Subclass the existing control.

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

    return TRUE;
}

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

/*
 * Function CHyperLink::setURL
 */
BOOL CHyperLink::setURL(LPCWSTR strURL)
{
    m_strURL = std::make_unique<wchar_t[]>(lstrlen(strURL) + 1);

    lstrcpy(m_strURL.get(), strURL);

    return TRUE;
}

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

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

    switch (message)
    {
        case WM_CTLCOLORSTATIC:
        {
            HDC         hdc        = reinterpret_cast<HDC>(wParam);
            HWND        hwndCtl    = reinterpret_cast<HWND>(lParam);
            CHyperLink *pHyperLink = static_cast<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::m_gCrLinkColor);
                }
                else
                {
                    SetTextColor(hdc, CHyperLink::m_gCrVisitedColor);
                }
                return lr;
            }
            break;
        }
        case WM_DESTROY:
        {
            SetWindowLongPtr(hwnd, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(pfnOrigProc));
            RemoveProp(hwnd, PROP_ORIGINAL_PROC);
            break;
        }
    }
    return CallWindowProc(pfnOrigProc, hwnd, message, wParam, lParam);
}

/*
 * Function CHyperLink::Navigate
 */
inline void CHyperLink::Navigate()
{
    SHELLEXECUTEINFO sei;
    ::SecureZeroMemory(&sei, sizeof(SHELLEXECUTEINFO));
    sei.cbSize = sizeof(SHELLEXECUTEINFO); // Set Size
    sei.lpVerb = TEXT("open");             // Set Verb
    sei.lpFile = m_strURL.get();           // 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, reinterpret_cast<LPPOINT>(&rc));
        ::ScreenToClient(hwndParent, reinterpret_cast<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 = static_cast<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,
                            reinterpret_cast<WPARAM>(CHyperLink::m_gUnderlineFont), FALSE);
                InvalidateRect(hwnd, nullptr, FALSE);
                pHyperLink->OnSelect();
                SetCapture(hwnd);
            }
            return 0;
        }
        case WM_SETCURSOR:
        {
            SetCursor(CHyperLink::m_gHLinkCursor);
            return TRUE;
        }
        case WM_CAPTURECHANGED:
        {
            pHyperLink->m_bOverControl = FALSE;
            pHyperLink->OnDeselect();
            SendMessage(hwnd, WM_SETFONT,
                        reinterpret_cast<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 && wcslen(pHyperLink->m_strURL.get()))
            {
                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,
                             reinterpret_cast<LONG_PTR>(pHyperLink->m_pfnOrigCtlProc));

            SendMessage(hwnd, WM_SETFONT, reinterpret_cast<WPARAM>(pHyperLink->m_stdFont), 0);

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

            RemoveProp(hwnd, PROP_OBJECT_PTR);
            break;
        }
    }

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

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

    m_gUnderlineFont = CreateFontIndirect(&lf);
}

/*
 * Function CHyperLink::createLinkCursor
 */
void CHyperLink::createLinkCursor()
{
    m_gHLinkCursor = ::LoadCursor(nullptr, IDC_HAND); // Load Windows' hand cursor
    if (!m_gHLinkCursor)                              // 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.
         */
        m_gHLinkCursor = ::LoadCursor(nullptr, IDC_ARROW);
    }
}