screensave.c

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//
//  screensave.c
//
//  Entrypoint for a win32 screensaver
//
//  NOTES: Screen savers don't like being UPX'd (compressed). Don't
//         know why, it just is. C-runtime has been stripped with
//         "libctiny.lib".
//
//  v1.0 1/12/2003 J Brown
//
#include <windows.h>
#include <windowsx.h>
#include <tchar.h>
#include "globals.h"
#include "message.h"
#include "matrix.h"
#include "resource.h"
 
//#pragma comment(lib, "libctiny.lib")
//#pragma comment(linker, "/OPT:NOWIN98")
 
//
//  Added: Multimonitor support!!
//
HMONITOR (WINAPI * pfnEnumDisplayMonitors)(HDC, LPCRECT, MONITORENUMPROC, LPARAM);
BOOL     (WINAPI * pfnGetMonitorInfo)(HMONITOR, LPMONITORINFO);
 
//
//  Callback function for EnumDisplayMonitors API. Use this function
//  to kickstart a screen-saver window for each monitor in the system
//
BOOL CALLBACK MonitorEnumProc(HMONITOR hMonitor, HDC hdcMonitor, RECT *rcMonitor, LPARAM Param)
{
    HWND hwnd;
 
    // Create a screensaver on this monitor!
    hwnd = CreateScreenSaveWnd((HWND)Param, rcMonitor);
 
    // For some reason windows always places this window at 0,0...
    // position it ourselves
    SetWindowPos(hwnd, 0, rcMonitor->left, rcMonitor->top, 0, 0,
        SWP_NOZORDER|SWP_NOACTIVATE|SWP_NOSIZE|SWP_SHOWWINDOW);
 
    return TRUE;
}
 
//
//  Start screen saver!
//
BOOL ScreenSaver(HWND hwndParent)
{
    HMODULE     hUser32;
    UINT        nPreviousState;
    MSG         msg;
 
    InitScreenSaveClass(hwndParent);
 
    SystemParametersInfo(SPI_SETSCREENSAVERRUNNING, TRUE, &nPreviousState, 0);
 
    // Dynamically locate API call from USER32 - not present in all versions
    hUser32                 = GetModuleHandle(_T("USER32.DLL"));
    pfnEnumDisplayMonitors  = (PVOID)GetProcAddress(hUser32, "EnumDisplayMonitors");
 
    // If we're running Win2k+ then the API is available...so call it!
    if(pfnEnumDisplayMonitors && hwndParent == 0)
    {
        pfnEnumDisplayMonitors(NULL, NULL, MonitorEnumProc, 0);
    }
    // Otherwise simulate by calling enum-proc manually
    else
    {
        RECT rect;
 
        rect.left   = 0;
        rect.right  = GetSystemMetrics(SM_CXSCREEN);
        rect.top    = 0;
        rect.bottom = GetSystemMetrics(SM_CYSCREEN);
 
        MonitorEnumProc(NULL, NULL, &rect, (LPARAM)hwndParent);
    }
 
    // run message loop to handle all screen-saver windows
    while(GetMessage(&msg, NULL,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
 
    SystemParametersInfo(SPI_SETSCREENSAVERRUNNING, FALSE, &nPreviousState, 0);
 
    return TRUE;
}
 
//
//  Look for any options Windows has passed to us:
//
//  -a <hwnd>       (set password)
//  -s              (screensave)
//  -p <hwnd>       (preview)
//  -c <hwnd>       (configure)
//
VOID ParseCommandLine(LPWSTR szCmdLine, UCHAR *chOption, HWND *hwndParent)
{
    UCHAR ch = *szCmdLine++;
 
    if(ch == '-' || ch == '/')
        ch = *szCmdLine++;
 
    if(ch >= 'A' && ch <= 'Z')
        ch += 'a' - 'A';        //convert to lower case
 
    *chOption = ch;
    ch = *szCmdLine++;
 
    if(ch == ':')
        ch = *szCmdLine++;
 
    while(ch == ' ' || ch == '\t')
        ch = *szCmdLine++;
 
    if(isdigit(ch))
    {
        ULONG_PTR i = _wtoi(szCmdLine - 1);
        *hwndParent = (HWND)i;
    }
    else
        *hwndParent = NULL;
}
 
//
//  Entrypoint for screen-saver: it's just a normal win32 app!
//
int CALLBACK wWinMain (HINSTANCE hInst, HINSTANCE hPrev, LPWSTR lpCmdLine, int iCmdShow)
{
    HWND   hwndParent;
    UCHAR  chOption;
 
    // Make sure that only 1 instance runs at a time -
    // Win98 seems to want us to restart every 5 seconds!!
    if(FindWindowEx(NULL, NULL, APPNAME, APPNAME))
    {
        return 0;
    }
 
    LoadSettings();
 
    ParseCommandLine(lpCmdLine, &chOption, &hwndParent);
 
    switch(chOption)
    {
    case 's':   return ScreenSaver(NULL);           // screen save
    case 'p':   return ScreenSaver(hwndParent);     // preview in small window
    case 'a':   return ChangePassword(hwndParent);  // ask for password
    case 'c':   return Configure(hwndParent);       // configuration dialog
    default:    return Configure(hwndParent);       // configuration dialog
    }
 
    return 0;
}