[Dev-C++] Newbie: building a screen-saver

[Philippe de R. <phi...@ww...>]

Hello,

I am trying to compile the code below, which comes from Schildt's 
Windows 2000 Programming book and builds a screen-saver.

Unfortunately, I am not sure what to build the project as: Win32 GUI 
(it has no GUI), Win32 Console (it is not a console app), Win32 Static 
Lib (not a static lib), or Win32 DLL (not a DLL).

Furthermore, I had to import the SCRNSAVE.LIB from a demo copy of VC++, 
since dev-C++ does not include such libraries.

What should I build my project as (Win32 GUI, Win32 Console, etc.)?

Where can you get LIBs on the Web when you compile a project with 
Dev-C++ that requires one?

Many thanks.

Philippe de Rochambeau


========

listing 1
// A miminal screen saver.
#include <windows.h>
#include <scrnsave.h>

// This is the message displayed on the screen.
char str[80] = "Screen Saver #1";

// This is timer delay.
int delay = 200;

// Screen Saver Function
LRESULT WINAPI ScreenSaverProc(HWND hwnd, UINT message,
                                WPARAM wParam, LPARAM lParam)
{
   static HDC hdc;
   static unsigned int timer;
   static RECT scrdim;
   static SIZE size;
   static int X = 0, Y = 0;
   static HBRUSH hBlkBrush;
   static TEXTMETRIC tm;

   switch(message) {
     case WM_CREATE:
       timer = SetTimer(hwnd, 1, delay, NULL);
       hBlkBrush = (HBRUSH) GetStockObject(BLACK_BRUSH);
       break;
     case WM_ERASEBKGND:
       hdc = GetDC(hwnd);

       // get coordinates of screen
       GetClientRect(hwnd, &scrdim);

       // erase the screen
       SelectObject(hdc, hBlkBrush);
       PatBlt(hdc, 0, 0, scrdim.right, scrdim.bottom, PATCOPY);

       // get and save height and length of string
       GetTextMetrics(hdc, &tm);
       GetTextExtentPoint32(hdc, str, strlen(str), &size);

       ReleaseDC(hwnd, hdc);
       break;
     case WM_TIMER:
       hdc = GetDC(hwnd);

       // erase previous output
       SelectObject(hdc, hBlkBrush);
       PatBlt(hdc, X, Y, X + size.cx, Y + size.cy, PATCOPY);

       // move string to new location
       X += 10; Y += 10;
       if(X > scrdim.right) X = 0;
       if(Y > scrdim.bottom) Y = 0;

       // output string
       SetBkColor(hdc, RGB(0, 0, 0));
       SetTextColor(hdc, RGB(0, 255, 255));
       TextOut(hdc, X, Y, str, strlen(str));

       ReleaseDC(hwnd, hdc);
       break;
     case WM_DESTROY:
       KillTimer(hwnd, timer);
       break;
     default:
       return DefScreenSaverProc(hwnd, message, wParam, lParam);
   }

   return 0;
}

// Placeholder Dialog Box Function.
BOOL WINAPI ScreenSaverConfigureDialog(HWND hdwnd, UINT message,
                                 WPARAM wParam, LPARAM lParam)
{
   return 0;
}

// No classes to register.
BOOL WINAPI RegisterDialogClasses(HANDLE hInst)
{
   return 1;
}

listing 2
#include <windows.h>
#include <scrnsave.h>

ID_APP ICON SCRICON.ICO

STRINGTABLE
{
   IDS_DESCRIPTION "My Screen Saver #1"
}

listing 3
// A Configurable Screen Saver
#include <windows.h>
#include <scrnsave.h>
#include <commctrl.h>
#include <cstring>
#include "scr.h"

#define DELAYMAX 999
#define MSGSIZE 80

// This is the screen saver's message.
char str[MSGSIZE+1] = "Screen Saver #2";

// This is timer delay.
long delay;

unsigned long datatype, datasize;
unsigned long result;

// This is a registry key.
HKEY hRegKey;

// Screen Saver Function
LRESULT WINAPI ScreenSaverProc(HWND hwnd, UINT message,
                                WPARAM wParam, LPARAM lParam)
{
   static HDC hdc;
   static unsigned int timer;
   static RECT scrdim;
   static SIZE size;
   static int X = 0, Y = 0;
   static HBRUSH hBlkBrush;
   static TEXTMETRIC tm;

   switch(message) {
     case WM_CREATE:
       // open screen saver key or create, if necessary
       RegCreateKeyEx(HKEY_CURRENT_USER,
          "Control Panel\\Screen Saver.MyScrSaver",
          0, "Screen Saver", 0, KEY_ALL_ACCESS,
          NULL, &hRegKey, &result);

       // if key was created
       if(result==REG_CREATED_NEW_KEY) {
         // set its initial value
         delay = 100;
         RegSetValueEx(hRegKey, "delay", 0,
            REG_DWORD, (LPBYTE) &delay, sizeof(DWORD));
         RegSetValueEx(hRegKey, "message", 0,
            REG_SZ, (LPBYTE) str, strlen(str)+1);
       }
       else { // key was already in registry
         // get delay value
         datasize = sizeof(DWORD);
         RegQueryValueEx(hRegKey, "delay", NULL,
            &datatype, (LPBYTE) &delay, &datasize);

         // get message
         datasize = MSGSIZE;
         RegQueryValueEx(hRegKey, "message", NULL,
            &datatype, (LPBYTE) str, &datasize);
       }

       RegCloseKey(hRegKey);

       timer = SetTimer(hwnd, 1, delay, NULL);
       hBlkBrush = (HBRUSH) GetStockObject(BLACK_BRUSH);
       break;
     case WM_ERASEBKGND:
       hdc = GetDC(hwnd);

       // Get coordinates of screen
       GetClientRect(hwnd, &scrdim);

       // erase the screen
       SelectObject(hdc, hBlkBrush);
       PatBlt(hdc, 0, 0, scrdim.right, scrdim.bottom, PATCOPY);

       // get and save height and length of string
       GetTextMetrics(hdc, &tm);
       GetTextExtentPoint32(hdc, str, strlen(str), &size);

       ReleaseDC(hwnd, hdc);
       break;
     case WM_TIMER:
       hdc = GetDC(hwnd);

       // erase previous output
       SelectObject(hdc, hBlkBrush);
       PatBlt(hdc, X, Y, X + size.cx, Y + size.cy, PATCOPY);

       // move string to new location
       X += 10; Y += 10;
       if(X > scrdim.right) X = 0;
       if(Y > scrdim.bottom) Y = 0;

       // output string
       SetBkColor(hdc, RGB(0, 0, 0));
       SetTextColor(hdc, RGB(0, 255, 255));
       TextOut(hdc, X, Y, str, strlen(str));

       ReleaseDC(hwnd, hdc);
       break;
     case WM_DESTROY:
       KillTimer(hwnd, timer);
       break;
     default:
       return DefScreenSaverProc(hwnd, message, wParam, lParam);
   }

   return 0;
}

// Configuration Dialog Box Function
BOOL WINAPI ScreenSaverConfigureDialog(HWND hdwnd, UINT message,
                     WPARAM wParam, LPARAM lParam)
{
   static HWND hEboxWnd;
   static HWND udWnd;

   switch(message) {
     case WM_INITDIALOG:
       // open screen saver key or create, if necessary
       RegCreateKeyEx(HKEY_CURRENT_USER,
          "Control Panel\\Screen Saver.MyScrSaver",
          0, "Screen Saver", 0, KEY_ALL_ACCESS,
          NULL, &hRegKey, &result);

       // if key was created
       if(result==REG_CREATED_NEW_KEY) {
         // set its initial value
         delay = 100;
         RegSetValueEx(hRegKey, "delay", 0,
            REG_DWORD, (LPBYTE) &delay, sizeof(DWORD));
         RegSetValueEx(hRegKey, "message", 0,
            REG_SZ, (LPBYTE) str, strlen(str)+1);
       }
       else { // key was already in registry
         // get delay value
         datasize = sizeof(DWORD);
         RegQueryValueEx(hRegKey, "delay", NULL,
            &datatype, (LPBYTE) &delay, &datasize);

         // get message
         datasize = MSGSIZE;
         RegQueryValueEx(hRegKey, "message", NULL,
            &datatype, (LPBYTE) str, &datasize);
       }

       // create delay spin control
       hEboxWnd = GetDlgItem(hdwnd, IDD_EB1);
       udWnd = CreateUpDownControl(
                     WS_CHILD | WS_BORDER | WS_VISIBLE |
                     UDS_SETBUDDYINT | UDS_ALIGNRIGHT,
                     20, 10, 50, 50,
                     hdwnd,
                     IDD_UPDOWN,
                     hMainInstance,
                     hEboxWnd,
                     DELAYMAX, 1, delay);

       // initialize edit box with current message
       SetDlgItemText(hdwnd, IDD_EB2, str);

       return 1;
     case WM_COMMAND:
       switch(LOWORD(wParam)) {
         case IDOK:
           // set delay value
           delay = GetDlgItemInt(hdwnd, IDD_EB1, NULL, 1);

           // get message string
           GetDlgItemText(hdwnd, IDD_EB2, str, MSGSIZE);

           // update registry
           RegSetValueEx(hRegKey, "delay", 0,
             REG_DWORD, (LPBYTE) &delay, sizeof(DWORD));
           RegSetValueEx(hRegKey, "message", 0,
              REG_SZ, (LPBYTE) str, strlen(str)+1);

           // fall through to next case ...
         case IDCANCEL:
           RegCloseKey(hRegKey);
           EndDialog(hdwnd, 0);
           return 1;
         }
       break;
   }
   return 0;
}

// No classes to register.
BOOL WINAPI RegisterDialogClasses(HANDLE hInst)
{
   return 1;
}

listing 4
// Dialog box for screen saver.
#include <windows.h>
#include <scrnsave.h>
#include "scr.h"

ID_APP ICON SCRICON.ICO

STRINGTABLE
{
   IDS_DESCRIPTION "My Screen Saver #2"
}

DLG_SCRNSAVECONFIGURE DIALOGEX 18, 18, 110, 60
CAPTION "Set Screen Saver Options"
STYLE DS_MODALFRAME | WS_POPUP | WS_VISIBLE | WS_CAPTION |
       WS_SYSMENU
{
   PUSHBUTTON "OK", IDOK, 20, 40, 30, 14
   PUSHBUTTON "Cancel", IDCANCEL, 60, 40, 30, 14
   EDITTEXT IDD_EB1, 5, 5, 24, 12, ES_LEFT | WS_TABSTOP | WS_BORDER
   EDITTEXT IDD_EB2, 5, 20, 65, 12, ES_LEFT | WS_TABSTOP |
            WS_BORDER | ES_AUTOHSCROLL
   LTEXT "Delay in milliseconds", IDD_TEXT1, 35, 7, 100, 12
   LTEXT "Message", IDD_TEXT2, 76, 22, 30, 12
}

listing 5
#define IDD_EB1      200
#define IDD_EB2      201

#define IDD_UPDOWN   202

#define IDD_TEXT1    203
#define IDD_TEXT2    204

listing 6
// Configuration Dialog Box Function
BOOL WINAPI ScreenSaverConfigureDialog(HWND hdwnd, UINT message,
                     WPARAM wParam, LPARAM lParam)
{
   static HWND hEboxWnd;
   static HWND udWnd;

   switch(message) {
     case WM_INITDIALOG:
       // open screen saver key or create, if necessary
       RegCreateKeyEx(HKEY_CURRENT_USER,
          "Control Panel\\Screen Saver.MyScrSaver",
          0, "Screen Saver", 0, KEY_ALL_ACCESS,
          NULL, &hRegKey, &result);

       // if key was created
       if(result==REG_CREATED_NEW_KEY) {
         // set its initial value
         delay = 100;
         RegSetValueEx(hRegKey, "delay", 0,
            REG_DWORD, (LPBYTE) &delay, sizeof(DWORD));
         RegSetValueEx(hRegKey, "message", 0,
            REG_SZ, (LPBYTE) str, strlen(str)+1);
       }
       else { // key was already in registry
         // get delay value
         datasize = sizeof(DWORD);
         RegQueryValueEx(hRegKey, "delay", NULL,
            &datatype, (LPBYTE) &delay, &datasize);

         // get message
         datasize = MSGSIZE;
         RegQueryValueEx(hRegKey, "message", NULL,
            &datatype, (LPBYTE) str, &datasize);
       }

       // create delay spin control
       hEboxWnd = GetDlgItem(hdwnd, IDD_EB1);
       udWnd = CreateUpDownControl(
                     WS_CHILD | WS_BORDER | WS_VISIBLE |
                     UDS_SETBUDDYINT | UDS_ALIGNRIGHT,
                     20, 10, 50, 50,
                     hdwnd,
                     IDD_UPDOWN,
                     hMainInstance,
                     hEboxWnd,
                     DELAYMAX, 1, delay);

       // initialize edit box with current message
       SetDlgItemText(hdwnd, IDD_EB2, str);

       return 1;
     case WM_COMMAND:
       switch(LOWORD(wParam)) {
         case IDOK:
           // set delay value
           delay = GetDlgItemInt(hdwnd, IDD_EB1, NULL, 1);

           // get message string
           GetDlgItemText(hdwnd, IDD_EB2, str, MSGSIZE);

           // update registry
           RegSetValueEx(hRegKey, "delay", 0,
             REG_DWORD, (LPBYTE) &delay, sizeof(DWORD));
           RegSetValueEx(hRegKey, "message", 0,
              REG_SZ, (LPBYTE) str, strlen(str)+1);

           // fall through to next case ...
         case IDCANCEL:
           RegCloseKey(hRegKey);
           EndDialog(hdwnd, 0);
           return 1;
         }
       break;
   }
   return 0;
}