/* filecomd.c  A text editing application with extensive file handling */
/* capability. Uses the Common Dialog Functions GetOpenFileName() &    */
/* GetSaveFileName()                                                   */

#include <windows.h>
#include <commdlg.h>
#include <string.h>
#include <stdio.h>
#include "filecomd.h"

int PASCAL WinMain (HANDLE hInstance, HANDLE hPrevInstance, LPSTR lpszCmdLine,
    int nCmdShow)
{
    HWND        hWnd ;        /* the window's "handle" */
    MSG         msg ;         /* a message structure */
    WNDCLASS    wndclass ;    /* window class structure */
    char        cBuf [128] ;  /* character buffer */

        wndclass.style          = CS_HREDRAW | CS_VREDRAW ;
        wndclass.lpfnWndProc    = WndProc ;
        wndclass.cbClsExtra     = 0 ;
        wndclass.cbWndExtra     = 0 ;
        wndclass.hInstance      = hInstance ;
        wndclass.hIcon          = LoadIcon (hInstance, "MyIcon") ;
        wndclass.hCursor        = LoadCursor (NULL, IDC_ARROW) ;
        wndclass.hbrBackground  = GetStockObject (WHITE_BRUSH) ;
        wndclass.lpszMenuName   = "MYMENU" ;
        wndclass.lpszClassName  = "MyClass" ;
                        /* register the window class */
        if (!RegisterClass (&wndclass))
            return 0 ;
 
    LoadString (hInstance, S_PROGRAMCAPTION, cBuf, sizeof (cBuf)) ;

    hWnd = CreateWindow ("MyClass", cBuf, WS_OVERLAPPEDWINDOW, 
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 
        NULL, NULL, hInstance, NULL) ;
    ShowWindow (hWnd, nCmdShow) ;   /* display the window */    
    UpdateWindow (hWnd) ;

    while (GetMessage (&msg, NULL, 0, 0))   /* message loop */
    {
        TranslateMessage (&msg) ;   /* translate keyboard messages */
        DispatchMessage (&msg) ;    /* send message to WndProc() */
    }
    return (msg.wParam) ;
}

LRESULT CALLBACK WndProc (HWND hWnd, UINT wMessage, 
                                        WPARAM wParam, LPARAM lParam)
{
    static  HANDLE          hInstance ;
    static  OPENFILENAME    ofn;    /* open file name structure */
    FILE                    *fp ;
    PSTR                    pEditBuf ;
    static  HWND            hEditWindow ;
    int                     nFileLong ;
    char                    cBuf2 [128] ;
    static  char     szFileTitle[_MAX_FNAME + _MAX_EXT], /* filename and extension */
                     szFile[_MAX_PATH];                  /* filename including path */
    static  char     szFilter[] = "Edit Files (*.edt)\0*.edt\0" \
                                  "Text Files (*.txt)\0*.txt\0" \
                                  "All Files (*.*)\0*.*\0\0";

    switch (wMessage)       /* process windows messages */
    {
        case WM_CREATE:     /* create edit control window */
            hInstance = (HINSTANCE)GetWindowLong (hWnd, GWL_HINSTANCE) ;
            hEditWindow = CreateWindow ("EDIT", "",
                WS_CHILD | WS_VISIBLE | ES_AUTOVSCROLL | ES_MULTILINE |
                ES_LEFT | ES_NOHIDESEL | WS_VSCROLL| ES_AUTOHSCROLL |
                WS_HSCROLL, 0, 0, 1, 1, hWnd, NULL, hInstance, NULL) ;
            SendMessage (hEditWindow, EM_LIMITTEXT, 32000, 0); 
            break ;

        case WM_SIZE:       /* keep edit control filling client area */
            MoveWindow (hEditWindow, 5, 0, LOWORD (lParam) - 5, 
                                         HIWORD (lParam), TRUE) ;
            break ;

        case WM_COMMAND:
            switch (LOWORD(wParam))      /* menu items */
            {
            case IDM_OPEN:   /* ff: opens and reads file selected by user */
                             /* into edit buffer using file common dlg box*/
                             /* set all open file structure members to zero */
                memset(&ofn, 0, sizeof(OPENFILENAME));
                ofn.lStructSize = sizeof(OPENFILENAME);
                ofn.hwndOwner = hWnd;
                ofn.lpstrFilter = szFilter;
                ofn.lpstrFile = szFile;
                ofn.nMaxFile = _MAX_PATH;
                ofn.lpstrFileTitle = szFileTitle;
                ofn.nMaxFileTitle = _MAX_FNAME + _MAX_EXT;
                ofn.lpstrInitialDir = NULL;     /* use current directory */
                ofn.lpstrDefExt = "edt";        /* default file extension */
                                
                GetOpenFileName(&ofn);  /* fill ofn struct */
                lstrcat(szFile,"\0");   /* make sure it's null terminated */

                /***** Now open file, get info, and put in edit box *****/
                fp = fopen (szFile,"rb") ; /* open the file */ 
                if (fp == NULL)
                {
                    LoadString (hInstance,S_FILENOTOPEN,cBuf2,sizeof (cBuf2)) ;
                    MessageBox (hWnd, szFileTitle, cBuf2, MB_OK | MB_ICONHAND) ;
                }
                else                 /* file is open, so read it */
                {                    /* window title = file name */
                    SetWindowText (hWnd, szFileTitle) ;
                    /* find the length of file */
                    fseek (fp, 0, SEEK_END) ;
                    nFileLong = ftell(fp) ;
                    /* go back to front of file */
                    fseek (fp, 0, SEEK_SET) ;
                    /* allocate new edit buffer block */
                    pEditBuf = (PSTR)malloc (nFileLong+1) ;
                    if (pEditBuf != NULL)
                    {                /* copy file data to block */
                        fread (pEditBuf, 1, nFileLong, fp) ;
                        fclose (fp) ; /* close the file */
                        pEditBuf[nFileLong] = 0 ; /* null terminate text */
                        /* send it to the edit control */
                        SetWindowText (hEditWindow, pEditBuf) ;
                        free (pEditBuf) ;
                    }
                    else
                        StringTableMessageBox (hWnd,S_NOTALLOC,S_MEMERROR,MB_OK | MB_ICONHAND) ;
                }
                break ;

            case IDM_SAVE:  /* save edit buffer to file selected by user */
                            /* set all structure members to zero */
                memset(&ofn, 0, sizeof(OPENFILENAME));
                ofn.lStructSize = sizeof(OPENFILENAME);
                ofn.hwndOwner = hWnd;
                ofn.lpstrFilter = szFilter;
                ofn.lpstrFile = szFile;
                ofn.nMaxFile = _MAX_PATH;
                ofn.lpstrFileTitle = szFileTitle;
                ofn.nMaxFileTitle = _MAX_FNAME + _MAX_EXT;
                ofn.lpstrInitialDir = NULL;     /* use current directory */
                ofn.lpstrDefExt = "edt";        /* default extension */

                GetSaveFileName(&ofn); /* fill ofn struct */

                /*** Now open file, get contents of edit box, save to file ***/

                fp = fopen (szFileTitle, "wb") ; /* open the file */  
                if (fp == NULL)
                {
                    LoadString (hInstance,S_FILENOTCREATE,cBuf2,sizeof(cBuf2)) ;
                    MessageBox (hWnd, szFileTitle, cBuf2, MB_OK | MB_ICONHAND) ;
                }
                else
                {   /* window title = file name */
                    SetWindowText (hWnd, szFileTitle) ;
                    /* ff: copies edit buffer to file */
                    nFileLong = GetWindowTextLength (hEditWindow) ;
                    if (NULL == (pEditBuf = (PSTR)malloc(nFileLong+1)))
                    {
                        StringTableMessageBox (hWnd,S_NOTALLOC,S_MEMERROR,MB_OK|MB_ICONHAND) ;
                        fclose (fp) ;
                    }
                    else
                    {   /* get text from the edit control */
                        GetWindowText (hEditWindow, pEditBuf, nFileLong+1); 
                        /* write to the file */
                        fwrite (pEditBuf, 1, nFileLong, fp) ;
                        fclose (fp) ;
                        free (pEditBuf);
                    }       
                }     
                break ;

                case IDM_ABOUT:
                    StringTableMessageBox (hWnd, S_ABOUTTEXT, S_ABOUTCAPTION,
                        MB_OK | MB_ICONINFORMATION) ;
                    break ;             

                case IDM_QUIT:              /* "Quit" menu item */
                    DestroyWindow (hWnd) ;  /* destroy window, */
                    break ;                 /* terminating application */
            }
            break ;

        case WM_DESTROY:                    /* stop application */
            PostQuitMessage (0) ;
            break ;

        default:        /* default windows message processing */
            return (DefWindowProc (hWnd, wMessage, wParam, lParam)) ;
    }
    return (0) ;
}

/*** display a message box based on two string table entries ***/
int StringTableMessageBox (HWND hWnd, int nString, int nCaption, WORD
    wFlags)
{
    char    cBuf1 [128], cBuf2 [128] ;
    HANDLE  hInstance ;
    
    hInstance = (HINSTANCE)GetWindowLong (hWnd, GWL_HINSTANCE) ;
    LoadString (hInstance, nString, cBuf1, sizeof (cBuf1)) ;
    LoadString (hInstance, nCaption, cBuf2, sizeof (cBuf2)) ;
    return (MessageBox (hWnd, cBuf1, cBuf2, wFlags)) ;
}