filer.c

This source code has been tested under OpenWindows 2.0, Sun s X11/NeWS server. For Xlib programs th

/***********************************************************************
**                                                                    **
**  filer.c                                                           **
**                                                                    **
**  Text Editor -- File Open/Save Module                              **
**                                                                    **
***********************************************************************/


#include <stdio.h>
#include <string.h>

#include <Xm/FileSB.h>
#include <Xm/Text.h>

#include "textedit.h"


/***********************************************************************
**                                                                    **
**               F O R W A R D   D E F I N I T I O N S                **
**                                                                    **
***********************************************************************/

static	void InitStdFile();
static	void ManageStdFile();
static	void UnmanageStdFile();

static	void SFProc();
static	void ReadProc();
static	void WriteProc();



/***********************************************************************
**                                                                    **
**                    L O C A L   V A R I A B L E S                   **
**                                                                    **
***********************************************************************/

char	*curfile = NULL;		/* The current filename       */
Widget	stdfile_db;			/* The Standard File dialog   */

void	(*fileproc)();			/* The Read/Write function    */



/***********************************************************************
**                                                                    **
**  InitFiler()                                                       **
**                                                                    **
**  This function initializes the filer module: it clears the current **
**  filename, disables the File/Save menu choice, and creates the     **
**  Standard File dialog.                                             **
**                                                                    **
***********************************************************************/

void InitFiler()
{
    Widget	temp;

    stdfile_db = XmCreateFileSelectionDialog( mainwin, "StdFile", NULL, 0 );

    XtAddCallback( stdfile_db, XmNokCallback, SFProc, NULL );
    XtAddCallback( stdfile_db, XmNcancelCallback, UnmanageStdFile, NULL );
    XtAddCallback( stdfile_db, XmNhelpCallback, UnmanageStdFile, NULL );
}


/***********************************************************************
**                                                                    **
**  ManageStdFile( title, proc, defspec )                             **
**                                                                    **
**  This function manages the Standard File dialog. It sets the       **
**  dialog's title to the string passed as "title", installs the      **
**  function passed as "proc" in the "fileproc" variable (it gets     **
**  called by the StdFile callback handler), and stores the string    **
**  passed in "defspec" in the "dirSpec" resource.                    **
**                                                                    **
***********************************************************************/

static	void ManageStdFile( title, proc, defspec )
    char	    *title;
    XtCallbackProc  proc;
    char	    *defspec;
{
    XmString	    temp1, temp2;

    temp1 = XmStringCreate( title,   XmSTRING_DEFAULT_CHARSET );
    if (defspec == NULL)
        temp2 = XmStringCreate( "", XmSTRING_DEFAULT_CHARSET );
    else
        temp2 = XmStringCreate( defspec, XmSTRING_DEFAULT_CHARSET );

    XtSetArg( arglist[0], XmNdialogTitle, temp1 );
    XtSetArg( arglist[1], XmNdirSpec,     temp2 );
    XtSetValues( stdfile_db, arglist, 2 );

    XmStringFree( temp1 );
    XmStringFree( temp2 );

    XmFileSelectionDoSearch( stdfile_db, NULL );

    XtManageChild( stdfile_db );

    fileproc = proc;
}


/***********************************************************************
**                                                                    **
**  UnmanageStdFile()                                                 **
**                                                                    **
**  This function unmanages the Standard File dialog. It is attached  **
**  to the "Cancel" and "Help" buttons, because XmFileSelectionBox    **
**  does not handle the "autoUnmanage" resource.                      **
**                                                                    **
***********************************************************************/

static	void UnmanageStdFile()
{
    XtUnmanageChild( stdfile_db );
}


/***********************************************************************
**                                                                    **
**  SFProc( w, client_data, call_data )                               **
**                                                                    **
**  This function is the callback procedure for the Standard File     **
**  dialog. It stores the chosen filename in "curfile", and then      **
**  calls the function pointed-to by "fileproc".                      **
**                                                                    **
***********************************************************************/

static	void SFProc(w, client_data, call_data )
    Widget				w;
    caddr_t				client_data;
    XmFileSelectionBoxCallbackStruct	*call_data;
{
    if (curfile != NULL)
        XtFree( curfile );
    XmStringGetLtoR( call_data->value, XmSTRING_DEFAULT_CHARSET, &curfile );

    UnmanageStdFile();

    (*fileproc)();
}


/***********************************************************************
**                                                                    **
**  ReadProc()                                                        **
**                                                                    **
**  This function reads the file specified by "curfile" into the      **
**  editor's text buffer.                                             **
**                                                                    **
***********************************************************************/

static	void ReadProc()
{
    FILE    *infile = fopen( curfile, "r" );
    char    *txtbuf;
    long    size;

    if (infile == NULL)
        /* Should display error */
        return;

    fseek( infile, 0L, 2 );
    size = ftell( infile );
    rewind( infile );

    txtbuf = XtMalloc( size+1 );

    fread( txtbuf, sizeof(char), size, infile );
    XmTextSetString( textwin, txtbuf );

    XtFree( txtbuf );
}


/***********************************************************************
**                                                                    **
**  WriteProc()                                                       **
**                                                                    **
**  This function writes the editor's text buffer into a file named   **
**  by "curfile".                                                     **
**                                                                    **
***********************************************************************/

static	void WriteProc()
{
    FILE    *outfile;
    char    *txtbuf;
    long    size;

    outfile = fopen( curfile, "w" );
    if (outfile == NULL)
        /* Should display error */
        return;

    txtbuf = XmTextGetString( textwin );
    size   = strlen(txtbuf);

    fwrite( txtbuf, sizeof(char), size, outfile );
    fclose( outfile );

    XtFree( txtbuf );
    saved = TRUE;
}


/***********************************************************************
**                                                                    **
**  FileNew()                                                         **
**                                                                    **
**  This function is called from the File/New menu choice. It clears  **
**  the text buffer, resets the current file, and disables the File/  **
**  Save menu choice.                                                 **
**                                                                    **
***********************************************************************/

void FileNew()
{
    XmTextSetString( textwin, "" );

    if (curfile != NULL)
        XtFree( curfile );
    curfile = NULL;
}


/***********************************************************************
**                                                                    **
**  FileOpen()                                                        **
**                                                                    **
**  This function is called from the File/Open menu choice. All it    **
**  does is invoke the Standard File dialog -- SFProc and ReadProc    **
**  do the real work.                                                 **
**                                                                    **
***********************************************************************/

void FileOpen()
{
    ManageStdFile( "Open...", ReadProc, NULL );
}


/***********************************************************************
**                                                                    **
**  FileSave()                                                        **
**                                                                    **
**  This function is a link to WriteProc(), which writes the text     **
**  buffer into a file using the current filename.                    **
**                                                                    **
***********************************************************************/

void FileSave()
{
    if (curfile == NULL)
        FileSaveAs();
    else
        WriteProc();
}


/***********************************************************************
**                                                                    **
**  FileSaveAs()                                                      **
**                                                                    **
**  This function is called from the File/Save-As menu choice. It     **
**  invokes the Standard File dialog, and links it to WriteProc.      **
**                                                                    **
***********************************************************************/

void FileSaveAs()
{
    ManageStdFile( "Save As...", WriteProc, curfile );
}