Monster Media 1994 #1/monster.zip/monster/PROG_GEN/FACETV.ZIP/ANNOUNCE.CPP

C/C++ Source or Header | 1994-01-04 | 9KB | 373 lines

/************************************************************************
**
** @(#)announce.cpp        05/26/93    Chris Ahlstrom
**
**    C++ version.
**
**    Implements a general and extensible set of error and informational
** messages.
**
*************************************************************************/

#define ANNOUNCE_cpp

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

#include "tinput.h"    // "Variations on TInputLine in C++", Op. 3.10
#include "announce.h"    // generic error-handling on a small budget
#include "boxtools.h"    // helpful support tools for simple monologues


/************************************************************************
** UserMessages constructors
**
**    (Eventually) reads a file to obtain a list of messages; these
** messages are pointed to by errorMessages.
**
**    Actually, we have three versions of the constructor available
** (eventually):
**
**    1.  Creates a class with no messages available.  All callers
**        of this class must provide their own ad hoc messages and
**        use only the string version of the error handler.
**
**    2.  Creates a class assuming a list of messages has been created
**        at compile-time as an array of strings.  The callers of this
**        class can then use either version of errorHandler().
**
**    3.  Same as 2, but the messages are read in from a text-file.
**        This version is not ready yet.
**
*************************************************************************/

UserMessages::UserMessages        // construct messages on the fly
(
    TDeskTop *desk            // the desktop for display
) :
    deskTop        (desk),
    Error        (ERR_NONE),
    userMessages    (NULL),
    userMessagesLength    (0),
    usedErrorFile    (0)
{
}


UserMessages::UserMessages        // construct messages from memory
(
    TDeskTop *desk,            // the desktop for display
    char **msg_buffer,            // pointer to array of messages
    unsigned length            // the number of pointers
) :
    deskTop        (desk),
    Error        (ERR_NONE),
    userMessages    (msg_buffer),
    userMessagesLength    (length),
    usedErrorFile    (0)
{
    if (msg_buffer == NULL)
    {
    Error = ERR_NULL_POINTER;
    deskTop = NULL;
    }
}


UserMessages::UserMessages        // construct messages from a file
(                    // NOT READY YET
    TDeskTop *desk,
    char *msg_file_name
) :
    deskTop        (desk),
    Error        (ERR_NONE),
    usedErrorFile    (0)        // will set this to 1 if successful
{
    char **msg_buffer = NULL;
    unsigned length = 0;

    /*
    ** We will eventually implement messages in a data file.
    ** For now, though, we'll use only memory
    */

    userMessages        = msg_buffer;
    userMessagesLength        = length;

    if (msg_buffer == NULL)
    {
    Error = ERR_NULL_POINTER;
    deskTop = NULL;
    }
}


/************************************************************************
** UserMessages::errorHandler (2 versions)
**
**    This function interfaces between any kind of code, and
** Turbo Vision.  If Turbo Vision is available, its resources are used
** for showing error messages, otherwise straight text output is
** used.
**
** ERR_SHOW_NO_MESSAGE    Behavior needs no flagging to user
** ERR_NONE        Not an error message
** ERR_BAD_MESSAGE    Not to be used as an error code
**
**    Rather than provide one version, which uses a bogus parameter
** value (NULL) to indicate that a code is available, we provide
** two overloaded versions.  One accepts a message-code as a parameter
** (so the caller doesn't need to know the message contents), and the
** other uses a message pointers (so the caller provides the text
** of the message... a little dangerous or inflexible).
**
*************************************************************************/

static char *DEFAULT_BAD_MESSAGE =
    "%%Message support erroneous for this part of the program!";

void
UserMessages::errorHandler        // a message is provided
(
    char *message
)
{
    if (message == NULL)
    message = DEFAULT_BAD_MESSAGE;
    Error = ERR_USER;

    errorBox(message, 0U);
}


void
UserMessages::errorHandler        // a message code is provided
(
    int message
)
{
    char *messstr;

    ErrorCode messagecode = (ErrorCode) message;
    if (messagecode != ERR_SHOW_NO_MESSAGE)
    {
    if (messagecode < 0 || messagecode > userMessagesLength)
        messstr = DEFAULT_BAD_MESSAGE;
    else
        messstr = userMessages[messagecode-1];
    errorBox(messstr, 0U);
    }
    Error = messagecode;            // set this "global"
}


/************************************************************************
** UserMessages::errorBox
**
**    Displays a simple dialog box proclaiming an error condition.
** A single value may be optionally provided, in which case we
** hope the value and the message string (in the guise of a format
** string) match up.  If 0, the value is not used.
**
**    Called by errorHandler(), but can be called on its own, too.
**
*************************************************************************/

void
UserMessages::errorBox
(
    char *message,
    unsigned value
)
{
    if (message == NULL)
    {
    message = "%Programming error";
    }
    else
    {
    if (strlen(message) > ERR_STRING_SIZE-8)    // for safety
    {
        message = "%Programming error";
    }
    else
    {
        if (value != 0U)
        {
        sprintf(errorString, message, value);
        message = errorString;
        }
    }
    }
    messageBox(message, mfError | mfOKButton);
}


/************************************************************************
** UserMessages::confirmation
**
**    Simple way to get yes or no status.
**
*************************************************************************/

YesNoType
UserMessages::confirmation
(
    char *string            // short message inside the box
)
{
    ushort action;
    YesNoType code;

    code = NO;

    action = messageBox(string, mfWarning | mfOKCancel);
    if (action == cmOK)
    code = YES;
    return code;
}


/************************************************************************
** UserMessages::lastError()
**
**    Provides access to the private error code for the latest error.
**
*************************************************************************/

ErrorCode
UserMessages::lastError ()
{
    return Error;
}


/************************************************************************
** UserMessages::prompt
**
**    Simple way to get yes or no status.
**
*************************************************************************/

int
UserMessages::prompt
(
    char *string            // short message inside the box
)
{
    ushort action;
    int code;

    code = NO;

    action = messageBox(string, mfInformation|mfOKCancel);
    if (action == cmOK)
    code = YES;
    return code;
}


/************************************************************************
** UserMessages::msgHandler()
**
**    More robust and flexible way to present messages.
**
*************************************************************************/

void
UserMessages::msgHandler
(
    char *string
)
{
    if (string == NULL)
    string = "\n%%Programmer: null string passed to msgHandler\n";

    (void) messageBox(string, mfInformation|mfOKButton);
}


/************************************************************************
** UserMessages::bannerHandler
**
**    Handles banner strings by first determining the width (in
** characters) and height (in lines) of the banner, then generating
** the appropriate box.
**
**    The user must click on the OK button to continue.  There
** is only a return value of non-ERR_NONE if an internal problem
** occurred.
**
*************************************************************************/

ErrorCode
UserMessages::bannerHandler
(
    char *message
)
{
    if (message == NULL)
    {
    message = "%%Programming error";
    }

    ErrorCode error = ERR_NONE;
    TPoint banner;            // calculated size of text
    TRect box;                // calculated size of dialog

    banner    = banner_size(message);    // dimensions of the banner
    box        = banner_spec(banner);    // box banner fits into

    TDialog *pd = new TDialog(box, "Information");

    if (pd)                // did it work above?
    {
    TRect text;            // location and extent of text

    text.a.x = BOX_MARGIN;        // move to text boundary
    text.a.y = BOX_TOP;        // move to text line
    text.b.x = banner.x;        // width of the text
    text.b.y = banner.y;        // heigth of the text
    text.b  += text.a;        // lower right corner of text

    TView *b = new TStaticText(text, message);
    if (b)
    {
        pd->insert(b);        // display the text

        TRect button;

        button = banner_OK(box);    // location of button in box
        b = new TButton(button, "~O~K", cmOK, bfDefault);
        if (b)
        pd->insert(b);        // display the OK button

        ushort control;
        control = deskTop->execView(pd);    // display the whole box

        /*
        ** Since there is no Cancel button, the following code
        ** serves no purpose.  Oh, well!
        */

        if (control != cmCancel)
        error = ERR_NONE;
        else
        error = ERR_USER_ABORT;
    }
    else
    {
        TView *b = new TStaticText(TRect(4,4,16,5), "DIALOG ERROR");
        if (b)
        pd->insert(b);
        deskTop->execView(pd);
        error = ERR_DIALOG;
    }
    deskTop->destroy(pd);        // remove the box now
    }
    return error;
}