TweetFollow Us on Twitter

XCMD Shell
Volume Number:9
Issue Number:6
Column Tag:Object-programming

Think C Shell for XCMDs

Incorporating XCMDs into your application without alteration

By Gerry H. Kenner, Magna, Utah

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

About the author

Gerry Kenner is a professional electrical and computer engineering consultant, university researcher and sometimes writer who specializes in image analysis systems for investigative scientists.

INTRODUCTION

Recently, I submitted an article to MacTech Magazine entitled “Three Subclasses for Screen Input/Output” in which I described the creation of three THINK C classes which I use as general utilities when developing applications. These classes were named BGetTCLInfo, BDisplayDoc and BBitMapDoc whose functions were to ask for data input, output data and output bitmap dumps respectively. In this article, I am going to show how BGetTCLInfo and BDisplayDoc can be used for development of XCMDs. The use of two other classes, BEditDoc and BEditPane will also be demonstrated.

The idea is to write XCMDs in such a way that they can be incorporated in either THINK C application or code resource projects without alteration. The XCMD can be written in standard C or it can be object oriented. Once incorporated into a THINK C object oriented application shell, standard debugging techniques can be used to follow the execution of the code.

The code resource project consists of the standard main function for interfacing with HyperCard. This function then calls the code for the XCMD which is in a separate file.

The application project is somewhat more complicated in that it initially creates an object of class BGetTCLInfo for getting whatever information is needed by the XCMD, puts it in HyperCard usable form, executes the XCMD code and then uses a BDisplayDoc object to pass the results back to the programmer.

If the programmer wants to use HyperTalk utility functions, he must create a code file named something like HyperUtil.c (or HyperXcmd.c for that matter) and provide alternate source code for any functions called. I have not done this because I feel that HyperTalk utilities should be avoided in favor of THINK C library functions or SANE toolbox calls.

I haven’t had occasion to try it but programming windoids may be a problem.

Descriptions of the classes BGetTCLInfo, BDisplayDoc, BEditDoc and BEditPane are not included in this article. The reader will need to obtain the February, 1993 issue (page 18) of MacTech Magazine in which they are described and/or purchase a copy of the MacTech Magazine disk for this issue to get the source code. [Or you can download it from one of the online services. - Ed.]

Disclaimer

As in my previous article, I am only including the code necessary to understand the project. This code is enough for an intermediate programmer to fill in what is missing. Typically, I do not declare variables or state which header files must be included. A copy of the complete project is available on the MacTech Magazine disk.

CODE RESOURCE PROJECT

Description

This is a regular code resource with the difference that code resource specific code is included in the main function while a call is made to the XCMD code which is in a separate file. In this example the code necessary for setting up A4 addressing will not execute properly in a standalone application so it executed in the main function of the XCMD.

Project

Create a new project named Flash.Π and two empty code files named FlashXCMD.c and Flash.c. Incorporate these files as well as the libraries ANSI-A4 and MacTraps into the project. Flash.c will contain the XCMD code that is common to both the code resource project and the application project. FlashXCMD.c will contain the main function of the Flash code resource.

Set up the project to build a code resource named FlashXCMD of type XCMD with a resource number such as 30.

Implementation

The code of the main function is as follows:

/* 1 */
pascal void main(XCmdPtr pp)
{
 RememberA0();   //Setup and save register A4
 SetUpA4();

 FlashMain(pp);

 RestoreA4();
}

RememberA0 and SetUpA4 set up A4 addressing while RestoreA4 removes it. FlashMain is a call to the XCMD code. For the above code to compile, it is necessary to #include the files SetUpA4.h and Flash.h.

FlashMain is part of a file named Flash.c. It contains code for flashing the screen and beeping the number of times the user specifies in the HyperCard stack where the XCMD is called. It then returns this number to HyperCard. Its code is as follows. This method is based on a HyperCard XCMD demonstration program originally written by Apple Computer.

/* 2 */

#include <string.h>
#include <QuickDraw.h>
#include “Flash.h”

pascal void FlashMain(XCmdPtr paramPtr)
{
 short  again;
 long   flashCount;
 Handle returnHdl;
 GrafPtrport;
 Str255 str, tempStr;

 // First param is flash count.  
 // Convert it to a pascal string
 returnHdl = NewHandle(256L);
 strcpy((char*)str, 
 (char*)*(unsigned char **)paramPtr->params[0]);
 CtoPstr((char*)str);
 
 // Convert the string to a number
 StringToNum(str, &flashCount);
 PtoCstr((char*)str);
 
 // Invert the screen and sound the beep.
 GetPort(&port);
 for (again = 0; again < flashCount; again++) 
 {
 InvertRect(&port->portRect);
 InvertRect(&port->portRect);
 SysBeep(5);
 }
 
 // Build the return string.
 strcpy((char*)tempStr, “The number of flashes was “);
 strcat((char*)tempStr, (char*)str);
 strcat((char*)tempStr, “ “);
 strcat((char*)tempStr, (char*)”\r”);
 strcpy((char*)*returnHdl, (char*)tempStr);
 paramPtr->returnValue = returnHdl;
}

Short, brief and simple as an example should be. The only other thing you need to know is that Flash.h contains the prototype declaration of the function FlashMain and #includes HyperXCmd.h.

Create a HyperCard stack named Flash Stack with one button which contains the following script.

/* 3 */

on mouseUp
  put FlashXCMD(5) into msg
end mouseUp

Compile the code resource and merge it with the above stack. Run the XCMD to confirm that it is functional.

STANDALONE APPLICATION

Description

The purpose of this object oriented code is to provide a dialog box asking for input, convert it to a HyperCard usable format, call the XCMD code and then display return information.

Project

The easiest way to get the necessary project is to make a copy of THINK C’s Starter Project, compile it and then make the appropriate name changes, i.e., Starter.Π to FlashObject.Π, Starter.c to FlashObject.c, StarterApp.c to flApp.c, etc. Remove the StarterDoc and StarterPane classes from the project and eliminate any references to them as they are not necessary. In the StarterApp files change all instances of the prefix Starter with fl. Add all the dialog box classes. Add CButton, CCheckBox, CIconPane, CRadioControl and CRadioGroupPane of the control classes. The ANSI and SANE libraries will be required before the project is finished. Finally, add Flash.c from above to the project.

Implementation

In this case, the main function will look something like this when the changes have been made.

/* 4 */

#include “flApp.h”

void main()
{
 flApp  *theApp; 

 theApp = new flApp;
 
 theApp->IflApp();
 theApp->XcmdRun();
 theApp->Exit();
}

The flApp object is entered via the XcmdRun method to avoid complications which would result from overriding the Run method of the CApplication class.

In the flApp class, the methods CreateDocument and OpenDocument must be overridden to become donothing methods or else removed entirely. This is to prevent the creation of unwanted windows.

Four new methods need to be added to the flApp class. These are named XcmdRun, GetParams, FillParamPtr and DumpData. They have the following functions.

XcmdRun Access method. Launch XCMD.

GetParams Get input parameters.

FillParamPtr Convert input parameters to HyperCard readable form.

DumpData Dump results to a window.

XcmdRun gets the input, sends it out for conversion, calls the XCMD and then outputs the result. Its code is as follows.

/* 5 */

void flApp::XcmdRun(void)
{
 XCmdPtrparamPtr;
 char   returnStr[1024];
 
 paramPtr = (XCmdPtr)NewPtr(136L); // Size of XCmdBlock.
 GetParams(returnStr);
 
 FillParamPtr(paramPtr, returnStr);
 FlashMain(paramPtr);
 
 DumpData(paramPtr->returnValue);
 // A real program would dispose of paramPtr and its handles
 // at this point.
}

The parameter data is input by creating an object of class BGetTCLInfo which displays a dialog box containing an edit text box into which information can be entered. The format used for entering the information is “First set of data”,”Second set of data”, etc just as is done in HyperCard scripts. In the case of our example, we would enter something like “3”. By enclosing it between quotes just about anything including 32k text files can be read in this way.

/* 6 */

void flApp::GetParams(char *paramStr)
{
 #define DLOGinfo601 // Resource ID for DLOG template    
 
 BGetTCLInfo*theDocument = NULL;
 Rect   boxDescription;
 
 SetRect(&boxDescription, 20, 20, 260, 60);
 
 theDocument = new(BGetTCLInfo);
 theDocument->IBGetTCLInfo(DLOGinfo, this);
 theDocument->GetInfo(“Number of flashs”, paramStr);
 theDocument->Dispose();
}

The FillParamPtr method is a conversion routine which takes data input in the format given above and creates handles pointing to the text between each pair of quotation marks.

/* 7 */

void flApp::FillParamPtr(XCmdPtr paramPtr, char *paramStr)
{
 short  count = 0;
 size_t theLength;
 char   *tempPtr, *tokenPtr;
 char   tokenStr[256];
 
 tempPtr = paramStr;
 while (*tempPtr != 0x00)
 {
 tokenPtr = (char*)&tokenStr;
 if (*tempPtr == 0x22)
 {
 ++tempPtr;
 while (*tempPtr != 0x22)
 {
 *tokenPtr = *tempPtr;
 ++tempPtr;
 ++tokenPtr;
 }
 ++tempPtr;
 if (*tempPtr == 0x2C)
 ++tempPtr;
 }
 else
 {
 while (*tempPtr != 0x2C)
 {
 *tokenPtr = *tempPtr;
 ++tempPtr;
 ++tokenPtr;
 }
 ++tempPtr;
 }
 *tokenPtr = 0x00;
 theLength = strlen(tokenStr);
 paramPtr->params[count] = NewHandle(theLength + 1);
 strcpy((char*)*(paramPtr->params[count]), tokenStr);
 ++count;
 }
 paramPtr->paramCount = count;
}

FlashMain was listed above as part of the code resource project. It is found in the Flash.c file.

Once the program has returned from the FlashMain call, the DumpData method is called to create an output window displaying the data returned by the XCMD code. This is done by creating an object of class BDumpData. The code is as follows.

/* 8 */

void flApp::DumpData(Handle theData)
{
 BDisplayOutput  *theOutput;
 
 gBartender->DisableMenuBar();
 theOutput = new BDisplayOutput;
 theOutput->IBDisplayOutput(this, TRUE);
 theOutput->DisplayRun(theData);
 theOutput->Dispose();
}

Use the above listings to add the methods to the flApp.c file. Add the following #include statements.

/* 9 */

#include "flash.h"
#include "CBartender.h"
#include "BGetTCLInfo.h"
#include "BDisplayOutput.h"
#include "size_t.h"
#include "string.h"

Make the appropriate changes in the flApp.h file and add #include “HyperXCmd.h”. Add BGetTCLInfo.c, BDisplayOutput.c, BEditDoc.c and BEditPane.c to the project. Add the DLOG and DITL resources listed below to the resource file. Compile and do whatever additional tweaking is necessary. One of the tweaks will be to increase the project memory to about 500k if it hasn’t already been done.

RESOURCES

DLOG and DITL resources numbered 601 must be added to provide a template for the prompt dialog box. This consists of an OK button centered at the bottom, one line of static text at the top with a large edit text box in between. The exact size and layout of the resource are determined by programmer tastes and requirements.

RUNNING

When the project is run, a dialog box will appear soliciting user input. Type in a number in quotation marks such as “5” just as it would appear in the parameter list for a Hypercard call. The computer will then beep for the listed number of times but will not flash. Finally, a window will appear with the message “The number of flashes was 5”. Although interesting, I did not consider it worth the effort for this paper to determine why the screen did not flash on a Power Book 100.

FINAL REMARKS

I have been using this system for over a year. The principle advantages over using compiler statements to alternate between creating XCMDs and applications is that readability is not sacrificed and the input/output capabilities make it easy to keep track of what is going on.

I can be reached on internet at ghkenner@cc.utah.edu and AppleLink at UUTL.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Viber 11.9.1 - Send messages and make fr...
Viber lets you send free messages and make free calls to other Viber users, on any device and network, in any country! Viber syncs your contacts, messages and call history with your mobile device, so... Read more
Vallum 3.3.2 - $15.00
Vallum is a little tool that helps you monitor and block apps connections and throttle apps bandwidth. It is able to intercept connections at the application layer, and hold them while you decide... Read more
Microsoft OneNote 16.31 - Free digital n...
OneNote is your very own digital notebook. With OneNote, you can capture that flash of genius, that moment of inspiration, or that list of errands that's too important to forget. Whether you're at... Read more
Apple Pages 8.2.1 - Apple's word pr...
Apple Pages is a powerful word processor that gives you everything you need to create documents that look beautiful. And read beautifully. It lets you work seamlessly between Mac and iOS devices, and... Read more
Numbers 6.2.1 - Apple's spreadsheet...
With Apple Numbers, sophisticated spreadsheets are just the start. The whole sheet is your canvas. Just add dramatic interactive charts, tables, and images that paint a revealing picture of your data... Read more
f.lux 39.9873 - Adjusts the color of you...
f.lux makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day. Ever notice how people texting at night have that eerie blue glow? Or wake... Read more
Deeper 2.5.0 - Enable hidden features in...
Deeper is a personalization utility for macOS which allows you to enable and disable the hidden functions of the Finder, Dock, QuickTime, Safari, iTunes, login window, Spotlight, and many of Apple's... Read more
NTFS 15.5.71 - Provides full read and wr...
NTFS breaks down the barriers between Windows and macOS. Paragon NTFS effectively solves the communication problems between the Mac system and NTFS. Write, edit, copy, move, delete files on NTFS... Read more
MTR 5.3.0.0 - The Mac's oldest and...
MTR (was MacTheRipper)--the Mac's oldest and smartest DVD-backup app. MTR - the complete toolbox, not a one-trick, point-and-click extractor. MTR is intended for making fair-use, backup copies of... Read more
Keynote 9.2.1 - Apple's presentatio...
Easily create gorgeous presentations with the all-new Keynote, featuring powerful yet easy-to-use tools and dazzling effects that will make you a very hard act to follow. The Theme Chooser lets you... Read more

Latest Forum Discussions

See All

Black Desert Mobile gets an official rel...
Pearl Abyss has just announced that its highly-anticipated MMO, Black Desert Mobile, will launch globally for iOS and Android on December 11th. [Read more] | Read more »
Another Eden receives new a episode, cha...
Another Eden, WFS' popular RPG, has received another update that brings new story content to the game alongside a few new heroes to discover. [Read more] | Read more »
Overdox guide - Tips and tricks for begi...
Overdox is a clever battle royale that changes things up by adding MOBA mechanics and melee combat to the mix. This new hybrid game can be quite a bit to take in at first, so we’ve put together a list of tips to help you get a leg up on the... | Read more »
Roterra Extreme - Great Escape is a pers...
Roterra Extreme – Great Escape has been described by developers Dig-It Games as a mini-sequel to their acclaimed title Roterra: Flip the Fairytale. It continues that game's tradition of messing with which way is up, tasking you with solving... | Read more »
Hearthstone: Battlegrounds open beta lau...
Remember earlier this year when auto battlers were the latest hotness? We had Auto Chess, DOTA Underlords, Chess Rush, and more all gunning for our attention. They all had their own reasons to play, but, at least from where I'm standing, most... | Read more »
The House of Da Vinci 2 gets a new gamep...
The House of Da Vinci launched all the way back in 2017. Now, developer Blue Brain Games is gearing up to deliver a second dose of The Room-inspired puzzling. Some fresh details have now emerged, alongside the game's first official trailer. [Read... | Read more »
Shoot 'em up action awaits in Battl...
BattleBrew Productions has just introduced another entry into its award winning, barrelpunk inspired, BattleSky Brigade series. Whilst its previous title BattleSky Brigade TapTap provided fans with idle town building gameplay, this time the... | Read more »
Arcade classic R-Type Dimensions EX blas...
If you're a long time fan of shmups and have been looking for something to play lately, Tozai Games may have just released an ideal game for you on iOS. R-Type Dimensions EX brings the first R-Type and its sequel to iOS devices. [Read more] | Read more »
Intense VR first-person shooter Colonicl...
Our latest VR obsession is Colonicle, an intense VR FPS, recently released on Oculus and Google Play, courtesy of From Fake Eyes and Goboogie Games. It's a pulse-pounding multiplayer shooter which should appeal to genre fanatics and newcomers alike... | Read more »
PUBG Mobile's incoming update bring...
PUGB Mobile's newest Royale Pass season they're calling Fury of the Wasteland arrives tomorrow and with it comes a fair chunk of new content to the game. We'll be seeing a new map, weapon and even a companion system. [Read more] | Read more »

Price Scanner via MacPrices.net

Weekend Sale: Apple AirPods Pro for $234.98 a...
Abt Electronics has Apple’s new AirPods Pro in stock and on sale today for $234.98 including free shipping and free returns. Their price is $15 off Apple’s MSRP for these AirPods and tie Amazon... Read more
New 2019 16″ MacBook Pros on sale for $100 of...
Apple Authorized Reseller Adorama has new 2019 16″ MacBook Pros on sale today for $100 off Apple’s MSRP, each including free shipping. In addition, Adorama charges sales tax for NY & NJ residents... Read more
Apple Watch Series 3 GPS models on sale for l...
Amazon has Apple Watch Series 3 GPS models on sale starting at only $179. There prices are the lowest we’ve ever seen for these models from any Apple reseller. Choose Amazon as the seller rather than... Read more
iOS Bug In Facebook News Feed Lets Device Ca...
NEWS: 11.15.19- Users of the Facebook social media platform’s mobile app running on iOS devices won’t, like, this piece of news one bit in where a bug in the News Feed gave access to the camera... Read more
16″ MacBook Pros on sale! Preorder at Amazon...
Apple’s new 16″ MacBook Pros were only introduced yesterday, but Amazon is already offering a $100 discount on preorders. Prices for the base 6-Core 16″ MacBook Pros start at $2299: – 2019 16″ 2.6GHz... Read more
Use our exclusive MacBook Price Trackers to f...
Our Apple award-winning MacBook price trackers are the best place to look for the best sales & lowest prices on new and clearance MacBook Airs and MacBook Pros–including Apple’s new 16″ MacBook... Read more
New November Verizon iPhone deal: Get an iPho...
Verizon has the 64GB iPhone Xr on sale for 50% off for a limited time, plus they will include a free $200 prepaid MasterCard and a free Amazon Echo Dot. That reduces their price for the 64GB iPhone... Read more
Apple cuts prices on clearance, refurbished 2...
Apple has clearance 2018 15″ 6-Core Touch Bar MacBook Pros, Certified Refurbished, now available starting at only $1829. Each model features a new outer case, shipping is free, and an Apple 1-year... Read more
Up to $450 price drop on clearance 15″ MacBoo...
B&H Photo has dropped prices Apple’s 2019 15″ 6-Core and 8-Core MacBook Pros by $400-$450 off original MSRP, starting at $1999, with free overnight shipping available to many addresses in the US... Read more
Here’s how to save $200 on Apple’s new 16″ Ma...
Apple has released details of their Education discount associated with the new 2019 16″ 6-Core and 8-Core MacBook Pros. Take $200 off the price of the new 8-Core model (now $2599) and $200 off the 16... Read more

Jobs Board

Best Buy *Apple* Computing Master - Best Bu...
**746887BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Store NUmber or Department:** 001512-Ankeny-Store **Job Read more
Best Buy *Apple* Computing Master - Best Bu...
**746836BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Store NUmber or Department:** 000341-Scranton-Store **Job Description:** **What Read more
QA Manager, *Apple* - CBS Corporation (Unit...
# QA Manager, Apple **REF#:** 35331 **CBS BUSINESS UNIT:** CBS Interactive **JOB TYPE:** Full-Time Staff **JOB SCHEDULE:** **JOB LOCATION:** Burbank, CA **ABOUT Read more
*Apple* Mobility Pro - Best Buy (United Stat...
**744315BR** **Job Title:** Apple Mobility Pro **Job Category:** Store Associates **Store NUmber or Department:** 000662-Auburn AL-Store **Job Description:** At Best Read more
Nurse Practitioner - Field Based (San Bernard...
Nurse Practitioner - Field Based (San Bernardino, CA, Apple Valley, Hesperia) **Location:** **United States** **New** **Requisition #:** PS30312 **Post Date:** 4 Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.