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

Latest Forum Discussions

See All

Call of Duty Warzone is a Waiting Simula...
It's always fun when a splashy multiplayer game comes to mobile because they are few and far between, so I was excited to see the notification about Call of Duty: Warzone Mobile (finally) launching last week and wanted to try it out. As someone who... | Read more »
Albion Online introduces some massive ne...
Sandbox Interactive has announced an upcoming update to its flagship MMORPG Albion Online, containing massive updates to its existing guild Vs guild systems. Someone clearly rewatched the Helms Deep battle in Lord of the Rings and spent the next... | Read more »
Chucklefish announces launch date of the...
Chucklefish, the indie London-based team we probably all know from developing Terraria or their stint publishing Stardew Valley, has revealed the mobile release date for roguelike deck-builder Wildfrost. Developed by Gaziter and Deadpan Games, the... | Read more »
Netmarble opens pre-registration for act...
It has been close to three years since Netmarble announced they would be adapting the smash series Solo Leveling into a video game, and at last, they have announced the opening of pre-orders for Solo Leveling: Arise. [Read more] | Read more »
PUBG Mobile celebrates sixth anniversary...
For the past six years, PUBG Mobile has been one of the most popular shooters you can play in the palm of your hand, and Krafton is celebrating this milestone and many years of ups by teaming up with hit music man JVKE to create a special song for... | Read more »
ASTRA: Knights of Veda refuse to pump th...
In perhaps the most recent example of being incredibly eager, ASTRA: Knights of Veda has dropped its second collaboration with South Korean boyband Seventeen, named so as it consists of exactly thirteen members and a video collaboration with Lee... | Read more »
Collect all your cats and caterpillars a...
If you are growing tired of trying to build a town with your phone by using it as a tiny, ineffectual shover then fear no longer, as Independent Arts Software has announced the upcoming release of Construction Simulator 4, from the critically... | Read more »
Backbone complete its lineup of 2nd Gene...
With all the ports of big AAA games that have been coming to mobile, it is becoming more convenient than ever to own a good controller, and to help with this Backbone has announced the completion of their 2nd generation product lineup with their... | Read more »
Zenless Zone Zero opens entries for its...
miHoYo, aka HoYoverse, has become such a big name in mobile gaming that it's hard to believe that arguably their flagship title, Genshin Impact, is only three and a half years old. Now, they continue the road to the next title in their world, with... | Read more »
Live, Playdate, Live! – The TouchArcade...
In this week’s episode of The TouchArcade Show we kick things off by talking about all the games I splurged on during the recent Playdate Catalog one-year anniversary sale, including the new Lucas Pope jam Mars After Midnight. We haven’t played any... | Read more »

Price Scanner via MacPrices.net

Deal Alert! B&H Photo has Apple’s 14-inch...
B&H Photo has new Gray and Black 14″ M3, M3 Pro, and M3 Max MacBook Pros on sale for $200-$300 off MSRP, starting at only $1399. B&H offers free 1-2 day delivery to most US addresses: – 14″ 8... Read more
Department Of Justice Sets Sights On Apple In...
NEWS – The ball has finally dropped on the big Apple. The ball (metaphorically speaking) — an antitrust lawsuit filed in the U.S. on March 21 by the Department of Justice (DOJ) — came down following... Read more
New 13-inch M3 MacBook Air on sale for $999,...
Amazon has Apple’s new 13″ M3 MacBook Air on sale for $100 off MSRP for the first time, now just $999 shipped. Shipping is free: – 13″ MacBook Air (8GB RAM/256GB SSD/Space Gray): $999 $100 off MSRP... Read more
Amazon has Apple’s 9th-generation WiFi iPads...
Amazon has Apple’s 9th generation 10.2″ WiFi iPads on sale for $80-$100 off MSRP, starting only $249. Their prices are the lowest available for new iPads anywhere: – 10″ 64GB WiFi iPad (Space Gray or... Read more
Discounted 14-inch M3 MacBook Pros with 16GB...
Apple retailer Expercom has 14″ MacBook Pros with M3 CPUs and 16GB of standard memory discounted by up to $120 off Apple’s MSRP: – 14″ M3 MacBook Pro (16GB RAM/256GB SSD): $1691.06 $108 off MSRP – 14... Read more
Clearance 15-inch M2 MacBook Airs on sale for...
B&H Photo has Apple’s 15″ MacBook Airs with M2 CPUs (8GB RAM/256GB SSD) in stock today and on clearance sale for $999 in all four colors. Free 1-2 delivery is available to most US addresses.... Read more
Clearance 13-inch M1 MacBook Airs drop to onl...
B&H has Apple’s base 13″ M1 MacBook Air (Space Gray, Silver, & Gold) in stock and on clearance sale today for $300 off MSRP, only $699. Free 1-2 day shipping is available to most addresses in... Read more
New promo at Visible: Buy a new iPhone, get $...
Switch to Visible, and buy a new iPhone, and Visible will take $10 off their monthly Visible+ service for 24 months. Visible+ is normally $45 per month. With this promotion, the cost of Visible+ is... Read more
B&H has Apple’s 13-inch M2 MacBook Airs o...
B&H Photo has 13″ MacBook Airs with M2 CPUs and 256GB of storage in stock and on sale for $100 off Apple’s new MSRP, only $899. Free 1-2 day delivery is available to most US addresses. Their... Read more
Take advantage of Apple’s steep discounts on...
Apple has a full line of 16″ M3 Pro and M3 Max MacBook Pros available, Certified Refurbished, starting at $2119 and ranging up to $600 off MSRP. Each model features a new outer case, shipping is free... Read more

Jobs Board

Medical Assistant - Surgical Oncology- *Apple...
Medical Assistant - Surgical Oncology- Apple Hill Location: WellSpan Medical Group, York, PA Schedule: Full Time Sign-On Bonus Eligible Remote/Hybrid Regular Apply Read more
Omnichannel Associate - *Apple* Blossom Mal...
Omnichannel Associate - Apple Blossom Mall Location:Winchester, VA, United States (https://jobs.jcp.com/jobs/location/191170/winchester-va-united-states) - Apple Read more
Cashier - *Apple* Blossom Mall - JCPenney (...
Cashier - Apple Blossom Mall Location:Winchester, VA, United States (https://jobs.jcp.com/jobs/location/191170/winchester-va-united-states) - Apple Blossom Mall Read more
Operations Associate - *Apple* Blossom Mall...
Operations Associate - Apple Blossom Mall Location:Winchester, VA, United States (https://jobs.jcp.com/jobs/location/191170/winchester-va-united-states) - Apple Read more
Business Analyst | *Apple* Pay - Banco Popu...
Business Analyst | Apple PayApply now " Apply now + Apply Now + Start applying with LinkedIn Start + Please wait Date:Mar 19, 2024 Location: San Juan-Cupey, PR Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.