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

Audio Hijack 3.2.0 - Record and enhance...
Audio Hijack (was Audio Hijack Pro) drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio... Read more
FontExplorer X Pro 5.0.1 - Font manageme...
FontExplorer X Pro is optimized for professional use; it's the solution that gives you the power you need to manage all your fonts. Now you can more easily manage, activate and organize your... Read more
Calcbot 1.0.2 - Intelligent calculator a...
Calcbot is an intelligent calculator and unit converter for the rest of us. Featuring an easy-to-read history tape, expression view, intuitive conversion, and much more! Features History Tape -... Read more
MTR 5.0.0.1 - The Mac's oldest and...
MTR (was MacTheRipper)--the Mac's oldest and smartest DVD-backup app--is now updated to version 5.001 MTR -- the complete toolbox, not a one-trick, point-and-click extractor. MTR is intended for... Read more
LibreOffice 4.4.5.2 - Free, open-source...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
Adobe Lightroom 6.1.1 - Import, develop,...
Adobe Lightroom is available as part of Adobe Creative Cloud for as little as $9.99/month bundled with Photoshop CC as part of the photography package. Lightroom 6 is also available for purchase as a... Read more
File Juicer 4.41 - Extract images, video...
File Juicer is a drag-and-drop can opener and data archaeologist. Its specialty is to find and extract images, video, audio, or text from files which are hard to open in other ways. It finds and... Read more
A Better Finder Rename 9.52 - File, phot...
A Better Finder Rename is the most complete renaming solution available on the market today. That's why, since 1996, tens of thousands of hobbyists, professionals and businesses depend on A Better... Read more
OmniFocus 2.2.3 - GTD task manager with...
OmniFocus helps you manage your tasks the way that you want, freeing you to focus your attention on the things that matter to you most. Capturing tasks and ideas is always a keyboard shortcut away in... Read more
TinkerTool 5.4 - Expanded preference set...
TinkerTool is an application that gives you access to additional preference settings Apple has built into Mac OS X. This allows to activate hidden features in the operating system and in some of the... Read more

Cosmonautica (Games)
Cosmonautica 1.1 Device: iOS Universal Category: Games Price: $6.99, Version: 1.1 (iTunes) Description: Cast off! Are you ready for some hilarious adventures in outer space? | Read more »
Rescue humanity from a Demon horde in An...
Angel Stone is Fincon's follow up to the massively successful Hello Hero and is out now on iOS and Android. You play as a member of The Resistance, a group of mighty human warriors who have risen up in defiance of the Demon horde threatening to... | Read more »
Gallery Doctor (Photography)
Gallery Doctor 1.0 Device: iOS iPhone Category: Photography Price: $2.99, Version: 1.0 (iTunes) Description: Free up valuable iCloud and iPhone storage with Gallery Doctor, the only iPhone cleaner that automatically identifies the... | Read more »
You Against Me (Games)
You Against Me 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: A simple game… You. Me. Claim, steal, lock, score, win! | Read more »
Yep, it's True - Angry Birds 2 is O...
The not exactly rumors were true and the birds are back. Angry Birds 2 has come to the App Store and the world will... well I suppose it'll still be the same, but now we have more bird-flinging options! [Read more] | Read more »
You Could Design Your Own Card for Chain...
If you've ever wanted to create your own item, weapon, trap, or even monster for Chainsaw Warrior: Lords of the Night, this is your chance. Auroch Digital is currently holding a contest so that fans can fight to the death (not really) to see which... | Read more »
Bitcoin Billionaire is Going Back in Tim...
If you thought you managed to buy everything there is to buy in Bitcoin Billionaire and make all the money, well you though wrong. Those of you who made it far enough might remember investing in time travel - and it looks like that investment is... | Read more »
Domino Drop (Games)
Domino Drop 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Domino Drop is a delightful new puzzle game with dominos and gravity!Learn how to play it in a minute, master it day by day.Your... | Read more »
OPERATION DRACULA (Games)
OPERATION DRACULA 1.0.1 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0.1 (iTunes) Description: 25% off launch sale!!! 'Could prove to be one of the most accurate representations of the Japanese bullet hell shmup... | Read more »
Race The Sun (Games)
Race The Sun 1.01 Device: iOS iPhone Category: Games Price: $4.99, Version: 1.01 (iTunes) Description: You are a solar craft. The sun is your death timer. Hurtle towards the sunset at breakneck speed in a futile race against time.... | Read more »

Price Scanner via MacPrices.net

Sale! 13-inch MacBook Pros on sale for $100 o...
B&H Photo has 13″ MacBook Pros on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.5GHz/500GB MacBook Pro: $999.99 save $100 - 13″ 2.7GHz/128GB Retina... Read more
Sale! Save $100 on 13-inch MacBook Airs this...
B&H Photo has the 13″ 1.6GHz/128GB MacBook Air on sale for $899.99 including free shipping plus NY tax only. Their price is $100 off MSRP, and it’s the lowest price available for this model.... Read more
Worldwide Tablet Market Decline Continues, Ap...
The worldwide tablet market declined -7.0% year-over-year in the second quarter of 2015 (2Q15) with shipments totaling 44.7 million units according to preliminary data from the International Data... Read more
TP-LINK TL-PA8030P KIT Powerline Featuring Ho...
Consumer and business networking products provider TP-LINK is now shipping its TL-PA8030P KIT AV1200 3-Port Gigabit Passthrough Powerline Starter Kit that expands your home’s network over its... Read more
Apple refurbished iPad Air 2s available for u...
The Apple Store has Apple Certified Refurbished iPad Air 2s available for up to $140 off the price of new models. Apple’s one-year warranty is included with each model, and shipping is free: - 128GB... Read more
Updated Apple iPad Price Trackers
We’ve updated our iPad Air Price Tracker and our iPad mini Price Tracker with the latest information on prices and availability from Apple and other resellers. Read more
Apple refurbished 2014 13-inch 128GB MacBook...
The Apple Store has Apple Certified Refurbished 2014 13″ MacBook Airs available starting at $759. An Apple one-year warranty is included with each MacBook, and shipping is free: - 13″ 1.4GHz/128GB... Read more
Apple’s Education discount saves up to $300 o...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store has Apple Certified Refurbished Mac Pros available for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more
Mac Pros on sale for up to $260 off MSRP
B&H Photo has Mac Pros on sale for up to $260 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2799, $200 off MSRP - 3.5GHz 6-core Mac Pro: $3719.99... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales. Specialist - Retail Customer Service and Sales. Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Online Store UAT Lead - Apple (Unite...
**Job Summary** The Apple Online Store is a fast paced and ever evolving business environment. The User Acceptance Testing (UAT) lead in this organization is able to Read more
*Apple* MAC Support Services Subject Matter...
Title: Apple MAC Support Services Subject Matter Expert Location: Pleasanton, CA Type of position: Temporary Contract for approximately 6 weeks Tasks The tasks for the Read more
Lead Infrastructure Engineer - *Apple* /Mac P...
…of a team * Requires proven problem solving skills Preferred Additional: * Apple Certified System Administrator (ACSA) * Apple Certified Technical Coordinator (ACTC) Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.