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

Capo 3.2 - Slow down and learn to play y...
Capo lets you slow down your favorite songs so you can hear the notes and learn how they are played. With Capo, you can quickly tab out your songs atop a highly-detailed OpenCL-powered spectrogram... Read more
OmniOutliner 4.2.3 - Organize your ideas...
OmniOutliner is a flexible program for creating, collecting, and organizing information. Give your creativity a kick start by using an application that's actually designed to help you think. It's... Read more
pwSafe 4.0.1 - Secure password managemen...
pwSafe provides simple and secure password management across devices and computers. pwSafe uses iCloud to keep your password databases backed-up and synced between Macs and iOS devices. It is... Read more
WALTR 1.5.4 - Drag-and-drop any media fi...
WALTR is designed to make it easy to upload and convert any music or video file to an iPad or iPhone format for native playback. It supports a huge variety of media file types, including MP3, MP4,... Read more
Audio Hijack 3.1 - Record and enhance au...
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
PopChar 7.1 - Floating window shows avai...
We're also selling a 5-license family pack for only $25.99! PopChar helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to... Read more
BBEdit 11.1.1 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Picasa 3.9.139 - Organize, edit, and sha...
Picasa and Picasa Web Albums allows you to organize, edit, and upload your photos to the Web from your computer in quick, simple steps. Arrange your photos into folders and albums and erase their... Read more
Mac DVDRipper Pro 5.0.5 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
NetShade 6.2 - Browse privately using an...
This promotion is for NetShade and 1 year of Proxy and VPN services NetShade is an anonymous proxy and VPN app+service for Mac. Unblock your Internet through NetShade's high-speed proxy and VPN... Read more

Dungeoneers Quest (Games)
Dungeoneers Quest 1.0.0.9994 Device: iOS iPhone Category: Games Price: $2.99, Version: 1.0.0.9994 (iTunes) Description: Dungeoneers Dungeoneers is a party based, first-person, dungeon exploration game. Create your party from 6 unique... | Read more »
Block Fortress has a Big New Update for...
Block Fortress is a survival-style game that's as fun as it is blocky. It's also just gotten a rather sizeable update that adds a lot more cool stuff. [Read more] | Read more »
Simple and Surreal Star Base Sim rymdkap...
I really like rymdkapsel. Not just because I'm a sucker for games that are cleverly simple or highly stylisitc, but because it's fun and challenging. Actually it's extremely challenging, which is why I was excited to learn that it's getting a couple... | Read more »
Check out the anticipated Angel Stone in...
Fincon has finally revealed Angel Stone in action in the first ever official gameplay trailer for the anticipated hack and slasher. Angel Stone is set in a post-apocalyptic world in which humanity is in danger of being wiped out by the demonic... | Read more »
Moleskine Timepage is an All-New Calenda...
Moleskine Timepage is a bit of a departure for the notebook manufacturer (since it has little to do with notebooks), but it certainly carries their simple and elegant style quite well. [Read more] | Read more »
Jog on Over and Check Out the New Runtas...
Runtastic has put out a fair number of apps to help you sleep, track excercise, and train various parts of your body. Now it's time for your legs to have their own time in the spotlight with Runtastic Leg Trainer. [Read more] | Read more »
It's Lights Out in the Upcoming Pla...
Ember’s Journey is a stark puzzle platformer with a twist: the entire game is played in darkness. The only light you can see by is the one emanating from your own character. [Read more] | Read more »
MooVee - Your Movies Guru (Entertainmen...
MooVee - Your Movies Guru 1.0 Device: iOS iPhone Category: Entertainment Price: $1.99, Version: 1.0 (iTunes) Description: MooVee helps you effortlessly manage your movies, on your iPhone. | Read more »
Geometry Wars 3: Dimensions (Games)
Geometry Wars 3: Dimensions 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Enjoy the next chapter in the award-winning Geometry Wars franchise and enjoy stunning, console-quality... | Read more »
CHAOS RINGS Ⅲ (Games)
CHAOS RINGS Ⅲ 1.0.0 Device: iOS Universal Category: Games Price: $19.99, Version: 1.0.0 (iTunes) Description: The newest addition to the popular smartphone RPG series is finally here! ・CHAOS RINGS Overview | Read more »

Price Scanner via MacPrices.net

Apple restocks refurbished Mac minis for up t...
The Apple Store has restocked Apple Certified Refurbished 2014 Mac minis, with models available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz... Read more
13-inch 2.4GHz Retina MacBook Pro (refurbishe...
The Apple Store has 2013 Apple Certified Refurbished 13″ 2.4GHz/128GB Retina MacBook Pros available for $879–$320 off original MSRP. Apple’s one-year warranty is standard, and shipping is free: - 13... Read more
Apple refurbished iPad Air 2s now available f...
The Apple Store is now offering Apple Certified Refurbished iPad Air 2s for up to $140 off the price of new models. Apple’s one-year warranty is included with each model, and shipping is free: -... Read more
MacBook Airs on sale for up to $80 off MSRP
Save up to $80 on the purchase of a new 2015 13″ or 11″ 1.6GHz MacBook Air at the following resellers. Shipping is free with each model: 11" 128GB MSRP $899 11" 256GB... Read more
Free Glide Live Video Messaging App Brings Ne...
Glide, an Israeli startup whose popular live video messenger has attracted more than 15 million users, has released significant updates to its free iOS app. Glide for iOS now gives users more control... Read more
Top Markets Saturation To Slow Global Smartph...
According to a new mobile phone forecast from the International Data Corporation (IDC) Worldwide Quarterly Mobile Phone Tracker, smartphone shipments are expected to grow 11.3% in 2015 — down from 27... 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
13-inch 2.5GHz MacBook Pro (refurbished) avai...
The Apple Store has Apple Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.... Read more
Apple refurbished 2014 13-inch Retina MacBook...
The Apple Store has Apple Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and... Read more
What Would the ideal Apple Productivity Platf...
For the past four years I’ve kept a foot in both the Mac and iPad camps respectively. my daily computing hours divided about 50/50 between the two devices with remarkable consistency. However, there’... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Senior Software Engineer - *Apple* SIM - Ap...
Changing the world is all in a day039s work at Apple . If you love innovation, here039s your chance to make a career of it. You039ll work hard. But the job comes with Read more
*Apple* Pay Support Readiness Project Manage...
Changing the world is all in a day039s work at Apple . If you love innovation, here039s your chance to make a career of it. You039ll work hard. But the job comes with 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
Program Manager, *Apple* Community Support...
**Job Summary** Apple Support Communities ( discussions. apple .com) helps customers get the most from their Apple products and services by providing access to Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.