TweetFollow Us on Twitter

Windoid XCMD
Volume Number:6
Issue Number:12
Column Tag:XCMD Corner

Related Info: Event Manager Window Manager

Windoids and HyperCard 2.0

By Donald Koscheka, MacTutor Contributing Editor

If you’ve been writing XCMDs for some time now, you might be a little concerned over how much work is involved in porting your xcmds to Hypercard 2.0. For the most part, this is a trivial process and you need not modify any of your code to support Hypercard 2.0. You will need to recompile with the new xcmd libraries though as the callback engine has been completely re-written to allow for a larger number of callbacks (some 75 as opposed to the 30 or so in HC1.0; the number is a little vague because I found a few callbacks in the library that are not documented anywhere).

For those of you using Think “C”, you will need to convert the XCMD library, “HyperXLib.o” to a Think “C” library. I got this file in MPW format and ran the “oConv” utility on it to convert it to something that Think can use. I then built a library from this. There is one small catch, the Library entry points are all uppercase. You will need to modify your calls to uppercase. For example, PasToZero becomes PASTOZERO. Of course, you might just wait until someone comes along with a more convenient library than the one that is currently distributed.

As I said, your xcmd should work “for the most part”. Certain xcmds will not work very well under Hypercard 2.0 or they will work but their behaviour will be such that you won’t recognize them (kind of like my 2 year old when she skips her nap).

The reason for this is that Hypercard 2.0 implements a completely new external window schema which offers a tremendous benefit to the xcmd writer but which also requires that you rethink your windowing strategy. The benefit of making your xcmds HC2.0 “windoid” friendly is tremendous -- windoids that function in the HC windoid layer will be able to communicate directly with Hypercard and use the Hypercard callbacks. In effect, you get a multiple-window Hypercard stack.

Windoids don’t come for free in Hypercard 2.0 and that’s good. In effect, Apple is leaving it up to each developer to decide what to do with external windows. The only rules that you must obey are those that will allow your windows to function within the external windows layer. This way, your windows will work correctly with other xcmds that also create external windows. Hypercard keeps track of which windows are owned by which xcmds, and it passes window events to each external windoid appropriately.

Windoids.c

Listing 1, “Windoids.c” is an external window xcmd skeleton. It incorporates two new functions of HC 2.0 xcmds: (1) it handles the “?” and “!” queries from the user and (2) it responds to windoid events. The former was covered last month is quite straightforward. We will look at the windoid events in greater detail in this and future columns.

Take a look at the entry point in Listing 1. Note that the first thing we do is check the number of parameters being passed to us by Hypercard. If the parameter count is less than zero (specifically, -1), then we are being passed an external windoid event for a window that we created earlier. If there is only one parameter and it’s “?” or “!” then return the appropriate information about the xcmd back to the caller. In the case of the “?”, you should return usage information. In the case of the “!” you should return a note about who created the xcmd and what it does. This is also a good place to put your copyright notice.

If the parameter count is greater than or equal to zero, then you treat the parameters as ordinary xcmd parameters. However, if the parameter count is less than zero, then you decode the parameter block in an entirely different manner. In this case, the first parameter, params[0] (“C”) or params[1] (Pascal), contains a POINTER to an xcmd event record. This record contains the following fields:

/* 1 */
 
struct XWEventInfo {
 EventRecordevent;
 WindowPtreventWindow;
 long   eventParams[9];
 Handle eventResult;
 }XWEventInfo, *XWEventInfoPtr;

The eventrecord is identical to the event manager event record. The windowPtr is a pointer to the windoid that should get this event. The event parameters and event result have other meanings that we will no doubt explore in the future but which are not required for the code in Listing 1.

In the listing, we call HandleHCEvent with the xcmd parameter block if paramcount is less than zero, otherwise we move to HandleHCmessage which should treat the parameter block like an ordinary xcmd activation. After a little thought this mechanism begs a question -- if we are responding to events in HandleHCEvent, why do we pass the entire parameter block rather than just the xwindow event record? This question gives rise to yet another question -- if that’s the case, why isn’t the parameter block just declared thusly:

/* 2 */

 typedef union{
 XCmdPBlock xcmdParams;
 XWEventInfoxwEventRecord;
 }

These questions did seem troubling to me at first -- I like to pass only those parameters that will be needed by a routine to that routine. An event handler should not need access to the parameter block, should it? The answer is absolutely and herein lies the answer -- by passing the entire parameter block to HandleHCevent, we are able to access Hypercard globals and make callbacks from inside our event loop. The answer to the second question should now be obvious -- we need to keep the parameter block intact so that xcmds can get to the callbacks. Thus the mechanism developed for handling events is correct. We can put our minds at ease and get back to the business of writing the code which is always easier once you develop this sort of intuitive feel for the data that you’re working with; a concept which is axiomatic in object oriented programming, by the way.

If your code needs to dispathc to HandleHCMessage, then you can treat the activation as a routine xcmd call and do whatever you like in HandleHCMessage. You might create a new external window here or close an existing window. Keep in mind that you should not directly call the toolbox calls to open and close windows. Rather, you must use the calls, NewXWindow and CloseXwindow which will create the windows for you and “register” them in the xwindow layer. Aside from that, window management is almost identical in Hypercard as in a stand-alone application.

/* 3 */

extern pascal WindowPtr NEWXWINDOW( XCmdPtr paramPtr,
 Rect *boundsRect,
 StringPtr title, 
        Boolean visible,
 short procID,
 Boolean color,
 Boolean floating); 

extern pascal WindowPtr GETNEWXWINDOW(XCmdPtr paramPtr,
 ResType  templateType,
 short  templateID,
 Boolean  color,
 Booleanfloating);  
extern pascal void CLOSEXWINDOW(XCmdPtr paramPtr, WindowPtr window);

When you create an external window, you use either the call to NewXWindow or the call to GetNewXWindow. Don’t draw in the window or do anything more yet. Hypercard will tell you when the window is ready for use by sending your event loop an Xwindow event called “xOpenEvt”. Not until your xcmd gets this event are you guaranteed to have a window that is ready for use.

At openEvt, you might want to invalidate the window to force an update or append some private data to the refcon. What you do is up to you, just don’t do anything to the window until you get the xOpenEvt.

Similarly, if you have a call to xwindoids of the form: Xwindoids “Close”, windowID then you should do nothing more than issue a call to CloseXWindow and go away. Later on, your xcmd will get the “xCloseEvt” event. At this time you can deallocate any private memory that the window uses and set the passFlag to true advising Hypercard that it’s okay to close the window.

Between xOpenEvt and xCloseEvt, your window will receive more or less normal events and should respond to them in a more or less normal fashion. Things start getting a little fuzzy here as I have noticed that this event loop can have different behaviors depending on what you do with the passflag. The code in Listing 1 does work, and you might want to play with the event loop to learn a little more about the behaviour of xwindows (or xwindoids as I prefer to call them to avoid confusion with that other windowing environment).

Pay particular attention to the goaway and drag code in listing 1. The goaway method does nothing more than advise Hypercard that the user wants to close the window. Later on, HC will pass back to use the xCloseEvt event. In the meantime, the window should just be in limbo.

The drag code works fine here. I discovered that setting the passflag to true will cause Hypercard to handle dragging the window. I hope to learn more about these undocumented parts of the window code as we go along. The content, activate and update methods are pure vanilla. On activate, we just check to see if we’re going active. I take the liberty of invalidating the window to force an update, but this should not be necessary. The invalRgn should be accumulated correctly for the window.

One last thing I would like to recommend is how you respond to suspend/resume events. I like the idea of hiding all my windows on suspend so that they aren’t in the way of the next application. On resume, you should show those windows that were visible at the last suspend. You will need to keep a separate flag for this, the window’s visible won’t be much use here.

In subsequent articles, we’ll hang more decorations on this skeleton and explore Hypercard xWindoids in greater detail. In the meanwhile, take a little time to master listing 1 and get comfortable with this “call and wait” mechanism for opening and closing windows. Overall I think the structure is quite workable and should lead to some very exciting extensions to Hypercard 2.0 in the future. If you discover anything about HC2.0 that you would like to share with your fellow developers, please drop me a line. My new AppleLink is D6845. See you next month.

Listing:  Windoids.c

/************************************/
/* File: Donald Koscheka.c*/
/* --------------------------------*/
/* ©1990 Donald Koscheka  */
/* All Rights Reserved    */
/************************************/
#include<HyperXCMD.h>
#include<HyperUtils.h>
#include<SetUpA4.h>

#ifndef MouseMovedEvt
#define MouseMovedEvt0xFA 
 /* Mouse moved event code*/
#endif
#ifndef SuspendResumeEvt
#define SuspendResumeEvt  0x01
 /* Suspend/Resume event code */
#endif
#define ResumeEvtMask0x1  
 /* Supend or Resume selector */
#define ConvertScrapMask  0x2 
 /* Scrap conversion flag */

pascal void HandleHCEvent( XCmdPtr pp);
pascal void HandleHCMessage( XCmdPtr pp);
pascal void UpdateWindow( WindowPtr wind );
pascal void DoContent(  WindowPtr wind, XWEventInfoPtr ip);

pascal void main( pp )
 XCmdPtrpp;
/************************************
* MAIN ENTRY POINT
************************************/
{
 pp->returnValue = NIL;
 
 if( pp->paramCount < 0 )
 HandleHCEvent( pp );
 else{
 if( pp->paramCount == 1 )
 if( **(pp->params[0]) == '!'  || **(pp->params[0]) == '?' ){
 switch(  **(pp->params[0]) ){
 case '!': 
 pp->returnValue = PASTOZERO( pp, "\pWindoids ©1990, 1991 Donald Koscheka, 
Inc.");
 return;
 case '?':
 pp->returnValue = PASTOZERO( pp, "\pWindoids [command] <parameters>" 
);
 return;
 }
 }
 HandleHCMessage( pp ); 
 }
 UnloadA4Seg( 0L );
 RestoreA4();
}

pascal void HandleHCEvent( pp )
 XCmdPtrpp;
/**********************************
* Handle events in our xWindows  
* returns true if the event was handled ok
**********************************/
{
 short  windoPart;
 Rect   r;
 XWEventInfoPtr  ip= pp->params[0];
 WindowPtrwhichWindow;
 
 pp->passFlag = FALSE;

 switch( ip->event.what ){
 case mouseDown:
 whichWindow = ip->eventWindow;
 windoPart = FindWindow( ip->event.where, &whichWindow );
 if( whichWindow )
 switch ( windoPart ){
 case inGoAway:
 if (TrackGoAway(whichWindow, ip->event.where)) {
 CLOSEXWINDOW( pp,whichWindow );
 pp->passFlag = FALSE;
 }
 break;
 case inDrag: /* handled by hypercard */
 pp->passFlag = TRUE;
 break;
 case inGrow:
 break;
 case inContent:
 if (whichWindow != FrontWindow() )
 SelectWindow( whichWindow );
 else{
 DoContent( whichWindow, ip );
 }
 pp->passFlag = TRUE;
 break;
 default: 
 break;
 }/* window part */
 break;
 case mouseUp:
 break;
 case keyDown:
 case autoKey:
 break;
 case activateEvt: /* [DK] ON ACTIVATE, DRAW THE MENUS,
 ON DEACTIVATE HIDE THE MENUS */
 if ( ip->event.modifiers & activeFlag ){
 r= (ip->eventWindow)->portRect;
 InvalRect( &r );
 }
 pp->passFlag = TRUE;
 break;
 case updateEvt: 
 UpdateWindow(  ip->eventWindow );
 pp->passFlag = TRUE;
 break;
 case app4Evt:
 {
 unsigned char *evtType = &(ip->event.message);
 
 switch( *evtType ){
 case MouseMovedEvt:
 break;
 case SuspendResumeEvt:
 if( ip->event.message & ResumeEvtMask )
 show_all_windows();
 else
 hide_all_windows();
 break;
 }
 }
 pp->passFlag = TRUE;
 break;
 case xOpenEvt:
 ShowWindow( ip->eventWindow );
 pp->passFlag = TRUE;
 break;
 case xCloseEvt:
 pp->passFlag = TRUE;
 break;
 default: 
 break; 
 } /* switch theEvent->what */
}

pascal void DoContent( wind, ip )
 WindowPtrwind;
 XWEventInfoPtr  ip;
/*************************************
* Handle the content region in a mouse down in an xwindow. ip is  a pointer 
to the HyperXevent record, needed to see where the mouse is and what 
the modifiers are.
*************************************/
{ SetPort( wind ); }

pascal void HandleHCMessage( pp )
 XCmdPtrpp;
/*****************************************
* Hypercard has sent us a message which we need to respond to. The command 
is passed in parameter 1 and the arguments are passed in parameter 2..N
* Perhaps you'll add a little parser here to accept valid commands and 
dispatch to the correct command handler. You may pass a command here 
called "openwindow" and another called "closewindow" to allow users to 
create & destroy external windows. 
*****************************************/
{ }

pascal void UpdateWindow( xwind )
 WindowPtrwind;
/******************
* Draw the contents of the window.
* You need to develop some mechanism for storing window specific data. 
 You might try storing the info in the window's refcon.  The choice is 
up to you.  
******************/
{
 BeginUpdate( wind );
 SetPort( wind );
 ClipRect( &wind->portRect );
 EndUpdate( wind );
}

 
AAPL
$104.94
Apple Inc.
+1.95
MSFT
$45.41
Microsoft Corpora
+1.03
GOOG
$546.88
Google Inc.
+14.17

MacTech Search:
Community Search:

Software Updates via MacUpdate

Art Text 2.4.8 - Create high quality hea...
Art Text is an OS X application for creating high quality textual graphics, headings, logos, icons, Web site elements, and buttons. Thanks to multi-layer support, creating complex graphics is no... Read more
Live Interior 3D Pro 2.9.6 - Powerful an...
Live Interior 3D Pro is a powerful yet very intuitive interior designing application. View Video Tutorials It has every feature of Live Interior 3D Standard, plus some exclusive ones: Create multi... Read more
The Hit List 1.1.7 - Advanced reminder a...
The Hit List manages the daily chaos of your modern life. It's easy to learn - it's as easy as making lists. And it's powerful enough to let you plan, then forget, then act when the time is right.... Read more
jAlbum Pro 12.2.4 - Organize your digita...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code!... Read more
jAlbum 12.2.4 - Create custom photo gall...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results Simply drag and drop photos into groups, choose a design... Read more
ExpanDrive 4.1.7 - Access remote files o...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
OmniOutliner Pro 4.1.3 - Pro version of...
OmniOutliner Pro 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'... Read more
Evernote 5.6.2 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
OmniOutliner 4.1.3 - 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
BBEdit 11.0 - Powerful text and HTML edi...
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

Latest Forum Discussions

See All

Puzzle to the Center of the Earth Review
Puzzle to the Center of the Earth Review By Campbell Bird on October 23rd, 2014 Our Rating: :: SPELUNKING PUZZLESUniversal App - Designed for iPhone and iPad Do some puzzles to make some platforms in this smart and fun free-to-play... | Read more »
Sleep Attack TD Review
Sleep Attack TD Review By Jennifer Allen on October 23rd, 2014 Our Rating: :: A TRUE TWISTUniversal App - Designed for iPhone and iPad Sleep Attack TD is a tower defense game with a difference – you can rotate the layout – and it’s... | Read more »
Earn Your Master Camper Badge in Camp Po...
Earn Your Master Camper Badge in Camp Pokemon Posted by Jessica Fisher on October 23rd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Garruk Gets His Revenge in a New Magic 2...
Garruk Gets His Revenge in a New Magic 2015 Expansion, Coming This November Posted by Jessica Fisher on October 23rd, 2014 [ permalink ] | Read more »
Sentinels of the Multiverse Review
Sentinels of the Multiverse Review By Rob Thomas on October 23rd, 2014 Our Rating: :: SENTINELS ASSEMBLEiPad Only App - Designed for the iPad Greater Than Games’ tabletop classic, Sentinels of the Multiverse swoops in to save the... | Read more »
Build Your Own Fantasy Football Dynasty...
Build Your Own Fantasy Football Dynasty with Draft Day Posted by Jessica Fisher on October 23rd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Cars: Fast as Lightning – Tips, Tricks,...
Hey there, Stickers: Want to know all about how impressed we were with Radiator Springs? Check out our Cars: Fast as Lightning review! Cars: Fast as Lightning is a cute and fun app that combines racing and town-building with the charisma and... | Read more »
Jam Messenger Review
Jam Messenger Review By Jennifer Allen on October 23rd, 2014 Our Rating: :: SIMPLE MESSAGINGiPhone App - Designed for the iPhone, compatible with the iPad Want a very quick way to send push-based messages? Jam Messenger is basic... | Read more »
Felllice (Games)
Felllice 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: EXCLUSIVE PRICE DROP! 50% OFF FOR A LIMITED TIME! EAT EAT EAT AND GROW ! | Read more »
The Arrow Game: by Grazie Media (Games)
The Arrow Game: by Grazie Media 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Guide a flying arrow through skyscrapers and city streets to hit a distant target. Experience an endless... | Read more »

Price Scanner via MacPrices.net

Save up to $125 on Retina MacBook Pros
B&H Photo has the new 2014 13″ and 15″ Retina MacBook Pros on sale for up to $125 off MSRP. Shipping is free, and B&H charges NY sales tax only. They’ll also include free copies of Parallels... Read more
Apple refurbished Time Capsules available sta...
The Apple Store has certified refurbished Time Capsules available for up to $60 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $255... Read more
Textilus New Word, Notes and PDF Processor fo...
Textilus is new word-crunching, notes, and PDF processor designed exclusively for the iPad. I haven’t had time to thoroughly check it out yet, but it looks great and early reviews are positive.... Read more
WD My Passport Pro Bus-Powered Thunderbolt RA...
WD’s My Passport Pro RAID solution is powered by an integrated Thunderbolt cable for true portability and speeds as high as 233 MB/s. HighlightsOverviewSpecifications Transfer, Back Up And Edit In... Read more
Save with Best Buy’s College Student Deals
Take an additional $50 off all MacBooks and iMacs at Best Buy Online with their College Students Deals Savings, valid through November 1st. Anyone with a valid .EDU email address can take advantage... Read more
iPad Air 2 & iPad mini 3 Best Tablets Yet...
The new iPads turned out to be pretty much everything I’d been hoping for and more than I’d expected.”More” particularly in terms of a drinking-from-a-firehose choice of models and configurations,... Read more
Drafts 4 Reinvents iOS Productivity App
N Richland Hills, Texas based Agile Tortoise has announced the release of Drafts 4 for iPhone and iPad. Drafts is a quick capture note taking app with flexible output actions. Drafts 4 scales from... Read more
AT&T accepting preorders for new iPads fo...
AT&T Wireless is accepting preorders for the new iPad Air 2 and iPad mini 3, cellular models, for $100 off MSRP with a 2-year service agreement: - 16GB iPad Air 2 WiFi + Cellular: $529.99 - 64GB... Read more
Apple offering refurbished Mac Pros for up to...
The Apple Store is offering Apple Certified Refurbished 2013 Mac Pros 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
Select MacBook Airs $100 off MSRP, free shipp...
B&H Photo has 2014 a couple of MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only. They also include free copies of Parallels Desktop and LoJack for... Read more

Jobs Board

Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work 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
Position Opening at *Apple* - Apple (United...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.