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 );
}

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

xScope 4.1.2 - Onscreen graphic measurem...
xScope is powerful set of tools that are ideal for measuring, inspecting, and testing on-screen graphics and layouts. Its tools float above your desktop windows and can be accessed via a toolbar,... Read more
MacFamilyTree 7.3.3 - Create and explore...
MacFamilyTree gives genealogy a facelift: it's modern, interactive, incredibly fast, and easy to use. We're convinced that generations of chroniclers would have loved to trade in their genealogy... Read more
Skype 7.5.0.738 - Voice-over-internet ph...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
PushPal 3.0 - Mirror Android notificatio...
PushPal is a client for Pushbullet, which automatically shows you all of your phone's notifications right on your computer. This means you can see who's calling or read text messages even if your... Read more
Logic Pro X 10.1.1 - Music creation and...
Apple Logic Pro X is the most advanced version of Logic ever. Sophisticated new tools for professional songwriting, editing, and mixing are built around a modern interface that's designed to get... Read more
VLC Media Player 2.2.0 - Popular multime...
VLC Media Player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, MP3, OGG, ...) as well as DVDs, VCDs, and various streaming protocols. It... Read more
Sound Studio 4.7.8 - Robust audio record...
Sound Studio lets you easily record and professionally edit audio on your Mac. Easily rip vinyls and digitize cassette tapes, or record lectures and voice memos. Prepare for live shows with live... Read more
LibreOffice 4.4.1.2 - 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
VueScan 9.5.03 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Freeway Pro 7.0.3 - Drag-and-drop Web de...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With its user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more

This Week at 148Apps: February 23-27, 20...
Final February Fun at 148Apps   How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you’re looking for. The ones we love become Editor’s Choice, standing out... | Read more »
GDC 2015 – Does Not Commute is Definitel...
GDC 2015 – Does Not Commute is Definitely a Game You Should Keep an Eye on Posted by Rob Rich on March 2nd, 2015 [ permalink ] We were teased about Mediocre Games’ (Smash Hit, | Read more »
F84 Games & POW! Announce Stan Lee V...
F84 Games has announced that it is working with legendary comic creator Stan Lee and POW! Entertainment to produce Stan Lee’s Hero Command. The game will be a action adventure of heroic proportions. | Read more »
Setlyst Keeps Your Set Straight So You C...
Setlyst Keeps Your Set Straight So You Can Focus On Rocking Out. Posted by Jessica Fisher on March 2nd, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Space is Vast, So Space Agency Has a Vas...
Space is Vast, So Space Agency Has a Vast New Update! Posted by Jessica Fisher on March 2nd, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Size DOES Matter Review
Size DOES Matter Review By Campbell Bird on March 2nd, 2015 Our Rating: :: HARD TO BEATUniversal App - Designed for iPhone and iPad This rhythm game has a unique control scheme and performance system that make it feel like a true... | Read more »
The first ever action 3D card battler Al...
On the other hand, you probably haven’t played an action 3D card battler – until now. Step forward, All Star Legion. All Star Legion is a 3D QTE-based action RPG card battler, but fear not – the game itself isn’t as convoluted as its description.... | Read more »
Travel Back to the 1980s With the Making...
Headup Games has released a hilarious making of video for its upcoming title, Pixel Heroes: Byte & Magic. The game is a RPG/Roguelike where you control three heroes set to save the township of Pixton from an evil cult called The Sons of Dawn.... | Read more »
Heavenstrike Rivals Review
Heavenstrike Rivals Review By Campbell Bird on March 2nd, 2015 Our Rating: :: HEAVENLY STRATEGICUniversal App - Designed for iPhone and iPad Despite a few flaws, this free-to-play strategy game is a fun mix of new and old strategy... | Read more »
Get The Whole Story – Lone Wolf Complete...
Get The Whole Story – Lone Wolf Complete is Now Available and On Sale Posted by Jessica Fisher on February 27th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »

Price Scanner via MacPrices.net

Sale! 15-inch 2.2GHz Retina MacBook Pro for $...
 Best Buy has the 15″ 2.2GHz Retina MacBook Pro on sale for $1774.99 $1799.99, or $225 off MSRP. Choose free home shipping or free local store pickup (if available). Price valid for online orders... Read more
27-inch 3.5GHz 5K iMac in stock today and on...
 B&H Photo has the 27″ 3.5GHz 5K iMac in stock today and on sale for $2299 including free shipping plus NY sales tax only. Their price is $200 off MSRP, and it’s the lowest price available for... Read more
Apple Launches Free Web-Based Pages and Other...
Apple’s new Web-only access to iWork productivity apps is a free level of iCloud service available to anyone, including people who don’t own or use Apple devices. The service includes access to Apple... Read more
Survey Reveals Solid State Disk (SSD) Technol...
In a recent SSD technology use survey, Kroll Ontrack, a firm specializing in data recovery, found that while nearly 90 percent of respondents leverage the performance and reliability benefits of SSD... Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store is offering Apple Certified Refurbished 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
Updated Mac Price Trackers
We’ve updated our Mac Price Trackers with the latest information on prices, bundles, and availability on systems from Apple’s authorized internet/catalog resellers: - 15″ MacBook Pros - 13″ MacBook... Read more
Apple CEO Tim Cook to Deliver 2015 George Was...
Apple CEO Tim Cook will deliver the George Washington University’s Commencement address to GWU grads on May 17, at which time he will also be awarded an honorary doctorate of public service from the... Read more
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
Save up to $50 on iPad Air 2s, NY tax only, f...
 B&H Photo has iPad Air 2s on sale for $50 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469.99 $30 off - 64GB iPad Air 2 WiFi: $549 $50 off - 128GB iPad Air 2... Read more
16GB iPad Air 2 on sale for $447, save $52
Walmart has the 16GB iPad Air 2 WiFi on sale for $446.99 on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale price for online orders only,... Read more

Jobs Board

*Apple* Pay Automation Engineer - iOS System...
**Job Summary** At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring passion and dedication to your job Read more
Sr. Technical Services Consultant, *Apple*...
**Job Summary** Apple Professional Services (APS) has an opening for a senior technical position that contributes to Apple 's efforts for strategic and transactional Read more
Event Director, *Apple* Retail Marketing -...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global engagement strategy and team. Delivering an overarching brand Read more
*Apple* Pay - Site Reliability Engineer - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Solutions Consultant - Retail Sales...
**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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.