TweetFollow Us on Twitter

Dialog Events
Volume Number:3
Issue Number:1
Column Tag:Basic School

Dialog Events in ZBasic

By Dave Kelly

DIALOG MANIA

The word 'mania' as used in the title of this month's Basic column has a kind of dual meaning. My dictionary says that 'mania' means: 1. wild or violent mental disorder 2. an excessive enthusiasm; obsession. I find both definitions express what it is like to program with ZBasic. Many of you have been following the 'Basic Wars' as they have been progressing. MS Basic 3.0 has been announced as of the writing of this column, although I have not seen it yet. This is supposed to be a $25 upgrade. The MS Basic compiler is also supposed to be out, at least Microsoft is marketing it by direct mail. (Note: The MS Basic compiler and version 3.0 of the MS Basic interpreter are two different products, both of which you need to compile programs!) Pterodactyl Software's PCMacBasic has not come back off the drawing board and True Basic is no better off than when I reviewed it back in August. But there has still been some hope. Zedcor has been scrambling to fix bugs in ZBasic and release version 3.02. They are to be commended for their dedication to making their product a success.

Why do I say that both definitions of 'mania' describe programming with ZBasic? The second definition comes to mind first. I'm excited to see the big improvements that have been incorporated into ZBasic. In fact, the BOMB is a much less frequent sight. In fact, the BOMBs that appear from time to time now are more obscure. In fact, some of the BOMBs are 'self inflicted'. In other words, sometimes things that I am not doing correctly turn out to be the problem. But there have been a few problems that demonstrate that not all the problems have been removed from the compiler.

One such example of what I am talking about was brought to my attention by one of our subscribers from Switzerland. He summed up ZBasic nicely when he said "...ZBasic is really a great Basic if only it worked!" He described to me a problem he was having when working with DIALOGs and ZBasic. He stated that he could not "flush the value of the DIALOG(1) function". The answer to his problem turns out to not be too hard, however, it reveals to us some other difficulties that ZBasic has 'built in' to it.

First, the solution to the DIALOG(1) problem is that it is not a problem. It will be helpful to understand how the DIALOG functions operate. The DIALOG function originates with MS Basic. The excitement comes when I see all the enhancements that have been added to the ZBasic implementation of DIALOGs. The purpose of the DIALOG function is to inform us when events (such as BUTTON, EDIT FIELD and WINDOWs) that occur between the DIALOG ON and DIALOG OFF statements.

It is important, when using DIALOG functions, to know when the function data is valid. The DIALOG(0) function is the key to it all. When an event occurs, the DIALOG functions are stored up in a 64 event queue. The ON DIALOG GOSUB statement is supposed to cause an interrupt to occur when some kind of event has happened. I say it is 'supposed to' because when writing the sample program included here I found that some of the items in the queue were not automatically read until another event occurred. Of course the new event was then pushed onto the queue and would not automatically interrupt via ON DIALOG. My solution was to poll the event queue continuously unless it was empty by accessing the DIALOG(0) function. Anyway, ideally the ON DIALOG should notify the program whenever any DIALOG events occur. The are seven events that are common to ZBasic and MS Basic. ZBasic now has 16 DIALOG functions including functions which support the Zoom windows and keyboard events. The DIALOG(0) function will return a number 1-16 (1-7 in MS BASIC) which will indicate to you what kind of event occurred. At the same time, the function that coresponds to the DIALOG(0) result will be updated. The functions ( DIALOG (1-16) ) are ONLY valid just after the DIALOG(0) function returns an event of that type. Otherwise the last event of that type remains on, stored up in the DIALOG functions. The figure shows a flow chart of what happens when DIALOG(0) has an event to be processed. Just remember to poll DIALOG(0) first to find out which of the other functions you will need to poll next.

Figure 2.

Another phenomenon that was observed was that when events are active ( the lines between DIALOG ON, MENU ON, BREAK ON, MOUSE ON and DIALOG OFF, MENU OFF, BREAK OFF, MOUSE OFF) the program seems to run much slower than without events on. I tried to turn off events wherever possible with some increase in speed, but there seems to be some delay between polling the time an event occurs and when it is finally processed. Has anyone done any benchmarks to compare speed when events are turned on? It is a difficult thing to compare as the implementation varies so much from one language to another.

Look out here comes another bug... As it turns out, the DIALOG(8) and DIALOG(9) statements work great. The problem is that Zoom windows still don't work quite right. In ZBasic 3.02 the demo program below will BOMB if Zoom windows are made active. I have set it up to demonstrate how it should work. The PEEK (&28E) AND 128 statement towards the beginning of the program checks to see if the Mac has old 64K ROMS or the new 128K ROMS installed. If the new ROMS are available then the window type should be set to 9 when the windows are created.

The example program outlines the basic flow which you will want to use when you implement your own ZBasic event loops. Notice that Menu events and Dialog events are mixed in the same event loop. This same structure also applies for MS BASIC. Any questions?

REM ZBasic V3.02 Dialog Example
REM ©MacTutor 1987
REM By Dave Kelly

WINDOW OFF:REM Always use this as first line of program to prevent default 
window from being created
COORDINATE WINDOW:REM Set window to  Macintosh coordinate system
False=0:True=NOT False
IF PEEK(&28E) AND 128 THEN Wtype=1 ELSE Wtype=9
Wtype=1:REM  Due to Bugs in ZBasic 3.02 Zoom window will not be used.

MENU 1,0,1,"File"
MENU 1,1,1,"Quit"
DIALOG OFF
WINDOW 1,"Window 1",(10,50)-(250,200),Wtype
TEXT 4,9,0,0
BUTTON 1,1,"Button 1",(20,20)-(100,50)
BUTTON 2,1,"Button 2",(20,60)-(100,90)
WINDOW 2,"Window 2",(275,50)-(500,200),Wtype
TEXT 4,9,0,0
EDIT FIELD 1,"",(10,10)-(100,35),1,1
EDIT FIELD 2,"",(10,40)-(100,65),1,1
WINDOW 3,"Dialog Event (Window #3)", (10,250)-(500,340),28
TEXT 4,9,0,0
ON DIALOG   GOSUB "DialogEvent"
ON BREAK    GOSUB "BreakEvent"
ON MENU GOSUB "MenuEvent"
DIALOG ON:BREAK ON:MENU ON
"Mainloop":DO:D=DIALOG(0)
IF D>0 THEN GOSUB "DEvent"
UNTIL D=0
GOTO "Mainloop"

"MenuEvent"
DIALOG STOP:
Menunumber=MENU(0):Itemnumber=MENU(1)
IF Menunumber=1 AND Itemnumber=1 THEN END
DIALOG ON
RETURN
"BreakEvent"
STOP

"DialogEvent"
D = DIALOG(0):REM check to see what event occured
"DEvent"
DIALOG STOP
Currentwindow = WINDOW(0)
Windowselection = WINDOW(1)
WINDOW OUTPUT 3
IF D = 1 GOSUB "Buttonevent"
IF D = 2 GOSUB "EditEvent"
IF D = 3 GOSUB "InactiveWindow"
IF D = 4 GOSUB "Closebox"
IF D = 5 GOSUB "Refresh"
IF D = 6 GOSUB "Returnkey"
IF D = 7 GOSUB "Tabkey"
IF D = 8 GOSUB "Zoomin"
IF D = 9 GOSUB "Zoomout"
IF D =10 GOSUB "Shifttab"
IF D =11 GOSUB "Clearkey"
IF D =12 GOSUB "LeftArrow"
IF D =13 GOSUB "RightArrow"
IF D =14 GOSUB "UpArrow"
IF D =15 GOSUB "DownArrow"
IF D =16 GOSUB "Keypress"
PRINT @(50,3) "DIALOG(0) :        ";D
PRINT @(50,4) "Active Window #";Currentwindow
PRINT @(50,5) "Output Window #";Windowselection
WINDOW OUTPUT Outwindow:WINDOW Windowselection
DIALOG ON
RETURN

"Buttonevent"
Buttonclicked=DIALOG(1)
Bstatus=BUTTON(Buttonclicked):BUTTON Buttonclicked,3-Bstatus
PRINT@(1,1)   "Button clicked :   ";Buttonclicked
RETURN

"EditEvent":
EditField=DIALOG(2)
PRINT@(1,2)   "Edit Field :       ";EditField
RETURN
"InactiveWindow"
Windowselection=DIALOG(3)
PRINT@(1,3)   "Inactive Window :  ";Windowselection
RETURN
"Closebox":
ClosedWindow=DIALOG(4)
IF ClosedWindow=3 THEN END
PRINT@(1,4)   "Closed Window :    ";ClosedWindow
RETURN
"Refresh":
ErasedWindow=DIALOG(5)
PRINT @(1,5)  "Erased Window :    ";ErasedWindow
RETURN
"Returnkey":
Returnpress=DIALOG(6)
PRINT @(25,1) "Return press :     ";Returnpress
RETURN
"Tabkey":
Tabpress=DIALOG(7)
PRINT @(25,2) "Tab press :        ";Tabpress
RETURN

"Zoomin": REM NEW ROMS ONLY
Zin=DIALOG(8)
WINDOW Zin
PRINT@(1,1) "Thank you for zooming in window";Zin
PRINT @(25,3) "Zoom in window :   ";Zin
RETURN
"Zoomout":
Zout=DIALOG(9)
WINDOW Zout
PRINT@(1,1)"Thank you for zooming out window";Zout
PRINT @(25,4) "Zoom out window :  ";Zout
RETURN
"Shifttab":
CurrentEdit=DIALOG(10)
PRINT @(25,5) "Current Edit Field:";CurrentEdit
RETURN
"Clearkey":
CurrentEdit=DIALOG(11)
PRINT @(25,5) "Current Edit Field:";CurrentEdit
RETURN

"LeftArrow":
CurrentEdit=DIALOG(12)
PRINT @(25,5) "Current Edit Field:";CurrentEdit
RETURN
"RightArrow":
CurrentEdit=DIALOG(13)
PRINT @(25,5) "Current Edit Field:";CurrentEdit
RETURN
"UpArrow":
CurrentEdit=DIALOG(14)
PRINT @(25,5) "Current Edit Field:";CurrentEdit
RETURN
"DownArrow":
CurrentEdit=DIALOG(15)
PRINT @(25,5) "Current Edit Field:";CurrentEdit
RETURN

"Keypress":
ASCIIkey=DIALOG(16)
PRINT @(50,1) "ASCII key pressed :";ASCIIkey;"  "
PRINT @(75,1) " ":PRINT @(75,1) CHR$(ASCIIkey)
RETURN
END
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

The best video player on mobile
We all know the stock video player on iOS is not particularly convenient, primarily because it asks us to hook a device up to iTunes to sync video in a world that has things like Netflix. [Read more] | Read more »
Four apps to help improve your Super Bow...
Super Bowl Sunday is upon us, and whether you’re a Panthers or a Broncos fan you’re no doubt gearing up for it. [Read more] | Read more »
LooperSonic (Music)
LooperSonic 1.0 Device: iOS Universal Category: Music Price: $4.99, Version: 1.0 (iTunes) Description: LooperSonic is a multi-track audio looper and recorder that will take your loops to the next level. Use it like a loop pedal to... | Read more »
Space Grunts guide - How to survive
Space Grunts is a fast-paced roguelike from popular iOS developer, Orange Pixel. While it taps into many of the typical roguelike sensibilities, you might still find yourself caught out by a few things. We delved further to find you some helpful... | Read more »
Dreii guide - How to play well with othe...
Dreii is a rather stylish and wonderful puzzle game that’s reminiscent of cooperative games like Journey. If that sounds immensely appealing, then you should immediately get cracking and give it a whirl. We can offer you some tips and tricks on... | Read more »
Kill the Plumber World guide - How to ou...
You already know how to hop around like Mario, but do you know how to defeat him? Those are your marching orders in Kill the Plumber, and it's not always as easy as it looks. Here are some tips to get you started. This is not a seasoned platform... | Read more »
Planar Conquest (Games)
Planar Conquest 1.0 Device: iOS Universal Category: Games Price: $12.99, Version: 1.0 (iTunes) Description: IMPORTANT: Planar Conquest is compatible only with iPad 3 & newer devices, iPhone 5 & newer. It’s NOT compatible with... | Read more »
We talk to Cheetah Mobile about its plan...
Piano Tiles 2 is a fast-paced rhythm action high score chaser out now on iOS and Android. You have to tap a series of black tiles that appear on the screen in time to the music, being careful not to accidentally hit anywhere else. Do that and it's... | Read more »
Ultimate Briefcase guide - How to dodge...
Ultimate Briefcase is a simple but tricky game that’s highly dependent on how fast you can react. We can still offer you a few tips and tricks on how to survive though. Guess what? That’s exactly what we’re going to do now. Take it easy [Read more... | Read more »
SoundPrism Link Edition (Music)
SoundPrism Link Edition 1.0 Device: iOS Universal Category: Music Price: $4.99, Version: 1.0 (iTunes) Description: ***Introductory price for a the first few days after launch - if you're reading this, get it while it's fresh out of... | Read more »

Price Scanner via MacPrices.net

12-inch 1.2GHz Silver Retina MacBook on sale...
B&H Photo has the 12″ 1.2GHz Silver Retina MacBook on sale for $1399 including free shipping plus NY sales tax only. Their price is $200 off MSRP, and it’s the lowest price for this model from... Read more
iPads on sale at Target: $100 off iPad Air 2,...
Target has WiFi iPad Air 2s and iPad mini 4s on sale for up to $100 off MSRP on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale prices for... Read more
Target offers Apple Watch for $100 off MSRP
Target has Apple Watches on sale for $100 for a limited time. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store prices may vary: - Apple... Read more
Apple refurbished 2014 13-inch Retina MacBook...
Apple has 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 shipping is free... Read more
Macs available for up to $300 off MSRP, $20 o...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and... Read more
Watch Super Bowl 50 Live On Your iPad For Fre...
Watch Super Bowl 50 LIVE on the CBS Sports app for iPad and Apple TV. Get the app and then tune in Sunday, February 7, 2016 at 6:30 PM ET to catch every moment of the big game. The CBS Sports app is... Read more
Two-thirds Of All Smart Watches Shipped In 20...
Apple dominated the smart watch market in 2015, accounting for over 12 million units and two-thirds of all shipments according to Canalys market research analysts’ estimates. Samsung returned to... Read more
12-inch 1.2GHz Retina MacBooks on sale for up...
B&H Photo has 12″ 1.2GHz Retina MacBooks on sale for $180 off MSRP. Shipping is free, and B&H charges NY tax only: - 12″ 1.2GHz Gray Retina MacBook: $1499 $100 off MSRP - 12″ 1.2GHz Silver... Read more
12-inch 1.1GHz Gray Retina MacBook on sale fo...
B&H Photo has the 12″ 1.1GHz Gray Retina MacBook on sale for $1199 including free shipping plus NY sales tax only. Their price is $100 off MSRP, and it’s the lowest price available for this model... Read more
Apple now offering full line of Certified Ref...
Apple now has a full line of Certified Refurbished 2015 21″ & 27″ iMacs available for up to $350 off MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are... 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* Subject Matter Expert - Experis (Uni...
This position is for an Apple Subject Matter Expert to assist in developing the architecture, support and services for integration of Apple devices into the domain. Read more
*Apple* Macintosh OSX - Net2Source Inc. (Uni...
…: * Work Authorization : * Contact Number(Best time to reach you) : Skills : Apple Macintosh OSX Location : New York, New York. Duartion : 6+ Months The associate would Read more
Computer Operations Technician ll - *Apple*...
# Web Announcement** Apple Technical Liaison**The George Mason University, Information Technology Services (ITS), Technology Support Services, Desktop Support Read more
Restaurant Manager - Apple Gilroy Inc./Apple...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.