TweetFollow Us on Twitter

June 95 - Newton Q & A: Ask the Llama

Newton Q & A: Ask the Llama

Newton Developer Tecchnical Support

Q When I try to print or fax something, the Newton usually runs out of memory. I'm sending a lot of data to my print format, but it seems that the fields frame passed to SetupRoutingSlip should have only a reference to the data. What am I doing wrong?

A Unfortunately, you're missing one important step in the process of printing. The fields frame is eventually placed in the outbox soup. Thus all references are followed, which means that all the data you placed in the fields frame is duplicated. The duplication occurs in the soup:Add call.

In other words, you probably have a large data structure (or view, or proto) in your application. You put a reference to this structure in the fields frame in SetupRoutingSlip. When the user accepts the item to be printed (or faxed, beamed, or whatever), the fields frame is placed in the outbox soup, causing your structure to be duplicated.

Ideally, you should pass as little data as possible in the fields frame. As an example, assume that your data is all in a soup. You would pass information that allowed you to construct a query that returned the soup data of interest. This may be the index to search on plus the key to search for. You may even pass the query frame itself. Note that any changes made from the time the print request is made to the time the printing occurs will be reflected in the printed items. This may not be what you want. As in most cases, there are tradeoffs.

Q I'd like to have something like a viewIdleScript in my communications endpoint. The endpoint proto doesn't contain a way to do this. What's a good way to do it?

A One solution is to include your endpoint in a view object, such as a clView. You can then treat the whole clView as the communications object. You can use the view messages associated with opening a view to manage the control of your endpoint. Similar things can be done with viewQuitScript. And of course you can use a viewIdleScript.

Also note that using a view gives you a way to provide visual feedback (assuming it makes sense). Take a look at protoLlamaTalk in the LlamaTalk sample on this issue's CD for an example.

Q How do I get a text view to redraw itself with a new font?

A Simply use SetValue on the viewFont slot:

SetValue(theParaView,
	'viewFont,
	{family: 'espy, face: kFaceBold, size: 12});

Q I'm trying to use a view that has vfFillGray as the background. I've found that it looks really bad. Why is this?

A The pattern vfFillGray is an alternating on/off checkerboard pattern of pixels (that is, 50% gray). With the current state of the technology, all passive LCDs have problems displaying large areas of 50% gray (or large areas of black). The problem (called crosstalk ) is worse when you have alternating on and off pixels. Basically, the LCD freaks out. You should avoid using large areas of 50% gray where possible.Q When I try to add an index to my soup I sometimes get an exception -48019, but not always. What's going on?

A That particular exception indicates that an entry in your soup has a value of NIL in the slot you're trying to create an index for (that is, the entry contains the slot with a value of NIL). You can easily recreate this error by trying to add an index on the bday slot in the names file. Here's some code that you can type in the inspector:

call func()
begin
	local nameSoup := GetStores()[0]:GetSoup(ROM_cardfilesoupname);
	nameSoup:AddIndex(
		{structure: 'slot, path: 'bday, type: 'Int});
end with ();

In this case the error occurs because the default cardfile entry has a value of NIL for the bday slot. The solution is to make sure that there are no soup entries with a value of NIL for the slot that you want to use for the new index. This is best done in the design of your soup data.

If this isn't possible, the only solution is to make sure that all entries in the soup either have a valid value for the new index slot or do not contain the new index slot. Unfortunately, you don't know in advance if the new index will fail. In this case you can wrap the code that adds the index in a try/onexception clause. If an exception occurs that has the -48019 error number, you know that you have to iterate through the soup and fix entries.

Also note that you may want to keep a list of those "fixed" entries around since you may have to unfix them after the index has been added. In other words, it's OK for an entry to have a NIL value in an indexed slot after the index has been added to the soup.

Q I have a protoA2Z_TDS controlling a protoTextList. There are two things this combination doesn't do: (1) As the protoTextList contents are scrolled, the protoA2Z_TDS doesn't update the current letter, and (2) when the user clicks on a letter in the protoA2Z_TDS, I want to scroll the protoTextList to the appropriate place. How do I do these things?

A For those who may not know, protoA2Z_TDS is sample code provided by PIE Developer Technical Support. In answer to the first question, all you need to do is set the curIndex to the correct value, where A is 0 and Z is 25. If you use SetValue, the display will update for you. So if your protoA2Z_TDS was declared as indexer, and you wanted to change it to the letter B, you would do this:

SetValue(indexer, 'curIndex, 1);

You could also write a method of the protoA2Z_TDS that would update the display based on a character:

SetIndex := func(newChar)
begin
	local newIndex := Ord(Upcase(newChar)) - 65;
	if newIndex < 0 then newIndex := 0;
	if newIndex >= numIndices then newIndex := numIndices - 1;
		SetValue(self, 'curIndex, newIndex);
end;

Note that this function will try to do the right thing with weird input. However, if you're expecting the full range of Unicode values, you'll have to change the function to accommodate multibyte characters. Now let's tackle question number 2. You need to know about three things in the protoTextList that aren't yet documented in the Newton Programmer's Guide :

  1. There's a slot named lineHeight that contains the height of each line in pixels.
  2. The protoTextList uses SetOrigin to scroll. Therefore, the slot viewOriginY contains the number of pixels that the view is scrolled (and viewOriginY DIV lineHeight is the line number of the top displayed line).
  3. There's a method DoScrollScript(offset) that scrolls from the current position by the specified offset (in pixels).

Given these three pieces of information, here's a method for a protoTextList that will highlight a particular row and make it visible:

protoTextList.HiliteRow := func(index)
begin
	// highlight this item
	SetValue(self, 'selection, index);
	// scroll as necessary
	local topItem := viewOriginY DIV lineHeight;
	if index < topItem or (index >= topItem + viewLines) then begin
		// we need to scroll so that the index is the first item
		:DoScrollScript(-(topItem - index) * lineHeight);
	end;
end

Of course you still have to calculate what index to pass to the function. But that should be fairly straightforward. The protoA2Z_TDS will give you the first letter, which you can then find in your listItems array in the protoTextList. Note that if the listItems array is sorted, you can use a binary search to find the correct index.

Q What is the origin of the llama?

A The first evidence of llamas dates back to the llama raptor discovered by Dr. Leakey in the jungles of the Amazon. This find was dated back to the late "Jurassic Park" period. Early llamas are thought to have been both more violent and more intelligent than today's breeds. Cave paintings from the hills of Venezuela clearly depict early humans in use as pack animals for tribes of llamas.


The llama is the unofficial mascot of the Developer Technical Support group in Apple's Personal Interactive Electronics (PIE) division. Send your Newton-related questions to NewtonMail DRLLAMA or AppleLink DR.LLAMA. The first time we use a question from you, we'll send you a T-shirt. *

Thanks to Erik York and our PIE Partners for the questions used in this column, and to Bob Ebert, J. Christopher Bell, Mike Engber, Neil Rhodes, Kent Sandvik, Jim Schram, Maurice Sharp, and Bruce Thompson for the answers. *

Have more questions? Need more answers? Take a look at PIE Developer Info on AppleLink. *

 
AAPL
$118.93
Apple Inc.
-0.07
MSFT
$47.81
Microsoft Corpora
+0.06
GOOG
$541.83
Google Inc.
+1.46

MacTech Search:
Community Search:

Software Updates via MacUpdate

Adobe Photoshop Elements 13.0 - Consumer...
Adobe Photoshop Elements 12--the #1 selling consumer photo editing software--helps you edit pictures with powerful, easy-to-use options and share them via print, the web, Facebook, and more.Version... Read more
Skype 7.2.0.412 - 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
HoudahSpot 3.9.6 - Advanced file search...
HoudahSpot is a powerful file search tool built upon MacOS X Spotlight. Spotlight unleashed Create detailed queries to locate the exact file you need Narrow down searches. Zero in on files Save... Read more
RapidWeaver 6.0.3 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
iPhoto Library Manager 4.1.10 - Manage m...
iPhoto Library Manager lets you organize your photos into multiple iPhoto libraries. Separate your high school and college photos from your latest summer vacation pictures. Or keep some photo... Read more
iExplorer 3.5.1.9 - View and transfer al...
iExplorer is an iPhone browser for Mac lets you view the files on your iOS device. By using a drag and drop interface, you can quickly copy files and folders between your Mac and your iPhone or... Read more
MacUpdate Desktop 6.0.3 - Discover and i...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
SteerMouse 4.2.2 - Powerful third-party...
SteerMouse is an advanced driver for USB and Bluetooth mice. It also supports Apple Mighty Mouse very well. SteerMouse can assign various functions to buttons that Apple's software does not allow,... Read more
iMazing 1.1 - Complete iOS device manage...
iMazing (was DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and from... Read more
PopChar X 7.0 - Floating window shows av...
PopChar X helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to access any font's special characters. Expanded... Read more

Latest Forum Discussions

See All

Mystery Case Files: Dire Grove, Sacred G...
Mystery Case Files: Dire Grove, Sacred Grove HD Review By Jennifer Allen on November 28th, 2014 Our Rating: iPad Only App - Designed for the iPad A decent new installment for the popular Mystery Case Files series.   | Read more »
Castaway Paradise – Tips, Tricks, and St...
Ahoy there, castaways: Were you curious about our own thoughts regarding this pristine shipwreck? Check out our Castaway Paradise review! Castaway Paradise is out for iOS, finally giving mobile gamers the opportunity to enjoy the idyllic lifestyle... | Read more »
Castaway Paradise VIP Subs are on Sale f...
Castaway Paradise VIP Subs are on Sale for a Limited Time, and a Special Holiday Update is Coming Soon Posted by Rob Rich on November 28th, 2014 [ | Read more »
Primitive Review
Primitive Review By Jordan Minor on November 28th, 2014 Our Rating: :: FOLK ARTUniversal App - Designed for iPhone and iPad True to its name, Primitive is about as straightforward as runners get.   | Read more »
7 tips to get ahead of the competition i...
7 tips to get ahead of the competition in Dynasty of Dungeons Posted by Simon Reed on November 28th, 2014 [ permalink ] Playcrab has launched their action-packed new dungeon crawler, Dynasty of Dungeons, today. | Read more »
Master of Tea Kung Fu Review
Master of Tea Kung Fu Review By Jordan Minor on November 28th, 2014 Our Rating: :: ONE DROP RULESUniversal App - Designed for iPhone and iPad Master of Tea Kung Fu is a creative and complex caffeinated brawler.   | Read more »
Monster Strike Review
Monster Strike Review By Campbell Bird on November 28th, 2014 Our Rating: :: BILLIARD STRATEGYUniversal App - Designed for iPhone and iPad Collect monsters and battle by flinging them across the battlefield in this strangely... | Read more »
Proun+ Review
Proun+ Review By Jennifer Allen on November 28th, 2014 Our Rating: :: TWITCHY RACINGUniversal App - Designed for iPhone and iPad Twitchy racing aplenty in Proun+, an enjoyably tricky title.   | Read more »
Lucha Amigos (Games)
Lucha Amigos 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Forget Ninja Turtles, and meet Wrestlers Turtles! Crazier, Spicier and…Bouncier! Sling carapaces of 7 Luchadores to knock all... | Read more »
Record of Agarest War Zero (Games)
Record of Agarest War Zero 1.0 Device: iOS Universal Category: Games Price: $7.99, Version: 1.0 (iTunes) Description: HyperDevbox Holiday Turkey Black Friday Special Pricing! To celebrate the opening of the holiday season HyperDevbox... | Read more »

Price Scanner via MacPrices.net

Best Black Friday Deal: 15-inch Retina MacBoo...
 B&H Photo has the new 2014 15″ Retina MacBook Pros on sale for $300 off MSRP as part of their Black Friday sale. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina... Read more
Up To 75% Off Infovole Text Apps Over Black F...
Infovole’s entire range of apps, including the Textkraft family of word processors for iPads and iPhones, is being offered at 50-75% off over the Black Friday and Cyber Monday weekend. The five-day... Read more
Black Friday: Up to $60 off Mac minis, NY tax...
 B&H Photo has new 2014 Mac minis on sale for up to $60 off MSRP as part of their Black Friday sale. Shipping is free, and B&H charges NY sales tax only: - 1.4GHz Mac mini: $449.99 $50 off... Read more
Black Friday: 27-inch 5K iMac for $2299, save...
 B&H Photo continues to offer Black Friday sale prices on 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... Read more
Karalux Announces 24K Gold-Plated iPhone 6
Karalux, a Vietnam-based jewellery firm, has launched a unique 24 karat gold-plated iPhone 6 version with gold-cast monolithic dragon on its back panel. The real 24 karat gold plated enclosure doesn’... Read more
Black Friday: 13-inch 2.6GHz Retina MacBook P...
 B&H Photo has lowered their price for the 13″ 2.6GHz/128GB Retina MacBook Pro to $1159 for Black Friday. That’s $140 off MSRP, and it’s the lowest price for this model (except for Apple’s $1099... Read more
View all the Black Friday sales on our Mac Pr...
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. View Black Friday sale prices at a... Read more
Black Friday: 11-inch MacBook Air for $779, s...
 Best Buy has lowered their price for the 2014 11″ 1.4GHz/128GB MacBook Air to $779.99 for Black Friday. That’s $120 off MSRP. Choose free shipping or free local store pickup (if available). Sale... Read more
Apple Store Black Friday sale for 2014: $100...
BLACK FRIDAY The Apple Store has posted their Black Friday deals for 2014. Receive a $100 PRODUCT(RED) branded iTunes gift card with the purchase of select Macs, $50 with iPads, and $25 with iPods,... Read more
Black Friday: 15% off iTunes Gift Cards
Staples is offering 15% off $50 and $100 iTunes Gift Cards on their online store as part of their Black Friday sale. Click here for more information. Shipping is free. Best Buy is offering $100... Read more

Jobs Board

*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
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* 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
*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
*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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.