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
$98.15
Apple Inc.
-0.23
MSFT
$43.58
Microsoft Corpora
-0.31
GOOG
$587.42
Google Inc.
+1.81

MacTech Search:
Community Search:

Software Updates via MacUpdate

Knock 1.1.7 - Unlock your Mac by knockin...
Knock is a faster, safer way to sign in. You keep your iPhone with you all the time. Now you can use it as a password. You never have to open the app -- just knock on your phone twice, even when it's... Read more
Mellel 3.3.6 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
LibreOffice 4.3.0.4 - Free Open Source o...
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
Freeway Pro 7.0 - Drag-and-drop Web desi...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With it's user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more
Drive Genius 3.2.4 - Powerful system uti...
Drive Genius is an OS X utility designed to provide unsurpassed storage management. Featuring an easy-to-use interface, Drive Genius is packed with powerful tools such as a drive optimizer, a... Read more
Vitamin-R 2.15 - Personal productivity t...
Vitamin-R creates the optimal conditions for your brain to work at its best by structuring your work into short bursts of distraction-free, highly focused activity alternating with opportunities for... Read more
Toast Titanium 12.0 - The ultimate media...
Toast Titanium goes way beyond the very basic burning in the Mac OS and iLife software, and sets the standard for burning CDs, DVDs, and now Blu-ray discs on the Mac. Create superior sounding audio... Read more
OS X Yosemite Wallpaper 1.0 - Desktop im...
OS X Yosemite Wallpaper is the gorgeous new background image for Apple's upcoming OS X 10.10 Yosemite. This wallpaper is available for all screen resolutions with a source file that measures 5,418... Read more
Acorn 4.4 - Bitmap image editor. (Demo)
Acorn is a new image editor built with one goal in mind - simplicity. Fast, easy, and fluid, Acorn provides the options you'll need without any overhead. Acorn feels right, and won't drain your bank... Read more
Bartender 1.2.20 - Organize your menu ba...
Bartender lets you organize your menu bar apps. Features: Lets you tidy your menu bar apps how you want. See your menu bar apps when you want. Hide the apps you need to run, but do not need to... Read more

Latest Forum Discussions

See All

Ice Wings Plus (Games)
Ice Wings Plus 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: THE GREAT ENDLESS RUNNER OF COMBAT JETS IS BACK !! With more than 680.000 downloads in the App Store, Ice Wings: Skies of Steel... | Read more »
Murl the Squirrel (Games)
Murl the Squirrel 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Meet Murl. He is teased by a group of flying squirrels because he can't fly. Determined to show them he's can fly, he meets... | Read more »
Celleste (Games)
Celleste 0.1 Device: iOS Universal Category: Games Price: $2.99, Version: 0.1 (iTunes) Description: Lots of cute action with amazing 3D graphics and a new type of gameplay! Take control over the forces of the universe to help a group... | Read more »
Super Heavy Sword (Games)
Super Heavy Sword 0.0.1 Device: iOS Universal Category: Games Price: $.99, Version: 0.0.1 (iTunes) Description: Get Ready to Get HEAVY! Monster Robot Studios presents SUPER Heavy Sword! The sequel to the smash hit HEAVY sword which... | Read more »
Angels In The Sky (Games)
Angels In The Sky 1.00 Device: iOS Universal Category: Games Price: $6.99, Version: 1.00 (iTunes) Description: - A.I.S will only run smoothly on iPhone 5s. It's NOT compatible with iPad, iPhone 5 or earlier devices.- In order to... | Read more »
80 Days (Games)
80 Days 1.0.2 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.2 (iTunes) Description: 1872, with a steampunk twist. Phileas Fogg has wagered he can circumnavigate the world in just eighty days. Choose your own route... | Read more »
Micromon (Games)
Micromon 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: 130+ Animated Monsters to Catch & Battle! No waiting, play at your own pace! Embark on an epic monster capture RPG like none... | Read more »
Empire Manager (Games)
Empire Manager 1.0 Device: iOS iPhone Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: Become ruler of an empire. Manage your economy, develop technology, hire an army and conquer the world in this addictive turn-... | Read more »
Empire Manager HD (Games)
Empire Manager HD 1.0 Device: iOS Universal Category: Games Price: $7.99, Version: 1.0 (iTunes) Description: Become ruler of an empire. Manage your economy, develop technology, hire an army and conquer the world in this addictive... | Read more »
Star Admiral Review
Star Admiral Review By Rob Thomas on July 30th, 2014 Our Rating: :: ADMIRABLE ADMIRALSUniversal App - Designed for iPhone and iPad While this new digital CCG may feel a bit familiar, Star Admiral offers a sci-fi twist and galaxy’s... | Read more »

Price Scanner via MacPrices.net

iPad Cannibalization Threat “Overblown”
Seeking Alpha’s Kevin Greenhalgh observes that while many commentators think Apple’s forthcoming 5.5-inch panel iPhone 6 will cannibalize iPad sales, in his estimation, these concerns are being... Read more
Primate Labs Releases July 2014 MacBook Pro P...
Primate Labs’ John Poole has posted Geekbench 3 results for most of the new MacBook Pro models that Apple released on Tuesday. Poole observes that overall performance improvements for the new MacBook... Read more
Apple Re-Releases Bugfixed MacBook Air EFI Fi...
Apple has posted a bugfixed version EFI Firmware Update 2.9 a for MacBook Air (Mid 2011) models. The update addresses an issue where systems may take longer to wake from sleep than expected, and... Read more
Save $50 on the 2.5GHz Mac mini, plus free sh...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $140 on an iPad Air with Apple ref...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more
$250 price drop on leftover 15-inch Retina Ma...
B&H Photo has dropped prices on 2013 15″ Retina MacBook Pros by $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.3GHz Retina MacBook Pro: $2249, $250 off... Read more
More iPad Upgrade Musings – The ‘Book Mystiqu...
Much discussed recently, what with Apple reporting iPad sales shrinkage over two consecutive quarters, is that it had apparently been widely assumed that tablet users would follow a two-year hardware... Read more
13-inch 2.5GHz MacBook Pro on sale for $999,...
Best Buy has the 13″ 2.5GHz MacBook Pro available for $999.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $100 off MSRP. Price is... Read more
Save up to $300 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
WaterField Unveils 15″ Outback Solo & 13″...
Hard on the heels of Apple’s refreshed MacBook Pro Retina laptops announcement, WaterField Designs has unveiled a 15-inch version of the waxed-canvas and leather Outback Solo and a 13-inch version of... Read more

Jobs Board

Sr. Product Leader, *Apple* Store Apps - 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
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full 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
Sr. Product Leader, *Apple* Store Apps - 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.