Solipsism Gradient

Yet Another interim progress report on XRay II.

Turns out some of my problems with the hex editor were due to overuse of the idea to have my scrollview’s delegate do everything (including standing in for the First Responder). So I changed back to a simpler model. I now have a single view inside my scroll view as the delegate, and it stays in place – it just checks the scrollbar’s status to decide what to draw.

As this subview is declared as NSView<NSTextInput> – meaning it’s a plain subclass of NSView that obeys the NSTextInput protocol – it’s also a descendant of NSResponder, and now stuff started “just working”. Seems obvious in retrospect, of course. There’s lots of details about implementing that protocol, but it’s mostly working now; I’m still not doing any actual editing, but that’s the top item on my list of things to do next.

Several other issues are being worked on in the meantime. Many things are more complex than I anticipated, but I believe the final result will be worthwhile. The actual plugin interface is still mutating from day to day, mostly because the actual usage patterns are hard to anticipate. I have two plugins partially working: File Metadata and File Forks (which use the basic hex editor to do its work).

I’m now making a separate version of the main XRay II application to be used as the plugin developer base. This will be a stripped-down version of the application: it’ll run only the two basic plugins and a third one, the one being developed. It will also have some debugging infrastructure in place.

Next, I’ll use this to start up projects for at least two more, perhaps more, plugins of different types, both reusing basic UI elements from the main application. Hopefully this will give me enough variations to publish a rich but robust plugin interface. I envision stopping development on the main application as soon as possible – perhaps even this year, if all goes well – and doing all the rest inside plugins.

Autoresizing NSTextFields are now working quite well, except in one instance – when there are several of them stacked and the window is resized several times very rapidly. I’ve left this alone for now while tackling another problem: text editing. Let me explain this a little.

One of my basic UI elements is a fast hex editor view. Here’s what it looks like at present:

Three columns, hex displacement at the left, hex characters in the center, MacOSRoman (or any other encoding) to the right. All in a scrolling view. That’s where things began to get strange. For normal Cocoa use, you’d normally define an NSTextView inside an NSScrollView. The three columns might be done by NSTextBlocks, as this will be Tiger-only. Or three different NSTextContainers, each one referencing an aspect of the same NSTextStorage…

The main stumbling point here is, I want to be able to edit very large files with no performance penalty. Files tens of gigabytes in size or even larger. All the standard Cocoa text objects above are out; they use 32-bit offsets and ranges for text sizes and selections, meaning things are limited to 4GB (or even 2GB in some cases). Also, NSTextView becomes slow as molasses well before text sizes reach those magnitudes, as the entire text needs to be laid out first to determine line breaks. Also, RAM requirements to generate the hex interpretation go up – remember a standard Mac OS X app can allocate just a little over 2GB of RAM. Finally, NSScrollView uses floats to track the scroll thumb position, meaning that scroll tracking becomes imprecise when you’re trying to track millions of lines.

Well, my fate apparently is to recode most of the NeXT-era UI widgets anyway – see RBSplitView. I tackled the scroller problem first, as I needed it for the file browser anyway, and soon had a special scroll view that tracked scrolling positions with unsigned 64-bit displacements – large enough for the largest file supported by Mac OS X – and faster and simpler than the standard one. It basically consists of the vertical NSScroller and the empty (document) space to its left; no intervening NSClipView. Any subviews are relocated by the offset when the scroller changes and drawing is optimized to the visible portion.

I also put in the option to have the view’s delegate redraw the visible portion directly – this was the idea I had to optimize the hex editor. Indeed, drawing is very fast; I have my own cached CoreGraphics bitmaps of the characters, and blit them to the visible portion of the sscroll view. And only the necessary part of the displayed file needs to be accessed, thanks to mapping only that part to memory with mmap(). And putting in editing later would be easy once the display portion is finished…

Famous last words. Turns out that the Cocoa text system is rather more complex than I expected – the standard NSTextView/NSTextField objects hide that very successfully from the “normal” developer. After several days of reading the very terse docs, and trying to find out which methods are called where, I’m finally at a point where the normal text input methods are working. However, I still can’t figure out how the standard copy/cut/paste menu items are enabled, and the whole process is still too clunky for wider use.

Stay tuned for developments…

So, I needed to autoresize NSTextFields in XRay II (vertically only). Sort of a poor man’s WebView. This had to “just work” on certain NSTextFields used by third-party plugins, though, without any extra code or subclassing by the plugin writer.

There are two problems there. One is finding out the actual optimum vertical size, while editing and while not, for any type of border or bezel. Here’s the code I finally worked out, with the kind help of Daniel Jalkut:

- (NSSize)minSizeForContent {
   NSRect frame = [self frame];
   NSRect newf = frame;
   NSTextView* editor = nil;
   if ((editor = (NSTextView*)[self currentEditor])) {
      newf = [[editor layoutManager] usedRectForTextContainer:[editor textContainer]];
      newf.size.height += frame.size.height-[[self cell] drawingRectForBounds:frame].size.height;
   } else {
      newf.size.height = HUGE_VALF;
      newf.size = [[self cell] cellSizeForBounds:newf];
   }
   frame.size.height = newf.size.height;
   return frame.size;
}

So I put this into a category of NSTextField and did some runtime diddling with implementation pointers, but for other uses it could well be in a subclass.

The second problem is properly pushing down the views below the field when it is resized. The solution I ended up coding is a little too gnarly to post here, and it depends on the field and its sibling views being inside a custom NSView subclass with flipped coordinates… still, it seems to work well enough now, so I’ll leave it there and work on other stuff.

WWDC 2006 had two main topics: the new Mac Pros and Leopard. Regarding the Mac Pros, they seem quite competitive and well-built. I’m very content with my current iMac G5 (which I bought at last year’s WWDC), so I haven’t looked at them closely; desk space is important to me. By the way, it seems that Apple Brazil has just released the local price of the standard configuration, and it comes out to US$5400. Ouch.

Regarding Leopard, there’s a nice write-up at Wikipedia, so I won’t try to enumerate everything here.

All in all, I can say this was one of my best WWDCs yet. As I’ve said before, the timing was excellent. Apple has obviously made the most of the (unusual) June-to-August delay and from the developer standpoint all important stuff was in place. Most of the Leopard APIs seem to be well-defined, reasonably stable, and of course the tools are all in place. Xcode 3.0 and the new developer tools “just work”. In one Q&A session Chris Espinosa, was asked about the stability of the tools – whether developers should rely on them for new products, or should wait for the GM release – answered “we all use them daily for building Leopard, so they have to work well!”

So, this is important news for developers. Before, existing tools were used to build a new system and the next generation of tools came out with (or after) the GM release. Now, Apple has obviously been working on the new stuff iteratively; first versions of the new frameworks were used to build first versions of the new tools, then those were in turn re-used to work on the new frameworks. Certainly this has always happened to some extent, but I believe that this synergy between tools and frameworks has now hit an important inflection point.

Apple has clearly been working towards this for years. Mac OS X ‘s frameworks are now 4-way universal, containing binaries for PowerPC 32, PowerPC 64, Intel 32 and Intel 64 bits. Therefore, applications can now be built for all 4 environments, and all are fully supported by the new developer tools. This is a well-known capability of the Mach-O executable format by the way, not a new thing; NeXT applications were also distributed for several architectures, and the Virtual PC 7 executable has binaries optimized for 5 (!) different PowerPC variants.

Framework synergy is a marvelous thing. Apple has just released a short movie showing off CoreAnimation. The “city towers” effect in the second half can be now rendered in realtime on a MacPro – something that even two years ago would have been impossible. Looking very closely you can see that some of those squares are actually playing movies! But only a developer can fully appreciate the other important aspect: the code to generate this movie has shrunk down to less than 10% of what would have been necessary in Tiger.

Let’s talk somewhat vaguely (NDA mumble mumble) about how synergy might have made this happen in the CoreAnimation case. The MacPro has a faster, 64-bit CPU architecture, as well as faster video cards. 64-bit processes can use extra CPU registers and the new vector operations which seem to, finally, have equivalent power to the PowerPC G5′s AltiVec. The LLVM compiler is now used in the OpenGL stack to add a significant speedup (and this even for low-end machines!). Add in Quartz optimizations. Add in easy Cocoa support for all of these. Add in runtime efficiences introduced by Objective C 2.0. Add in new debugging and optimization made possible by implementing DTrace. Add in the ease of programming all this with less and more reliable code. Add in some extra stuff I can’t talk about… it adds up! And comparable gains are visible all through the new system.

At the risk of repeating myself, all this ho-hum talk about Leopard just being Spaces, Time Machine and some UI tweaks to iChat and Mail is so wrong. Granted that Steve Jobs had to show some non-developer news at the keynote, given the wildly unrealistic expectations. But, it really was a Developer Preview. It was released at the right time and to the right people in order to make sure that, whenever the Leopard GM comes out (my guess would be in January at MacWorld Expo), some hundred cool new applications will be available on the same day. And they’ll necessarily be Leopard-only; expect Leopard to be adopted by a significant portion of the user base in a very short timeframe.

Now to my own projects. I’d really love to have the upcoming XRay II to be Leopard-only, but that would delay release too much, and it doesn’t really need 64-bit capabilities. However, I’ll really need some fixes introduced in the last Tiger updates, so 10.4.7 will be the minimum supported version, which should be no hardship, as I can’t imagine anyone voluntarily staying with older Tiger versions. However, some of the stuff I’ve seen at WWDC has completely changed my plans regarding certain features and capabilities, so I’ll opt for implementing things in a way that might be a little constrained under Tiger but will really be much better under Leopard.

RBSplitView has been a marvelous experience for me. It’s been very widely adopted and even the Cocoa team has promised to take a look at it (no promises, of course). And it was very gratifying to be instantly recognized by many famous developers – of course my XRay II/RBSplitView t-shirt was intended to make this very easy! I’ve received lots of positive feedback and I’m working hard on implementing my own fixes and all suggestions. Hopefully I’ll have version 1.1.4 out in a very short time. This should be universal and fully compatible with Xcode 2.4. A 64-bit version compatible with the new Interface Builder will, unfortunately, have to wait until a more widely available Leopard beta comes out – I’m waiting for word from Apple about when it’ll be kosher, as I’ll necessarily have to include some new Leopard headers and APIs.

I have updated Nudge to be universal, and it seems to still be useful on Tiger for mounted network volumes. Expect the update to be available in a few days – I’m still doing some last-minute checking. Zingg! is, unfortunately, much harder to update at the moment. I haven’t touched it since 1.4.1 came out over 2 years ago, and the source code has been pushed out to some CDR backups – and the two I’ve found are, sadly, unreadable. I still have some hope of finding a copy someday (there’s a ton of stuff stashed away from my move), but don’t count on it. Recoding it from the ground up will have to wait for Leopard, where it’ll be much easier to do – there were some awful undocumented things I had to do at the time. Sorry about that. The USInternational keyboard layout will soon be repackaged in a way that (hopefully) will work around the “custom keyboard layout is randomly deselected” bug in Tiger. I’ll need to wait for a Leopard beta to come out to check if it’ll be upwardly compatible, though. I’m trying (again) to go through Apple channels to have it included with the standard system, perhaps this time it’ll work out?

Well, here are some questions I’ve been asked frequently at the conference, and the answers. (Some will no doubt be asked afterwards too, so I’ve included those too…)

Q: Why is my application not included on the RBSplitView adopters page?

A: Probably you didn’t send me e-mail about it, or my spam filter didn’t like it. So tell me again.

Q: I’ve been looking for you at the conference and didn’t find you!

A: I’m mostly around the labs. Look for me there, or in the intervals. I’m wearing a white XRay t-shirt and carrying a blue backpack.

Q: Where did you get that XRay t-shirt?

A: I had several made at CafePress just in time for the conference.

Q: Why isn’t Apple using RBSplitView? NSSplitView sucks.

A: Well, this time I actually talked to people in charge of that process (and of NSSplitView itself); they’ve agreed that it could be better and also agreed to take a look, no promises. So start bugging them instead of me.

Q: When is the next version of RBSplitView coming out, and what will be new?

A: Hopefully a few weeks after I get home. I’ve already fixed some bugs and extended some functionality. In particular, if you push a divider towards a direction where there are subviews already collapsed or at minimum dimension they’ll be pushed away. Also, RBSplitView will now behave correctly when inside a NSScrollView, and I’ve already used this to build a Finder-like filebrowser (columns mode). Finally, the new version will be Xcode 2.4-compliant and Universal out of the box, errh, download.

Q: Will RBSplitView run on Leopard?

A: Well, I’ll certainly have to do a completely new version implementing all the new stuff – 64 bits, palette for the new Interface Builder, Objective-C 2.0, NSAnimation, other stuff I can’t talk about. Meanwhile, the upcoming version will probably be the last one for Tiger. RBSplitView apps compiled for Tiger seem to run OK under Leopard as far as I could test.

Q: Will you/Apple sue Apple/you? Did they pay you big bucks? Will Apple/you change the XRay/Xray name?

A: No, no, no, and no. See my last post.

Q: When is XRay II coming out?

A: Well, my hope was to show a public beta perhaps a month after the conference. What I’ve seen at the conference has changed my mind about a number of things, made others obsolete, some impossible, some much easier than I anticipated. Still, I’ll have something visible out ASAP.

Q: What changed in Objective-C/Finder/Xcode/iChat/Mail/…/Leopard???

A: Not much, only Steve knows, nothing yet, a lot, didn’t see that, can’t tell. Guess which…

Rainer Brockerhoff wrote:

Still, Steve Jobs said many features were still “top secret”. I suppose most of them will be revealed later under NDA.

And so they were. Well, at the least most of them that developers should be concerned about. I’ll talk about some fundamental issues here, but of course I can’t talk about details not released elsewhere.

Rainer Brockerhoff wrote:

Xcode 3.0 features a cool new debugging feature called… “Xray”. So. Good thing I’m at XRay II already. Where’s my lawyer…?

Well, I’ve had the opportunity to talk to Apple – informally, I hasten to add – and we’ve agreed there’s no conflict. A good thing too, as they have more lawyers than I do, hehe. Unofficially, I’ve heard that it was called PowerSomethingOrOther until nearly the last day before the show and then someone (marketing?) decided on the name change without doing a Google search. (Probably because PowerSomethings are on their way out, anyway.)

I’ve been floating ideas of possible name changes with other developers – GammaRay? CAT? PET? PowerSameThing? Nothing has quite the same zing, and I’d have to change the icon – and so I’ve decided keeping XRay II will be OK for me. It’s a full version ahead!

Anyway, I’ve been not-too-surprised about the mostly ho-hum reactions the keynote got among journalists, analysts and non-developer entities. And of course the stock is down. Well, no new iPod was revealed, right? And some people to this day think that Tiger was only Dashboard, Spotlight and some small cosmetic changes in the iApps…

…and from that point of view, the Leopard preview was only Time Machine, 64-bit support on some machines, and… HTML Mail templates? To-do in Mail. And erh, more effects in iChat and PhotoBooth, right? Personally, I was disappointed to see Steve Jobs waste so much detail on such trivia. And of course, HTML e-mail should be stamped out, not fomented!! Death to Mail templates!!! Argh. Sorry. Hm.

Well, it’s a developer conference and this was a preview for non-developers. The timing of this conference was very interesting. I’ve been to conferences where the timing was unfortunate. Way back when they showed the Copland preview absolutely nothing worked and most of the sessions were pure hand-waving. Last year, Tiger had already been out for a time and that conference was interesting more for its historical value (and for testing on the Intel kits, of course).

This time, the Leopard preview is at the right stage. Most of the new APIs and things are either working or in the final stages. There’s documentation! There are machines running the new system! The new system kernel panic a few times a day under hard use, but that’s normal. There’s the usual list of deprecated APIs we should avoid in the future, and the usual list of cool new APIs I’ll have to wait a year or more to really use. What is mostly not there is what those guys were looking for: a new kernel, a new Finder, the death of metal, new applications, radically improved applications (and I’ll explain below why they shouldn’t be here now).

More importantly, there’s a clear sense of direction. I’ve changed several ideas I had about XRay II’s implementation and most of them will make my life easier, mostly through having to write less code. Or, in the future, of being able to take code away, or to do cool new stuff on Leopard in the “just-works” mode.

So, what the non-developers don’t get is that Leopard is all about infrastructure – as was Tiger too, come to think of it. As someone (Lincoln?) is reputed to have said, “if I have 8 hours to fell a tree, I prefer to spend 6 hours sharpening my ax”. And that’s what’s going on. They’re sharpening the infrastructure. Then, a very short time (comparatively) before release, all the new infrastructure will make doing those cosmetic and application changes much easier, and they’ll be faster as a side-effect too. And they’ll be doing things not possible today. Some folks are catching this hint. For instance, Time Machine’s cool new UI is possible thanks to the new CoreAnimation framework, which itself rests on other stuff I can’t mention… and all this new infrastructure is interacting synergistically, so the rate of change of innovation is increasing without Apple having to add more engineers, or developers like me having to write more code. The new boring Mail features are based on new frameworks available to other apps, and so on.

More later…