WWDC2003 Session 406

Transcript

Kind: captions Language: en thankies a BA so as love you said my name is Robin yukawa I'm the manager of the type engineering team at Apple computer and i'll be talking to you today about fonts but not just fun i'm going to be talking about the font system architecture and how it works how it interacts with your application software and how you can take advantage of it to make a really really excellent user interface and user experience for your customers with regards to font so why am I talking about fun why are fonts important well think about it this way imagine rolling the clock back 20 30 years and think about how fonts work back then you would have had one font on the system maybe a green or amber screen and that's it maybe at best you had a handful of fonts that you have to deal with well things just obviously changed since then we have dozens of fonts that get installed by default on Mac OS 10 users can install even more fonts on their systems applications come with specialized fonts along with them so you have tons of fonts you get to deal with even by default another thing that we've gotten feedback on with Mac os10 has been that its sponsor complicated you know people have to deal with a whole variety of issues with regards to fonts even with this installing or previewing them you might have encountered that with your family members asking well where do I put these fonts you know there's like I see a bunch of different directories with the name font on it where where does it go and so what we've tried to do with Panthers is tie into that whole initiative to put the user at the center as opposed to having fonts very computer centric and file centric we want to make it so that the users can really take advantage of fonts and really find it easy and convenient to use and really take advantage of all the stuff that thought developers and you guys have put in to make these things expressive and fully functional so what I'll be talking about today I'm going to be starting off with a description of the font architecture you're going to get a chance to understand what the system does what it does for you and what all the different components do and how they interact with each other the second part of the session I'll be talking about what you can do to take advantage of the system and bring it across to your applications and really make things shine so let me just guide straight into the first section you can think of it this way I'm going to be lifting up the hood on the system pulling out the font engine or the font system and showing you how all the different pieces work and right up here I've got a short list of all the different components related to the font architecture so let me just run through them first off we've got the font database system the font registry as we call it this keeps track of all the information related to the fonts and manages all the fonts that the user can access secondly we have the font raster visors this TV spot engine that basically takes the font data the raw font data converts it over to data that can be used by other parts of the system such as the graphic system or the printing architecture or even your application the next level up we've got the messaging system one thing that you should understand is that we have implemented a centralized font server that keeps track of all of this information in order for it to communicate the font data to your applications and two other processes on the system it needs to send messages and these are based on the mock colonel messaging system another level up we've got the caching system we've got the caches to optimize performance so that you don't have to always hit the lower levels of the system to get the font data that you need and then this is the next level up we've got the programming interface this is what you've traditionally heard in the past and what we've really focused on what I'm trying to do here is connect you to the operating system and show you what the programming interface can do for you and why we told you to do certain things as opposed to others and then finally on top of that as part of this initiative to put the user at the center we've implemented and exposed a number of standard user interface elements that you could take advantage of so that your applications really fit in have a consistent user interface and take advantage of all the new features that we've implemented for cancer so what I've just described is a short list of all the different components or as a major components in the font system what this diagram shows you are how they interact with each other so over on the far right you'll see two of the components those are the components that reside within the font server or the 80's server as you might have seen it calls within the system 80s by the way stands for Apple type services and that's actually the main component that my team is responsible for so within the server centralized for all of the different processes of available on the system we've got the font rasterizer and the font database management system or the font registry on the left-hand side of the screen you see everything that resides mainly within your application context as opposed to the font server that includes the user interface whether you implement it or the system implemented or some combination between that we have the programming interface and we have the caches and in between the two of them we have messages going back and forth across to communicate the font related data that your applications need and your more importantly what your users need okay so let me start diving into the details of this diagram first off let me work from the very basics here the font registry itself if is the central repository of font information you can also think of it as interface to the file system that lives underneath everything else so users for example might install fonts we track that information we handle mapping in all of the file related information and pull it into the font database the font registry also tracks all the different locations that are supported on mac OS 10 for installing fonts and it also keeps track of the files that are associated with the fonts within each of those locations the font registry is also responsible for managing the support for access privileges and multiple users so for example we've done a considerable amount of work for Panther to support the new fast user switching feature that you might have seen in the keynote another piece of information that we keep track of with the fonts has to do with the state and also the usage of the font part of the work that we do within the font registry is we synthesize data and provide a canonical format for accessing font related data there's a number of different pieces of information including the character mapping information the past the outline data the bitmap information the metrics we handle all of that through the font registry and other parts of the font architecture we also keep track of fonts that somehow get corrupted or actually bad starting off we can actually tag those fonts as corrupted or bad or potentially causing a crash during run time and prevent other users or other processes from running into that problem again and that state information is kept track of in the font registry one additional piece of information or one additional service provided fides provide the font registry is keeping track of all of different the multitude of file formats available for fonts so for example some fonts are stored in single files other ones are stored in multiple files that get associated with each other in certain ways you know by file name or maybe something very deep within the font file another thing we keep track of is whether or not that particular font data is stored within the data for core resource work of a font of a file so that covers the basics of what the font registry does next I'll be describing what the font wraps the risers do now you can think of these as the basic engine these know all the details about the font data they can take the font data that's stored on in the file system run through it and spit out other forms of data that can be used by other parts of the system so that includes graphic data the bitmaps the path the outlines that get rendered through the graphic systems we also provide support for converting data from what natively stored on disk to the formats used in for example PDF documents when you embed fontina within them also we convert data to the form used with when downloading fonts to the printing system generating postscript forms of the fonts for example the other thing that we do with the font rasterizer is very similar to the way the file registe the font registry handles different file formats the font master risers they actually know all the details about the different formats available out there so not only can fonts be stored in different file formats they can be stored in different data formats themselves so we've got the standard technologies that are out there right now truetype postscript we support multiple forms of them including the type one format that you're probably used to a mac OS Mac OS 9 and older and we also support the new BFF or contact font format that's available with the open type form of the posted font and also used in PDF document and then last but not least we support the older or legacy bitmap only formats that were available for quick draw based applications okay so next let me talk about the messaging system as I mentioned before the main thing about messages is that they are based on the lower level Colonel messaging system there's the inter process communication mechanism for going back and forth between the font server and your processes and other processes on the system another key thing that you can remember from this is that pretty much any programming interface related to the font may ultimately result in a message that goes from your application out to the server and potentially back note that this can take time and I'll be touching on this subject a little bit later on now messages can be categorized into different different classes the one that's probably most relevant to you is that when changes occur within the font registry the font server will actually broadcast messages out to any clients that are interested notification about these changes similarly there's also supports for your applications to send notifications messages back to the ATF server so that you can notify us to do certain actions or update our font registry there's one additional flavor of messages or quark on it that we've implemented through our API and that includes support for actually hooking into the messaging system the way this works for example is basically since a number of messages that applications can send out for querying about missing fonts let's say you open a document it doesn't have the fonts you need what that can often do is trigger a message across to the font server to ask for a replacement or to find out whether it's actually present or not we've provided a mechanism so that you can hook into that process intercept that message and provide your own level of support for handling that missing font so some new font utility application vendors have actually taken advantage of this and provide a user or even automatically provides the appropriate font and activate it within the system so this shows you some of the strengths and and benefits of going to a messaging system the next level are the caches now as I mentioned before there is a cost to doing messages and having this whole font server based architecture what we try to do with the caches and what we succeeded actually is making sure that the most commonly used functions and the most commonly used data that you access is available as fast as possible through this caching mechanism you'll notice that the key areas that we're trying to shield you from are the lower levels in the font system so for example the font registry corresponds to the file system usage it takes time to pull in a font file read it in and handle it and process it in fact processing it is the next level up that we try to reduce the impact performance wise on your applications it takes time to run through in fact for postcard fonts we have to parse through the entire post Kurtz font program in order to get even basic data such as the metrics or one glyph outline and finally as i mentioned messaging takes time it's often much faster to just do a simple function call to access your font data locally from within a cash than sending a message off to the font server and coming back with the data okay so this is what you're probably most familiar with and what you deal with on a day-to-day basis when it comes to font so as I mentioned earlier 80s Apple type services we provide a direct API into the font system through the HTS font API what this programming interface allows you to do is modify or manage the contents of the font registry you can also query the font registry for information we also provide support for accessing data directly from the font rasterizer and finally you can hook into the messaging system and take advantage of it with your own application software there are other api's that are available that are built on top of the underlying 80's API and those include the tech system available within cocoa or carbon and also the legacy quick-draw based font manager is built on top of the 80s font system now this is the last block diagram from the architectures that I'll go over this is a description of all the features that you might want to have the user interface with regard to fonts support for you and your customers first and foremost you want to be able to select or change the font and style information in your document or in any piece of text you also want to be able to access glyph specific information within a font this includes stuff like what characters does this particular font support or can I get access to different variants on character and this is especially important in the Asian market where there are different forms of the Han characters that people use in for example their last name another feature of the fonts that you can get access through the user interface are the typographic features this includes support for turning on and off ligatures or other variant forms within the font and then finally as I mentioned one thing that people have really asked us for in the operating system is a really easy way to manage the fonts that you have your collection of fonts this includes your entire library of fun they're having users have asked for ways to install their fonts much more easily and to be able to preview their fonts much more easily and so with panther we try to make that much more robust much more simple and also we want to have room for growing and providing additional services so with that I'd like to bring up one of the other engineers on my team his name is Nathan Taylor and he'll give you a demonstration of some of the work we've done for Panther Thank You Robin as robin said I'm Nathan Taylor I'm an engineer with the apple type engineering group and I'm very excited to show you the new user interface and the user interfaces that you should implement for your for a presenting sponsor and consistent way to your users of the system we've taken the user centric approach to heart here and if you saw the keynote you saw a brief glimpse of something I am very excited to show you today so with that I'd like to switch to demo one please ok you just just bought a bunch of pawns downloaded some fonts from the internet doesn't really know necessarily what they look like and biggest question like button is where should we put these fonts you know there are many font folders which is the best one to place them in we've tried to tell it people how to do it in tech notes but there's a much easier way and let me show you I'm going to open up the folder of fonts here and go to one that's not currently installed in Mac OS 10 the font that you know and love from Mac OS 9 the type 1 version of it and if user just double click the font the font book application comes up and shows a quick preview of the font where they can switch between and examine the different styles and with a single click of a single button here the font will be installed in what we considered the appropriate place at this point in time that is the user sponsor folder when the font is installed the main font book user interface comes up select the font and they can see that their action is actually taken effect you know this is a quick and easy interface to browse the fonts in the system now with the simple arrow keys or Mouse actions the users can look at the various fonts that are install get an idea what's available and if there are some that they don't want or they're never going to use there's an option to turn them off I don't speak Korean I don't read Korean I don't write Korean I'm never going to use the korean font to always show up at the font of the top of the font list well I can simply select them in font book and disable them when the one font one spot book is disabled to font they will no longer be available and not show up in the font window in cocoa or carbon applications then go back it's also possible to just add a bunch of fun we have a breakdown of the font library that shows how fonts our group and categorized there are the user fonts that are just my fonts there are the computer fonts which are shared between all users of the system network in classic similarly usually can move on to round between these directories that they want to what I'm going to do now is out a bunch of fonts the rest of the fonts from that big folder i took palatino from and just add all the fonts there i'm going to show you building collections and searching for fun so all those fonts has been added is he I've got a venir bodoni all the ones i just added are all selected what I can do now is I know I just installed a bunch of ITC fonts but I want to group them suck and easily find them within my application so we have collection management and Mac OS tend to do this and using the new collection management system provided by as a Coco layer we can create a new collection maybe at my ITC fonts and i want to add fonts to this well just somewhere in this list right let's find them pi PI DC and I get all the fonts that match my search string I can unselect all these fonts and drag them over to my collection there if I switch back to TextEdit now you'll see that the ITC fonts collection is available and selecting that collection shows those fonts I can then simply use them they are available immediately likewise there are ways for users to quickly manipulate collections they can tweak the collections they can remove individual faces from them they can remove families they can also disable the collections from within the font panel or from within font book application say for example I don't like the heavy faces here can select them and disable them from this let me do that again disable them from the ITC collection rather than the library which have already showed you and now if I look at that family Franklin Gothic the heavy faces are not there any more easily just we enabling them brings them back mmm if I don't want to use that collection of fonts now I can simply disable the collection and the collection is hidden from the UI the fonts are still active for other apps to use but the collection has been hidden from the UI while you may ask I want to group these and disable the fonts as a whole as optional behavior we do have the possibility to disable the whole thing holding down the option key and disabling this will do like the alert here it says and to say well all of those fonts from the library by looking all fonts here you can see that the ITC fonts are marked off and they are not they're no longer in the fonts window so what do you need to do in your applications to take advantage of this new functionality we're providing to the users we've made it easier for the users to manipulate their fonts we think this is going to allow them to do it more often they don't need to know where fonts live in the system they can just launch an application and turn things off as they wish if your app doesn't reacts to these changes the user interface that you presents will not be consistent across the board and we'd like this to be user centric so that everything feels the same in every application the first thing you can do and the least we ask you to do is implement support for ats font notifications if you have a carbon application or cocoa application but in carbon application if you should implement support for notifications we will notify you and call back a callback that you create and in this case I put up alert to be extremely obvious if we take a look in the neck defontes menu a venir bodoni response has been added to the fonts menu and immediately updated if i were to disable them they would not show up next time the font once activated the fonts on you was opened this correct the problem of having to quit the app and we launch the app from the old days and makes it so much more consistent but there's one step further you can go and this is what we really ask you to do you can implement the fonts window if you're doing a cocoa application it's pretty easy it's right there for you in carbon it's quite possible but it's not quite as easy but it's not hard at all and let me give you an example well let me just show you real quick I've got another similar version of simple text here that has a fox plant window implemented you know close it bring it back up like the other one you know I've got the same font and if I reenable that ITC collection I can show you that all the support for collection management and the man user managed collections are there if you implement the fonts window subscribing to acs notifications actually become unnecessary because the window fonts window handles that automatically for you behind the scene so what do you need to do to do this well adding notification it's really a piece of cake first I chose to implement the standard fonts menu three new function calls and effectively only three new lines of code to ads notifications I just created one call back and made one function call whenever that notification came across my callback updated the font menu and that was it a little more work to put in the font window but we really don't think it's that hard if you've been moving to a carbon event based application you probably already have a standard carbon event handler but that's the first thing you need to do and the handler I happen here is about 20 lines of code next I put it in handler attached to the window to handle the font window events the font changes the user made in the fonts panel and that's about 25 lines of code the last thing you need to do is update the fonts window with the user selection with one new function call well Robin also mentioned that there were a bunch of other new features to the fonts window you see that there's a search fields here we also have a direct access to managing font brings up a fonts book directly and if the user has another font management application we expect it to bring that up further we have typography palette this provides access to the various fonts features that are not default and they're very sensible as FB no is a very pretty font that we install with mac OS 10 but it has a lot of features that you can't get to right on the surface if you implement support for the press the typography palette you can get access to specialized ligatures ornaments stylistic variants old-style figures small caps a whole bunch of works japanese fonts even have a lot more to offer in this type of gothic palette for example here ajeno one of the deputy sponsorship of the system has many features you can see this is a huge palette here there's support for Japanese features like kana wits where you can have full width half-wits or performs proportional widths for Connor characters there's also support for stylistic variants and other features that the font may provide the last thing I want to show you is the character palette you may have seen this in other presentations but there's direct access to get too specific characters and to see all the characters supported by the font now unfortunately may have a little bit more work to do on the character palette but I think you've seen it before you'll have a window access to all the glyphs or all the Unicode points of the font and the usual how to be able to see everything that's available we hope you like the new user centric approach to managing fonts on Mac OS 10 and we really hope you take two points home from today's presentation one we want a user focused approach to do that we actually do implement one of two approaches in your application at a minimum respond to a TS Mont notifications don't make the user relaunch your application to see new font or to even better anywhere you would use a font menu provide access to the fonts panel so we can have a standard user interface for fonts across the entire system thank you I'd like to invite Robyn back to stay just finish the rest of the presentation [Applause] Thanks anxious so you've seen some of the really cool user level features that we've been working on for Mac OS 10 and panzer so let me recap this is the second part of the presentation this is where i go into what you can do in your application software to take advantage of some of the features that we've implemented and also to implement newer cooler features in your application so if there's just two things you're going to take away from this presentation and you go back home from WWT and implement in your application if as Nathan pointed out the first two items up here one adds support for the standard user interface ie the font window or the font panel if you're old school like me also add support number two for handling not fonte nova fond notifications this will allow you to make sure that your applications are as responsive as possible to any changes in the font registry that the user initiates or other applications trigger I'll also cover some lower-level topics that are of interest to you the third item is particularly important because people have asked we have a number of different font referencing systems in both carbon and cocoa and I'll go into detail about how you can interact with the font system the HTS font system which underlies everything and take advantage of those features within those layers I'll also go into some more detail about specifics within ATS itself such as getting access or managing the contents of the font registry getting access to information stored within it and querying the font raster risers for information specific to glyph okay so as I said one of two things were asking you to do is adopt the standard user interface now if you use cocoa you get a lot of that for free in fact you get most of that for free as Nathan pointed out but with in carbon applications you still do need to do some amount of work it's not too bad in fact if you look up here I've encapsulated the real the main work that you need to do in fact the first one so easy I don't even have to make it slide for it if you have a standard if you're using the standard carbon event based application event handler all you have to do is add a menu items that triggers off of that standard command ID which is to show and hide the font panel once that's in place you're done any time the user selects that menu items it will switch between the two different states for showing and hiding the font panel and it will initiate the font panel code pull it in instantiate it and show it on screen for you the other three items I'll go into a little bit more detail in the next couple of slides but they include support for handling font selection events that come from the font panel to your application so that includes whenever the user changes the state as a font panel you get a notification about that through a standard carbon event similarly if somehow the state of your document changes for example if a user clicks through and sets the cursor in different location within your document you want the pot panel to reflect those changes and sync up and so there is an API to allow you to do that and then finally the font panel as you can tell if specific to the current user focus so what you want to do is if a user switches between different windows you want to be able to notify the font panel that something has changed and that it should pay attention and also notify a different window or event reference so first off handling font selection event is straightforward and it's built in and integrated with the carbon event system all you need to do is handle the standard font selection event it's of the event class fonts and we have a specific event type called font selection within that event you can pull out the parameters related to that event using the standard carbon event call and we provide information on the current state of the font panel so originally it was mainly the typeface family the font or the typeface and the side that was important now as you can see we've added a bunch of additional new features with panther such as the typography talat and there's other features that are related to stylistic effects such as handling strike throughs and underlines and other cooler effect states you might not have been able to get natively within the font or on previous system so that information is stored within a dictionary that gets passed back through the carbon event that you can also parse and grab standard pieces of information so the typography in the information about the typographic features are actually stored for example as a absolute style attribute absolutely style attribute that you can then pass through the absolutely text system in carbon to render appropriately similarly we've added support for the textile information such as the strike through the underline and the other cool features there's one more thing that's pretty cool is that we also include information about multiple maps or variations so you didn't get a chance to see it here but if you install a multiple master font you can use the typography palette to go through all the different axes in the multiple master fonts and take advantage of those cool features in fact the Apple standard font mouths Nereus is provided as a multiple master font so I take advantage of that person all the time on my system right now okay so when you set the font selection through either changes in the cursor position or the user uses some other mechanism in your application to change the setting of the font in your document what you need to do is provide notification back to the font panel that something has changed the way you do this is you use the standard a chai toolbox function to get the target event graph this is a new data type that's available this is what's used by the font panel and in its function to set the information for the current selection you pass the target event rough and an array of data types that are specific to the text system that you're currently using so for example you can pass in an array of absolutely style objects that correspond to the current selection of your text it might actually just be one if it's only a single style run or it could be multiple ones once the font panel gets it it parses through that and it sets the state accordingly so for example if you had to style runs ahead like helvetica is the family but may be bold and italics you'll see that reflected accordingly in the font panel where the family will be set to Helvetica with the style or typeface information left blank to indicate multiple selection similarly we also support passing in quick draw style or quick draw text information which consists of the traditional quick draw a family name and the style bit array ok so when users switch between windows on your application you need to notify the font panel that that's of the change and so within York within your event handler what you want to do is provide support for the expanded carbon event that notifies you that the window focus has changed or that the window focus has been relinquished and all you have to do at that point is call that same function to set the state of the font panel but just pass it a null eventtarget rush what that does is it Lee sets the font panel so it knows it doesn't need to send events out so that the previous window anymore and it can clear it state usually what happens right after that is the user has selected another window and you get a a window focus acquired event when you handle that event you basically do the same thing you can pull out the window reference from the event parameters pull out the target event rest from that and then pass that information plus any additional style information that you have to the font panels to indicate the new selection within the new window ok so that was it that's all you have to do to support the font window within your carbon applications so next handling fought notifications that's the other key thing I like for you to remember from this particular session let me go into some more details on that what handling font notification does for you is it allows your applications to be much more responsive to changes that users do or other applications due to the state of the fonts that are in their library so as Nathan kept pointing out you don't have to shut down your application or your users don't have to shut down your application just to be able to get a new font that's been dropped into it one of their fonts folders that's a big thing and we need your help to be able to do that secondly and I won't go into much more detail here today but it's it bears mentioning you can also send notifications to the font server if for example your application install fonts program equal using let's say the file manager calls or standard UNIX file system calls that pass underneath the radar of the system we've got hooks into places like the finders that let us know when changes occur within the standard font directory but if your application for example at launch time installed application specific fonts this is a key way to actually notify the font system that something else has changed and what we will do is will scan the directory identify those changes and then do a broadcast out to all the clients who are interested and have subscribed for changes so getting back to the first point in order to make your applications more responsive all you have to do is implement one callback function to handle the notification what you next to have to do is basically register it with the system and you're done all you have to do is call the standard ATX fonts notification subscribe function pass in your callback you can also pass in a rest con if you want to so you can get additional data into your callback function but otherwise that's all it takes when you want to deregister it's not required but if you want to get rid of it before your appt shuts down you can certainly do that with a similar function in the 80s font API okay so the next topic I'll be talking about how to exchange data back and forth with the other components in the system first and foremost the easiest thing to remember about exchanging data with cocoa and the underlying court system is that fonts are uniquely identified by PostScript name whenever you get a name back from app kit from within Coco it will be generally a postscript name similarly if you want to instantiate an innocent instance when you're asked for a name you can query the APS font system for the post rittany pass it in along with the side and you can instantiate and then its font reference on Panthers we've also implemented support for a more powerful kind of mega and as font reference it's the Ennis font descriptor you could think of it this way as opposed to just one instance or one font within the font panel you can take a whole slice across it and actually specify a descriptor for that so here's an example you can actually specify an init font descriptor just by the family name and that will include all the fonts that belong within that family as one descriptor similarly you can go off in the other direction get more detail you can specify a family or just with the ax font like PostScript name and that's more like the traditional and as font or you can go even further specify a size which gives you what we traditionally call a strike it's one specific combination of font and size within that class there are other attributes that you can actually pass in as opposed to passing in a postscript name or other information that includes stuff well the way it works is with the font descriptor class you can pass in a dictionary of attributes and the more information you put in the more specific the descriptor will be ok so when you work with carbon that's had a longer history in terms of the different font references that available but one key thing to remember is that both the effluents they support identifying fonts uniquely by the traditional quick draw font family name in style bit array note that a soui is actually pretty cool in that it actually handles the core graphics of the court mechanism also so you can handle those font references using the post trip name also one thing that we provide and both the quick well primarily at the quick draw layer is conversion functions that allow you to go back and forth between the newer HTF font references and the older font references and font family references one of the key reasons we asked you to do that is that in the future or also even now there are slight differences within the data type some are there's fine differences and there's also size differences some of the references are 16 bit as opposed to 32 bit or 32 bit signs what these conversion functions allow you to do is kind of shield yourself from any future changes and also any potential changes that might happen if you simply assign one of the older data types to the new or 80s font one so please avoid typecasting use the conversion function avoid direct assignment because you might get implicit type promotion that causes problems with the signage use the conversion function okay so let me get into some more details about mucking around with the contents of the font registry now why would you want to do this well think of it this way here's a typical example you've got a font that you've license with your application you use you in your user interface but you don't want to stick it for general purpose usage out in the standard library and so what you can do is you can actually activate that privately just exactly the same way the file system or the operating system would do but just for your fun similarly as Nathan pointed out we're making a big effort to kind of integrate the support for font collections across the system what I'll be talking about is giving you a chance to kind of hook into that to take advantage of that also you're interested so when you activate and deactivate fun what we recommend that you do is pass in a file reference that's really the easiest way for you to do it mainly because there's a lot of information there that we can actually parse through file types contents to the files even suffixes on the files figure out what exact format it is we can take care of the rest for you so you don't have to worry about it note that up here I'm passing in an unspecified format me because I'm passing in the file reference another cool thing that you can take advantage of is if you put let's say your abscess if font within your bundle someplace maybe within the resource folder of the bundle you can just pass pin a pointer to the top level of the bundle will trundle down through it recursively and activate any fonts that reside in any of the subdirectory another part of this example is that I've actually activated the font locoweed so that it's only available for my application what you get back from this function is a container reference with this container reference you can later deactivate exactly the same set of fonts that were stored in that file or in that directory using this function to deactivate the fun there's one thing that's pretty cool though is that 80's will keep track of fonts that are activated locally within your applications so you don't have to get rid of it yourself when your app sets down will deactivate the response for you okay so with cancer we've provided support for additional api's or classes that allow you to modify the contents and remove and add font collections just as the font book does in cocoa you simply use the NS font manager class with a variety of new api's that are available to do this similarly we've implemented support in carbon with see callable wrapper functions through those same functions to those same methods that let you do let you call these functions from within your carbon applications so far collections they're identified uniquely by name what you see up on the font panel are the unique names for those fond collections another cool thing is that font collection go back to those sponsor scriptures I described earlier so the same actions that users can do to kind of grab an instance of a font or you know a particular font strike drag it in and set up a font collection entry you can do the same thing at this level as long as you define a font descriptor okay we're almost there I've got two sections describing how to interact directly with the ATM font system the first one if you notice I badges with the caches entry in the architecture diagram the reason for this is that we've implemented a number of high-level functions that optimize access to this data through the caching system as much as possible so we've identified that you guys tend to use postscript names a lot especially with my recommendation on interacting with the cocoa tech system we've got that out of mind we also have an optimized function to get at the file references associated with a particular font all of this information is cached so that you don't have to worry about triggering messages hitting file system making file system calls and potentially even triggering font rasterization efforts now what I'll go into in more detail in the next two slides are the lower level functions that bypass those higher-level easy to use functions and that includes the function that lets you kind of go straight to the file system grab the font data out of those files and parse it yourself I'll also give you some information on how to enumerate every single fonts or font family within the font registry and do whatever you want with those entries so when you want to pull out data related to fonts directly from the file system we provided a couple of standard functions to do that this one happens to be the one to get the font table think of it this way the way we've made a standard format for the font is similar to the way truetype fonts or opentype fonts are defined they consist of a directory of font tables each of which contains specific class of data so I mentioned earlier in the presentation that we have character mapping tables those are sort in tables that are indicated by the cmap tag or CM AP we also have support for accessing the glyph data you can access any of the fun data that's available for these fonts now the convention is you make an initial call to these functions either 80s fonts get table or the directory version you pass it into the font dress and the tag indicating what data you want and you pass in a null buffer in return you get back the length of the data that the function will return to you and this is what happens in the second call in the second call you can actually Malik right then and there a buffer to hold that database from the size you got in the first call pass in the buffer this time and get it filled in with the data that you need now if you have any more questions about how to process this information it's available in the specs for the opentype font format and a true type font format so as you can see this is pretty low level stuff but for a lot of you out there this is your meat and potatoes this is what you want to deal with the other people in the involved with this usually use the high level function so if you have any requests for us we'd be happy to implement it so please use the the bug reporter let us know what features you'd like to have that otherwise you have to go through the lower levels of the ATF's font system to get at ok when you enumerate fonts and font family there's a similar convention or there's a standard convention also and they consist of iterator objects essentially all you have to do is create an iterator object based on a bunch of criteria set up a while loop that calls the iterator objects for each successive entries and when it's done it'll give you a status code back indicating that the iteration is done and then finally you release the iterator object to return the system resources back to the operating system so some of the different things you can do with the iterator objects include filtering them you can pass in any of a variety of standard predefined filters such as filtering by font location or by the generation in which they got activated so if you want to find out if there were any fonts that were activated after you check the fine the registry you can check a generation count and in filter based on that you can also pass in your own custom filter function to do the filtering yourself based on whatever criteria you specify and if you notice here I'm actually using a similar way to restrict or actually in this case totally unrestricted scope of the iteration I've chosen a global context with unrestricted scope so I can see every single font available on the system for all the processes okay one last item when you want to access caliph data this is where you interact directly with the font rasterizer or in this particular case the absolutely tech system eases the burden on you someone and allows you to mimic exactly what the soe tech system does but gets you back this data directly so it has two functions to access to different flavors of glyph data format with glyphs path into different formats essentially the glist path define the shape of the glyphs that you can then tap into let's say the court system or draw yourself directly on fleeing or manipulate this as if it were a regular graphics object now the escapee is take advantage of the higher levels of the earth Lloyd system so you can pass the information from a standard absolutely text layout object so you can take advantage of how its specified let's say a run of characters pass that information in and get just the glyph information for those characters in addition they match exactly the way I see withdrawn so you can still take advantage of trying to mimic exactly what actually does but get into the lower layers of it and directly access the the font data through these ap is so usually what you do is you determine what the native glyph data format is for a particular font and there's an API to do that if you don't do that the function for accessing the glist path will actually convert the accordingly to for you so if you ask for quadratic and you ask to get the glyph data for a postscript font that's normally defined in cubic data then it will converge in a court accordingly the other thing that you have to do is implement a series of callback functions that process the standard standard operations that define the glyphs shape so this includes for example let's say in cubic you have a move to operator a line to operator a curve to operator and a closed path operator the line to operator basically defines a straight line segments and the curb to defines any arbitrary curve okay so just to wrap things up here what I've talked about today is that there's a lot going on in the operating system that hides the complexity of fonts for you we've implemented a lot of stuff you've seen how the architecture works and how they interact and how they touch on api's that you take advantage of at your level in your software the other thing I've covered is that if you go away from WWDC and implement just these two aspects of the system you're going to help us push forward this idea of putting the user at the center and making it so much easier to use their fonts and so much powerful that people will be flocking to your application so adopt the standard user interface add support for handling the fonts window you see how much you'll get with it the typography palette a character palette the interaction with font book and handling support for come font collection to the very least you should also support handling font notifications so that your apps become much more responsive to changes in the system there are a couple of related topics either later on this week or that you can review after wwf/e includes the unicode session and the cocoa text session our evangelist for this area is zabiela grill but you can contact him specifically about some of those bugs or features or new api's that you like and something that you guys have been asking for documentation on this part of the system well my team has worked really hard this year to put together the documentation with the technical publications people and we've got them up there so take a look at them they're really cool there's also related documentation about the various tech systems available on Mac os10 including Atsui cocoa and there's also documentation for the legacy font manager API is available in quick draw