---
title: WWDC2003 Session 423
framework: wwdc
role: article
path: wwdc/wwdc2003-423
---

# WWDC2003 Session 423

## Transcript

Kind: captions Language: en my name is Xavier lagoon and the Mac os10 Avengers I work in the reparations and i'd like to welcome you to session making hamburger and kevin application the funny thing is that we were talking with the guys from which I to lburg and we're wondering about the sessions this year we had great content for HIV we had wanted to give you a good update on what's going on with developing using vhi toolbox and then we go to the conclusion that there were still one missing piece you see people have been using cover any different terms in the last three or four years since Mac os10 there is this notion that carbon you know it's ready to carbon leave and so you know some people think that well you know they're coming to the platform is wondering well should i use carbon it is carbon leave don't want to work on mac OS 9 so wanted to emphasize the fact that you know when we talk about crabber and development now on mac OS 10 we r we talking about developing using the tool box and it's the idea is writing a border and c and c++ application and the goal of this session is really to like kind of scratch what we've been doing of like you know scratch like the fact that you know you have covered it to support and mac OS 9 because we think now we are past that point and we want you guys to let make sure we understand that as well and the goal of this station is way to focus on new technologies we've been introducing new concepts that are very very important on mac OS 10 for you to develop a modern c and c++ application all right so vital like to invite David McLeod on stage who is going to be taking you to like the different concepts and the main key architecture that you should think of when you develop your application on my question thank you very much and thanks for coming I really am happy about that because it means to me that our message is getting out that the H I Toolbox isn't renewed and you can make a modern carbon application with a new h I to a book first I'd like to kind of qualify who should be here it's kind of three groups first people that haven't made a carbon application yet second people that have made applications but remember maybe Mac OS 9 based and made to wait next event applications and third there's probably a group of you that are responsible for porting applications to Mac OS 10 so this will be helpful for you and that's sort of the target audience today oops what do we mean by a modern carbon application modern carbon application is a full OS can citizen behaves efficiently doesn't block and use up too many resources and we get that because we've introduced a simplified event dispatching model called carbon events were you not pulling any more to get carbon to get it to handle your event and this makes for a very efficient application also your user interface is now defined using nibs get into those in more detail as a session goes on also your modern carbon application uses up-to-date OS services like navigation services CF preferences icon services quartz all the modern services that are available to you on the operating system so what I'm going to go over today we're to show you how to make a new carbon application using Xcode go over making a user interface using interface builder making your user interface a noob files I'm going to show you some of the user interface elements that are available in a chai toolbox it's actually very complete and you can make a very full application just using the pieces that are available from h-i toolbox having those pieces of nice but also show you how to handle events and commands so you can deal with the user as the user application I'm also going to touch on using alerts in your applications to sort of interrupt and notify the user of things and communicate with them the last thing I'll touch on is navigation services a little bit just so you can show how to interact with users in terms of selecting files and folders so I'm really only going to cover two frameworks today and they're both sub frameworks of the carbon frame work so I'm going a couple cover a chai toolbox was going to cover all of the user interface stuff I'm also going to touch on navigation services overall what is carbon like when we talk about carbon what does it mean a lot of people think you know its carbon lib likes of you is hanging or that it's some sort of bridging technology just to get you onto s 10 it's actually not true carbon is a full set of C and C++ API is that you can use to make a full Native Client a native application on OS 10 gives you full access a P eyes give you full access to the left and services that are available to you like the user interface accessing the file system using the drawing primitives in courts specifically a chai toolbox is the seat set of scene C++ ap is that you can use to make a user interface so we're throwing around the term modern a little bit what do I mean by being a modern application something that's important to us is that you use xcode so that you can make a mock o application another benefit of using xcode is that your application will get may be made as a bundle what kind of cover that in the next slide also being modern means that you're going to use interface builder to design your interface and make it and make them user interface with nib files so they see the pre stated previously being modern also means using existing mac OS tennis services that are appropriate for your application such as quartz navigation services a chive use to make your application also you want to use the carbon event dispatcher so that the modern efficient non polling event dispatching mechanism that's available in a chai toolbox I'm going to cover that later on so for those of you that may be familiar with writing Mac applications the old way may be similar to the way you wrote them on OS 9 or the way you wrote them using carbon lives and weight next event applications there's a few differences first the old way a lot of the API is dealt with pascal strings that made it very hard to internationalize your products because you couldn't use extended character sets are available and are needed for other languages like Japanese Chinese etc all of the new AP is ucf strings and that means that they're Unicode savvy and you can use all these extended character sets to provide your your application specifically the user interface the old way of dealing with events with use wait next event and pull continuously using up cpu cycles the new ways is to use carbon events and not really pull at all and only be notified when important events are coming to you that means that you block and you're not using the cpu you and your an efficient great performing application on OS 10 the old way of dealing with files is not even available anymore standard file and is replaced by using navigation services to select files and folders and tell the communicate between the user and the application where files are going to be saved and retrieved from another difference is moving from a single application file where the application was totally enclosed in this one big file with resource forks and all kinds of things in there to an application bundle application bundle it seems the same to you when you use OS 10 but it's still like when you go to use OS 10 it's it appears to be one icon with everything all squished into one binary but it's actually represented by a folder underneath that's only evident to you as a developer and that folder contains the binary of your application and your nib files any other additional files like maybe some sounds or some image files as well as your plist to describe yourself so it's actually a whole hierarchy that's underneath you can also provide localization information in there and it's all seamlessly done through the application bundle the old way of making your user interface was to build it up in a set of resources and maybe low gets loaded with the dialogue manager or something the new way is to use a nib based user interface by designing your user interface with interface builder I'm going to talk about mibs a little bit later on in the presentation the old way of actually creating your user interface was to use controls and the new ways to use a chive use they've totally replace controls even the things that you're used to calling controls like buttons etc are actually underneath the covers really just a chive use so the modern way is a chive use because they also do what we call the compositing system and that means that the drawing model is much more efficient when your user interface draws only what needs to be drawn gets drawn and lastly the old way of drawing what to do it with quick draw and ports and all that and the new way it's course it's got all kinds of really great features it's very efficient and it's used system-wide so you want to use the system-wide drying mechanism in your carbon application so I'd like to invite guy fullerton up on the stage he's a chai toolbox engineer with me and he's just going to show you how to make an application with Xcode switch over to the demo yeah good all right so what I'm going to show you today is just kind of a reinforcing of some of the things David's going to talk about on his slides let's say I want to build a new application let's say I want to make some kind of picture viewer so I'll take you through the steps I might do for that first thing I'm going to do is launch Xcode to create my project and I'll choose new project now though there's a couple different choices for carbon applications there's just plain old carbon application and then there's the need-based carbon application I want the mid-bass one because that's the more modern alternative so I'll choose that let me put it on my desktop and let's call it I'm spacing I've got to get this right otherwise everything's going to go bad let's call it strip okay so Xcode creates the project for me and Xcode is going to take care of a lot of the other sort of modern features automatically going to build the application into a bundle and it'll have a plist and all those kinds of things so Xcode already sets up a main for me it's just a very skeleton main does the basic things you need to do a tap bring up time which is very little these days for a modern carbon app and I'll go through that in a little bit more detail in a later demo but for now let's just build it and run it and see what we get so the app launches it just gives us a basic window we've got a menu bar that you know you can track in and whatnot you can resize the window unfortunately that's not the most modern UI for resizing but we'll take care of that little while later so that shows you just how to get sort of a bare bones skeleton application up and I'll go into more details in successive demos later so it's david so hopefully you've installed panther on your machines already and maybe have tried to do this and you've seen that it's pretty easy just to get a simple app up and running but a simple apps not very fun unless you have a user interface it's not all about being fun but you want to be able to have some functionality and your functionality can't really be provided to user without a user interface when you make your user interface you want to make a modern user interface and I'd like to kind of touch on the point that really define what a modern user user interfaces first you want to adhere as closely as possible with exceptions to the human interface guidelines so there's a document that will refer will put up a reference to you later on and you could read through that it sort of gives you the guidelines about how you're supposed to use user interface elements in conjunction with each other one thing about laying out the user interface you can see in the top right here I have a picture of interface builder there's some little blue dashed lines so it has a guidelines feature an interface builder helps you lay out your user interface according to some of the guidelines provided by the human interface guidelines document the next thing you can do to adhere to the user interface guidelines the aqua excuse me the human interface guidelines is to use a chai toolbox controls we worked very hard on the controls to make sure they adhere as strongly as possible to the guidelines given to us by the human interface team and if you use them you get all of our hard work for free next you want to use modern compositing windows I mentioned compositing earlier it's a drawing model where only what's needed to be drawn gets drawn in your application and it's much more efficient you can provide an application that's much more modern by using this it's kind of nice because it's just a checkbox in interface builder you click the checkbox for compositing you use all of our controls they can be used in composited windows and you get the efficiency right there for free that's nice the next thing is live resizing guy showed he was resizing the window there in the application it just shows showed an outline of the window and that's not really a responsive user interface so you want to turn on live resizing again it's just a checkbox in interface builder you check it and that means that as the user modifies the window changing the size etc the user interface response instantaneously and the user can see what resizing that window you also want to use the standard event handler again guess where the check boxes using the standard event handler for a window means that all of the routine event handling for a window like what to do when some clicks on the title bar and drag it around or clicks in the closed box or the grow box all gets handled automatically through the standard event handler also when it comes time to interact with the user may be to interrupt them and give them information you can use sheets or standard alerts as appropriate when it comes time to interact with the user to describe locations of files and folders you can use navigation services so all of these things together will give you the basics of a modern carbon application so I'll talk about the user interface elements that are available to you there's quite a few I can't stick them all on one slide so I had to break them up into bits because there's just so much available to you first there's a few kinds of menus you can use there's many as you're used to that come out of the menu bar there are contextual menus that you get when you command click or right click on user interface and these contextual menu menus changed according to what piece of user interface is being interacted with and there's also pop-up button menus all of these are just lists of commands that the user can can make a select to perform action so they're just simple actions that a user can pick next we have a whole bunch of different kinds of windows and you want to use windows to present your user interface and your information to the user so the biggest window we have up there is a document window you'll put your the contents of any sort of document functionality of your application there here it's just a picture from text edit I think or simple text simple text out the side of that window is a drawer where you can provide additional information about specific content on the bottom left there's a utility window that's a good place to show properties of objects in a user in fish and the bottom right I show a sheet and a sheet is a kind of window that actually is grouped with like a document window and it comes out of the top and is associated directly with that window so you can interrupt the user and provide information about a specific window that way next there are a few kinds of toolbars you have metal tool bars I show a few examples here the second one is large icons with text and then I shall see me is there's different modes that you get all automatically and free you can select small icons without text and you can have icon list entirely I don't know if you can see right well in this slide but there's a little Chevron on the right and that that's all provided automatically the chevron on the right turns into a set of menu items when there's not enough room to display the toolbar functionality is available now the controls there's a lot of controls available to you and I'll break it out into a few slides in a second but I've highlighted some in yellow or orange here these are the new ones that we've introduced in Panther we have that segment view has a little asterisk there because we didn't finalize the api's in time to get on to your seed CD sorry about that my fault a little bit also we've introduced a text view which is a wrapper around the MLT text em ltd text objects that's very powerful we've also added a search field so that you can provide the search functionality like you see in the finder and that you've seen introduced in many places in Panther let's go back for a second so I've kind of divided those up into a few different groups that's kind of the way I group them mentally I don't know if everybody does well I'm just going to go through those groups to talk about the different kinds of controls that are available so the first group is buttons there's push buttons that you're all used to radio buttons and checkboxes that if you don't know what they are by now you've been using them for quite a long time the standard ones you're used to we have bevel buttons sort of squares buttons they can have icon and textual content little arrows which you see are the top on the top right there it's a little set of arrows used to well allow a user to increment or decrement some values and we have the new segment view which is you can see on the bottom like take a second to tell you what the segment view is the segment view is a way to allow the user either to select something or to provide some sort of state functionality when you click on the buttons it's very powerful guy had a session earlier where he talked about it in detail if you can see that on a DVD he really provides it a lot of good information about the segment view the next group is text controls we have a lot of those now because we've been adding some first there's edit text which are used to for putting small textual items in say a forum user interface of some sort static text for labeling pieces of your user interface we have the new text view where you can provide much more complex textual information allow the user to edit it and have it styled etc using the ML te objects at the Edit Center we have the clock control which is what we call the feature that used to display the time and the date and you can allow the user to set the display times or dates to users or allow them to set times and dates we have the new search field which you can use to provide the user a chance to give you feedback about what they want to search for it should be use exclusively for searching rather than any other specialized content because it's it's been branded to be a search field and it's very important to maintain that look as something a user will automatically think about as a searching item and lastly up there we have a combo box which is sort of a combination between a pop-up button with a menu and a text field where they can sort of type select things the next group is tracks so we have the scroll bars in there where a user can scroll the user interface a slider for indicating values of us on a sliding scale progress indicator for you to provide feedback both the progress of your application that's the one that i got a blue rectangle on it there and a relevance bar for providing feedback about how relevant maybe something in a sort of searches is to user the more full the relevant spark more relevant it is to the user we have kinds of controls I call grouping controls like the tab control which is the outermost group here says 12 at the top or you can group the user interface by tabbed pains a group box show that there is just to sort of put a box around these are interface elements to relate it to each other there's also the radio group which is kind of a nice feature does some automatic behaviors for you you can put up a series of radio buttons then as the user selects the radio button it communicates with the other radio buttons to turn them off and on automatically and the last kind of controls is kind of a miscellaneous pack it's our specialized controls we're getting to have a quite a few of those now so we have an imageview got spongebob up in an image view here is anybody who no who is fungible obvious if you come to my office you can meet them we also have the chasing arrows so that used to be a control that had arrows chasing each other now it kind of looks like a pinwheel or a spoke effect shows an animation that shows your applications doing something we have separator bars there's a vertical and horizontal lines you can draw those to the user interface guidelines by using that control they use their use to separate your user interface into different compartments we have the icon control and image well where you can show a sort of other image content in it they're clickable we have the scrolling view here that's that other image here with a person then pink in it and it allows you to put content in it and automatically scroll it a lot of functionality that you got used to have to do by hand and also for brought providing sort of hierarchical data representation or table data representations we have a sort of a complex control called a data browser so back to the big list that shows that there's a lot of user interface that you can use without creating your own to create your user to create your applications user interface you shouldn't really have to create too many custom controls you should be able to use these I make a fairly full-featured application all these user interface elements it's nice to talk about them but I'd like to just touch on nibs and talk about what i mean by nims nibs are an xml-based extensible way of describing a user interface I'm going to get I think it's best of all to show guy it to get guy to show you how to make them but before he shows you I'm going to talk about how you can load your user interface out of a nib loading a nib is very straightforward there's an API cells create nib reference so you're going to have a file inside of your application bundle and you'll know the name of it you provide it to this API in the incoming nib name parameter tell it you want to load that nib reference and that's all there is to loading it you'll bloat after that you'll load all of your nib content out of it when you're finished with it you're just both of the nib reference now I don't mean that you have to keep your nib reference around for the whole lifetime of your application just open the nib reference get what you need out of it and close it again if you need to use it later on in your application you can reopen it without a problem that's okay but you know all you're doing is opening the neighbor reference the interesting part is taking your user interface out as an impressions so there's a few api's for doing that you can set your menu bar from a nib you can create a menu from a nib or you can kind of most interestingly because you're going to be making a lot of your user interface in Windows you can create window from the all of these api's take a reference to the nib that you created with creating of reference the API showed a previous slide as well as a name that you have decided while you were creating the nib so say you need you named your window main window you provide that string there and that is the nib that will be loaded with create window from nib once you've loaded a few things out of your nibs so what you know you have you've loaded them what do you do then how do they work there's a simple API called run application event loop and it's simple because it's very easy to call I have a prototype at the bottom here run application event loop and it kind of get everything going it starts the event dispatcher which starts all of the standard of and handling that happens in your application it's important to note that this API you call it and it goes away it doesn't come back for the duration of your application until your application quit does all the standard event handling like application d activation and deactivation not kind of thing it calls all the event handlers that are necessary for your user interface to work and it's pretty easy to use and why I bring this up is because just in the API is that I've gone through I can show you a nib sample code right up here and it's a full application doesn't do much it's just user interface user interface but it's a full application so I create a nib reference referring to the nib file in my application bundle I set up a menu bar from that nib by passing in them I have a menu bar named my menu bar in this example then i create a window from the nib called my window i'm done with the nib reference so i disposed nib reference i run application event loop this is a full application and it'll start up put up a menu bar put up a window that we can be dragged around and used so i'd like to right guy to show the next step making a user interface with interface builder thank you David okay so we've got all the he told us about all the tool we need to put together an interface and I will show you how to build one so when I created the project with Xcode it automatically created a main nib for me and in fact it loaded some of those things automatically in the little skeleton app that Xcode created for me and this code looks almost identical to the code David showed you before so no surprise there so let's take a look at the nib that Xcode created for us and we'll look at that with interface builder first thing you'll notice is that the title of the name is main name that is the minus e dot nib part minus the extension that is the name you would pass to the create nib reference API to create your nib and similarly everything that's in your nib also has a name for instance the many bars just called menu bar so you would load it with that name and the main window is just called main window and loaded with that name alright so let's actually do something interesting with this nib open up our window in the nib and I want to make a picture viewer so I need a place to display some pictures first of all so I'm going to Oh before I do that I actually want this thing to look a little bit better than just a plain white canvas so when we bring up the inspector and I want to set a few attributes on the window so there is a notion of a theme brush that can be associated with the window and this determines how the window background paints since this is going to be a normal window in the document layer of an application and that's sort of the modeless layer I want the modeless look which will give me the aqua line now another thing I need to set on the window is I want some of those modern features turned on so I'm going to cook the library size checkbox and a compositing check box so that i can use a chive use and so i can get a nicer looking resize and just that sort of rectangle alright so now let me actually add some stuff to the window I want a place to put my images so I'm going to drag out a group box here but I don't want to title on it so i'll delete that and let me put it in the right place so here's an example of some of the guides david was mentioning for interface builder it lets you sort of snap your your controls and views to the right place according to the user interface guidelines and interface builder does that automatically so let me grow this thing out a little bit and I want some push buttons you've done the right spot here on the previous button one thing I want to do to this button is I want to be able to react to it when the user clicks on it and the way I'm going to do that is to set up a command associate a command with this button just a little for character code this command will automatically be sent out via the carbon I met mechanism whenever the user clicks on the button now another way i want to set up this button is by giving it a signature this signature allows me in my code to be able to fetch that button from the window i can say for you know give me give me the control with the signature previous and id0 out of a window so I can manipulate it later if I need to so I'll go ahead and set that up and in addition to the previous button I want a next button let's get that in the right spot give it the right title of course a signature and a command to get broadcast and now I want to make sure I get that at the bottom of the group box at the right position according to the human interface guidelines and now I actually need to be able to display an image and we've got a view all set up for that for you out already it's called a chai image of you drop that into my group box throw that to the right size and I need to set a image view specific oh I needed you two things to the image you first of all need to give it the right signature so I can find it later just one does need a command so I don't need to do that let's set up an attribute I'm going to set the scale to fit attribute it just modifies the way the image will get actually displayed in the image view okay so let's save our noob and rebuild our project and it comes up just like that so the interface got loaded now unfortunately even though we've got live resize turned on the views are not relaying out this is something we addressed in Panther we have a new set of API is called HIV layout we're going to talk about it in session I think it's for 25 which is immediately following this one but in the room upstairs and we'll go into details on exactly how to use that now I've already written some code to do that and go ahead and add that to our application and add a bunch of files we add it to a different place here add a bunch of files so I'm also adding some files for some other functionality I'll show off later the important thing I needed is in filmstrip view see let's go back into main and let's set up the layout so I will need to include a prototype that's in filmstrip view and all right so see I've created my window right before I show it i want to set up the layouts that take advantage of HIV layout automatically resize all my widgets and that is yeah my setup window layout function so now the theft and i should be able to build and run and now when i resize the window oh you know what I must not I must have missed something in the NIT but I'll see that later so anyway the the buttons move around appropriately and the group should move around as well but I bought something up but that's okay I'll fix that for the next one so that shows you how you can construct a basic interface and like I said we'll go into more details on how to use HIV layouts which is a really powerful technology and we'll go into details in another session but so in subsequent demos I'm going to actually add some functionality to this app but before I do that David needs steadily some more groundwork for you Thank You guy so guys showed that it's pretty easy to use interface builder to add some of the user interface elements that are available from h-i toolbox into your application so that you can provide feedback to the user about how your application is going to look and work next I want to go over roughly what the architecture of a modern carbon application is so we showed you the nibs that define the user interface I think that's very important once those nibs are up carbon events or what makes it would animate it and what give it life so the handling of carbon events is important like I mentioned before it's a non polling way of handling events where you only listen to the events that are important to the application I'm going to talk about event handlers in a few slides there's also the handling of H I command an H i command the way I think about them is that they're sort of simplified H I its simplified carbon events where they just describe an action that the user wants to take and you do this through an H I command which is just a 32-bit values that identifies an action you also want to provide a reactive user interface what I mean by that is that as the user as the application changes its state underneath you want the buttons and menus etc to react to that change of state by becoming enabled or disabled or how the names of menus change etc menu items change etc other than that all you need to focus on is the functionality that you're providing in your application that makes it special and makes your customers want to buy it so here's kind of a pictorial overview of what I just said a minute ago so we've got these yellow blocks up here they represent the nibs that you made as guy showed you as you load them in you can maybe programmatically modify them as he did with adding layouts to them and we'll show you that you can also install event handlers to provide your custom functionality from the application once you load them you run obligation event loop and the standard of ant handler is going to take care of all the rules the routine operations that's what those orange circles mean that means that all the window dragging and menu tracking etc are going to be handled by the application for free it's all routine stuff and you don't have to worry about it let's say you put in a vent handler command handler on the ok button when they click the ok button you can have a custom event handler that's there that gets called and then you can deal with your functionality afterwards and that's really what you want to focus on is your functionality that you're providing that makes your application special like you're talking about events what are these events there's a basic messaging system of a chai toolbox so when a user clicks oh there's any typing or there's communication buff between user interface elements or they or the any part of the application there's these messages going around and their carbon events a chai toolbox internally sends tons and tons of events and it's really that's what makes the whole event a dispatching system so powerful the cool thing is that you don't really need to handle too many in fact you don't need to handle any at all you only have to focus on the ones you care about you ignore most of them all the time there's many many events that are happening that you never even know are happening you don't really care i mentioned standard event handling a few times now what is standard event handling and what's so special about it well like getting your eyesight this WWDC or getting a t-shirt or whatever the best thing about it is there's tons of free things in there it means that you don't have to do any work and the less work that you have to do the more you can focus on the functionality of your application so H I toolbox really deals with all those event of the events that happen automatically like application activation and deactivation you don't really want to pay attention to that unless you care menu tracking control tracking and all the window handling the more you use this automatic behavior the better off you are because you haven't had to do much work and if we change the way the handling works we're going to change it in the standard event handler so that it behaves the specified way and you'll get that behavior for free even in an already shifting application if we can best of all it simplifies your UI code so there's less work for you less work for you to keep track of and it's easier for you to maintain your code so I got a standard event handle off because you notice some of the spaces fell out a standard event handler all squished together that's kind of a special event handler that we have for windows I mention it because you need to turn it on with that checkbox that I showed in a previous slide and was on in the interface builder one guy was making the user interface it handles all of the standard window behavior for free so you don't have to worry about dragging the window around or resizing it or handling the clicks in the closed box it also much more importantly routes all the mouse and keyboard events to the controls and the user interface that you use inside of a window to make up your your applications interface as I mentioned earlier you just click a checkbox an IV and you can forget about it that windows just going to behave properly for the duration of your application so I'd like to kind of break down events and event handlers a little bit events are identified by their class and their kind it's a pair it's a pair of two 32-bit values so there's an event class like k event control class like a bit class control or k event class window or k event class menu and then there's different event kinds in those classes so say with the the control class there's k event control bounds changed or k event control part hits or whatever there's a lot of events as i mentioned and we work very hard to document all of them very well if you go and read carbon events th inside the H I toolbox headers in system library frameworks they're very well documented and the more you learn these the more you learn about what kind of power you can add your application when you need to now there are a few different event types we break them down into sort of three categories there are methods types of events and that's an event that gets sent to something to tell it that it's it's it's a chance to handle its functionality specific to to itself for example you could have a key event controlled draw event gets into a control and that's that's the event system calling a control and letting it know that it should do its functionality then there's also notification events that get sent to different event targets Follette let the target know that something is happening an example of this might be a que event control bounce changed event so you can let a control know that somebody has changed its bounds and a control needs to react to that somehow and there's also hook kind of events we call them hook kind of hook event and that's where the event system what's a target know that something's happening and then that target can optionally do something about it if it wants to good example of that would be maybe a que event window bounds changing event notice ing at the NSF changed instead of changing instead of changed that means that the window is in the process of changing and if you want to override that behavior bit and modify the way exchanging before it actually changes that's your hook to be able to do that so I set of event targets a few times there there are a few different kinds of event targets the main ones are the application eventtarget so any any events that are going to the application like the quick commander of the application event applications activated command event will go to the application eventtarget there's also a window eventtarget so any events that are related to windows will go to the window eventtarget same goes for controls in there there's a few other specialized kinds that I won't get into this is all nice but what you want to do is install your own custom event handler on the pieces on the targets that are important to you to add your functionality and you do that with a custom event handler and here's the prototype of how your customer event handler should look so I have it's called my control event handler be great if it was bigger I guess I didn't make it big enough and it takes when it gets called it gets passed an event handler call Ref generally don't really care about that unless you're passing the event on to some other part of the system you get an event ref which is important it tells you what kind of event is coming in and you're also given a chance to set up some user data beforehand and that user data will be passed into the event handler let's go into that a little bit more detail here's an example of an handler it's a it's a control event handler and it happens to be handling a a notification that the control has changed its bounds so first thing it does is it takes some user data that's passed in and it changes to cast it into a control I'll show you why that is in a little bit but it's a good way of passing in which control is being handled which control is being passed this event next thing you want to do is use get event parameter to extract information out of the event as you handle it in this case is extracting the current bounds of the control as a rectangle and sticking it into the new bound hrs once you have that this is where your new your chance to provide your functionality you do something with what the new bounds of the control was maybe you relay out a control or I don't know exactly what you're going to do and then when you're finished you return nowhere to mean I handle to control so you really only want to return to different types of things from an event handler but the the event subsystem is going to care about nowhere which means I handle it and there's no errors you don't have to worry about anything or an event not handled there which means I didn't handle event you can do whatever you want on top of that installing an event handler is very simple you use its stall event handler and you pass in the target and that means who is who you're installing the event handler on and who's going to be receiving these events that you're going to be allowed to do some handling on passing an event handler upp that's a upp universal procedure pointer I think to the universal proc pointer to the eventhandler custom event handler that you've written you going to tell it how many events you're interested in and you're able to pass in an event type spec a pointer to an event type spec array which is a bunch of pairs of class and kind event class and event kind that describes which events your handler is interested in receiving calls for the last highlighted item in user data you can pass in whatever user data you want what I like to do is pass in a the instance of the kind of target that I'm passing in so if I'm installing a ton of control almost always fast in the control ref is my user data it's a good easy fast way of setting your control rest back out when your event handler gets called so on a window I passing the window ref as my user data etc and what you get out of the event handler ref which you can use in various ways afterwards if you care to can be null most of the time you don't really care there are a few shortcuts to get the target so everything has a target doesn't mention or like an application a window or control and so there are some macros that are just going to wrappers around this API where you can say install install control event handler and specify the control rather than getting the target out of the control and specifying that and just makes a little bit easier for you to call it there's a nice one for install window event handler and you can call install application event handler and it'll just go get the current event application target and pass that in very similar to the one above so here's an example of installing an event handler like I said it's very straightforward we got the prototype for my van handler which this is implemented elsewhere this is just a prototype for it it's implemented a few slides back I have an event types back array where I've specified that I am interested in caving class control class events and K event control bounce chains event kinds and then I just install control event handler on my control goes and gets the this visit the wrapper goes and gets the event handler the event target rf4 for that control passing a upp to my control van handler conveniently on OS can you pee pee's are just the function pointer so in this case I'm just passing the function pointer for an easy example I count how many event types were in that event list there's a nice macro in carbon event about H get event type count which we'll just do a size calculation and passing the right number there all the time no matter what you change the array to pass in the event list and also the last one there is my control so I'm as my user data I'm passing in the the point of the control ref to my control so I can extract out later on easily here's an example of a little more complicated event handler works handling more than one kind of event by using get event class and get event kind to check the class and kind of the incoming event so uses the in event parameter that's coming in who's get event class and get event kind to check if it's a again cave in class controller key event control balance change that's all nice but it's kind of like to give you a little overview about sort of the flow of the events and commands in your application when an event is first sent mr. kind of a general thing out I'll talk more maybe some specifics at the end goes to the focus control if the focus control doesn't handle it say in this case the bottom of the focus control the if button doesn't handle it it gives its apparent the group box a chance to handle it if the group box has any parents say a tabcontrol in this example if that parent a chance to handle it if that control this and handle it gives the parent window a chance to handle it preparing window doesn't handle it gives the application chance analyt so it kind of goes up this it goes up the hierarchy and gives everybody a chance to handle events now there are a few exceptions you know sometimes notifications aren't really important to propagate or some method calls you tell the control hey dry yourself you know you don't want to give the window a chance to draw the control it just doesn't make sense so there are a few exceptions and those are all well documented and carbon up instead H but I just want to touch on handling commands a bit like I said they're simplified carbon events where you just have a 32-bit value identifying an action that user wants to take and what's what's really nice about these is that the source of the command is not really relevant issue if you want to close the window you don't care if the user is going to close the window by clicking the closed box or selecting clothes from the close menu all you care about is they want to close the window so that it's nice that you can kind of ignore the source of a command and that's what makes them special doesn't really matter where they come from if they can come from menus they can come from controls they can be programmatically generated you just want to handle them say hey that's command happens I want to handle that command and it doesn't that the handle handling of the command is really contextual so whoever handled the command it kind of depends on what the command is so you can install a command handler on different controls and your user interface to respond or anywhere in any of your user in any of your event handlers like I said you don't really care about where the command comes from and what's nice about that is that a command can come from multiple different sources and you don't care as long as you're getting from an in this case I'm getting a khi command close which is a sort of a standardized command that you could use out of carbon event H and it doesn't matter that it's coming from the closed box or maybe an okay box on a window or from a menu item all you care about is that the user wants to close and you can handle it and not worry about where it came from so here's an example command handler and it's just a specialized event handler where we're checking we're doing good event class and get event kind again but we're checking for this specialized class commit a class and kind pair cave in class command and k event command process kind the command ID is a parameter of the events we just extract the H I command out of the event using get event parameter and then we switch based on the command ID and this is where we dispatch out and handle our action this is where you can provide your functionality so next I want to ask guy just to go through handling events and commands in the application a bit and kind of build up our application a bit more okay yeah so let's let's add some event handling here because Xcode and interface builder already set up my window to use the standard event handler most of the functionality happens for free you can click on the menus you can resize the window drag the window around click on buttons and stuff all I really care about is when the user clicks on a couple of buttons in my application now if you recall back when I set up the nib I put commands and in each of the previous and next buttons and so those commands are going to automatically be sent out whenever the user clicks on those buttons so I just need to listen for those commands let's go ahead and wire up that functionality okay so what I need to do here is include another header for the prototype I've got a handler already written and I'm just going to make sure to install that on my window after I've set up the layout and before I show the window now let's take a look at that handler actually before I show you the hand let me show you something else I've already defined some constants that represent those same commands that I associated with a button and I'll be using those a little bit later on in the code so here's my little wrapper routine that shows you how to install an event handler on a window I built up one of those event types of X which is a list of all the events I want to handle in this case I only want to handle one event it's an event of class cabin class command k event command process or sorry k event process command this is the event that gets sent out when the command is chosen from something and then I install my handler on the window and the handler looks an awful lot like the code you just saw from David if I get one of these events the cave and class command K event process command event I need to extract this H I command structure that describes things about the clan it tells you specifically what that command ideas as well as some information about where the command came from so you can find out if it came from a menu and if so which menu item should you need to know that in my particular case I don't need to know any of that so I just switch on the command ID that comes in and right now I've got some subs out functionality but just for this demo real quick here I'm going to beat whenever the user chooses the previous or next damage so let's go ahead and build and run and hopefully we've got volume on on this machine oh I don't know if the volume is turned on okay there we go yeah so you can hear this to speak working that's not a whole lot of great functionality I'll actually show you how to put some real functionality behind this in a few minutes after David goes over some other features Thank You guy so you can see that it is very easy to install an event handler to take care of the events that you care about in this case it with some commands handling commands thanks I just want to touch on we're not really going to use alert alert in our demo application I just want to touch on alerts and when you should use them so what are they there a way of intercepting interrupting the users tell them something important you've seen them before so you can inform the user of errors or warnings or bad things that have happened maybe good things that have happened I want you to use them well you should use them when it's important enough to interrupt the users workflow with something that they need to address there's two different kinds of alerts you get standard alerts which come up in a dialogue as you see on the top there and that interrupts the application application why that means that the user can't use the application anymore until they address the alert that's come up in front of them you want to do that with something that's important say they quit the application and they have multiple open documents you want to interrupt the whole application and say hey you don't want to quit until you have you you've saved all your hard work you're going to lose it there's also sheet alerts and these don't interrupt the application the user application why'd they interrupt the user just on a per window basis so they come up out of a sheet maybe out of a document window and interrupt that one window and give information about that one window so say user just going to close a window that they had modified you can have a sheet come out of there a sheet alert come out of there and say hey you've changed things in this document you're going to lose them if you just close it without saving using standard works is very straightforward there's an API called create standard alert you pass in the alert type you can give it a string for what kind of error has happened or and you can give a little explanation about that error there's a few settings that you can set up in a / am blocked I'm not really going to cover that you can read about it in dialogues H and what comes out is a standard alert what comes out is a dialogue ref to the standard alert which you can then pass to the next API run standard alert where you pass in the alert dialog ref of the alert you've just created and that will block the application and won't return until the user is dealt with that interruption by clicking out one of the buttons and closing the dialog and when they click on one of the buttons which button gets clicked gets passed back in the out item hit parameter that you pass in so it's a pointer to a dialogue item index and you'll get the index of the the part of that dialogue that was clicked there's a set of standard ones that are listed in dialogue H that you can use to determine which how that dialogue was dismissed and then you could take the right course of action using here's an example of them in use so I'm creating a stop lurk because I can't save because a file is locked in a can override it so I just use create standard alert to do that and I run standard lurk an interruption comes up the dialog that contains that message with maybe an ok button that's all I care about i run i run the standard alert and when it comes back the only way they can dismiss it is by clicking the ok button my party it will indicate that the ok button was clicked using alert sheets is very similar you're passing the alert type in there an explanation everything is exactly the same except they also passing a notified target and this is important because you're not going to stop the application and block it application wide you're only getting interrupted one window so you'll want to pass in a target it's going to get events from this this sheet that comes up to let your application know when when it's been dealt with so most of the time you'll pass the window target of the window that's being interrupted and what you get out of that is a dialogue ref to the standard alert sheet that is created to show this sheet use the show sheet window it's another API you'll notice though that it takes as its a parameter in sheet is a window ref that's we've been using that dialogue rest for a sheet of the standard sheets up till now and it's kind of a little bit of a legacy work around where you have to get the window out of the dialog ref I'll show that in a second here so here's an example of using a standard sheet so stop alert that comes up there's this very similar message to what I use before can't save that file because the file is locked but in this case I'm half passing a notification target and that who's going to receive events when things happen to the sheet so i get window.event target of my window and that's the window that's being interrupted by this standard sheet I get that sheet back as a dialogue rest and then I need to pass a window rest to show sheet window so I get dialog window from that sheet and that brings up the sheet and then your application will then continue and you'll only get notifications about that she clothing later on as events coming into your event target in this case your window vent target another way that you will kind of need to interrupt to interact with your user is file very very common one users are doing all kinds of things of files you want to be able to select files and folders maybe select save destinations and do you excuse me to do this you want to use navigation services it does all the work for you don't have to worry about how the file system looks or wherever things laid out or anything like that you just call the api's and it'll do all of the open save panel stuff for you these are very used to it they know how to use it and you're providing user interface that they are used to good thing about this is that when navigation services revs like it did for Panther you might have noticed you get all these improvements for your for free in your application so everybody that was using navigation services got the new open and save panels application was just and wide for Panther it's also very customizable so if you need to do something special like have a pop-up box box to select kind or some checkboxes for some settings you can add that to navigation services easy easily if you're not doing any customization it's very straightforward to use navigation services in fact I'd say it's pretty easy although the API looks a bit daunting so say you want to choose a file nav tues file you can specify a whole bunch of parameters and I encourage you to go to navigation services framework navigation dot H and read about them but in general unless you're doing some customization don't really care about those you'll notice that they're all documented down the right-hand side is being able to be null so if you pass a null for all of them you'll get the standard the standard behaviors of navigation services tracked all I really care about it's the reply coming out that's the most important thing because that tells you what the user selected or that they have selected now choose folder is very similar again you can see there's a whole bunch of different parameters but the only real important one to you is reply unless you want to do some customization so here's navigation services in action I use nav choose folder I'm passing null for all the parameters except for the reply which I'm passing is a pointer to a nav reply record after that returns I check to see if the reply with a valid record if the user actually selected something and then because the reply can contain a lot of a lot of information like multiple selections etc eat we use Apple events to extract the selection out of the returned reply and it's pretty straightforward so you use AE gets an pointer you pass in the selection from the reply you tell it you only want one thing and you're interested in fsr and you get you can get out your folder f so let's bring guy back and he'll show you how to use one of those api's in the application okay so a picture viewers not very good unless I can provide these are a way to choose some pictures to view so I'm going to add that sort of functionality but I need to add another button to mine in here so that the user can choose something so let's add another button cool it though I don't know that folder make it a little bit bigger so it looks nice and put it in the right place now in order to react to a click in this button I need to give it a command so we'll do that and to show off the power of clans a little bit let's also modify our menu bar why don't we skip the menu pronounced running oh we're running short on time oh and EVR okay so I could put that command in the menu bar and book it that way as well but for now we'll just put it in the button here okay so we're saved the next thing I need to do so I don't want to really worry myself about the very image formats that there are on Mac OS that we support I'm going to let quicktime deal with that because it does it very well so what I need to do here is add another framework quicktime framework to my project do that like so now the quick dry was in place the other thing i need to do is I'd like to do is take out those two speech I put in place and put the real functionality behind the previous and next buttons and so you'll also see that I handle a third command and that handler I already showed you which handles the set folder button now my code I've already written for set folder just uses that NAB choose folder API exactly the way David showed you know if there before so we'll just build and run this click set folder up comes the nav dialogue and now I'm browsing some pictures and I react to that is the user clicks the next and previous button so I did all that just by installing one carbon event handler and building my nib now that's cool but not every application can just use these standard views that we already provide a lot of applications you need their own custom views and I'd like one as well I'd like this interface to be a little bit better I'd like to kind of show previews if you will of all the images are of the images in the folder that I'm browsing so we'll add that very quickly reopen my nib screw the window a little bit bigger and oh there we go I'm going to throw a user painting place just sort of a plate as a placeholder and my code goes in and replaces just with my actual view put that in the right spot let's give him the who I'm trying to remember my command hyah give them the right signature so I can find him later and I don't actually need to give him a command so give it a command I think I should give it a claim ok looks like a mess Oh David knows we should give it a command that means we we must all right and so my codes already been modified actually to deal with that so all I need to do is rebuild and rerun the application and choose another folder this one and all of a sudden hey I can see myself and I get previews in myself as well and I can scroll around and react to the next and previous buttons these are images from last year's demo so they just happen to have these previews so that's it that's pretty much straightforward stuff will actually go into details in the HIV you in-depth session on how you can create a custom view not exactly this one that I showed here but something that's actually a lot cooler because this one here is actually fairly simple so anyway I'll hand it back over to David you wrap up Thank You guy so finally we got some functionality into the application that the end functionally that you're going to add to your application which is important and you can kind of forgets about some of the user interface details they didn't have to worry about the window resizing and the window handling and all that get the full application by focusing on the functionality of the application so in summary it's hard to show you everything that's available in a chai toolbox we just want to give you a good start so you want to use the new h I toolbox to make it fully featured full Mac os10 citizen using C and C++ API s I want to use nib files to create a great user interface but one that you don't have to really you worried about how how it's all implemented because you'll use carbon events you only pay attention to the attention to the events that you're interested in to make your functionality to make you a great app so I'd like to bring as avi a up to go over some of the documentation that's available and the roadmap for other sessions that relate to a chai toolbox thank apologize we've been running a little bit late so I'm going to try to like quickly over the documentation to Western for some questions we have a bunch of documentation available now for carbon events and H had you in general I encourage you to go on VDC home where you check to your list of the new documentation and all the things that I've available for doing C and C++ development when you look for the key no documentation or simple could check out H I toolbox first and then go to the comment section depending on what you want to find out some documentation as well is available for like the human interface guidelines to help you design great user experience on Mac OS 10 and hopefully none of you need the carbon-14 guide anymore as I said lot of sample code looking the H I toolbox you know for mac OS 10 folder on the sample code in the carbon folder and you see a bunch of things for like a shadow as prisoners and encourage you to go which brings me again to the documentation and which is something actually the team wanted miri twin size size which has been spent a lot of time actually documenting the headers as much as possible as the first you know the first point of documentation for you guys it doesn't replace you know of course real documentation but I think it's a good start for you like when you're looking for like what a carbon event does a special carbon event and things like that so check the header files one session if you have kissed em controls that you should really really really go and see is the next one on the third floor procedure room where actually edge will be talking about HIV and we're going to give you with very cool demos when we're going to show you on how to implement your own custom h-have you very nice encouraged to attend that session of course you