Lập trình Wrox Professional Xcode 3 cho Mac OS part 77 potx

DEVICES The Devices and iPhone Development groups in the organizer are designed specifi cally to support the special needs of iPhone and iPod developers.. The difference is in their pers

DEVICES

The Devices and iPhone Development groups in the organizer are designed specifi cally to support the special needs of iPhone and iPod developers Much of the information in these two groups overlap The difference is in their perspective; the Devices group displays information about actively connected devices, whereas the iPhone Development group — described in a later section — aggregates historical development information from all of your devices

Adding and Removing Devices

iPhone and iPod Touch devices are automatically added to the organizer whenever you connect one to your computer while Xcode is running Once added, they persist until removed from the organizer The organizer shown in Figure 22 - 6 has had two devices added The device named

“ iPhone ” is currently connected, as indicated by the green dot next to its name, whereas the device named “ Tea tray ” is not

FIGURE 22 - 6

The activities in the Devices group interact directly with the connected device A device that ’ s not connected does little but display the message “ This device is not currently connected ” You ’ ll see the identity of the device and you can browse previously downloaded crash reports — but that ’ s about it

To remove an obsolete device from your organizer, Right/Control+click the device name and choose the Remove From Organizer command You can also have Xcode ignore a particular device, such as

a personal iPod that you do not use for development To do that, plug in the device and choose the Ignore Device command from the same menu

You interact with your development device by connecting it to your computer, selecting it in the organizer, and then choosing the desired tab that appears in the details pane The tabs are Summary, Crash Logs, Console, and Screenshots The functions of each are described in the next few sections

Devices❘ 629

The Summary tab shows the name, serial number, unique device identifi er (UDID), and the version

of the operating system installed on your device You ’ ll need the UDID to register your device for

development You can obtain it by copying text from the details pane, or by Right/Control+clicking

the device name in the Devices group and choosing the Copy Device Identifi er command

For the sake of brevity, both the organizer and this book use the generic term “ iPhone ” to mean any

iPhone, iPod Touch, or similar device that ’ s supported by Xcode This is not a slight to any iPod

Touch users nor is it meant to exclude any future Apple devices

Installing Provisioning Profi les

Before you can get started doing any kind of iPhone development — or more precisely, before

you can begin to do any Apple-sanctioned iPhone development on an Apple device — you must

provision your iPhone Provisioning is basically the installation of a set of digital signatures,

some that you generate and others obtained from Apple, that authorize your iPhone to execute

your application for the purposes of development The iPhone will refuse to install or launch an

application that has not been digitally signed by both its author (that ’ s you) and Apple

The process of provisioning is adequately explained in both the iPhone Development Guide ,

included in the Xcode documentation, and in the instructions in the iPhone Developer Program

Portal, the web site you ’ ll use to obtain provisioning profi les Nevertheless, I ’ ll summarize the steps

here:

1. Join the iPhone Developer Program This is a requirement for accessing the iPhone

Developer Program Portal

2. If you ’ ve joined the iPhone Developer Program as an organization, you — or someone —

must defi ne the team members allowed to use the iPhone Developer Program Portal, hereafter just called the Portal

3. Follow the instructions at the Portal for using the Keychain Assistant to create a certifi cate

signing request (CSR) This is a digitally signed request that contains your offi cial identity

4. Upload your CSR to the Portal Review the request and approve it

5. Apple then creates a development certifi cate , which is digitally signed by both you and

Apple An iPhone uses these signatures to determine the authenticity of an application

6. Download the development certifi cate and install it on your keychain If you need to do

iPhone development using other computers or accounts, you will have to transfer copies of your private key (the one used to create the CSR) and your development certifi cate to those computers

7. Make backups of your private key and development certifi cate and put them in a safe place,

or places

8. With the development certifi cate in place, you can now authorize individual devices for

development Plug each device into Xcode and use the organizer to obtain its Unique Device Identifi er (UDID) Copy your device ’ s UDID to the clipboard by selecting the ID

in the Summary tab, or Right/Control+click on the device name and choose the Copy Device Identifi er command Register your device in the Portal

9. Create an application identifi er for the application you want to run on your registered development iPhone Your application ’ s identifi er is a combination of a reverse - DNS name that you assign and a Bundle Seed ID generated by the Portal An example would be

project, set the Identifi er fi eld to be the same identifi er, without the Bundle Seed ID In this example, the application identifi er must be set to com.wiley.proxcode.iPrime

10. Register you application ID with the Portal

11. With all the preliminaries out of the way, you can now use the Portal to generate provisioning profi les A provisioning profi le combines your development certifi cate, developer identity, device identity, and application identifi er It defi nes what combination

of developers and devices your application is permitted to run on, to be debugged on, and similar development privileges

12. Download the provisioning profi le from the Portal

Once you ’ ve obtained one or more provisioning profi les, you need to install them into your development device Plug in and select the device in the organizer Either drag the provisioning profi le document into the Provisioning list of the Summary tab, or click the + button below the list

of provisioning profi les, as shown in Figure 22 - 7, and choose the provisioning profi le to install

FIGURE 22 - 7

You ’ re likely to create a new provisioning profi le for each application you develop, although it ’ s possible to create a wildcard profi le that provisions multiple applications with similar IDs

To remove a provisioning profi le from the device, select it and click the – button

Managing Development Applications

The next section in the Summary tab lists the applications that you have installed on your device,

as shown in Figure 22 - 8 This list includes applications from Apple and other vendors, in addition

to the applications that you ’ ve installed during development The only applications that you can affect here are those that you ’ ve installed for development purposes To remove any commercial applications, do so using the device or iTunes

Devices❘ 631

Normally your applications get installed on your device as a consequence of development.

Whenever you run or debug an iPhone app on a device, Xcode fi rst downloads and installs the

application before starting it For whatever purpose, you can also install applications you ’ ve built

(and provisioned) manually Click the + button and select the application bundle to install The

application is installed immediately

The more useful feature is the ability to remove applications that you ’ re done developing Select an

application and click the – button After removing the application, you ’ ll probably want to remove

its provisioning profi le as well

Downloading Application Data

Each iPhone application has a private directory in which it can store data, user preferences, and

resources To access this data, expand the application to expose its Application Data package, also

shown in Figure 22 - 8

Next to the package is a download button Click this button to extract the application ’ s private

directory from the device and save it on your local drive The package is automatically expanded

and appears as a folder of fi les

Installing Alternate Operating Systems

During development, you will want to test your application against different versions of the

operating system The currently installed operating system on your device appears in the pop - up

menu in the Summary tab

If you have other iPhone OS SDKs installed, select one from the menu Apple also makes

pre - release or seed versions available to developers from time to time If you ’ ve downloaded one

of these software seeds, select it by choosing the Other Version command in the OS version menu,

as shown in Figure 22 - 9

FIGURE 22 - 8

After choosing a new OS, click the Restore iPhone/iPod button next to it Xcode will erase your device — deleting all applications and data — and install the selected operating system You can now install and test your application

Installing a different OS erases everything on your device If you have applications or data you want to preserve, fi rst synchronize your device with iTunes iTunes will make a backup of your device After testing, launch iTunes again In the Summary tab for the device, click the Restore button and do not request another backup After your device has been reset, select an existing backup iTunes will restore your device and all of its data.

Reviewing Crash Logs

The Crash Logs tab lets you examine any crash logs or panic reports that have been downloaded from the device, as shown in Figure 22 - 10 Crash logs are automatically downloaded by the organizer and iTunes

FIGURE 22 - 9

Devices❘ 633

This is the actual running console log, downloaded from the connected device If you have an

application running on your device, you can check the console log for messages in real time The

console log doesn ’ t update automatically; click the Reload button to fetch any new messages

Much like the Console application in Mac OS X, you can clear the log, save a selected portion of

the log to a text fi le, or fi lter the contents of the log using the search fi eld above the pane The search

fi eld performs both case - sensitive and case - insensitive searches

Use the console to fi nd diagnostic messages output by your application while it ’ s running Note that

when you run or debug an app via Xcode, the output of NSLog() and similar functions is redirected

to the Run Console window of the project These messages will also appear in the console log of the

device, but you don ’ t have to open the console log to fi nd them

FIGURE 22 - 11

You can browse a report by selecting it in the list Right/Control+click a report to delete it or reveal

its text fi le in the Finder

Monitoring the Device ’ s Console

Like Mac OS X, the iPhone OS also has a console log This is the collection point for diagnostic

messages emitted by iPhone applications and other processes

The Console Logs tab, as shown in Figure 22 - 11, reads the console log from the device

Capturing Screenshots and the Default Image

The Screenshots tab displays the screenshots that been captured for this device, let s you take a screenshot, and will automatically install a screenshot as the default — that is, launch screen — for

an iPhone application

Screenshots are useful for documenting your application, sharing results with other developers, and examining interface anomalies

The Screenshots tab is divided into two panes, as shown in Figure 22 - 12 One the left are all of the screenshots collected for this device On the right you can view a selected screenshot or take a new screenshot

FIGURE 22 - 12

To take a screenshot, run your application and arrange the screen to your liking In the Xcode organizer, click the Capture button Xcode instructs the device to take a screenshot and then downloads it into the organizer

You can browse previously taken screenshots on the left Select a screenshot to view it full size You can also do any of the following:

Drag a screenshot into the Finder to copy the screenshot fi le

Press Delete, or Right/Control + click and choose the Delete Screenshot command, to delete a screenshot

Install the screenshot as the Default screen for an iPhone application

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Devices❘ 635

The default screen of an iPhone application is an image fi le that appears while the application

is still loading It can be used to present an entertaining splash screen or annoy users with crass

advertising, but it ’ s often used to make the application appear to load faster than it really does This

last trick is accomplished by making a screenshot of the initial view of your application with no

content, and then installing that as the default image When the user taps your app, a full - fl edged

interface appears (without content) almost immediately What ’ s really happening is the application

is still launching while the user is looking at the default image As soon as the app starts up, the

display seamlessly refreshes

To create this bit of prestidigitation, follow these steps:

1. Open your iPhone application project

2. Run your application on the device and wait until its fi rst window appears, with no content

3. In the organizer, take a screenshot

4. Click the Save As Default Image button and choose your Xcode project

The Save As Default Image button adds a Default.png fi le to your project ’ s Resources group Of

course, you could have done this yourself, and you ’ re free to provide any kind of Default.png fi le

that you want

Screenshots taken in the organizer and screenshots taken using your device are not intermingled If you’ve taken a screenshot on the device — by holding down the sleep and home buttons — use iPhoto to download the image fi le You can then import it into your project.

iPHONE DEVELOPMENT

The iPhone Development group is largely a rehashing of local and historical information that

you ’ ve already seen in the Devices group The key difference is that the information in the iPhone

Development group is obtained from your local system and applies to all of your devices, connected

or not

Crash Logs

The Crash Logs group is an aggregate list of all the crash logs from all of your devices It functions

the same way the Crash Logs tab in the Devices group does

Provisioning Profi les

This group lists the status of all of the provisioning profi les you ’ ve installed on your system, as

shown in Figure 22 - 13

Select a profi le to display its details and the list of devices where it is currently installed

Press Delete or Right/Control+click a profi le and choose the Delete Profi le command to permanently delete a provisioning profi le from your system You can also choose the Reveal Profi le in Finder command to locate the fi le

Screenshots

This group is identical to the Screenshots tab of an individual device, except that it shows all of the screenshots captured in the organizer

Software Images

Finally, the Software Images group lists the operating system packages that are installed on your system These are the packages that allow you to install different versions of the iPhone OS on your device See the “ Installing Alternate Operating Systems ” section, earlier in this chapter

SUMMARY

The organizer is a powerful new addition to Xcode that let s you organize your project, devices, and tasks at a level above your individual projects By customizing and sharing actions you automate repetitive workfl ow and can share those solutions with other developers You now know how to connect, register, and interact with your iPhone and iPod Touch devices

The fi nal chapter turns to what many consider to be an endless source of joy and entertainment:

tweaking obscure options and settings in Xcode, customizing it to suit your every whim

FIGURE 22 - 13

Summary❘ 637