Lập trình Wrox Professional Xcode 3 cho Mac OS part 2 ppt

The project window, shown in Figure 2 - 1, is the manifestation of that document... 10 ❘ CHAPTER 2 THE GRAND TOUR Because you can ’ t explore much in Xcode without a project, take the ti

The Grand Tour

WHAT'S IN THIS CHAPTER?

Learning about the Project Understanding Menus and Editors Getting Help

Starting up Xcode is sort of like walking through the front gates of Disneyland, or onto the campus of a major university, or even a big shopping mall for the very fi rst time It ’ s vast and you have no idea where to go fi rst If you just start walking, you ’ ll quickly be lost and disoriented, so you do what every fi rst - time visitor does; you get a map

Neither Xcode, nor any of those other places, has been intentionally designed to be cryptic

or confusing In fact, they all go out of their way to be as friendly and accommodating

as possible However, the sheer size and complexity of what they offer cause them to be perplexing and frustrating at times If you take a moment to get a feel for the scope and organization of Xcode, your initial forays will be much more enjoyable Start by getting your bearings

THE PROJECT

The central construct in Xcode, both physically and metaphorically, is the project Everything

you will accomplish in Xcode begins with a project In fact, without an open project Xcode won ’ t do much beyond letting you browse the documentation and set some preferences The

spirit of your project is stored in a project document on your fi le system The project window,

shown in Figure 2 - 1, is the manifestation of that document

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10 ❘ CHAPTER 2 THE GRAND TOUR

Because you can ’ t explore much in Xcode without a project, take the time to create one now You

can throw it away later

Launch the Xcode application and follow these steps:

1. From the Xcode File menu, choose the New Project command (Shift+Command+N) If

you ’ ve just launched Xcode, click the big Create New Xcode Project button in the Welcome

to Xcode window

2. In the Application group, choose the Cocoa Application template (the options don ’ t matter),

as shown in Figure 2 - 2 Click the Choose button

3. Enter Grand Tour for the project name

4. Pick a location for the new project and click the Save button

FIGURE 2-1

Xcode creates a project folder , containing a project document in addition to the source and resource

fi les generated by the template

Use this project to explore the various groups in the project window You can also build, run, and even debug this project right now Explore the properties of source items, groups, and other objects

by Right/Control+clicking them

The project window is your central workspace Here you organize and navigate your project ’ s resources, settings, and targets From here you can initiate builds, launch the application, or start the debugger Most of the menu commands apply to the currently active project window

The left side of the project window is the Groups & Files pane This is where everything that constitutes your project is represented and organized Resources can be put into groups for better management Click the expansion triangle to the left of a group ’ s icon to explore its contents

The right side of the project window is a multipurpose pane It usually shows the details of the selection made in the Groups & Files pane, but it can also be used as an editor — or you may not even have a right side to your window Xcode provides different window layouts to suit your work style Chapter 3 explains these different styles and how to navigate your workspace

Source Groups

Broadly, the Groups & Files pane contains two kinds of groups At the top is the project group This

has the same icon and name as the project document The project group organizes all of the source

fi les and resources that make up your project, and is generically referred to as the source group

Sources are the fi les and folders used in your project This could consist of program source fi les, headers, property lists, image fi les, dynamic libraries, frameworks, testing code, and even other projects None of these constituent parts are stored in the project document itself The fi les you will use to build your project exist elsewhere on your fi le system The project group only contains

references to those sources, not the sources themselves Chapter 5 explains how to create, manage,

and organize source references in the project group

Double - clicking any source item opens it in an editor, assuming the item type is one that can be edited in Xcode

Smart Groups

The remaining groups are referred to as smart groups Unlike the project group, which you can organize however you like, the smart groups each represent some specifi c kind of information about your project These groups are self - organizing and update automatically to refl ect the state

of your project

One of the most important smart groups is the Targets group This group shows the targets defi ned

in the project Each product your project produces, typically an executable program, is represented

by a target A target is organized into build phases Each build phase performs a specifi c step

in the build process, such as compiling all of the source fi les for a target or copying a set of fi les into the resource folder of an application bundle A source is said to be a member of a target if the target includes that source item in any of its phases Targets can depend on other targets, and they

12 ❘CHAPTER 2 THE GRAND TOUR

are highly customizable and extensible Chapter 16 explains the kinds of targets Xcode provides

and how to create your own It also shows you how to organize and customize targets to meet

your needs

The Executables smart group lists the executables (programs that can be launched and run) in the

project Typically, each target produces one executable The executables in a project can be run or

debugged from within Xcode

Most of the remaining smart groups gather information about your project, collecting them into

readily accessible locations For example, the Find Results smart group contains the history and

results of recent searches The Project Symbols smart group lists all of the symbols defi ned in your

project You can create your own smart groups that automatically collect source fi les that meet a

certain criteria If you ’ ve ever used smart playlists in iTunes, you are already familiar with

this concept

MENUS

The menus in Xcode are grouped by function The File menu is where you ’ ll fi nd basic fi le and

project commands Use these commands to create new projects, fi les, and groups; close windows;

save fi les; take snapshots; and print

The Edit menu deals primarily with the editing of source fi les The View menu controls the visual

appearance of source fi les, windows, and lists It also contains a number of fi le and window

navigation commands The Project menu contains commands specifi c to the project and its targets

The Build, Run, Design, and SCM menus contain commands for building the project, debugging

an executable program, class and data model design, and source control management, respectively

Each of these topics is covered in its own chapter The Help menu is the gateway to the ADC

reference library and the programming documentation It also provides a few shortcuts to common

topics

The Window menu is one means of listing, and navigating between, the currently open windows It

also provides access to the organizer, described in Chapter 22

EDITORS

Xcode includes a sophisticated and fl exible set of editors The one you ’ ll use the most is the text fi le

editor, shown in Figure 2 3 The text editor is context sensitive, language aware, and includes auto

-completion features It can automatically format, color, and highlight programming symbols and

structures The editor is integrated into the documentation, build system, and debugger You can

look up a symbol defi nition, jump to its declaration, review compiler errors, display the value of a

variable, or step through your program without ever leaving the editor window Its extensive editing

and navigation features are covered in Chapters 6 and 7

Xcode includes other kinds of editors, such as the property list editor, that enable you to edit the content of other document types easily More sophisticated documents, most notably Interface Builder documents, are edited using separate applications that integrate with Xcode You can also tap your favorite text, image, audio, or resource editor to augment, or replace, the editors provided

by Xcode

Chapter 13 discusses Interface Builder Chapter 15 explains the data model editor

SEARCHING, SYMBOLS, AND REFACTORING

Xcode includes many tools for exploring and altering the content and structure of your project

These are useful for fi nding something specifi c in your application and for understanding the structure of classes in an application

The simplest of these tools are the various search commands You can search a single fi le, or a group

of fi les, for text patterns ranging from a sequence of characters to complex regular expressions

These commands are covered in Chapter 8

The Class Browser, shown in Figure 2 - 4, compiles the classes and data structures in your application into a structured table Chapter 9 shows you how to use it

FIGURE 2-3

14 ❘ CHAPTER 2 THE GRAND TOUR

Chapter 14 introduces you to the class modeler Like the Class Browser, it constructs a picture of

your project ’ s classes and their relationships Unlike the Class Browser, the picture drawn by the

class modeler is — well — a picture The class modeler produces a graph of the classes in your

application (see Figure 2 - 5) Models can be customized and are dynamically updated as you alter

your code

FIGURE 2-4

FIGURE 2-5

Chapter 10 describes the refactoring tool This tool enables you to rename classes and variables intelligently, insert new classes into the hierarchy, relocate methods to a superclass or subclass, and upgrade legacy programming patterns to modern standards

GETTING HELP

Someone once said, “ It ’ s not what you know, it ’ s what you can fi nd out ” This sentiment is especially applicable to programming It is impossible to remember every function name, every parameter, and every data type in the thousands of classes, headers, and libraries available to you

Often the question is not so much which specifi c function to call as it is “ Where do I begin? ” Integrated into Xcode is the bulk of the Apple Developer Connection Reference Library, shown in Figure 2 - 6 This contains a vast wealth of introductory articles, examples, and programming guidance

FIGURE 2-6

The Reference Library also includes a detailed, indexed, and searchable database documenting every major API in the Mac OS X and iPhone operating systems, an example of which is shown in Figure 2 - 7 You can instantly access the symbols in the Reference Library from within your source code or search the documentation interactively

16 ❘ CHAPTER 2 THE GRAND TOUR

Being a productive programmer will largely depend on being able to quickly extract what you ’ re

looking for from this mountain of detail Chapter 12 helps you fi nd what you need

BUILDING

The ultimate goal of any project is to produce something Building takes the source items in

your project and transforms them into a fi nal product Building can be roughly divided into two

activities: defi ning how to build each product and then controlling what gets built and when

The “ how ” portion is largely defi ned by the targets Each target defi nes the steps and sources used

to construct its product This is explained in Chapter 16

The “ what and when ” portion is explained in Chapter 17 This chapter explains how to initiate

a build process and select exactly what you want to build Most of the build process is witnessed

through the project build window, shown in Figure 2 - 8

FIGURE 2-7

Chapter 16 also explains Xcode ’ s system of build settings and build confi gurations Build settings

are collections of options that control everything from what warnings the compiler will emit to the names of your executable fi les A project contains multiple sets of build settings, forming a layered hierarchy of values A build setting may apply to the entire project, or only to the fi les of certain targets, depending on where in the hierarchy the build setting is defi ned

Build confi gurations add another dimension (literally) to build settings Build confi gurations make

it easy to confi gure projects that produce subtle variations of the same products, such as debug and release versions You can also manage not - so - subtle variations; a single project target could produce

an application for in - house testing, another version for use by the sales department, and a third variation for the fi eld service engineers

GETTING IT RIGHT

After your project is built, you then have to verify that it performs the way you intended it to If any bugs are found, you must locate and correct them

Xcode is integrated with several debuggers Launching your application under the control of a debugger, as shown in Figure 2 - 9, enables you to step through the code in your application, view variables, and even fi x bugs and alter data while it ’ s running The debugger facilities and commands are all explained in Chapter 18

FIGURE 2-8

18 ❘ CHAPTER 2 THE GRAND TOUR

In addition to the debugger, you can employ unit testing and a cadre of performance and program

analysis tools to help you identify, locate, and eliminate unwanted program behavior Chapter 19

explains the analysis tools Chapter 20 shows you how to set up your own unit tests

COLLABORATION AND VERSION CONTROL

You can share projects and project sources with other projects and other developers You can also

confi gure your project to work directly with a variety of source control systems Chapter 21 shows

you how to create common pools of project resources and how to integrate your projects with a

source control manager

SUMMARY

This should give you some idea of the breadth and scope of the Xcode development environment

As you can see, there ’ s a lot to cover in the subsequent chapters You ’ re probably anxious to get

started, so move on to the next chapter to organize your workspace and learn your way around

the interface

FIGURE 2-9