Beginning Android 3D Game Development Part-2

LogCat Window

At the bottom of the Eclipse IDE there are by default a few rectangular windows. One of the more

important ones is called the LogCat window, and this window displays debug and error messages

that are directly coming from a program that is running on the Android device that is attached to your

computer via a USB cable 

 

Launching the SDK Manager and AVD Manager from Eclipse

To launch the Android SDK Manager and the AVD Manager from within the Eclipse IDE, click “Window”

in the top menu bar and use the menu items near the bottom of the list. The SDK Manager enables

you to download new versions of the Android platform and other tools to develop with. The AVD

Manager allows you to create and manage virtual Android devices for the Android device emulator

Hands-on Example: Non–OpenGL ES Text “Hello World”

Program

In this hands-on example, we will create a new Android project that will output a simple “Hello World”

text string. Start up the Eclipse IDE.

The first thing to do is to specify a work space where you will put this new project. Select

File ➤ SwitchWorkSpace ➤ Other from the main Eclipse menu to bring up a pop-up window in

which you can select a directory that will serve as the current work space where new projects will be

stored. Use the Browse button on the pop-up window to navigate to the folder you want to use as

the work space, then hit the OK button to set this folder as your current work space.

Creating a New Android Project

To create a new Android project, select “Android Application Project” under the File ➤ New menu

(see Figure 1-16).

This will bring up a pop-up window in which you can specify your application name, project name,

package name, and SDK information (see Figure 1-17).

In the Application Name edit box, enter “RobsHelloWorld,” which is the name of your application that

will appear to users of your program. In the Project Name edit box, enter “RobsHelloWorld,” which is

the name of the project that is displayed in the Eclipse IDE. Enter “com.robsexample.robshelloworld”

as the package name associated with this new Android project. This package name must be unique.

For the Minimum Required SDK select Android 2.2 (Froyo), because this is the lowest Android

platform that supports OpenGL ES 2.0. For the Target SDK, select the highest Android platform API

that you anticipate to have successfully tested your application against. For the Compile With list

box, select the API version that you wish to compile your application for. You can leave the Theme

list box at the default value. Click the Next button to move to the next screen.

The next thing to do is to configure the project. For this example, just accept the default values and

click the Next button (see Figure 1-18).

In the next screen, you can configure the launcher icon, if you wish. However, for this example, you can

just accept the defaults (see Figure 1-19).

Click the Next button. The next screen allows you to select the type of activity you want to create.

Select the Blank Activity and click the Next button (see Figure 1-20).

Accept the defaults for the blank activity. The default activity name is “MainActivity.” The default

Layout Name is “activity_main,” and the default Navigation Type is “None.” Click the Finish button to

create the new Android application (see Figure 1-21).

On the left-hand side of the Eclipse IDE in the Package Explorer window, you should see a new

entry called “RobsHelloWorld,” which is our new example program. The key directories are the

“src” directory, where the Java source code is stored; the “libs” directory, where external libraries

are stored; and the “res” directory, where resources such as graphics, 3D models, and layouts are

stored. Under the “res” directory, the “layout” directory stores the application’s graphical layout

specifications; the “menu” directory stores the applications menu-related layout information; and

the “values” directory stores the actual “Hello World” string that is displayed. Finally, a key file is

the AndroidManifest.xml file, which contains information about permissions and other application

specific information. (See Figure 1-22 for the layout of the “RobsHelloWorld” project.)

Running on an Android Emulator

Before we run our example on the emulator, we must first set up an Android Virtual Device. Select

Window ➤ Android Virtual Device Manager from the Eclipse menu to start up the Virtual Device

Manager. Click the New button. Another window should pop up with the heading “Create new

Android Virtual Device (AVD).” Enter a name for your virtual device in the “AVD Name:” field. Select a

device to emulate and Target, as shown in Figure 1-23. Accept the default values for the rest of the

inputs. Click the OK button.

Next, we have to run our example. If you are running this for the first time, you will have to specify how

to run this application. Make sure the “RobsHelloWorld” project is highlighted. Select Run ➤ Run from

the Eclipse main menu.

When the pop-up window appears, select “Android Application” and click the OK button to run the

example. If you do not have an actual Android device attached to your computer via USB cable,

Eclipse will run the program on the Android emulator (see Figure 1-24).

The Android emulator should start by default and run our sample program. The actual code for this

program is shown later in this chapter (see Figure 1-25).

Running on an Actual Android Device

In order to download and run the program on an actual Android device, the device must be put

into USB Debugging mode. Press the Menu key, which is the left-most key on the bottom portion

of an Android phone. Click the Settings button, then click the Applications button and then the

Development button. Click the “USB Debugging” option. After doing so, the item should be

checked, as in Figure 1-26

Note On Android 4.0 and newer models, the USB Debugging option is under the Settings ➤ Developer

options. On Android 4.2 and newer models, the Developer options are hidden by default. To make it available,

go to Settings ➤ About Phone and tap the Build number seven times. Return to the previous screen to find

Developer options.

Next, you have to install the appropriate USB software driver for your model of Android phone onto

your development system. Try to connect your Android device to your computer first, to see if it

automatically installs the correct drivers. If you can’t run the program on your device, then you will

have to install a device driver from the manufacturer. Usually the manufacturer of your phone has

a web site with downloadable drivers. After doing this, connect your phone to your development

system, using a USB cable, which most likely was included with your mobile phone.

Now you are ready to start using the device. Select Run ➤ Run from the main Eclipse menu.

A window should appear in which you can choose to run the program on an actual Android device or

an Android Virtual Device (see Figure 1-27). Select the hardware device and click the OK button.

The program running on the device should be the same as depicted in Figure 1-25. Press the Back

key to exit the program.

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