1. Android 2: A First Project Kirk Scott 1

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3. 2.1 Creating a New, Example Android Application Project in Eclipse 2.2 Creating a Virtual Device, an Emulator 2.3 Running an App on the Emulator in Eclipse 2.4 Running the Project on an Attached Device Instead of an Emulator 3

4. 2.1 Creating a New, Example Android Application Project in Eclipse 4

5. These overheads give a general overview of what is involved in getting a sample application to work—without even looking at its code, how it works, or what Android features it is making use of or depends on This is the initial monkey work mentioned in the previous set of overheads 5

6. These overheads are based on the initial example app that is given in the tutorial on the Android developer’s Web site If you discover that something in the overheads doesn’t seem to work, it means you can go directly to the tutorial for additional information 6

7. A New Android Application In the Eclipse menu take the option File, New, Android Application Project The result of this is shown in the screenshot on the following overhead 7

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9. In the first box, type in the following: My First App The other boxes will auto-complete as shown in the following screenshot (If the other boxes don’t auto-complete, this is the first stage where you will have to go fish) 9

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11. If things auto-completed as hoped, then you click the Next > button I will not show the next screenshots for the wizard Just keep on accepting the defaults and taking Next until you reach the Finish option Notice how this is an area where you’re just doing monkey work God knows what all of the options mean at this point 11

12. Once you click finish “things will happen” They may happen slowly I have a reasonably powerful machine and it takes things a while to happen There is a progress bar at the bottom which gives you some indication of what’s going on 12

13. The initial Welcome screen may remain visible If so, it covers up what has happened Minimize anything in the way, and with luck, what you will see in the Eclipse environment will look more or less like the screenshot on the following overhead 13

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15. There are several things to notice in this screenshot The simplest and most reassuring is that if you can actually read the fine print, you will see that My First App is a Hello World app Whenever a new app is created using the defaults, this Hello World layout is provided by default 15

16. Obviously you’re not looking at code The name of the file that is being shown has an XML extension What you’re seeing is the layout of the output of the app What you’re seeing is a representation of the layout as provided in the development environment This is not the output showing in the emulator 16

17. You might notice that this screenshot of the editor doesn’t look quite like the one given earlier It doesn’t show the tools mentioned in the previous set of overheads, but it’s not exactly the same The toolbar happens to have disappeared It’s not a big cause for concern You can cause it to appear again or you can access the tools through the menu 17

18. 2.2 Creating a Virtual Device, an Emulator 18

19. Running the Project on a Virtual Device, an Emulator If you want to run the project using the emulator, you need to use the Android Virtual Device Manager to create a new virtual device If you take the Android Virtual Device Manager tool (or menu option) you should arrive at something similar to the screenshot shown on the following overhead 19

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21. Click the New button to create an Android Virtual Device The window shown in the screenshot on the following overhead comes up 21

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23. It’s shown on the following overhead with the drop down list for Device expanded 23

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25. I tried using various devices For initial test purposes I finally settled on the device at the bottom of the list My theory was that emulation for older, simpler devices might work better or faster than for newer devices On the following overhead the form is shown filled out with representative values for that simple device 25

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27. Using Snapshot Another mystery: Certain reference sources waffle on the desirability of the Snapshot option If you do select Snapshot and then make other changes, you may have troubles later Without Snapshot things might run more slowly, but again, for the first time, try it without Snapshot 27

28. Warning Here is an example of what can go wrong I also tried making a virtual device that was a Nexus tablet (the real hardware I’m working with) The memory option defaulted to a RAM value of 1024 Unfortunately, when I continued with that value of 1024, I got a mystery error 28

29. My Web search informed me that if I changed the RAM value to 512, things should be OK For the device I’ve chosen to illustrate with, I took memory size values of 256 For whatever reason, these values worked, and for the time being, that’s good enough for me 29

30. Continuing with Virtual Device Creation Once you’ve got the parameters set, click on OK The system can drag on for a noticeable amount of time creating the virtual device Successful completion is indicated by the appearance of the device in the list as shown in the screenshot on the following overhead 30

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32. There is no final OK step after virtual device creation You’re done—and you have to close this window If you just minimize it, it sits there but is still the active window To go on from here, close this window 32

33. 2.3 Running an App on the Emulator in Eclipse There are several different ways of running an app in the emulator Later on you will find out that you can create run configurations and debug configurations which are linked to a project This is a fine way of doing business, but more complicated than necessary initially 33

34. Starting the emulator can take a lot of time Trying to run the app and having that process start the emulator doesn’t seem to be the best plan The alternative is to start the emulator and then run the app in it This second approach is a better way to do it initially 34

35. Starting the Emulator The Android Virtual Device screen is shown again on the following overhead with the created virtual device in it The screenshot shows the device as being selected and you’ll note a Start… button on the right hand side 35

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37. If you click the Start button the following screen should appear This is the magic moment Click Launch 37

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39. After clicking launch, you should see the screen with the progress bar shown on the following overhead So far so good 39

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41. Even before the previous screen goes away, or at the very least, as soon as it finishes, you should see the emulator on the screen It’s conceivable that you’ll have to close some things to find it It may be hidden In any case, the initial stage of launch shouldn’t take a long time, and this is what you should see 41

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43. Even If Things are Going OK, This is the Painful Part What you need now is patience (potentially a lot of it) and faith The Android message on the emulated device will flash white for an indeterminate period of time The emulator is still launching As long as that process is going on, there’s nothing else that you should do Find something to kill a little time with, because a watched pot never boils 43

44. Edging Towards Success Eventually, with good luck, the emulator will look as shown on the following overhead In the screenshot that is shown, the emulator screen is grayed out 44

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46. If your emulator is grayed out, click and drag over the emulator screen with the mouse This should wake it up, as shown on the following overhead 46

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48. Click on the circle as directed If the apps are shown, as they are in the following screenshot, you have been successful The emulator has been launched and is running 48

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50. Running the Project in the Emulator If you want to run the project (without setting up run or debug) configurations, you need a source file for the project open in the Eclipse environment The screenshot on the following overhead shows the explorer on the left tracing the path to the MyFirstApp.java file, with that file open in the editor in the middle 50

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52. By default, the project is likely to have been built, or will be built when you opt to run In the interests of thoroughness, you can also build the project yourself In the menu you would take Project, Build All 52

53. To run the app, go to the Run menu in the menu bar and take the Run option in it Or, there is a Run tool in the toolbar which you can click on There’s no need to take the dropdown option on the tool 53

54. The first time you to try to run it, you may get another dialog box asking what kind of thing you’re trying to run You’re given a list of choices, and the choice you want to make is “Android application” This dialog is shown on the following overhead 54

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56. After choosing the right run type, once again there may be a certain amount of waiting, but with luck, when you look at the emulator, you’ll see what’s shown in the screen shot on the following overhead 56

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58. Click and drag over the emulator screen, and it comes to life, as shown on the following overhead 58

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60. 2.4 Running the Project on an Attached Device Instead of an Emulator 60

61. If you haven’t yet run a homemade app on your device, there are essentially 3 steps: Getting the Device Ready – You have to get into developer mode so that you it’s possible to transfer the app to the device Downloading and Installing the Driver – You need a USB driver in order to transfer through a USB port Running the App on the Device – Then you can run the app on the device 61

62. For reference purposes, these overheads were prepared with the following: Windows 7 Eclipse, as already described A Nexus 7 tablet The fact that it was the Nexus 7 tablet is relevant to the specific instructions for getting the device ready 62

63. Getting the Device Ready On the running device, go to the App screen Tap on Settings Under System, find About tablet Tap Build number 7 times When you return from doing this you should find Developer options under System 63

64. Take Developer options Under Debugging, enable USB debugging You can now connect the device to your system using a USB cable 64

65. Downloading and Installing the Driver For information on the Nexus 7 USB driver, if you want any, go to the Android Web site: http://developer.android.com A search on “USB driver” will take you to a page that has information on the driver The driver is only necessary when developing in a Windows environment 65

66. You have a choice on getting the driver Either you can download from this page Or you can use the Android SDK Manager from the ADT bundle in Eclipse If you’re following this set of overheads and not using your own development environment, using the SDK Manager is easier 66

67. Using the manager is so easy, there’s not much to say about it Click on the tool in the Eclipse environment Find the line for the driver Click and follow any instructions 67

68. If for some reason you want to download and install this the hard way, here is a brief list of the steps involved: Note which folder the driver is saved in Right click on the “computer” icon on your machine Take the Manage option Select the Device Manager on the left Find and expand the Other devices 68

69. Find the Nexus 7 device in the list You may find the Nexus 7 device somewhere else depending on your situation When you find the Nexus 7 device, right click on it Take the Update Driver Software… option Follow the directions and browse to the location where the driver was saved to Blah blah blah 69

70. Running the App on the Device The assumption is that you successfully installed the driver and your device is attached with a USB cable Open your app in Eclipse Take the Run tool or the Run option in the menu This should cause the Android Device Chooser to appear on the screen, with the Nexus 7 device in the list This is shown on the following overhead 70

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72. Select your device and click OK The magic should happen The app should run on your device In addition to running, it will effectively be installed on the device If you go to the apps screen you’ll find the little green Android icon for it and you can run it from there in the future 72

73. Summary and Mission This is the end of the description of the first project As noted, it was only about nuts and bolts The presentation had nothing to do with code or the components of the app Those topics will be pursued in the following sets of overheads 73

74. You have two missions, neither of which are graded homework: 1. Get “Hello World” to work on an emulated virtual device in whatever development environment you’re using 2. Get “Hello World” to work on a real attached Android device 74

75. The End 75