Lesson 2

🎯 Goal

Save your work with commits and send it to GitHub, all from inside Android Studio. No terminal needed.

Think online shopping 🛒: selecting files = put them in the cart. Commit = check out (a saved checkpoint with a message). Push = ship it to GitHub.

Task 1: Make your own branch

You never save work directly on nonRobot-module-2. You make your own branch (a copy where you can work safely). Lesson 3 explains branches properly.

1. Click the branch name in Android Studio. It’s in the top-left of the window, next to the project name. (On older versions it’s at the bottom-right corner and says Git:.)
2. Click New Branch…
3. Name it training-yourname (use your real name) and click Create.

✅ Checkpoint: the branch name at the top now says training-yourname.

Task 2: Make a file

1. In the Project panel, open the folder Training.
2. Right-click Training → New → File. Name it yourname.txt.
3. If Android Studio asks “Add file to Git?”, click Add.
4. Write 3 lines in the file: your name, why you joined FEDS, and one thing you want to learn.

Task 3: Meet the Commit window

1. Open the Commit window on the left side. (Click Commit in the left toolbar, or press Alt + 0. Mac: Cmd + 0.)
2. Look for your file. It’s either under Changes or under Unversioned Files. Your file is new, so Git hasn’t seen it before.
3. Click the checkbox next to your file. That puts it in the cart 🛒
4. Right-click your file and choose Show Diff (Ctrl + D, Mac Cmd + D). What do you see?

✅ Checkpoint: your file is checked, and you can explain what the colors in the diff mean. 🟩 green = added, 🟥 red = removed.

Task 4: Your first commit

1. In the message box at the bottom of the Commit window, type a message that says what you did, like: Add practice file for yourname
2. Click Commit.

✅ Checkpoint: the file disappears from the Commit window. That means it’s saved! To see your commit, open the Git tool window (Alt + 9, Mac Cmd + 9) and click the Log tab. Your commit is at the top.

Task 5: Three commits

Real commits are small. Make two more, one at a time:

1. Add a fourth line to your file. Open the Commit window and look at the diff before you commit. What’s green?
2. Commit it with a message that says what you changed.
3. Do one more edit and commit that too.

Only check the files you mean to commit. If other files show up in the list that you didn’t change, leave them unchecked and ask David.

✅ Checkpoint: the Log tab shows 3 commits from you.

Write good messages

• ❌ stuff, fix, asdf
• ✅ Add practice file for david
• ✅ Change Passing counter color to green

Mini task: write a good message for each of these (in your doc):

1. You made the home screen button say “Training Zone”.
2. You deleted a line that printed debug text.
3. You made a counter stop at zero.

Task 6: Push it to GitHub

Right now your commits only live on your computer. To send them:

1. Click Git → Push… in the menu (or press Ctrl + Shift + K, Mac Cmd + Shift + K).
2. You’ll see your 3 commits listed. Click Push.
3. If a sign-in window pops up, choose Log in via GitHub, sign in, and approve it.

Tip: the Commit window’s Commit button has an arrow next to it with Commit and Push…. That does both steps at once.

✅ Checkpoint: open the feds-central repo on GitHub. Click the branch dropdown, choose training-yourname, and find your file in scouting/android/lib/Training.

Push rejected? Someone else changed the branch first. Click Git → Update Project… (or Pull), then push again.

Task 7: Secrets

Some things must never be committed: passwords, private keys, API tokens. Once they’re on GitHub they’re very hard to take back.

1. Press Ctrl + Shift + F (Mac: Cmd + Shift + F) and search for defaultApiKey.
2. Open the file it finds and read the comment above it.
3. In your doc, answer: why is this one OK to commit? What kind of key would not be OK?

To complete this lesson

Paste into this lesson’s tab in your training doc (text only):

1. Your branch name or link (training-yourname)
2. Your answer to Task 7