Tools of the Trade

Here are the slides to my talk at the Android Meetup tonight.


Thanks for all the great questions!

As promised, here are additional links:

Leak Canary (Square) - Really useful leak detection library
Multidex and Performance (Tim Mellor) - Great overview of everything multidex

String formatting and Lint

One piece of advice that we keep hearing over and over is to extract strings into resources. There really is no reason for you to hard code strings in code.

I wrote before about easily moving strings between Java and XML, and today I'd like to focus on string formatting. The Android dev guide gives a good overview of the support Android has for passing arguments into a String.format(String, Object...).

Worried about using incorrect syntax? I was! I can never remember which of the % or the $ comes first, or if I'm passing arguments in the correct order. To be clear, the syntax is

%[arg number]$[arg type]

Thankfully, Android Studio has come a long way with pointing us in the right direction when working with strings.

First off, a very useful warning when setting manually concatenated text into a TextView:

 And by "placeholders" they mean the format arguments.

You can mix and match multiple arguments and argument types in one string too!

And in case you removed an argument in the XML file but forgot to edit code, another helpful error for you!

If you change the argument type, Studio will tell you about it too.

If you forget the syntax, fear not for Studio will tell you. (May not be too obvious here but I used the incorrect "$1$s" format.)

Android Studio is really so helpful now, we are running out of excuses to be lazy coders. 😱

Pidcat <3 Android M

If you use Pidcat, there might be issues running the tool if your device is on M+. The issue has been fixed on master but hasn't been released yet.

The readme says to fix the issue, get the latest off master:

12:46 $ brew unlink pidcat
Unlinking /usr/local/Cellar/pidcat/HEAD... 1 symlinks removed
✔ ~/Android 
12:48 $ brew install --HEAD pidcat
Warning: pidcat-HEAD already installed, it's just not linked
✔ ~/Android 

That didn't quite work, so let's link it:

12:48 $ brew link pidcat
Linking /usr/local/Cellar/pidcat/HEAD... 1 symlinks created
✔ ~/Android 

I tried re-running pidcat, but it's still not displaying anything. Which probably means we really don't have the latest code off the repo. The --force switch has been deprecated, so to force an update we would have to call reinstall instead:

12:49 $ brew reinstall --HEAD pidcat
==> Reinstalling pidcat
==> Cloning https://github.com/JakeWharton/pidcat.git
Cloning into '/Library/Caches/Homebrew/pidcat--git'...
remote: Counting objects: 10, done.
remote: Compressing objects: 100% (8/8), done.
remote: Total 10 (delta 0), reused 7 (delta 0), pack-reused 0
Unpacking objects: 100% (10/10), done.
Checking connectivity... done.
==> Checking out branch master
==> Caveats
Bash completion has been installed to:
  /usr/local/etc/bash_completion.d
==> Summary
🍺  /usr/local/Cellar/pidcat/HEAD: 5 files, 19.5K, built in 4 seconds
✔ ~/Android

Or, if do not want to do all that, you can also do:

$ adb logcat -v brief | pidcat my.package.name