Derek Banas Android Development NOTES

Derek Banas Android Development NOTES:
What each folder and files do:
- The src folder holds all of the class files for your app.
- The gen contains 2 auto generated files that shouldn't be touched, EVER.
- The BuildConfig.java contains basic configuration.
- The R.java file provides access to resources in your application. Each resource
has an ID and they are located here.
- The assets contains text files, databases, and all the other data files you'll
need to create your app.
- In the libs (library) folder, it holds the android-support-v4 file.
- The android-support-v4 is the Android API that allows you to use the newest
API while remaining backwards compatible.
- The bin folder contains files built by the ADT.
- The APK (Application Package File) file format used for installing apps on
the Android OS.
- The AndroidManifest.xml defines: App name, App icon, Activities used, permissions
required for App to properly operate, android.intent.action.MAIN defines the entry
point for the App.
- The res folder contains all drawable folders, the layout folder.
- The drawable folders store images you need at different resolutions. xlarge screens
are at least 960dp x 720dp. large screens are at least 640dp x 480dp. Normal screens
are at least 470dp x 320dp. small screens are least 426dp x 320dp.
- The layout folder contains files that define apps user interface which are:
RelativeLayout - place elements relative to other elements.
LinearLayout - align all elements in one direction.
GridLayout - lays out elements in a series of rows and columns. Very flexible.
FrameLayout -  the most simple layout, which when a new elements comes, it's
just stacked onto the other elements.
The activity_main.xml allows you to define the layout you wanna use.

In the values folder which is inside of res, it has these 3 files:
- The dimens.xml stores all padding and DP.
- The strings.xml stores and retrieves all strings.
- The styles.xml defines format for UI.

DP stands for density independent of pixels.

We use match_parent or wrap_content rather then exact pixels so that our interface
can easily scale up and adjust things.