java - Is there any way to find out what these custom attributes do in the google iosched app? -

java - Is there any way to find out what these custom attributes do in the google iosched app? -

i've been looking google iosched 2014 app ensure im next right design patterns material design , pre-l devices back upwards v7 library , appcompat v21.

in order utilize material design theme must inherit "theme.appcompat", can't seem understand or find documentation of styles attributes in link below. aren't under "android:" namespace , dont seem able utilize them myself.

https://github.com/google/iosched/blob/master/android/src/main/res/values/styles.xml#l32-l38

<item name="actionbariconcolor">#fff</item> <item name="actionbarinsetstart">@dimen/keyline_2</item> <item name="homeasupindicator">@drawable/ic_up</item> <item name="spinnerbarinsetstart">@dimen/keyline_2_minus_16dp</item> <item name="popupitembackground">?android:selectableitembackground</item> <item name="photoitemforeground">?android:selectableitembackground</item> <item name="photoitemforegroundborderless">?android:selectableitembackground</item

i'm barely familiar custom attributes in /attr folder, how can find used.

<declare-styleable name="basetheme"> <attr name="actionbariconcolor" format="color" /> <attr name="actionbarinsetstart" format="dimension" /> <attr name="spinnerbarinsetstart" format="dimension" /> <attr name="popupitembackground" format="reference" /> <attr name="photoitemforeground" format="reference" /> <attr name="photoitemforegroundborderless" format="reference" /> </declare-styleable>

i don't understand how custom set of attributes beingness used , bugging me. can explain me whats going on here , how attributes beingness used?

here's search of repository shows instances of used:

https://github.com/google/iosched/search?utf8=%e2%9c%93&q=photoitemforeground

java android android-support-library android-theme material-design