A quick reminder: if you are doing serious Android development, and are using neither styles, includes nor fragments to maximize re-usability, you are creating your own hell. Here is the code to add appcompat library inside adle file. Open your Project’s adle ( Module : app ) and add :appcompat-v7:23.4.0 library file. Notice that we have included the onClick handler in the XML, and that we are using styles. Follow all the below steps very carefully to add Toolbar Widget in your project. Note: If you used Android Asset Studio for your small icon then this step may have. This example uses a TextView, but any View can be expanded/collapsed the same way. The small icon is displayed on the top status bar as well as the. The Android SDK provides the ExpandableListView class, but sometimes that option is overkill or unfit for our intents & purposes, and we may decide to roll out our own mechanism.

What we are doing is trying to maximize the use of the available space on the screen by giving an overall view of its content. Expandable/Collapsible Views (text, images, etc.) in Android are useful when we want to display all the available options on one screen, without the user having to scroll all the way to find the one he/she is interested in.

Android studio logo on collapsable toolbar