http://www.codexpedia.com/android/android-drawable-selector-and-shape-examples/ http://www.codexpedia.com/android/android-defining-border-drawables-in-xml/ http://www.codexpedia.com/android/defining-shapes-in-xml-file-in-android-drawable-folder/ https://github.com/codexpedia/android_shapes_borders/blob/master/app/src/main/res/layout/activity_main.xml https://github.com/codexpedia/android_shapes_borders/tree/master/app/src/main/res/drawable