19.1 Creating a Chain
Chains may be implemented either by adding a few lines to the XML layout resource file of an activity or by using some chain specific features of the Layout Editor.
Consider a layout consisting of three Button widgets constrained so as to be positioned in the top-left, top-center and top-right of the ConstraintLayout parent as illustrated in Figure 19-1:
Figure 19-1
To represent such a layout, the XML resource layout file might contain the following entries for the button widgets:
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="16dp"
android:text="Button"
app:layout_constraintHorizontal_bias...