This document provides an overview of ConstraintLayout, including how to add it as a dependency, how to use relative positioning with constraints like layout_constraintLeft_toLeftOf, how to use chains, guidelines, bias, auto-connect and ConstraintSet programmatically. It also references additional online resources for using ConstraintLayout.

1. ConstraintLayout
+ Diego Nascimento
Software Engineer at CESAR

2. Constraints overview

3. Add ConstraintLayout to you project
1. Ensure you have the maven.google.com repository declared in your module-level
build.gradle file:
repositories {
maven {
url 'https://maven.google.com'
}
}
1. Add the library as a dependency in the same build.gradle file:
dependencies {
compile 'com.android.support.constraint:constraint-layout:1.0.2'
}

4. Relative positioning
y
x

5. Relative positioning
layout_constraintLeft_toLeftOf
layout_constraintLeft_toRightOf
layout_constraintRight_toLeftOf
layout_constraintRight_toRightOf
layout_constraintTop_toTopOf
layout_constraintTop_toBottomO
f
layout_constraintBottom_toTopOf
layout_constraintBottom_toBottomOf
layout_constraintBaseline_toBaselineOf

6. Toolbar

7. Chains

8. Chains Style

9. Baseline Constraint Handle
This can be set in the layout editor by dragging the baseline anchor of the desired
TextView to the baseline of another TextView

10. There isn’t “match_parent” !

11. Guidelines

12. Vertical Bias and Horizontal Bias

13. Auto-connect

14. Pratice

15. ConstraintSet
This class allows you to define programmatically a set of constraints to be used with
ConstraintLayout. It lets you create and save constraints, and apply them to an existing
ConstraintLayout. ConstraintsSet can be created in various ways:
Manually
c = new ConstraintSet(); c.connect(....);
from a R.layout.* object
c.clone(context, R.layout.layout1);
from a ConstraintLayout
c.clone(clayout);

16. Reference
https://developer.android.com/training/constraint-layout/index.html#adjust-the-view-size
https://medium.com/google-developers/building-interfaces-with-constraintlayout-
3958fa38a9f7
https://codelabs.developers.google.com/codelabs/constraint-layout/#0
https://developer.android.com/reference/android/support/constraint/ConstraintSet.html