how to MODIFY a constraint layout programmatically?

Question

Ive got a view like below :

 <org.rayanmehr.atlas.shared.customview.CustomTextView     android:id="@+id/tvDownVoteCount"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_marginLeft="6dp"     app:layout_constraintVertical_bias="0"     app:layout_constraintTop_toBottomOf="@+id/anchorHelper"     app:layout_constraintLeft_toRightOf="@+id/tvDownVoteIcon"     app:layout_constraintBottom_toBottomOf="@+id/imgComment"     /> 

how can i modify the value of app:layout_constraintVertical_bias or any other constraint property programmatically without having top set the whole set of the properties again in my activity ?

Answer 1

Here is what I did (no need for ConstraintSet, we can work directly on the constraints themselves):

ConstraintLayout.LayoutParams params = (ConstraintLayout.LayoutParams) myView.getLayoutParams(); params.horizontalBias = 0.2f; // here is one modification for example. modify anything else you want :) myView.setLayoutParams(params); // request the view to use the new modified params 

it worked like a charm when I had a SeekBar and a TextView below it (aligned to it both left+right), and I wanted to update the TextView position to be under the SeekBar's cursor, so I had to update the horizontal bias params on the SeekBar's OnSeekBarChangeListener