IssueTracker

ConstraintLayout version: 2.2.0; 2.1.4, etc. It seems to be fixed on version 2.0.0-beta2, but then it broke once again.

Here you can see xml:

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/horizontal_guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.5" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline_start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_begin="16dp" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline_end"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_end="56dp" />

    <androidx.core.widget.NestedScrollView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constrainedHeight="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@id/guideline_end"
        app:layout_constraintStart_toEndOf="@+id/guideline_start"
        app:layout_constraintTop_toBottomOf="@+id/horizontal_guideline"
        app:layout_constraintVertical_bias="1">

        <androidx.appcompat.widget.AppCompatTextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Some phrase that is not gonna be measured right. Some more text to make 3 lines. And a little bit more more more" />

    </androidx.core.widget.NestedScrollView>
    
</androidx.constraintlayout.widget.ConstraintLayout>

Steps to reproduce:

• Create new Android project
• Input the xml above into activity_main.xml
• Check version of ConstraintLayout
• Run project

Expected behaviour

ScrollView fits all the text as it is constrained to the horizontal center of the screen through the Guideline.

Actual behaviour

ScrollView fits just 2 lines and gets scrolled.

Some comment

It happens because of attribute 'layout_constrainedHeight' and Guidelines (it is essential to add 'layout_constraintTop_toBottomOf' pointing to horizontal Guideline).

Guess that 'layout_constrainedHeight' causes 2 measure cycles to be held for NestedScrollView. On the first one TextView width is calculated without vertical Guidelines so it gets full screen width to put text (2 lines). On the next cycle it respects Guidelines so the number of lines is recalculated (3 lines).

But NestedScrollView gets height of the TextView from the first cycle. Might be some cached value.

Related issues:

https://issuetracker.google.com/issues/123551995
https://issuetracker.google.com/issues/132314169
https://issuetracker.google.com/issues/325928328