Troubles with changing FrameLayout size with ConstraintLayout child

Question

I have FrameLayout with ConstraintLayout inside it. ConstraintLayout has android:layout_height="wrap_content" attribute. FrameLayout has fixed size which is smaller than desired by ConstraintLayout. I expect that when I increase FrameLayout height at runtime, height of ConstraintLayout will also grow until it's content fit. But it does not happen. It works as expected if I switch to FrameLayout instead of ConstraintLayout or if I call requestLayout() directly on ConstraintLayout. What could be the reason of such behavior?

Layout:

 <FrameLayout
            android:id="@+id/view2"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginBottom="16dp"
            android:background="@drawable/frame_layout_bg">

            <androidx.constraintlayout.widget.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="@drawable/constraint_layout_bg">

                <TextView
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:gravity="top|center_horizontal"
                    android:padding="16dp"
                    android:text="Constraint layout content"
                    android:textSize="24sp"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toTopOf="parent" />
            </androidx.constraintlayout.widget.ConstraintLayout>
        </FrameLayout>

Change height code:

        val frameLayout = findViewById<ViewGroup>(res)

        val finalHeight = TypedValue
            .applyDimension(TypedValue.COMPLEX_UNIT_DIP, 100f, resources.displayMetrics)
            .toInt()

        val layoutParams = frameLayout.layoutParams
        layoutParams.height = finalHeight

        frameLayout.layoutParams = layoutParams
        frameLayout.requestLayout()

Created example project to demonstrate the issue

Calling `requestLayout()` for parent layout not make remeasure of child layouts. You should call `child.forceLayout()` with `parent.requestLayout()` or as you said you should call directly `child.requestLayout()`. You can read [this](https://stackoverflow.com/questions/13856180/usage-of-forcelayout-requestlayout-and-invalidate) and [this](https://stackoverflow.com/questions/45383948/how-does-forcelayout-work-in-android) to get more information. — Sergey Melnik, Jan 06 '21 at 15:02
Thank you for your reply and links. Interesting, and I can understand that. The thing I cannot understand is why after switching from ConstraintLayout to any other ViewGroup (FrameLayout, LinearLayout, GridLayout etc.) I have everything working correctly with single requestLayout() on parent layout? In my opinion, any ViewGroup should re-measure it's children after changing the size, because some of the children might want to have more space than they had before. At least ViewGroups which allow non-fixed size (constrained, stretched etc.) for their children — Mikhail, Jan 06 '21 at 16:17

score 0 · Accepted Answer · answered Jan 07 '21 at 08:17

This seems to be a bug in ConstraintLayout that started with the version 2.0.2, I just created a pull request suggesting a fix for this issue hope it will be fixed soon, you can just switch back to 2.0.1 to avoid this issue till it gets resolved in future versions

Troubles with changing FrameLayout size with ConstraintLayout child

1 Answers1