material-components/material-components-android · error · IllegalStateException

This behavior cannot be attached to a GONE view. Set the vie

Error message

This behavior cannot be attached to a GONE view. Set the view to INVISIBLE instead.

What it means

FabTransformationBehavior.layoutDependsOn (FabTransformationBehavior.java:96) throws IllegalStateException when the child view carrying this behavior is View.GONE. A GONE child is skipped by CoordinatorLayout's dependency/measure passes, so the FAB-to-content transformation machinery would never run correctly; INVISIBLE keeps the view laid out and merely not drawn, which is what the behavior requires. This is a fail-fast contract check, not a recoverable runtime condition.

Source

Thrown at lib/java/com/google/android/material/transformation/FabTransformationBehavior.java:96

  private final int[] tmpArray = new int[2];

  // The original translation of the dependency. Used to translate the dependency back to its
  // original position.
  private float dependencyOriginalTranslationX;
  private float dependencyOriginalTranslationY;

  public FabTransformationBehavior() {}

  public FabTransformationBehavior(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  @Override
  @CallSuper
  public boolean layoutDependsOn(
      @NonNull CoordinatorLayout parent, @NonNull View child, @NonNull View dependency) {
    if (child.getVisibility() == View.GONE) {
      throw new IllegalStateException(
          "This behavior cannot be attached to a GONE view. Set the view to INVISIBLE instead.");
    }

    if (dependency instanceof FloatingActionButton) {
      int expandedComponentIdHint =
          ((FloatingActionButton) dependency).getExpandedComponentIdHint();
      return expandedComponentIdHint == 0 || expandedComponentIdHint == child.getId();
    }
    return false;
  }

  @Override
  @CallSuper
  public void onAttachedToLayoutParams(@NonNull CoordinatorLayout.LayoutParams lp) {
    if (lp.dodgeInsetEdges == Gravity.NO_GRAVITY) {
      // If the developer hasn't set dodgeInsetEdges, lets set it to BOTTOM so that
      // we dodge any Snackbars, matching FAB's behavior.
      lp.dodgeInsetEdges = Gravity.BOTTOM;

View on GitHub (pinned to ac7e18efee)

Solutions

1. Set android:visibility="invisible" on the child instead of gone.
2. If you need the view visually hidden initially, keep INVISIBLE and additionally set android:alpha="0" or call setAlpha(0f).
3. If GONE is a hard requirement, remove the layout_behavior before hiding and re-attach after showing.

Example fix

<!-- before -->
<View android:id="+id/sheet"
    android:visibility="gone"
    app:layout_behavior="...FabTransformationBehavior" ... />

<!-- after -->
<View android:id="+id/sheet"
    android:visibility="invisible"
    android:alpha="0"
    app:layout_behavior="...FabTransformationBehavior" ... />

// before hiding a view that carries a FabTransformationBehavior:
if (view.getVisibility() == View.GONE && hasFabTransformationBehavior(view)) {
  view.setVisibility(View.INVISIBLE);
  view.setAlpha(0f);
} else {
  view.setVisibility(View.GONE);
}

boolean hasFabTransformationBehavior(View v) {
  ViewGroup.LayoutParams p = v.getLayoutParams();
  return p instanceof CoordinatorLayout.LayoutParams
      && ((CoordinatorLayout.LayoutParams) p).getBehavior() instanceof FabTransformationBehavior;
}

When it happens

Trigger: Declaring the expanded content view with android:visibility="gone" while attaching FabTransformationBehavior via app:layout_behavior; calling expandedView.setVisibility(View.GONE) before the first layout pass or while the behavior is attached.

Common situations: Wanting the transformed sheet hidden initially; the natural instinct is GONE, but this behavior requires INVISIBLE (optionally with 0 alpha/elevation so it is not visible to the user).

Related errors

• The view is not a child of CoordinatorLayout
• The view is not associated with SideSheetBehavior
• The view is not a child of CoordinatorLayout
• The view is not associated with ExpandableBehavior
• secondaryIconGravity cannot have the same alignment as iconG

AI-assisted analysis of material-components/material-components-android@ac7e18efee (2026-08-14). Data as JSON: /api/errors/64867c2f6e68692d. Report an issue: GitHub.