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

Attempted to get ShapeAppearanceModel from a MaterialButton

Error message

Attempted to get ShapeAppearanceModel from a MaterialButton which has an overwritten background.

What it means

getShapeAppearanceModel() is the read counterpart of setShapeAppearanceModel(): it returns the ShapeAppearanceModel of the button's original shape drawable. When the background was replaced (isUsingOriginalBackground() false), no such model exists, so MaterialButton throws IllegalStateException (MaterialButton.java:1870) rather than returning null or a fabricated default. This keeps the get/set API symmetric — both fail on an overwritten background.

Source

Thrown at lib/java/com/google/android/material/button/MaterialButton.java:1870

              + " background.");
    }
  }

  /**
   * Returns the {@link ShapeAppearanceModel} used for this {@link MaterialButton}'s original
   * drawables.
   *
   * <p>This {@link ShapeAppearanceModel} can be modified to change the component's shape.
   *
   * @throws IllegalStateException if the MaterialButton's background has been overwritten.
   */
  @NonNull
  @Override
  public ShapeAppearanceModel getShapeAppearanceModel() {
    if (isUsingOriginalBackground()) {
      return materialButtonHelper.getShapeAppearanceModel();
    } else {
      throw new IllegalStateException(
          "Attempted to get ShapeAppearanceModel from a MaterialButton which has an overwritten"
              + " background.");
    }
  }

  /**
   * Sets the {@link ShapeAppearance} used for this {@link MaterialButton}'s original
   * drawables.
   *
   * @throws IllegalStateException if the MaterialButton's background has been overwritten.
   * @hide
   */
  @RestrictTo(LIBRARY_GROUP)
  public void setShapeAppearance(
      @NonNull ShapeAppearance shapeAppearance) {
    if (isUsingOriginalBackground()) {
      if (materialButtonHelper.getCornerSpringForce() == null && shapeAppearance.isStateful()) {
        materialButtonHelper.setCornerSpringForce(createSpringForce());

View on GitHub (pinned to ac7e18efee)

Solutions

1. Remove the android:background override (use app:backgroundTint, app:strokeColor, app:strokeWidth, app:shapeAppearance instead) so the original background survives.
2. Make the utility defensive: check the button's background is a MaterialShapeDrawable or wrap the call in try/catch IllegalStateException before falling back to a fixed corner radius.
3. If a custom drawable is unavoidable, track the intended shape separately (e.g. in the style/tag) instead of reading it from the button.

Example fix

// before
ShapeAppearanceModel model = button.getShapeAppearanceModel(); // throws if background overwritten

// after
if (button.getBackground() instanceof MaterialShapeDrawable) {
  ShapeAppearanceModel model = button.getShapeAppearanceModel();
  button.setShapeAppearanceModel(model.toBuilder().setAllCornerSizes(24f).build());
} else {
  button.setBackground(createRoundedBackground(24f));
}

if (button.getBackground() instanceof MaterialShapeDrawable) {
  ShapeAppearanceModel model = button.getShapeAppearanceModel();
}

static boolean hasOriginalShape(Button b) {
  return b.getBackground() instanceof MaterialShapeDrawable;
}

try { return button.getShapeAppearanceModel(); } catch (IllegalStateException e) { return ShapeAppearanceModel.builder().setAllCornerSizes(0).build(); }

When it happens

Trigger: Calling button.getShapeAppearanceModel() (e.g. to read current corner sizes before modifying them) on a MaterialButton inflated with android:background set, or after code called setBackground/setBackgroundResource on it.

Common situations: Utility code that walks a view hierarchy and 'reads then tweaks' every MaterialButton's corners. Team A ships a themed button style with a custom android:background; team B's corner-customization helper calls getShapeAppearanceModel() and crashes at runtime only for those styles.

Related errors

• Attempted to set ShapeAppearanceModel on a MaterialButton wh
• Attempted to set ShapeAppearance on a MaterialButton which h
• Attempted to get ShapeAppearance from a MaterialButton which
• secondaryIconGravity cannot have the same alignment as iconG
• Scroll bar must contain a child to calculate interpolation.

AI-assisted analysis of material-components/material-components-android@ac7e18efee (2026-08-14). Data as JSON: /api/errors/3f481e2c5b5f611b. Report an issue: GitHub.