material-components/material-components-android · error · IllegalArgumentException

indicatorColors cannot be empty when indicatorColor is not u

Error message

indicatorColors cannot be empty when indicatorColor is not used.

What it means

BaseProgressIndicatorSpec loads indicatorColor either as a single color or as an array resource (TYPE_REFERENCE). When the attribute is a reference to an array resource that is empty (zero entries), it throws IllegalArgumentException, since an indicator with no colors cannot render any stroke.

Source

Thrown at lib/java/com/google/android/material/progressindicator/BaseProgressIndicatorSpec.java:225

      return;
    }

    TypedValue indicatorColorValue =
        typedArray.peekValue(R.styleable.BaseProgressIndicator_indicatorColor);

    if (indicatorColorValue.type != TypedValue.TYPE_REFERENCE) {
      indicatorColors =
          new int[] {typedArray.getColor(R.styleable.BaseProgressIndicator_indicatorColor, -1)};
      return;
    }

    indicatorColors =
        context
            .getResources()
            .getIntArray(
                typedArray.getResourceId(R.styleable.BaseProgressIndicator_indicatorColor, -1));
    if (indicatorColors.length == 0) {
      throw new IllegalArgumentException(
          "indicatorColors cannot be empty when indicatorColor is not used.");
    }
  }

  /**
   * Loads the trackColor from attributes if existing; otherwise, uses the first value in {@link
   * BaseProgressIndicatorSpec#indicatorColors} applying the alpha value for disable items from
   * theme. This method doesn't recycle the {@link TypedArray} argument.
   *
   * @param context The current active context.
   * @param typedArray The TypedArray object of the attributes.
   */
  private void loadTrackColor(@NonNull Context context, @NonNull TypedArray typedArray) {
    if (typedArray.hasValue(R.styleable.BaseProgressIndicator_trackColor)) {
      trackColor = typedArray.getColor(R.styleable.BaseProgressIndicator_trackColor, -1);
      return;
    }

View on GitHub (pinned to ac7e18efee)

Solutions

1. Populate the color array with at least one entry
2. If a single color is intended, set app:indicatorColor="@color/x" directly instead of an array reference
3. Add a resource-level sanity check for generated color arrays (fail build when empty)

Example fix

<!-- before: res/values/arrays.xml -->
<integer-array name="progress_colors"/>
<!-- after -->
<integer-array name="progress_colors">
  <item>@color/brand_primary</item>
  <item>@color/brand_secondary</item>
</integer-array>

fun hasNonEmptyColorArray(context: Context, arrayRes: Int): Boolean {
    val arr = context.resources.getIntArray(arrayRes)
    return arr.isNotEmpty()
}

catch (e: IllegalArgumentException) { Log.e(TAG, "indicatorColor array empty; using single color", e); setSingleIndicatorColor() }

When it happens

Trigger: Setting app:indicatorColor="@array/empty_colors" (an <integer-array> or similar with no <item> entries) on LinearProgressIndicator/CircularProgressIndicator; the TypedValue is TYPE_REFERENCE, getIntArray returns length 0, and the guard throws.

Common situations: Colors array generated from a build config or remote config that ends up empty; placeholder array resource left empty; wrong resource linked (points at an empty array).

Related errors

• No color resources provided for harmonization.
• Non color resource found: name={name}, typeId={typeId}
• Not supported with unknown package id: {packageId}
• No color resources found for harmonization.
• Cannot set framework drawable as progress drawable.

AI-assisted analysis of material-components/material-components-android@ac7e18efee (2026-08-14). Data as JSON: /api/errors/83b4c138a99f5443. Report an issue: GitHub.