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

indicatorColors cannot be empty when indicatorColor is not…

Error message

indicatorColors cannot be empty when indicatorColor is not used.

What it means

LoadingIndicatorSpec parses the indicatorColor attribute: when it points to a color everything is fine, but when it points to an array resource (@array/... via TYPE_REFERENCE) the array is read with getIntArray. An empty array resource leaves the indicator with no colors to draw, which is unrecoverable, so initialization throws IllegalArgumentException.

Solutions

1. Populate the referenced integer-array with at least one color: <integer-array name="indicator_colors"><item>@color/blue</item></integer-array>.
2. Or point app:indicatorColor at a single color instead of an array reference.
3. Audit all build variants/flavors to ensure the array resource is non-empty everywhere it resolves.

Example fix

<!-- before -->
<integer-array name="indicator_colors" />
<com...LoadingIndicator app:indicatorColor="@array/indicator_colors" ... />

<!-- after -->
<integer-array name="indicator_colors">
  <item>@color/m3_sys_color_primary</item>
</integer-array>

int[] colors = context.getResources().getIntArray(R.array.indicator_colors);
if (colors == null || colors.length == 0) {
  colors = new int[] { ContextCompat.getColor(context, R.color.default_indicator) };
}
// then set programmatically instead of relying on the attribute

When it happens

Trigger: Setting app:indicatorColor="@array/empty_colors" (or any <integer-array> with zero items) on a LoadingIndicator (CircularProgressIndicator-style loading spinner styled with LoadingIndicator attributes); referencing an array resource that resolves to empty in some build variant/flavor.

Common situations: Shared color arrays defined per-flavor where one flavor ships an empty list; typos pointing at the wrong array resource; arrays built by resource merging that end up empty.

Related errors

• indicatorColors cannot be empty when indicatorColor is not…
• No color resources found for harmonization.
• No color resources provided for harmonization.
• Non color resource found: name=
• Not supported with unknown package id

AI-assisted analysis of material-components/material-components-android@ac7e18efee (2026-08-14). Data as JSON: /api/errors/9aa7f67c7ec3245b. Report an issue: GitHub.

Appendix: source

Thrown at lib/java/com/google/android/material/loadingindicator/LoadingIndicatorSpec.java:109

          };
      return;
    }

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

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

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

  /**
   * Sets the scale specs to fit the given bound of the {@link LoadingIndicatorDrawable}.
   *
   * @param scaleToFit The new scaleToFit value.
   */
  public void setScaleToFit(boolean scaleToFit){
    this.scaleToFit = scaleToFit;
  }
}

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