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

Invalid motion path type: > pathInt <

Error message

Invalid motion path type: > pathInt <

What it means

TransitionUtils.resolveThemePath reads the theme attribute referenced by a Material transition's motionPath attr. When the resolved TypedValue is an integer (TYPE_INT_DEC) it must be one of the declared enum values: 0 = linear (no PathMotion override) or 1 = arc (MaterialArcMotion). Any other integer — 2, -1, or a plain int that is not part of the enum — throws IllegalArgumentException('Invalid motion path type: ' + pathInt). This guards the enum contract declared in the attr's format.

Source

Thrown at lib/java/com/google/android/material/transition/platform/TransitionUtils.java:113

        return true;
      }
    }
    return false;
  }

  @Nullable
  static PathMotion resolveThemePath(Context context, @AttrRes int attrResId) {
    TypedValue pathValue = new TypedValue();
    if (context.getTheme().resolveAttribute(attrResId, pathValue, true)) {
      if (pathValue.type == TypedValue.TYPE_INT_DEC) {
        int pathInt = pathValue.data;
        if (pathInt == PATH_TYPE_LINEAR) {
          // Default Transition PathMotion is linear; no need to override with different PathMotion.
          return null;
        } else if (pathInt == PATH_TYPE_ARC) {
          return new MaterialArcMotion();
        } else {
          throw new IllegalArgumentException("Invalid motion path type: " + pathInt);
        }
      } else if (pathValue.type == TypedValue.TYPE_STRING) {
        String pathString = String.valueOf(pathValue.string);
        return new PatternPathMotion(PathParser.createPathFromPathData(pathString));
      } else {
        throw new IllegalArgumentException(
            "Motion path theme attribute must either be an enum value or path data string");
      }
    }
    return null;
  }

  static ShapeAppearanceModel convertToRelativeCornerSizes(
      ShapeAppearanceModel shapeAppearanceModel, final RectF bounds) {
    return shapeAppearanceModel.withTransformedCornerSizes(
        cornerSize -> RelativeCornerSize.createFromCornerSize(bounds, cornerSize));
  }

View on GitHub (pinned to ac7e18efee)

Solutions

  1. Set the theme attribute to a valid enum: <item name="motionPath">@enum/linear or the integer 0, or arc/1, or a path-data string like "M0,0 L100,0".
  2. Search the whole theme chain (base theme, overlays, themes.xml values-night etc.) for the motionPath item and remove stale literals: grep for the attr name across res/values*.
  3. If you need a custom curve, pass a path string (TYPE_STRING) instead of an out-of-range int.
  4. If inherited from a library theme, override the attribute locally with a valid value in your app theme.

Example fix

<!-- before -->
<item name="motionPath">2</item>

<!-- after -->
<item name="motionPath">@enum/linear</item>
<!-- or a custom curve -->
<item name="motionPath">M0,0 L100,100</item>
Defensive patterns

Strategy: validation

Validate before calling

// Verify the theme-supplied value before applying a transition that resolves it.
TypedValue v = new TypedValue();
if (context.getTheme().resolveAttribute(R.attr.motionPath, v, true)) {
  boolean ok = v.type == TypedValue.TYPE_STRING
      || (v.type == TypedValue.TYPE_INT_DEC && (v.data == 0 || v.data == 1));
  if (!ok) throw new IllegalStateException("Fix motionPath in theme to 0, 1, or path data");
}

Try / catch

try {
  transition.setPathMotion(TransitionUtils.resolveThemePath(context, attr)); // example
} catch (IllegalArgumentException e) {
  if (e.getMessage() != null && e.getMessage().startsWith("Invalid motion path type")) {
    Log.w(TAG, "motionPath enum out of range; defaulting to linear", e);
    transition.setPathMotion(null); // null PathMotion = linear default
  } else {
    throw e;
  }
}

Prevention

When it happens

Trigger: A theme (often a base theme or overlay) sets the transition's motionPath attribute to a raw integer other than 0/1, e.g. <item name="motionPath">2</item>; a build tool or lint override substitutes the enum with a wrong constant; the attr was redeclared in the app with a different enum set and a stale value leaks in.

Common situations: Hand-editing generated theme XML and replacing @enum values with plain ints; themes inherited from a design system where motionPath was redefined; upgrading Material versions where the attr moved and an old literal value (e.g., a leftover 2 from a removed 'through' mode) survives.

Related errors

AI-assisted analysis of material-components/material-components-android@ac7e18efee (2026-08-14). Data as JSON: /api/errors/7200c3d5bd9a5947. Report an issue: GitHub.