private int measureWidth(final int measureSpec) {
        final int specMode = MeasureSpec.getMode(measureSpec);
        final int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {
            return specSize;
        }

        int result = ARROW_BITMAP_SIZE + getPaddingLeft() + getPaddingRight();

        if (specMode == MeasureSpec.AT_MOST) {
            result = Math.min(result, specSize);
        }

        return result;
    }
pixel size of the square arrow bitmap
main/src/main/java/cgeo/geocaching/ui/CompassMiniView.java