My Custom Quasar Input Number

QInputNumber.vue

<script>
import { QInput } from 'quasar'
import { Money } from 'v-money'
import Util from '@services/util'

export default {
  // Component <money> and Directive v-money https://github.com/vuejs-tips/v-money
  // https://github.com/quasarframework/quasar/blob/v0.17/src/components/input/QInput.js
  // https://github.com/quasarframework/quasar/blob/v0.17/src/mixins/input.js
  extends: QInput,
  name: 'QInputNumber',
  components: { Money },
  props: {
    precision: {
      type: Number,
      default: 2
    },
    decimal: {
      type: String,
      default: ','
    },
    thousands: {
      type: String,
      default: '.'
    },
    min: {
      type: Number,
      default: 0
    },
    max: {
      type: Number,
      default: Number.MAX_SAFE_INTEGER
    },
    step: {
      type: Number,
      default: null
    },
    maxLength: {
      type: [Number, String],
      default: null
    },
    align: {
      type: String,
      default: 'right'
    }
  },
  data () {
    return {
      model: this.value,
      lastValue: this.value
    }
  },
  mounted () {
    // Ajuste para "autofocus" não dar erro
    this.$refs.input.focus = function (e) {
      this.$el.focus(e)
    }
  },
  methods: {
    focus () {
      if (!this.disable && this.$refs.input && this.$refs.input.$el) {
        this.$refs.input.$el.focus()
      }
    },
    blur () {
      this.$refs.input && this.$refs.input.$el.blur()
    },
    select () {
      this.$refs.input.$el.select()
    },
    onInput (value) {
      // console.debug('QInputNumber - onInput - Value %s - Model: %s', value, this.model)
      // Evita menor que minimo
      if (value < this.min) {
        // console.warn('onInput - Volta ao minimo:', this.min)
        value = this.min
      }
      if (value !== this.model && value <= this.max) {
        // console.debug('QInputNumber - onInput - Value %s - Model: %s', value, this.model)
        this.$emit('input', value)
        this.$emit('change', value)
      }
    },
    preventNotNumber (event) {
      // Plus:107|187, Minus:109|189, Comma:110|188, Period:190|190, Up:38, Down:40
      if ([107, 187, 109, 189, 110, 188, 190, 194, 38, 40].includes(event.keyCode)) {
        // console.warn('preventNotNumber - value: %s - key: %s - result: OK', event.target.value, event.keyCode)
        event.stopPropagation()
        event.preventDefault()
        return false
      }
      return true
    },
    onKeydown (event) {
      // console.debug('keydown - Key: %s - Model: %s - lastValue: %s - value: %s', event.keyCode, this.model, this.lastValue, this.value)

      // Up:38, Down:40, Plus:107|187, Minus:109|189
      if (this.step && [38, 40, 107, 187, 109, 189].includes(event.keyCode)) {
        event.stopPropagation()
        event.preventDefault()
        // Aplica Step
        this.applyStep([38, 107, 187].includes(event.keyCode))
        return false
      }

      if (!this.preventNotNumber(event)) return false

      // Se está nos Limites
      if (Util.limitLength(event)) {
        this.lastValue = event.target.value
        this.$emit('keydown', event)
      }
      return false
    },
    onKeyup (event) {
      // console.debug('keyup - Key: %s - Model: %s - lastValue: %s - value: %s', event.keyCode, this.model, this.lastValue, this.value)
      if (!this.preventNotNumber(event)) return

      // Se não está nos limites
      if (!Util.limitLength(event)) {
        // console.warn('keyup - Volta ao valor anterior:', this.lastValue)
        event.target.value = this.lastValue
        this.$emit('error-max', true)
        return
      }
      // Evita menor que minimo
      if (this.min && event.target.value.toNumber() < this.min) {
        // console.warn('keyup - Volta ao minimo:', event.target.value)
        event.target.value = this.min.toNumeric(this.precision)
      }
      this.$emit('error-max', false)
      this.$emit('keyup', event)
    },
    onWheel (event) {
      // Sem delta ou nao usa Step
      if (!event.wheelDelta || !this.step) {
        event.stopPropagation()
        event.preventDefault()
        return false
      }
      // Aplica Step
      this.applyStep(event.wheelDelta > 0)
    },
    increment () {
      this.applyStep(true)
    },
    decrement () {
      this.applyStep(false)
    },
    applyStep (increment = true) {
      // Define novo valor
      const next = increment ? this.model + this.step : this.model - this.step
      // console.warn('applyStep ', increment ? '+' : '-', this.step, ' - next:', next, '- model:', this.model)
      // Se dentro dos limites, usa novo valor
      if (next >= this.min && next <= this.max) {
        this.model = next
        this.$emit('input', next)
      }
    },
    __getInput (h) {
      // console.log('__getInput', this.value, this.model)
      // @see https://vuejs.org/v2/guide/render-function.html
      return h('money', {
        ref: 'input',
        staticClass: 'col q-input-target q-no-input-spinner ellipsis text-' + this.align,
        'class': this.inputClasses,
        attrs: Object.assign({}, this.$attrs, {
          // type: 'tel', // this.inputType,
          placeholder: this.inputPlaceholder,
          disabled: this.disable,
          readonly: this.readonly,
          min: this.min,
          max: this.max,
          maxLength: this.maxLength,
          value: this.model,
          precision: this.precision,
          decimal: this.decimal,
          thousands: this.thousands,
          autocomplete: 'off'
        }),
        // domProps: { value: this.model },
        on: {
          input: this.onInput,
          focus: this.__onFocus,
          blur: this.__onInputBlur
        },
        nativeOn: {
          keydown: this.onKeydown,
          keyup: this.onKeyup,
          paste: this.__onPaste,
          animationstart: this.__onAnimationStart,
          wheel: this.onWheel
        }
      })
    }
  }
}
</script>

@services/util
where is this from?