<template>
  <div
    class="opacity-control style-control"
    :class="{ disabled: !present || disabled }"
  >
    <label
      :for="name"
      class="label"
    >
      {{ $t('settings.style.common.opacity') }}
    </label>
    <input
      v-if="typeof fallback !== 'undefined'"
      :id="name + '-o'"
      class="opt exclude-disabled"
      type="checkbox"
      :checked="present"
      @input="$emit('input', !present ? fallback : undefined)"
    >
    <label
      v-if="typeof fallback !== 'undefined' && showOptionalTickbox"
      class="opt-l"
      :for="name + '-o'"
    />
    <input
      :id="name"
      class="input-number"
      type="number"
      :value="value || fallback"
      :disabled="!present || disabled"
      max="1"
      min="0"
      step=".05"
      @input="$emit('input', $event.target.value)"
    >
  </div>
</template>

<script>
export default {
  props: {
    // Name of opacity, used for identifying
    name: {
      required: true,
      type: String
    },
    // Opacity value, should be required but vue cannot tell the difference
    // between "property missing" and "property set to undefined"
    value: {
      required: false,
      type: Number,
      default: undefined
    },
    // Opacity fallback to use when value is not defeind
    fallback: {
      required: false,
      type: Number,
      default: undefined
    },
    // Disable the control
    disabled: {
      required: false,
      type: Boolean,
      default: false
    },
    // Show "optional" tickbox, for when value might become mandatory
    showOptionalTickbox: {
      required: false,
      type: Boolean,
      default: true
    }
  },
  computed: {
    present () {
      return typeof this.value !== 'undefined'
    }
  }
}
</script>
