vaadin-number-field.html

<!--
@license
Copyright (c) 2017 Vaadin Ltd.
This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
-->

<link rel="import" href="../../polymer/polymer-element.html">
<link rel="import" href="../../polymer/lib/elements/custom-style.html">
<link rel="import" href="vaadin-text-field.html">

<dom-module id="vaadin-number-field-template">
  <template>
    <style>
      :host([readonly]) {
        pointer-events: none;
      }

      [part="decrease-button"]::before {
        content: "−";
      }

      [part="increase-button"]::before {
        content: "+";
      }

      [part="decrease-button"],
      [part="increase-button"] {
        -webkit-user-select: none;
        -moz-user-select: none;
        -ms-user-select: none;
        user-select: none;
      }

      /* Hide the native arrow icons */
      [part="value"]::-webkit-outer-spin-button,
      [part="value"]::-webkit-inner-spin-button {
        -webkit-appearance: none;
        margin: 0;
      }

      [part="value"] {
        /* Older Firefox versions (v47.0) requires !important */
        -moz-appearance: textfield !important;
      }
    </style>

    <div
      disabled$="[[!_allowed(-1, value, min, max, step)]]"
      part="decrease-button"
      on-click="_decreaseValue"
      on-touchend="_decreaseButtonTouchend"
      hidden$="[[!hasControls]]">
    </div>

    <div
      disabled$="[[!_allowed(1, value, min, max, step)]]"
      part="increase-button"
      on-click="_increaseValue"
      on-touchend="_increaseButtonTouchend"
      hidden$="[[!hasControls]]">
    </div>
  </template>

  <script>
    (function() {
      let memoizedTemplate;

      /**
      * `<vaadin-number-field>` is a Web Component for number field control in forms.
      *
      * ```html
      * <vaadin-number-field label="Number">
      * </vaadin-number-field>
      * ```
      *
      * @memberof Vaadin
      * @extends Vaadin.TextFieldElement
      * @demo demo/index.html
      */
      class NumberFieldElement extends Vaadin.TextFieldElement {
        static get is() {
          return 'vaadin-number-field';
        }

        static get version() {
          return '2.5.0-alpha1';
        }

        static get properties() {
          return {
            /**
            * Set to true to display value increase/decrease controls.
            */
            hasControls: {
              type: Boolean,
              value: false,
              reflectToAttribute: true
            },

            /**
            * The minimum value of the field.
            */
            min: {
              type: Number,
              reflectToAttribute: true,
              observer: '_minChanged'
            },

            /**
             * The maximum value of the field.
             */
            max: {
              type: Number,
              reflectToAttribute: true,
              observer: '_maxChanged'
            },

            /**
             * Specifies the allowed number intervals of the field.
             */
            step: {
              type: Number,
              reflectToAttribute: true,
              value: 1,
              observer: '_stepChanged'
            }

          };
        }

        ready() {
          super.ready();
          this.__previousValidInput = this.value || '';
          this.inputElement.type = 'number';
          this.inputElement.addEventListener('change', this.__onInputChange.bind(this));
        }

        _decreaseButtonTouchend(e) {
          // Cancel the following click and focus events
          e.preventDefault();
          this._decreaseValue();
        }

        _increaseButtonTouchend(e) {
          // Cancel the following click and focus events
          e.preventDefault();
          this._increaseValue();
        }

        static get template() {
          if (!memoizedTemplate) {
            // Clone the superclass template
            memoizedTemplate = super.template.cloneNode(true);

            // Retrieve this element's dom-module template
            const thisTemplate = Polymer.DomModule.import(this.is + '-template', 'template');
            const decreaseButton = thisTemplate.content.querySelector('[part="decrease-button"]');
            const increaseButton = thisTemplate.content.querySelector('[part="increase-button"]');
            const styles = thisTemplate.content.querySelector('style');

            // Add the buttons and styles to the text-field template
            const inputField = memoizedTemplate.content.querySelector('[part="input-field"]');
            const prefixSlot = memoizedTemplate.content.querySelector('[name="prefix"]');
            inputField.insertBefore(decreaseButton, prefixSlot);
            inputField.appendChild(increaseButton);
            memoizedTemplate.content.appendChild(styles);
          }

          return memoizedTemplate;
        }

        _createConstraintsObserver() {
          // NOTE: do not call "super" but instead override the method to add extra arguments
          this._createMethodObserver('_constraintsChanged(required, minlength, maxlength, pattern, min, max, step)');
        }

        _constraintsChanged(required, minlength, maxlength, pattern, min, max, step) {
          if (!this.invalid) {
            return;
          }

          const isNumUnset = n => (!n && n !== 0);

          if (!isNumUnset(min) || !isNumUnset(max)) {
            this.validate();
          } else {
            super._constraintsChanged(required, minlength, maxlength, pattern);
          }
        }

        _decreaseValue() {
          this._incrementValue(-1);
        }

        _increaseValue() {
          this._incrementValue(1);
        }

        _incrementValue(incr) {
          if (this.disabled) {
            return;
          }

          let value = parseFloat(this.value);

          if (!this.value) {
            if (this.min == 0 && incr < 0 ||
                this.max == 0 && incr > 0 ||
                this.max == 0 && this.min == 0) {
              incr = 0;
              value = 0;
            } else if ((this.max == null || this.max >= 0) &&
                       (this.min == null || this.min <= 0)) {
              value = 0;
            } else if (this.min > 0) {
              value = this.min;
              if (this.max < 0 && incr < 0) {
                value = this.max;
              }
              incr = 0;
            } else if (this.max < 0) {
              value = this.max;
              if (incr < 0) {
                incr = 0;
              } else {
                // FIXME(yuriy): find a proper solution to make correct step back
                if (this._getIncrement(1, value - this.step) > this.max) {
                  value -= 2 * this.step;
                } else {
                  value -= this.step;
                }
              }
            }
          } else if (value < this.min) {
            incr = 0;
            value = this.min;
          } else if (value > this.max) {
            incr = 0;
            value = this.max;
          }

          const newValue = this._getIncrement(incr, value);
          if (!this.value || incr == 0 || this._incrementIsInsideTheLimits(incr, value)) {
            this._setValue(newValue);
          }
        }

        _setValue(value) {
          this.value = this.inputElement.value = String(parseFloat(value));
          this.dispatchEvent(new CustomEvent('change', {bubbles: true}));
        }

        _getIncrement(incr, currentValue) {
          let step = this.step || 1,
            min = this.min || 0;

          // To avoid problems with decimal math, multiplying to operate with integers.
          const multiplier = Math.max(this._getMultiplier(currentValue),
            this._getMultiplier(step),
            this._getMultiplier(min));

          step *= multiplier;
          currentValue = Math.round(currentValue * multiplier);
          min *= multiplier;

          const margin = (currentValue - min) % step;

          if (incr > 0) {
            return (currentValue - margin + step) / multiplier;
          } else if (incr < 0) {
            return (currentValue - (margin || step)) / multiplier;
          } else {
            return currentValue / multiplier;
          }
        }

        _getDecimalCount(number) {
          const s = String(number);
          const i = s.indexOf('.');
          return i === -1 ? 1 : s.length - i - 1;
        }

        _getMultiplier(number) {
          if (!isNaN(number)) {
            return Math.pow(10, this._getDecimalCount(number));
          }
        }

        _incrementIsInsideTheLimits(incr, value) {
          if (incr < 0) {
            return this.min == null || this._getIncrement(incr, value) >= this.min;
          } else if (incr > 0) {
            return this.max == null || this._getIncrement(incr, value) <= this.max;
          } else {
            return this._getIncrement(incr, value) <= this.max && this._getIncrement(incr, value) >= this.min;
          }
        }

        _allowed(sign) {
          const incr = sign * (this.step || 1);
          const value = parseFloat(this.value);
          return !this.value || (!this.disabled && this._incrementIsInsideTheLimits(incr, value));
        }

        _stepChanged(step) {
          if (!this.__stepChangedCalled) {
            // Setting the initial value, avoid using it in validation.
            this.inputElement.step = 'any';
            this.__stepChangedCalled = true;
          } else {
            this.inputElement.step = step;
          }
        }

        _minChanged(min) {
          this.inputElement.min = min;
        }

        _maxChanged(max) {
          this.inputElement.max = max;
        }

        _valueChanged(newVal, oldVal) {
          // Validate value to be numeric
          if (newVal && isNaN(parseFloat(newVal))) {
            this.value = '';
          } else if (typeof this.value !== 'string') {
            this.value = String(this.value);
          }

          super._valueChanged(this.value, oldVal);
        }

        _onKeyDown(e) {
          if (e.keyCode == 38) {
            e.preventDefault();
            this._increaseValue();
          } else if (e.keyCode == 40) {
            e.preventDefault();
            this._decreaseValue();
          }
          super._onKeyDown(e);
        }

        __onInputChange() {
          this.checkValidity();
        }

        checkValidity() {
          // text-field mixin does not check against `min`, `max` and `step`
          if (this.min !== undefined || this.max !== undefined || this.step !== 1) {
            this.invalid = !this.inputElement.checkValidity();
          }
          return super.checkValidity();
        }
      }

      window.customElements.define(NumberFieldElement.is, NumberFieldElement);

      /**
       * @namespace Vaadin
       */
      window.Vaadin = window.Vaadin || {};
      Vaadin.NumberFieldElement = NumberFieldElement;
    })();
  </script>
</dom-module>