SGH / COMPONENTS

  <!--
  @license
  Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
  This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
  The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
  The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
  Code distributed by Google as part of the polymer project is also
  subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
  -->
  
  <link rel="import" href="../polymer/polymer.html">
  <link rel="import" href="../paper-styles/paper-styles.html">
  
  <!--
  `<paper-input-container>` is a container for a `<label>`, an `<input is="iron-input">` or
  `<iron-autogrow-textarea>` and optional add-on elements such as an error message or character
  counter, used to implement Material Design text fields.
  
  For example:
  
      <paper-input-container>
        <label>Your name</label>
        <input is="iron-input">
      </paper-input-container>
  
  ### Listening for input changes
  
  By default, it listens for changes on the `bind-value` attribute on its children nodes and perform
  tasks such as auto-validating and label styling when the `bind-value` changes. You can configure
  the attribute it listens to with the `attr-for-value` attribute.
  
  ### Using a custom input element
  
  You can use a custom input element in a `<paper-input-container>`, for example to implement a
  compound input field like a social security number input. The custom input element should have the
  `paper-input-input` class, have a `notify:true` value property and optionally implements

  `Polymer.IronValidatableBehavior` if it is validatable.

  
      <paper-input-container attr-for-value="ssn-value">
        <label>Social security number</label>
        <ssn-input class="paper-input-input"></ssn-input>
      </paper-input-container>
  
  ### Validation
  
  If the `auto-validate` attribute is set, the input container will validate the input and update
  the container styling when the input value changes.
  
  ### Add-ons
  
  Add-ons are child elements of a `<paper-input-container>` with the `add-on` attribute and
  implements the `Polymer.PaperInputAddonBehavior` behavior. They are notified when the input value
  or validity changes, and may implement functionality such as error messages or character counters.
  They appear at the bottom of the input.
  

  ### Prefixes and suffixes
  These are child elements of a `<paper-input-container>` with the `prefix`
  or `suffix` attribute, and are displayed inline with the input, before or after.
  
      <paper-input-container>
        <div prefix>$</div>
        <label>Total</label>
        <input is="iron-input">
        <paper-icon-button suffix icon="clear"></paper-icon-button>
      </paper-input-container>
  

  ### Styling
  
  The following custom properties and mixins are available for styling:
  
  Custom property | Description | Default
  ----------------|-------------|----------
  `--paper-input-container-color` | Label and underline color when the input is not focused | `--secondary-text-color`
  `--paper-input-container-focus-color` | Label and underline color when the input is focused | `--default-primary-color`

  `--paper-input-container-invalid-color` | Label and underline color when the input is is invalid | `--google-red-500`

  `--paper-input-container-input-color` | Input foreground color | `--primary-text-color`
  `--paper-input-container` | Mixin applied to the container | `{}`

  `--paper-input-container-disabled` | Mixin applied to the container when it's disabled | `{}`

  `--paper-input-container-label` | Mixin applied to the label | `{}`
  `--paper-input-container-label-focus` | Mixin applied to the label when the input is focused | `{}`
  `--paper-input-container-input` | Mixin applied to the input | `{}`

  `--paper-input-container-underline` | Mixin applied to the underline | `{}`
  `--paper-input-container-underline-focus` | Mixin applied to the underline when the input is focued | `{}`
  `--paper-input-container-underline-disabled` | Mixin applied to the underline when the input is disabled | `{}`

  `--paper-input-prefix` | Mixin applied to the input prefix | `{}`
  `--paper-input-suffix` | Mixin applied to the input suffix | `{}`

  
  This element is `display:block` by default, but you can set the `inline` attribute to make it
  `display:inline-block`.
  -->
  <dom-module id="paper-input-container">

    <template>

      <style>
        :host {
          display: block;
          padding: 8px 0;

          @apply(--paper-input-container);
        }

        :host[inline] {
          display: inline-block;
        }

        :host([disabled]) {
          pointer-events: none;
          opacity: 0.33;

          @apply(--paper-input-container-disabled);
        }

        .floated-label-placeholder {
          @apply(--paper-font-caption);
        }

        .underline {
          position: relative;
        }

        .focused-line {
          height: 2px;

          -webkit-transform-origin: center center;
          transform-origin: center center;
          -webkit-transform: scale3d(0,1,1);
          transform: scale3d(0,1,1);

          background: var(--paper-input-container-focus-color, --default-primary-color);

          @apply(--paper-input-container-underline-focus);
        }

        .underline.is-highlighted .focused-line {
          -webkit-transform: none;
          transform: none;
          -webkit-transition: -webkit-transform 0.25s;
          transition: transform 0.25s;

          @apply(--paper-transition-easing);
        }

        .underline.is-invalid .focused-line {
          background: var(--paper-input-container-invalid-color, --google-red-500);

          -webkit-transform: none;
          transform: none;
          -webkit-transition: -webkit-transform 0.25s;
          transition: transform 0.25s;

          @apply(--paper-transition-easing);
        }

        .unfocused-line {
          height: 1px;
          background: var(--paper-input-container-color, --secondary-text-color);

          @apply(--paper-input-container-underline);
        }

        :host([disabled]) .unfocused-line {
          border-bottom: 1px dashed;
          border-color: var(--paper-input-container-color, --secondary-text-color);
          background: transparent;

          @apply(--paper-input-container-underline-disabled);
        }

        .label-and-input-container {
          @apply(--layout-flex);
          @apply(--layout-relative);
        }

        .input-content {
          position: relative;
          @apply(--layout-horizontal);
          @apply(--layout-end);
        }

        .input-content ::content label,
        .input-content ::content .paper-input-label {
          position: absolute;
          top: 0;
          right: 0;
          left: 0;
          font: inherit;
          color: var(--paper-input-container-color, --secondary-text-color);
  

          @apply(--paper-font-common-nowrap);

          @apply(--paper-font-subhead);
          @apply(--paper-input-container-label);
        }

        .input-content.label-is-floating ::content label,
        .input-content.label-is-floating ::content .paper-input-label {
          -webkit-transform: translateY(-75%) scale(0.75);
          transform: translateY(-75%) scale(0.75);
          -webkit-transform-origin: left top;
          transform-origin: left top;
          -webkit-transition: -webkit-transform 0.25s;
          transition: transform 0.25s;

          /* Since we scale to 75/100 of the size, we actually have 100/75 of the
          original space now available */
          width: 133%;
  

          @apply(--paper-transition-easing);
        }

        .input-content.label-is-highlighted ::content label,
        .input-content.label-is-highlighted ::content .paper-input-label {
          color: var(--paper-input-container-focus-color, --default-primary-color);

          @apply(--paper-input-container-label-focus);
        }

        .input-content.is-invalid ::content label,
        .input-content.is-invalid ::content .paper-input-label {
          color: var(--paper-input-container-invalid-color, --google-red-500);
        }

        .input-content.label-is-hidden ::content label,
        .input-content.label-is-hidden ::content .paper-input-label {
          visibility: hidden;
        }

        .input-content ::content input,
        .input-content ::content textarea,
        .input-content ::content iron-autogrow-textarea,
        .input-content ::content .paper-input-input {
          position: relative; /* to make a stacking context */
          outline: none;
          box-shadow: none;
          padding: 0;
          width: 100%;
          background: transparent;
          border: none;
          color: var(--paper-input-container-input-color, --primary-text-color);
          -webkit-appearance: none;
  
          @apply(--paper-font-subhead);
          @apply(--paper-input-container-input);
        }

        ::content [prefix] {
          @apply(--paper-font-subhead);
          @apply(--paper-input-prefix);
        }

        ::content [suffix] {
          @apply(--paper-font-subhead);
          @apply(--paper-input-suffix);
        }

        /* Firefox sets a min-width on the input, which can cause layout issues */
        .input-content ::content input {
          min-width: 0;
        }

        .input-content ::content textarea {
          resize: none;
        }

        .add-on-content.is-invalid ::content * {
          color: var(--paper-input-container-invalid-color, --google-red-500);
        }
  
        .add-on-content.is-highlighted ::content * {
          color: var(--paper-input-container-focus-color, --default-primary-color);
        }
      </style>

  
      <template is="dom-if" if="[[!noLabelFloat]]">
        <div class="floated-label-placeholder">&nbsp;</div>
      </template>
  
      <div class$="[[_computeInputContentClass(noLabelFloat,alwaysFloatLabel,focused,invalid,_inputHasContent)]]">

        <content select="[prefix]" id="prefix"></content>
        <div class="label-and-input-container">
          <content select=":not([add-on]):not([prefix]):not([suffix])"></content>
        </div>
        <content select="[suffix]"></content>

      </div>
  
      <div class$="[[_computeUnderlineClass(focused,invalid)]]">
        <div class="unfocused-line fit"></div>
        <div class="focused-line fit"></div>
      </div>
  
      <div class$="[[_computeAddOnContentClass(focused,invalid)]]">
        <content id="addOnContent" select="[add-on]"></content>
      </div>
  
    </template>

  </dom-module>
  
  <script>

    Polymer({

      is: 'paper-input-container',
  
      properties: {

        /**
         * Set to true to disable the floating label. The label disappears when the input value is
         * not null.
         */
        noLabelFloat: {
          type: Boolean,
          value: false
        },
  
        /**
         * Set to true to always float the floating label.
         */
        alwaysFloatLabel: {
          type: Boolean,
          value: false
        },
  
        /**
         * The attribute to listen for value changes on.
         */
        attrForValue: {
          type: String,
          value: 'bind-value'
        },
  
        /**
         * Set to true to auto-validate the input value when it changes.
         */
        autoValidate: {
          type: Boolean,
          value: false
        },
  
        /**
         * True if the input is invalid. This property is set automatically when the input value

         * changes if auto-validating, or when the `iron-input-validate` event is heard from a child.

         */
        invalid: {
          observer: '_invalidChanged',
          type: Boolean,
          value: false
        },
  
        /**
         * True if the input has focus.
         */
        focused: {
          readOnly: true,
          type: Boolean,

          value: false,
          notify: true

        },
  
        _addons: {
          type: Array
          // do not set a default value here intentionally - it will be initialized lazily when a
          // distributed child is attached, which may occur before configuration for this element
          // in polyfill.
        },
  
        _inputHasContent: {
          type: Boolean,
          value: false
        },
  
        _inputSelector: {
          type: String,
          value: 'input,textarea,.paper-input-input'
        },
  
        _boundOnFocus: {
          type: Function,
          value: function() {
            return this._onFocus.bind(this);
          }
        },
  
        _boundOnBlur: {
          type: Function,
          value: function() {
            return this._onBlur.bind(this);
          }
        },
  
        _boundOnInput: {
          type: Function,
          value: function() {
            return this._onInput.bind(this);
          }
        },
  
        _boundValueChanged: {
          type: Function,
          value: function() {
            return this._onValueChanged.bind(this);
          }
        }

      },
  
      listeners: {
        'addon-attached': '_onAddonAttached',
        'iron-input-validate': '_onIronInputValidate'
      },
  
      get _valueChangedEvent() {
        return this.attrForValue + '-changed';
      },
  
      get _propertyForValue() {
        return Polymer.CaseMap.dashToCamelCase(this.attrForValue);
      },
  
      get _inputElement() {
        return Polymer.dom(this).querySelector(this._inputSelector);
      },
  

      get _inputElementValue() {
        return this._inputElement[this._propertyForValue] || this._inputElement.value;
      },
  

      ready: function() {
        if (!this._addons) {
          this._addons = [];
        }
        this.addEventListener('focus', this._boundOnFocus, true);
        this.addEventListener('blur', this._boundOnBlur, true);
        if (this.attrForValue) {
          this._inputElement.addEventListener(this._valueChangedEvent, this._boundValueChanged);
        } else {
          this.addEventListener('input', this._onInput);
        }
      },
  
      attached: function() {

        // Only validate when attached if the input already has a value.
        if (this._inputElementValue != '') {
          this._handleValueAndAutoValidate(this._inputElement);
        } else {
          this._handleValue(this._inputElement);
        }

      },
  
      _onAddonAttached: function(event) {
        if (!this._addons) {
          this._addons = [];
        }
        var target = event.target;
        if (this._addons.indexOf(target) === -1) {
          this._addons.push(target);
          if (this.isAttached) {
            this._handleValue(this._inputElement);
          }
        }
      },
  
      _onFocus: function() {
        this._setFocused(true);
      },
  
      _onBlur: function() {
        this._setFocused(false);

        this._handleValueAndAutoValidate(this._inputElement);

      },
  
      _onInput: function(event) {

        this._handleValueAndAutoValidate(event.target);

      },
  
      _onValueChanged: function(event) {

        this._handleValueAndAutoValidate(event.target);

      },
  
      _handleValue: function(inputElement) {

        var value = this._inputElementValue;

  
        // type="number" hack needed because this.value is empty until it's valid

        if (value || value === 0 || (inputElement.type === 'number' && !inputElement.checkValidity())) {

          this._inputHasContent = true;
        } else {
          this._inputHasContent = false;
        }
  
        this.updateAddons({
          inputElement: inputElement,
          value: value,
          invalid: this.invalid
        });
      },
  

      _handleValueAndAutoValidate: function(inputElement) {
        if (this.autoValidate) {
          var valid;
          if (inputElement.validate) {
            valid = inputElement.validate(this._inputElementValue);
          } else {
            valid = inputElement.checkValidity();
          }
          this.invalid = !valid;
        }
  
        // Call this last to notify the add-ons.
        this._handleValue(inputElement);
      },
  

      _onIronInputValidate: function(event) {
        this.invalid = this._inputElement.invalid;
      },
  
      _invalidChanged: function() {
        if (this._addons) {
          this.updateAddons({invalid: this.invalid});
        }
      },
  
      /**
       * Call this to update the state of add-ons.
       * @param {Object} state Add-on state.
       */
      updateAddons: function(state) {
        for (var addon, index = 0; addon = this._addons[index]; index++) {
          addon.update(state);
        }
      },
  
      _computeInputContentClass: function(noLabelFloat, alwaysFloatLabel, focused, invalid, _inputHasContent) {
        var cls = 'input-content';
        if (!noLabelFloat) {

          var label = this.querySelector('label');
  

          if (alwaysFloatLabel || _inputHasContent) {
            cls += ' label-is-floating';
            if (invalid) {
              cls += ' is-invalid';
            } else if (focused) {
              cls += " label-is-highlighted";
            }

            // The label might have a horizontal offset if a prefix element exists
            // which needs to be undone when displayed as a floating label.
            if (Polymer.dom(this.$.prefix).getDistributedNodes().length > 0 &&
                label && label.offsetParent) {
              label.style.left = -label.offsetParent.offsetLeft + 'px';
            }
          } else {
            // When the label is not floating, it should overlap the input element.
            if (label) {
              label.style.left = 0;
            }

          }
        } else {
          if (_inputHasContent) {
            cls += ' label-is-hidden';
          }
        }
        return cls;
      },
  
      _computeUnderlineClass: function(focused, invalid) {
        var cls = 'underline';
        if (invalid) {
          cls += ' is-invalid';
        } else if (focused) {
          cls += ' is-highlighted'
        }
        return cls;
      },
  
      _computeAddOnContentClass: function(focused, invalid) {
        var cls = 'add-on-content';
        if (invalid) {
          cls += ' is-invalid';
        } else if (focused) {
          cls += ' is-highlighted'
        }
        return cls;
      }

    });

  </script>