1 files changed, 174 insertions, 0 deletions
diff --git a/ui/app/components/bn-as-decimal-input.js b/ui/app/components/bn-as-decimal-input.js
new file mode 100644
index 000000000..f3ace4720
--- /dev/null
+++ b/ui/app/components/bn-as-decimal-input.js
@@ -0,0 +1,174 @@
+const Component = require('react').Component
+const h = require('react-hyperscript')
+const inherits = require('util').inherits
+const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
+const extend = require('xtend')
+
+module.exports = BnAsDecimalInput
+
+inherits(BnAsDecimalInput, Component)
+function BnAsDecimalInput () {
+  this.state = { invalid: null }
+  Component.call(this)
+}
+
+/* Bn as Decimal Input
+ *
+ * A component for allowing easy, decimal editing
+ * of a passed in bn string value.
+ *
+ * On change, calls back its `onChange` function parameter
+ * and passes it an updated bn string.
+ */
+
+BnAsDecimalInput.prototype.render = function () {
+  const props = this.props
+  const state = this.state
+
+  const { value, scale, precision, onChange, min, max } = props
+
+  const suffix = props.suffix
+  const style = props.style
+  const valueString = value.toString(10)
+  const newValue = this.downsize(valueString, scale, precision)
+
+  return (
+    h('.flex-column', [
+      h('.flex-row', {
+        style: {
+          alignItems: 'flex-end',
+          lineHeight: '13px',
+          fontFamily: 'Montserrat Light',
+          textRendering: 'geometricPrecision',
+        },
+      }, [
+        h('input.hex-input', {
+          type: 'number',
+          step: 'any',
+          required: true,
+          min,
+          max,
+          style: extend({
+            display: 'block',
+            textAlign: 'right',
+            backgroundColor: 'transparent',
+            border: '1px solid #bdbdbd',
+
+          }, style),
+          value: newValue,
+          onBlur: (event) => {
+            this.updateValidity(event)
+          },
+          onChange: (event) => {
+            this.updateValidity(event)
+            const value = (event.target.value === '') ? '' : event.target.value
+
+
+            const scaledNumber = this.upsize(value, scale, precision)
+            const precisionBN = new BN(scaledNumber, 10)
+            onChange(precisionBN, event.target.checkValidity())
+          },
+          onInvalid: (event) => {
+            const msg = this.constructWarning()
+            if (msg === state.invalid) {
+              return
+            }
+            this.setState({ invalid: msg })
+            event.preventDefault()
+            return false
+          },
+        }),
+        h('div', {
+          style: {
+            color: ' #AEAEAE',
+            fontSize: '12px',
+            marginLeft: '5px',
+            marginRight: '6px',
+            width: '20px',
+          },
+        }, suffix),
+      ]),
+
+      state.invalid ? h('span.error', {
+        style: {
+          position: 'absolute',
+          right: '0px',
+          textAlign: 'right',
+          transform: 'translateY(26px)',
+          padding: '3px',
+          background: 'rgba(255,255,255,0.85)',
+          zIndex: '1',
+          textTransform: 'capitalize',
+          border: '2px solid #E20202',
+        },
+      }, state.invalid) : null,
+    ])
+  )
+}
+
+BnAsDecimalInput.prototype.setValid = function (message) {
+  this.setState({ invalid: null })
+}
+
+BnAsDecimalInput.prototype.updateValidity = function (event) {
+  const target = event.target
+  const value = this.props.value
+  const newValue = target.value
+
+  if (value === newValue) {
+    return
+  }
+
+  const valid = target.checkValidity()
+
+  if (valid) {
+    this.setState({ invalid: null })
+  }
+}
+
+BnAsDecimalInput.prototype.constructWarning = function () {
+  const { name, min, max } = this.props
+  let message = name ? name + ' ' : ''
+
+  if (min && max) {
+    message += `must be greater than or equal to  ${min} and less than or equal to ${max}.`
+  } else if (min) {
+    message += `must be greater than or equal to ${min}.`
+  } else if (max) {
+    message += `must be less than or equal to ${max}.`
+  } else {
+    message += 'Invalid input.'
+  }
+
+  return message
+}
+
+
+BnAsDecimalInput.prototype.downsize = function (number, scale, precision) {
+  // if there is no scaling, simply return the number
+  if (scale === 0) {
+    return Number(number)
+  } else {
+    // if the scale is the same as the precision, account for this edge case.
+    var decimals = (scale === precision) ? -1 : scale - precision
+    return Number(number.slice(0, -scale) + '.' + number.slice(-scale, decimals))
+  }
+}
+
+BnAsDecimalInput.prototype.upsize = function (number, scale, precision) {
+  var stringArray = number.toString().split('.')
+  var decimalLength = stringArray[1] ? stringArray[1].length : 0
+  var newString = stringArray[0]
+
+  // If there is scaling and decimal parts exist, integrate them in.
+  if ((scale !== 0) && (decimalLength !== 0)) {
+    newString += stringArray[1].slice(0, precision)
+  }
+
+  // Add 0s to account for the upscaling.
+  for (var i = decimalLength; i < scale; i++) {
+    newString += '0'
+  }
+  return newString
+}