4 files changed, 125 insertions, 0 deletions
diff --git a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.component.js b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.component.js
index e69de29bb..bdf12b738 100644
--- a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.component.js
+++ b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.component.js
@@ -0,0 +1,54 @@
+import React, { Component } from 'react'
+import PropTypes from 'prop-types'
+
+export default class AmountMaxButton extends Component {
+
+  static propTypes = {
+    balance: PropTypes.string,
+    gasTotal: PropTypes.string,
+    maxModeOn: PropTypes.bool,
+    selectedToken: PropTypes.object,
+    setAmountToMax: PropTypes.func,
+    setMaxModeTo: PropTypes.func,
+    tokenBalance: PropTypes.string,
+  };
+
+  setMaxAmount () {
+    const {
+      balance,
+      gasTotal,
+      selectedToken,
+      setAmountToMax,
+      tokenBalance,
+    } = this.props
+
+    setAmountToMax({
+      balance,
+      gasTotal,
+      selectedToken,
+      tokenBalance,
+    })
+  }
+
+  render () {
+    const { setMaxModeTo, maxModeOn } = this.props
+
+    return (
+      <div
+        className="send-v2__amount-max"
+        onClick={(event) => {
+          event.preventDefault()
+          setMaxModeTo(true)
+          this.setMaxAmount()
+        }}
+      >
+        {!maxModeOn ? this.context.t('max') : ''}
+      </div>
+    )
+  }
+
+}
+
+AmountMaxButton.contextTypes = {
+  t: PropTypes.func,
+}
diff --git a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.container.js b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.container.js
index e69de29bb..a72f41775 100644
--- a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.container.js
+++ b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.container.js
@@ -0,0 +1,40 @@
+import { connect } from 'react-redux'
+import {
+  getGasTotal,
+  getSelectedToken,
+  getSendFromBalance,
+  getTokenBalance,
+} from '../../../send.selectors.js'
+import { getMaxModeOn } from './amount-max-button.selectors.js'
+import { calcMaxAmount } from './amount-max-button.utils.js'
+import {
+  updateSendAmount,
+  setMaxModeTo,
+} from '../../../../../actions'
+import AmountMaxButton from './amount-max-button.component'
+import {
+  updateSendErrors,
+} from '../../../../../ducks/send'
+
+export default connect(mapStateToProps, mapDispatchToProps)(AmountMaxButton)
+
+function mapStateToProps (state) {
+
+  return {
+    balance: getSendFromBalance(state),
+    gasTotal: getGasTotal(state),
+    maxModeOn: getMaxModeOn(state),
+    selectedToken: getSelectedToken(state),
+    tokenBalance: getTokenBalance(state),
+  }
+}
+
+function mapDispatchToProps (dispatch) {
+  return {
+    setAmountToMax: maxAmountDataObject => {
+      dispatch(updateSendErrors({ amount: null }))
+      dispatch(updateSendAmount(calcMaxAmount(maxAmountDataObject)))
+    },
+    setMaxModeTo: bool => dispatch(setMaxModeTo(bool)),
+  }
+}
diff --git a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.selectors.js b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.selectors.js
index e69de29bb..69fec1994 100644
--- a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.selectors.js
+++ b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.selectors.js
@@ -0,0 +1,9 @@
+const selectors = {
+  getMaxModeOn,
+}
+
+module.exports = selectors
+
+function getMaxModeOn (state) {
+  return state.metamask.send.maxModeOn
+}
diff --git a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.utils.js b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.utils.js
index e69de29bb..b490a7fd7 100644
--- a/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.utils.js
+++ b/ui/app/components/send_/send-content/send-amount-row/amount-max-button/amount-max-button.utils.js
@@ -0,0 +1,22 @@
+const {
+  multiplyCurrencies,
+  subtractCurrencies,
+} = require('../../../../../conversion-util')
+const ethUtil = require('ethereumjs-util')
+
+function calcMaxAmount ({ balance, gasTotal, selectedToken, tokenBalance }) {
+    const { decimals } = selectedToken || {}
+    const multiplier = Math.pow(10, Number(decimals || 0))
+
+    return selectedToken
+      ? multiplyCurrencies(tokenBalance, multiplier, {toNumericBase: 'hex'})
+      : subtractCurrencies(
+        ethUtil.addHexPrefix(balance),
+        ethUtil.addHexPrefix(gasTotal),
+        { toNumericBase: 'hex' }
+      )
+}
+
+module.exports = {
+  calcMaxAmount,
+}