1 files changed, 64 insertions, 0 deletions
diff --git a/app/scripts/controllers/computed-balances.js b/app/scripts/controllers/computed-balances.js
new file mode 100644
index 000000000..576746164
--- /dev/null
+++ b/app/scripts/controllers/computed-balances.js
@@ -0,0 +1,64 @@
+const ObservableStore = require('obs-store')
+const extend = require('xtend')
+const BalanceController = require('./balance')
+
+class ComputedbalancesController {
+
+  constructor (opts = {}) {
+    const { accountTracker, txController } = opts
+    this.accountTracker = accountTracker
+    this.txController = txController
+
+    const initState = extend({
+      computedBalances: {},
+    }, opts.initState)
+    this.store = new ObservableStore(initState)
+    this.balances = {}
+
+    this._initBalanceUpdating()
+  }
+
+  updateAllBalances () {
+    for (let address in this.balances) {
+      this.balances[address].updateBalance()
+    }
+  }
+
+  _initBalanceUpdating () {
+    const store = this.accountTracker.getState()
+    this.addAnyAccountsFromStore(store)
+    this.accountTracker.subscribe(this.addAnyAccountsFromStore.bind(this))
+  }
+
+  addAnyAccountsFromStore(store) {
+    const balances = store.accounts
+
+    for (let address in balances) {
+      this.trackAddressIfNotAlready(address)
+    }
+  }
+
+  trackAddressIfNotAlready (address) {
+    const state = this.store.getState()
+    if (!(address in state.computedBalances)) {
+      this.trackAddress(address)
+    }
+  }
+
+  trackAddress (address) {
+    let updater = new BalanceController({
+      address,
+      accountTracker: this.accountTracker,
+      txController: this.txController,
+    })
+    updater.store.subscribe((accountBalance) => {
+      let newState = this.store.getState()
+      newState.computedBalances[address] = accountBalance
+      this.store.updateState(newState)
+    })
+    this.balances[address] = updater
+    updater.updateBalance()
+  }
+}
+
+module.exports = ComputedbalancesController