From c9c50355db4e0a4b1bf20ad2e1eae448a697c469 Mon Sep 17 00:00:00 2001
From: jkylehumphrey <jkylehumphrey@gmail.com>
Date: Fri, 26 Jan 2018 12:56:26 -0500
Subject: [PATCH 1/2] implement prevRouteName

---
 index.js | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/index.js b/index.js
index 754d4df..b845527 100644
--- a/index.js
+++ b/index.js
@@ -12,9 +12,17 @@ function getCurrentRouteKey(navigationState) {
   return route.key
 }
 
-function updateFocus(currentState) {
-  const currentRouteKey = getCurrentRouteKey(currentState)
-  subscribedComponents.forEach((f) => f(currentRouteKey))
+function getRouteName(navigationState) {
+  if (!navigationState) return null
+  const route = navigationState.routes[navigationState.index]
+  if (route.routes) return getRouteName(route)
+  return route.routeName
+}
+
+function updateFocus(currentState, prevState) {
+  const currentRouteKey = getCurrentRouteKey(currentState);
+  const prevRouteName = getRouteName(prevState);
+  subscribedComponents.forEach((f) => f(currentRouteKey, prevRouteName))
 }
 
 
@@ -50,7 +58,7 @@ function _bind(WrappedComponent, isInitialRoute) {
       }
     }
 
-    _handleNavigationChange = (routeKey) => {
+    _handleNavigationChange = (routeKey, prevRouteName) => {
       // update state only when isFocused changes
       const currentScreenKey = this.props.navigation.state.key;
 
@@ -61,8 +69,9 @@ function _bind(WrappedComponent, isInitialRoute) {
       // immediately reflects any changes.
       if (this.isFocused !== (currentScreenKey === routeKey)) {
         this.setState({
-            isFocused: !this.isFocused,
-            focusedRouteKey: routeKey,
+          isFocused: !this.isFocused,
+          focusedRouteKey: routeKey,
+          prevRouteName: prevRouteName
         })
         this.isFocused = !this.isFocused
       }
@@ -73,6 +82,7 @@ function _bind(WrappedComponent, isInitialRoute) {
         <WrappedComponent
           isFocused={this.state.isFocused}
           focusedRouteKey={this.state.focusedRouteKey}
+          prevRouteName={this.state.prevRouteName}
           {...this.props}
         />
       )

From 96a8ea55d17a8aa14cf6bf812f36f75a47ad6832 Mon Sep 17 00:00:00 2001
From: jkylehumphrey <jkylehumphrey@gmail.com>
Date: Fri, 26 Jan 2018 13:27:09 -0500
Subject: [PATCH 2/2] create typings

---
 index.d.ts | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 index.d.ts

diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..b7aa961
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,16 @@
+import * as ReactNavigation from 'react-navigation'
+import * as React from 'react'
+
+declare module "react-navigation-is-focused-hoc" {
+    export function updateFocus(currentState: ReactNavigation.NavigationState, prevState: ReactNavigation.NavigationState);
+    export function getCurrentRouteKey(navigationState: ReactNavigation.NavigationState);
+    export function withNavigationFocus(WrappedComponent: string, isInitialRoute?: boolean);
+}
+
+declare module 'react-navigation' {
+    export interface NavigationScreenConfigProps {
+        isFocused?: boolean;
+        focusedRouteKey?: string;
+        prevRouteName?: string;
+    }
+}