feat: added new API which supports pop as well

BREAKING CHANGE: The old API where the shared elements could be passed as props has been dropped. Instead you should define a static variable called `sharedElements` on your Screen component. That variable can be either a function or a static array. See the README for more details

src/SharedElementRendererData.tsx

@@ -4,7 +4,9 @@ import {
   SharedElementsConfig,
   SharedElementAnimatedValue,
   SharedElementTransitionProps,
+  NavigationProp,
 } from './types';
+import { normalizeSharedElementsConfig } from './utils';
 
 export type SharedElementRendererUpdateHandler = () => any;
 
@@ -13,16 +15,33 @@ export interface ISharedElementRendererData {
   endTransition(): void;
   willActivateScene(
     sceneData: SharedElementSceneData,
-    sharedElements: SharedElementsConfig,
-    animValue?: SharedElementAnimatedValue
+    navigation: NavigationProp
   ): void;
-  didActivateScene(sceneData: SharedElementSceneData): void;
+  didActivateScene(
+    sceneData: SharedElementSceneData,
+    navigation: NavigationProp
+  ): void;
+}
+
+function getSharedElements(
+  sceneData: SharedElementSceneData,
+  navigation: NavigationProp,
+  otherNavigation: NavigationProp,
+  show: boolean
+): SharedElementsConfig | null {
+  const { sharedElements } = sceneData.Component;
+  if (!sharedElements) return null;
+  // TODO push/pop distinction?
+  return normalizeSharedElementsConfig(
+    sharedElements(navigation, otherNavigation, show)
+  );
 }
 
 export default class SharedElementRendererData
   implements ISharedElementRendererData {
   private sceneData: SharedElementSceneData | null = null;
   private prevSceneData: SharedElementSceneData | null = null;
+  private prevNavigation: NavigationProp | null = null;
   private updateSubscribers = new Set<SharedElementRendererUpdateHandler>();
   private sceneSubscription: SharedElementEventSubscription | null = null;
   private sharedElements: SharedElementsConfig = [];
@@ -38,22 +57,27 @@ export default class SharedElementRendererData
 
   willActivateScene(
     sceneData: SharedElementSceneData,
-    sharedElements: SharedElementsConfig,
-    animValue?: SharedElementAnimatedValue
+    navigation: NavigationProp
   ): void {
     /*console.log(
       'SharedElementRendererData.willActivateScene: ',
       sceneData.name,
       ', previous: ',
-      this.prevSceneData ? this.prevSceneData.name : '',
-      ', sharedElements: ',
-      sharedElements
+      this.prevSceneData ? this.prevSceneData.name : ''
     );*/
-    this.sceneData = sceneData;
-    if (!this.prevSceneData) return;
-    this.sharedElements = sharedElements;
-    if (animValue) this.animValue = animValue;
-    if (sharedElements.length) {
+    if (!this.prevSceneData || !this.prevNavigation) return;
+    const sharedElements =
+      getSharedElements(sceneData, navigation, this.prevNavigation, true) ||
+      getSharedElements(
+        this.prevSceneData,
+        this.prevNavigation,
+        navigation,
+        false
+      );
+    if (sharedElements && sharedElements.length) {
+      // console.log('sharedElements: ', sharedElements, sceneData);
+      this.sceneData = sceneData;
+      this.sharedElements = sharedElements;
       this.sceneSubscription = this.sceneData.addUpdateListener(() => {
         // TODO optimize
         this.emitUpdateEvent();
@@ -62,13 +86,17 @@ export default class SharedElementRendererData
     }
   }
 
-  didActivateScene(sceneData: SharedElementSceneData): void {
-    // console.log('SharedElementRendererData.didActivateScene: ', sceneData.name);
+  didActivateScene(
+    sceneData: SharedElementSceneData,
+    navigation: NavigationProp
+  ): void {
+    //console.log('SharedElementRendererData.didActivateScene: ', sceneData.name);
     if (this.sceneSubscription) {
       this.sceneSubscription.remove();
       this.sceneSubscription = null;
     }
     this.prevSceneData = sceneData;
+    this.prevNavigation = navigation;
     if (this.sceneData) {
       this.sceneData = null;
       if (this.sharedElements.length) {
@@ -93,20 +121,24 @@ export default class SharedElementRendererData
 
   getTransitions(): SharedElementTransitionProps[] {
     const { prevSceneData, sceneData } = this;
-    return this.sharedElements.map(({ id, sourceId, animation, debug }) => ({
-      position: this.animValue,
-      start: {
-        ancestor:
-          (prevSceneData ? prevSceneData.getAncestor() : undefined) || null,
-        node:
-          (prevSceneData ? prevSceneData.getNode(sourceId) : undefined) || null,
-      },
-      end: {
-        ancestor: (sceneData ? sceneData.getAncestor() : undefined) || null,
-        node: (sceneData ? sceneData.getNode(id) : undefined) || null,
-      },
-      ...animation,
-      debug,
-    }));
+    // console.log('getTransitions: ', sceneData, prevSceneData);
+    return this.sharedElements.map(({ id, sourceId, animation, debug }) => {
+      return {
+        position: this.animValue,
+        start: {
+          ancestor:
+            (prevSceneData ? prevSceneData.getAncestor() : undefined) || null,
+          node:
+            (prevSceneData ? prevSceneData.getNode(sourceId) : undefined) ||
+            null,
+        },
+        end: {
+          ancestor: (sceneData ? sceneData.getAncestor() : undefined) || null,
+          node: (sceneData ? sceneData.getNode(id) : undefined) || null,
+        },
+        ...animation,
+        debug,
+      };
+    });
   }
 }

src/SharedElementRendererProxy.tsx

@@ -1,7 +1,7 @@
 import SharedElementRendererData, {
   ISharedElementRendererData,
 } from './SharedElementRendererData';
-import { SharedElementAnimatedValue, SharedElementsConfig } from './types';
+import { SharedElementAnimatedValue, NavigationProp } from './types';
 import SharedElementSceneData from './SharedElementSceneData';
 
 export class SharedElementRendererProxy implements ISharedElementRendererData {
@@ -29,26 +29,28 @@ export class SharedElementRendererProxy implements ISharedElementRendererData {
 
   willActivateScene(
     sceneData: SharedElementSceneData,
-    sharedElements: SharedElementsConfig,
-    animValue?: SharedElementAnimatedValue
+    navigation: NavigationProp
   ) {
     if (!this.data) {
       console.warn(
         'SharedElementRendererProxy.willActivateScene called before Proxy was initialized'
       );
       return;
     }
-    return this.data.willActivateScene(sceneData, sharedElements, animValue);
+    return this.data.willActivateScene(sceneData, navigation);
   }
 
-  didActivateScene(sceneData: SharedElementSceneData) {
+  didActivateScene(
+    sceneData: SharedElementSceneData,
+    navigation: NavigationProp
+  ) {
     if (!this.data) {
       console.warn(
         'SharedElementRendererProxy.didActivateScene called before Proxy was initialized'
       );
       return;
     }
-    return this.data.didActivateScene(sceneData);
+    return this.data.didActivateScene(sceneData, navigation);
   }
 
   get source(): SharedElementRendererData | null {

src/SharedElementSceneData.tsx

@@ -1,4 +1,8 @@
-import { SharedElementNode, SharedElementEventSubscription } from './types';
+import {
+  SharedElementNode,
+  SharedElementEventSubscription,
+  SharedElementSceneComponent,
+} from './types';
 
 export type SharedElementSceneUpdateHandlerEventType =
   | 'ancestor'
@@ -17,10 +21,16 @@ export default class SharedElementSceneData {
   private nodes: {
     [key: string]: SharedElementNode;
   } = {};
+  public readonly Component: SharedElementSceneComponent;
   public readonly name: string;
 
-  constructor(name: string) {
-    this.name = name;
+  constructor(Component: SharedElementSceneComponent) {
+    this.Component = Component;
+    this.name =
+      Component.displayName ||
+      Component.name ||
+      (Component.constructor ? Component.constructor.name : undefined) ||
+      '';
   }
 
   getAncestor(): SharedElementNode | undefined {

src/createSharedElementScene.tsx

@@ -4,9 +4,12 @@ import hoistNonReactStatics from 'hoist-non-react-statics';
 import { nodeFromRef } from 'react-native-shared-element';
 import SharedElementSceneData from './SharedElementSceneData';
 import SharedElementSceneContext from './SharedElementSceneContext';
-import { SharedElementsConfig, SharedElementEventSubscription } from './types';
+import {
+  SharedElementEventSubscription,
+  NavigationProp,
+  SharedElementSceneComponent,
+} from './types';
 import { ISharedElementRendererData } from './SharedElementRendererData';
-import { normalizeSharedElementsConfig } from './utils';
 
 const styles = StyleSheet.create({
   container: {
@@ -15,7 +18,7 @@ const styles = StyleSheet.create({
 });
 
 type PropsType = {
-  navigation: any;
+  navigation: NavigationProp;
 };
 
 function getActiveRouteState(route: any): any {
@@ -31,19 +34,15 @@ function getActiveRouteState(route: any): any {
 }
 
 function createSharedElementScene(
-  Component: React.ComponentType<any>,
+  Component: SharedElementSceneComponent,
   rendererData: ISharedElementRendererData
 ): React.ComponentType<any> {
   class SharedElementSceneView extends React.PureComponent<PropsType> {
-    private initial: boolean = true;
     private subscriptions: {
       [key: string]: SharedElementEventSubscription;
     } = {};
     private sceneData: SharedElementSceneData = new SharedElementSceneData(
-      Component.displayName ||
-        Component.name ||
-        (Component.constructor ? Component.constructor.name : undefined) ||
-        ''
+      Component
     );
 
     componentDidMount() {
@@ -79,34 +78,17 @@ function createSharedElementScene(
       this.sceneData.setAncestor(nodeFromRef(ref));
     };
 
-    private getSharedElements(): SharedElementsConfig | null {
-      const { navigation } = this.props;
-      let sharedElements =
-        // @ts-ignore
-        navigation.getParam('sharedElements') || Component.sharedElements;
-      if (!sharedElements) return null;
-      if (typeof sharedElements === 'function') {
-        sharedElements = sharedElements(navigation);
-      }
-      return sharedElements
-        ? normalizeSharedElementsConfig(sharedElements)
-        : null;
-    }
-
     private onWillFocus = () => {
-      const sharedElements = this.getSharedElements();
-      if (sharedElements && this.initial) {
-        this.initial = false;
-        rendererData.willActivateScene(this.sceneData, sharedElements);
-      }
+      const { navigation } = this.props;
+      rendererData.willActivateScene(this.sceneData, navigation);
     };
 
     private onDidFocus = () => {
       const { navigation } = this.props;
       const activeRoute = getActiveRouteState(navigation.state);
       if (navigation.state.routeName === activeRoute.routeName) {
-        // console.log('onDidFocus: ', this.sceneData.name, activeRoute, this.props.navigation.state.routeName);
-        rendererData.didActivateScene(this.sceneData);
+        // console.log('onDidFocus: ', this.sceneData.name, navigation);
+        rendererData.didActivateScene(this.sceneData, navigation);
       }
     };
   }

src/createSharedElementStackNavigator.tsx

@@ -1,5 +1,4 @@
 import * as React from 'react';
-import { Animated } from 'react-native';
 import hoistNonReactStatics from 'hoist-non-react-statics';
 import SharedElementRendererView from './SharedElementRendererView';
 import SharedElementRendererData, {
@@ -38,10 +37,14 @@ function createSharedElementEnabledNavigator(
   return createNavigator(wrappedRouteConfigs, {
     ...navigatorConfig,
     onTransitionStart: (transitionProps: any, prevTransitionProps: any) => {
-      if (transitionProps.index === prevTransitionProps.index) return;
-      // console.log('onTransitionStart: ', transitionProps, prevTransitionProps);
+      const { index, position } = transitionProps;
+      const prevIndex = prevTransitionProps.index;
+      if (index === prevIndex) return;
       rendererData.startTransition(
-        Animated.subtract(transitionProps.position, transitionProps.index - 1)
+        position.interpolate({
+          inputRange: [index - 1, index],
+          outputRange: index > prevIndex ? [0, 1] : [2, 1],
+        })
       );
       if (navigatorConfig.onTransitionStart) {
         navigatorConfig.onTransitionStart(transitionProps, prevTransitionProps);