refactor: pass specific variables instead of `this` to YooForumUI, toggle `detailShowing` state as a callback of animation

src/ui/YooForumTopicUI.js

@@ -36,15 +36,22 @@ export default class YooForumTopicUI extends Component {
     };
     this.topicHeaderRef = createRef();
     this.onPress = this.onPress.bind(this);
+    this.onAnimationFinished = this.onAnimationFinished.bind(this);
+  }
+
+  onAnimationFinished() {
+    this.setState({detailShowing: !this.state.detailShowing});
   }
 
   onPress() {
     if (!this.state.detailShowing) {
-      this.setState({detailShowing: true});
+      this.props.showDetail(
-      this.props.showDetail(this);
+        this.state.translate,
+        this.state.layoutY,
+        this.onAnimationFinished,
+      );
     } else {
-      this.setState({detailShowing: false});
+      this.props.hideDetail(this.state.translate, this.onAnimationFinished);
-      this.props.hideDetail(this);
     }
   }
 

src/ui/YooForumUI.js

@@ -49,13 +49,13 @@ export default class YooForumUI extends Component {
     this.hideDetail = this.hideDetail.bind(this);
   }
 
-  showDetail(topicRef) {
+  showDetail(translate, layoutY, onAnimationFinished) {
     this.setState({scrollEnabled: false});
     Animated.parallel([
-      Animated.timing(topicRef.state.translate, {
+      Animated.timing(translate, {
         toValue: {
           x: screenWidth,
-          y: this.state.currentPosition - topicRef.state.layoutY + 8,
+          y: this.state.currentPosition - layoutY + 8,
         },
         duration: 250,
         useNativeDriver: true,
@@ -65,13 +65,13 @@ export default class YooForumUI extends Component {
         duration: 250,
         useNativeDriver: true,
       }),
-    ]).start();
+    ]).start(onAnimationFinished);
   }
 
-  hideDetail(topicRef) {
+  hideDetail(translate, onAnimationFinished) {
     this.setState({scrollEnabled: true});
     Animated.parallel([
-      Animated.timing(topicRef.state.translate, {
+      Animated.timing(translate, {
         toValue: {
           x: 0,
           y: 0,
@@ -84,7 +84,7 @@ export default class YooForumUI extends Component {
         duration: 250,
         useNativeDriver: true,
       }),
-    ]).start();
+    ]).start(onAnimationFinished);
   }
 
   render() {