Fix 1405 handle android back button in composer (#1446)

* handle android back button in composer

* improve backHandler error handling

* simplify composer onClose functionality

src/view/shell/Composer.tsx

@@ -11,7 +11,6 @@ export const Composer = observer(function ComposerImpl({
   winHeight,
   replyTo,
   onPost,
-  onClose,
   quote,
   mention,
 }: {
@@ -19,7 +18,6 @@ export const Composer = observer(function ComposerImpl({
   winHeight: number
   replyTo?: ComposerOpts['replyTo']
   onPost?: ComposerOpts['onPost']
-  onClose: () => void
   quote?: ComposerOpts['quote']
   mention?: ComposerOpts['mention']
 }) {
@@ -64,7 +62,6 @@ export const Composer = observer(function ComposerImpl({
       <ComposePost
         replyTo={replyTo}
         onPost={onPost}
-        onClose={onClose}
         quote={quote}
         mention={mention}
       />

src/view/shell/Composer.web.tsx

@@ -13,7 +13,6 @@ export const Composer = observer(function ComposerImpl({
   replyTo,
   quote,
   onPost,
-  onClose,
   mention,
 }: {
   active: boolean
@@ -21,7 +20,6 @@ export const Composer = observer(function ComposerImpl({
   replyTo?: ComposerOpts['replyTo']
   quote: ComposerOpts['quote']
   onPost?: ComposerOpts['onPost']
-  onClose: () => void
   mention?: ComposerOpts['mention']
 }) {
   const pal = usePalette('default')
@@ -47,7 +45,6 @@ export const Composer = observer(function ComposerImpl({
           replyTo={replyTo}
           quote={quote}
           onPost={onPost}
-          onClose={onClose}
           mention={mention}
         />
       </View>

src/view/shell/index.tsx

@@ -44,7 +44,10 @@ const ShellInner = observer(function ShellInnerImpl() {
   )
   const canGoBack = useNavigationState(state => !isStateAtTabRoot(state))
   React.useEffect(() => {
-    backHandler.init(store)
+    const listener = backHandler.init(store)
+    return () => {
+      listener()
+    }
   }, [store])
 
   return (
@@ -68,7 +71,6 @@ const ShellInner = observer(function ShellInnerImpl() {
       </View>
       <Composer
         active={store.shell.isComposerActive}
-        onClose={() => store.shell.closeComposer()}
         winHeight={winDim.height}
         replyTo={store.shell.composerOpts?.replyTo}
         onPost={store.shell.composerOpts?.onPost}

src/view/shell/index.web.tsx

@@ -48,7 +48,6 @@ const ShellInner = observer(function ShellInnerImpl() {
       )}
       <Composer
         active={store.shell.isComposerActive}
-        onClose={() => store.shell.closeComposer()}
         winHeight={0}
         replyTo={store.shell.composerOpts?.replyTo}
         quote={store.shell.composerOpts?.quote}