Restore Android gallery selections and validate editor source formats

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/AvatarCropDialog.kt

@@ -47,6 +47,9 @@ fun AvatarCropDialog(uri: Uri, onCancel: () -> Unit, onConfirm: (File, AvatarCro
         try {
             val image=withContext(Dispatchers.IO) {
                 val file=AvatarAssets.copySource(context,uri); copied=file
+                val format=android.graphics.BitmapFactory.Options().apply { inJustDecodeBounds=true }
+                android.graphics.BitmapFactory.decodeFile(file.path,format)
+                require(format.outMimeType in listOf("image/jpeg","image/png","image/webp")) { "unsupported source format=${format.outMimeType}" }
                 val (w,h)=PhotoUtil.orientedDimensions(file.path)
                 require(w>0 && h>0 && w.toLong()*h<=16L*1024*1024) { "original exceeds 16 megapixels" }
                 var sample=1; while (maxOf(w,h)/sample>1600) sample*=2

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/screens/AvatarViewerScreen.kt

@@ -34,6 +34,7 @@ fun AvatarViewerScreen(group: String?, owner: Long, name: String, onClose: () ->
     val source=remember(members,group,owner) { repository.gallerySource(group,owner) }
     var files by remember(group,owner,account) { mutableStateOf(emptyList<String>()) }
     var selected by rememberSaveable(group,owner,account) { mutableStateOf("") }
+    var sourceKey by rememberSaveable(group,owner,account) { mutableStateOf("") }
     var previews by remember(group,owner,account) { mutableStateOf(emptyMap<String,Bitmap>()) }
     var original by remember { mutableStateOf<Bitmap?>(null) }
     var failed by remember { mutableStateOf(false) }
@@ -42,6 +43,8 @@ fun AvatarViewerScreen(group: String?, owner: Long, name: String, onClose: () ->
     LaunchedEffect(account,revision) { if (account==0L) onClose() }
     LaunchedEffect(source?.first,source?.second?.avatarServer,source?.second?.avatarFile,retry) {
         val (channel,member)=source ?: return@LaunchedEffect
+        val key="$channel:${member.nodeId}:${member.avatarServer}"
+        if (sourceKey!=key) { sourceKey=key; files=emptyList(); selected=member.avatarFile; previews=emptyMap() }
         if (selected.isEmpty()) selected=member.avatarFile
         if (files.isEmpty()) files=listOf(member.avatarFile)
         catalogFailed=false
@@ -54,7 +57,7 @@ fun AvatarViewerScreen(group: String?, owner: Long, name: String, onClose: () ->
     LaunchedEffect(source?.first,source?.second?.avatarServer,selected,retry) {
         original=null; failed=false
         val (channel,member)=source ?: return@LaunchedEffect
-        if (index<0) return@LaunchedEffect
+        if (selected.isEmpty()) return@LaunchedEffect
         coroutineScope {
             launch {
                 try { previews=previews+(selected to repository.loadAvatar(channel,member.copy(avatarFile=selected),false)) }