android: add shared avatar components and guard picker account identity

tools/chatgui-android/app/src/main/java/com/utun/chat/MainActivity.kt

@@ -516,6 +516,7 @@ class MainActivity : AppCompatActivity() {
         MicrophonePermission.requester = microphoneRequester
         RadioOverlayService.overlayPermissionRequester = overlayPermissionRequester
         super.onStart()
+        ChatApplication.instance.avatars.setForeground(true)
         RadioAudioEngine.instance().setForeground(true)
         if (intent.getBooleanExtra(MicrophonePermission.EXTRA_REQUEST, false)) {
             intent.removeExtra(MicrophonePermission.EXTRA_REQUEST)
@@ -592,6 +593,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     override fun onStop() {
+        ChatApplication.instance.avatars.setForeground(false)
         RadioAudioEngine.instance().setForeground(false)
         super.onStop()
         if (MicrophonePermission.requester === microphoneRequester) MicrophonePermission.requester = null

tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarRepository.kt

@@ -8,6 +8,7 @@ import android.util.LruCache
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.sync.Semaphore
 import kotlinx.coroutines.sync.withPermit
 import java.io.File
@@ -48,6 +49,28 @@ class AvatarRepository(context: Context) {
     private val dirtyGroups = mutableSetOf<String>()
     private val pending = mutableMapOf<Long, Pending>()
     private var defaultAvatar: String? = null
+    private val foreground = MutableStateFlow(false)
+    fun setForeground(active: Boolean) { foreground.value = active }
+    val accountId: Long get() = account
+    fun profileBitmap(): Bitmap? = if (defaultAvatar == "-") null else
+        defaultAvatar?.substringAfter('/')?.let { cache.get(it) } ?: userBitmap(null, account)
+    fun ensureProfile() {
+        if (account == 0L) start()
+        val file = defaultAvatar?.substringAfter('/')
+        if (file == null || !AvatarProtocol.validFile(file)) { ensureUser(null, account); return }
+        if (cache.get(file) != null || !loads.add(file)) return
+        val uid = account; val epoch = generation
+        scope.launch {
+            try {
+                val bitmap = withContext(Dispatchers.IO) {
+                    decode(File(directory(uid), file).readBytes(), file.removeSuffix(".png"), false)
+                }
+                alive(epoch); cache.put(file, bitmap); changed()
+            } catch (e: CancellationException) { throw e }
+            catch (e: Exception) { log("ERROR", "Default avatar cache unavailable file=$file: ${e.message}") }
+            finally { if (generation == epoch) loads.remove(file) }
+        }
+    }
 
     private data class Pending(val type: Int, val group: Long, val server: Long, val owner: Long,
                                val command: Int, val result: CompletableDeferred<ByteArray>)
@@ -229,6 +252,7 @@ class AvatarRepository(context: Context) {
             try {
                 while (true) {
                     alive(epoch)
+                    foreground.first { it }
                     try {
                         val bitmap = transfers.withPermit {
                             val root = directory(uid); val file = File(root, key)
@@ -295,7 +319,7 @@ class AvatarRepository(context: Context) {
         }
     }
 
-    fun editGroup(group: String, uri: Uri?) = edit("group:$group") { epoch ->
+    fun editGroup(group: String, uri: Uri?, expectedAccount: Long) = edit("group:$group", expectedAccount) { epoch ->
         val bytes = if (uri == null) ByteArray(0) else prepare(uri, true)
         alive(epoch)
         require(editTokens["group:$group"] == epoch) { "group edit superseded" }
@@ -304,7 +328,7 @@ class AvatarRepository(context: Context) {
         ensureGroup(group, true)
     }
 
-    fun editProfile(server: Long, uri: Uri?) = edit("profile") { epoch ->
+    fun editProfile(server: Long, uri: Uri?, expectedAccount: Long) = edit("profile", expectedAccount) { epoch ->
         val uid = account
         val bytes = if (uri == null) null else prepare(uri, false)
         alive(epoch)
@@ -314,20 +338,32 @@ class AvatarRepository(context: Context) {
             withContext(Dispatchers.IO) {
                 val root = directory(uid)
                 if (!root.isDirectory && !root.mkdirs()) throw IOException("cannot create profile cache")
-                File(root, file).writeBytes(bytes)
+                val temp = File(root, ".profile-${ids.incrementAndGet()}")
+                try {
+                    temp.writeBytes(bytes)
+                    if (!temp.renameTo(File(root, file))) throw IOException("cannot publish profile cache")
+                } finally { if (temp.exists() && !temp.delete()) log("WARN", "Cannot remove profile temp=$temp") }
             }
             alive(epoch)
             defaultAvatar = "${AvatarProtocol.hex(server)}/$file"
             cache.put(file, withContext(Dispatchers.IO) { decode(bytes, file.removeSuffix(".png"), false) })
         } else defaultAvatar = "-"
         alive(epoch)
-        require(prefs.edit().putString(AvatarProtocol.hex(uid), defaultAvatar).commit()) { "cannot persist avatar intent" }
+        val desired = defaultAvatar
+        require(withContext(Dispatchers.IO) { prefs.edit().putString(AvatarProtocol.hex(uid), desired).commit() }) {
+            "cannot persist avatar intent"
+        }
+        alive(epoch)
         changed()
         _members.value.keys.map { it.group }.distinct().forEach { replicate(it) }
     }
 
-    private fun edit(key: String, block: suspend (Long) -> Unit) {
+    private fun edit(key: String, expectedAccount: Long, block: suspend (Long) -> Unit) {
         if (account == 0L) start()
+        if (expectedAccount == 0L || expectedAccount != account) {
+            log("WARN", "Ignored stale picker result target=$key expected=${AvatarProtocol.hex(expectedAccount)} actual=${AvatarProtocol.hex(account)}")
+            return
+        }
         if (account == 0L || _edits.value[key] == AvatarEditState.WORKING) return
         val epoch = generation; editTokens[key] = epoch
         _edits.value += key to AvatarEditState.WORKING
@@ -355,6 +391,7 @@ class AvatarRepository(context: Context) {
                 while (defaultAvatar == desired) {
                     try {
                         alive(epoch)
+                        foreground.first { it }
                         transfers.withPermit {
                             if (server != 0L) {
                                 val local = File(directory(uid), file)

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

@@ -0,0 +1,50 @@
+package com.utun.chat.ui.components
+
+import android.graphics.Bitmap
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import com.utun.chat.ChatApplication
+
+@Composable
+fun UserAvatar(group: String?, owner: Long, name: String, modifier: Modifier = Modifier,
+               size: Dp = 40.dp, profile: Boolean = false) {
+    val repository = ChatApplication.instance.avatars
+    val revision by repository.revision.collectAsState()
+    LaunchedEffect(group, owner, revision, profile) {
+        if (profile) repository.ensureProfile() else repository.ensureUser(group, owner)
+    }
+    AvatarImage(if (profile) repository.profileBitmap() else repository.userBitmap(group, owner), name, modifier, size)
+}
+
+@Composable
+fun GroupAvatar(group: String, name: String, modifier: Modifier = Modifier, size: Dp = 44.dp) {
+    val repository = ChatApplication.instance.avatars
+    val revision by repository.revision.collectAsState()
+    LaunchedEffect(group, revision) { repository.ensureGroup(group) }
+    AvatarImage(repository.groupBitmap(group), name, modifier, size)
+}
+
+@Composable
+private fun AvatarImage(bitmap: Bitmap?, name: String, modifier: Modifier, size: Dp) {
+    Box(modifier.size(size).clip(CircleShape).background(MaterialTheme.colorScheme.secondaryContainer),
+        contentAlignment = Alignment.Center) {
+        if (bitmap != null) Image(bitmap.asImageBitmap(), contentDescription = null,
+            modifier = Modifier.size(size), contentScale = ContentScale.Crop)
+        else Text(name.trim().split(Regex("\\s+")).filter { it.isNotEmpty() }.take(2)
+            .joinToString("") { String(Character.toChars(it.codePointAt(0))) }.uppercase().ifEmpty { "#" },
+            color = MaterialTheme.colorScheme.onSecondaryContainer, style = MaterialTheme.typography.titleMedium)
+    }
+}