Synchronize access to OcelotCardItem._entries

Fixes #129.

src/main/scala/ocelot/desktop/inventory/item/OcelotCardItem.scala

@@ -18,7 +18,7 @@ import totoro.ocelot.brain.nbt.{NBT, NBTBase, NBTTagCompound, NBTTagString}
 import totoro.ocelot.brain.util.Tier
 import totoro.ocelot.brain.util.Tier.Tier
 
-import scala.collection.{IndexedSeqView, mutable}
+import scala.collection.mutable
 import scala.jdk.CollectionConverters.BufferHasAsJava
 
 class OcelotCardItem(val ocelotCard: OcelotCard)
@@ -31,10 +31,10 @@ class OcelotCardItem(val ocelotCard: OcelotCard)
 
   private var _messageLimit: Int = 1000
 
+  // NOTE: access must be synchronized!
+  // ocelot.log() is a direct method, so it may push events even if the tick lock is not acquired
   private val _entries = mutable.ArrayDeque.empty[LogEntry]
 
-  def entries: IndexedSeqView[LogEntry] = _entries.view
-
   eventHandlers += {
     case BrainEvent(OcelotCard.LogEvent(_, message, OcelotCard.LogDirection.CardToUser)) =>
       addEntry(LogEntry.Rx(message))
@@ -116,7 +116,7 @@ class OcelotCardItem(val ocelotCard: OcelotCard)
     addEntries(entries.toSeq)
   }
 
-  override def save(nbt: NBTTagCompound): Unit = {
+  override def save(nbt: NBTTagCompound): Unit = _entries.synchronized {
     super.save(nbt)
 
     nbt.setTagList(EntriesTag, _entries.map(saveEntry(_).asInstanceOf[NBTBase]).asJava)
@@ -127,32 +127,36 @@ class OcelotCardItem(val ocelotCard: OcelotCard)
 
   def messageLimit: Int = _messageLimit
 
-  def messageLimit_=(limit: Int): Unit = {
+  def messageLimit_=(limit: Int): Unit = _entries.synchronized {
     require(limit > 0)
     ensureFreeSpace(_entries.length - limit)
     _messageLimit = limit
   }
 
-  def clear(): Unit = {
+  def entryCount: Int = _entries.synchronized {
+    _entries.length
+  }
+
+  def clear(): Unit = _entries.synchronized {
     val count = _entries.length
     _entries.clear()
     window.onMessagesRemoved(count)
   }
 
-  private def addEntry(entry: LogEntry): Unit = {
+  private def addEntry(entry: LogEntry): Unit = _entries.synchronized {
     ensureFreeSpace(1)
     _entries += entry
-    window.onMessagesAdded(1)
+    window.onMessagesAdded(Some(entry))
   }
 
-  private def addEntries(entries: Seq[LogEntry]): Unit = {
+  private def addEntries(entries: Seq[LogEntry]): Unit = _entries.synchronized {
     ensureFreeSpace(entries.length)
     val prevCount = _entries.length
     _entries ++= entries.view.takeRight(messageLimit)
-    window.onMessagesAdded(_entries.length - prevCount)
+    window.onMessagesAdded(_entries.view.takeRight(_entries.length - prevCount))
   }
 
-  private def ensureFreeSpace(n: Int): Unit = {
+  private def ensureFreeSpace(n: Int): Unit = _entries.synchronized {
     val prevCount = _entries.length
     _entries.takeRightInPlace(messageLimit - n)
     val removedCount = prevCount - _entries.length

src/main/scala/ocelot/desktop/ui/widget/LogWidget.scala

@@ -163,8 +163,6 @@ abstract class LogWidget extends Widget {
     scrollView.scrollToEnd = value
   }
 
-  protected def entries: Iterable[LogEntry]
-
   protected def textWidth: Int
 
   override def minimumSize: Size2D = Size2D(
@@ -175,13 +173,13 @@ abstract class LogWidget extends Widget {
       BorderThickness * 2, // outer border (top + bottom)
   )
 
-  def onEntryAdded(count: Int): Unit = {
-    for (entry <- entries.view.takeRight(count)) {
+  def addEntries(entries: Iterable[LogEntry]): Unit = {
+    for (entry <- entries) {
       MessageListWidget.addEntry(entry)
     }
   }
 
-  def onEntryRemoved(count: Int): Unit = {
+  def removeFirstEntries(count: Int): Unit = {
     MessageListWidget.removeFirst(count)
   }
 

src/main/scala/ocelot/desktop/ui/widget/card/OcelotCardWindow.scala

@@ -12,9 +12,7 @@ class OcelotCardWindow(item: OcelotCardItem) extends PanelWindow {
   override protected def title: String = s"Ocelot card ${item.component.node.address}"
 
   private val logWidget: LogWidget = new LogWidget {
-    override protected def entries: Iterable[LogEntry] = item.entries
     override protected def textWidth: Int = 50
-
     override def minimumSize: Size2D = super.minimumSize.copy(height = 300)
     override def maximumSize: Size2D = minimumSize
   }
@@ -32,7 +30,7 @@ class OcelotCardWindow(item: OcelotCardItem) extends PanelWindow {
     }
 
     children :+= new Label {
-      override def text: String = s"Messages: ${item.entries.length} / ${item.messageLimit}"
+      override def text: String = s"Messages: ${item.entryCount} / ${item.messageLimit}"
     }
 
     children :+= new Widget {
@@ -87,12 +85,12 @@ class OcelotCardWindow(item: OcelotCardItem) extends PanelWindow {
     item.clear()
   }
 
-  def onMessagesAdded(count: Int): Unit = {
-    logWidget.onEntryAdded(count)
+  def onMessagesAdded(entries: Iterable[LogEntry]): Unit = {
+    logWidget.addEntries(entries)
   }
 
   def onMessagesRemoved(count: Int): Unit = {
-    logWidget.onEntryRemoved(count)
+    logWidget.removeFirstEntries(count)
   }
 
   def pushLine(line: String): Unit = {