Rename some functions in EventListener (#1678)

The 'on' prefix is apporpriate for Redwood's ProtocolMismatchHandler,
which must make policy decisions. In Treehouse we've made those
policy decisions already (ignore mismatches!) and are merely
relaying our decisions as events for observability.

redwood-treehouse-host/src/commonMain/kotlin/app/cash/redwood/treehouse/EventListener.kt

@@ -84,48 +84,61 @@ public open class EventListener {
   }
 
   /**
-   * Invoked on a request to create an unknown widget [kind].
+   * Invoked on a request to create an unknown widget with [tag]. This is a schema mismatch and the
+   * widget is ignored.
    */
-  public open fun onUnknownWidget(
+  public open fun unknownWidget(
     tag: WidgetTag,
   ) {
   }
 
   /**
-   * Invoked on a request to create an unknown modifier [tag].
+   * Invoked on a request to create an unknown modifier with [tag]. This is a schema mismatch and
+   * the modifier is ignored.
    */
-  public open fun onUnknownModifier(
+  public open fun unknownModifier(
     tag: ModifierTag,
   ) {
   }
 
   /**
-   * Invoked on a request to manipulate unknown children [tag] for the specified widget [kind].
+   * Invoked on a request to manipulate unknown children with [tag] for a widget with [widgetTag].
+   * This is a schema mismatch and the child nodes are ignored.
    */
-  public open fun onUnknownChildren(
+  public open fun unknownChildren(
     widgetTag: WidgetTag,
     tag: ChildrenTag,
   ) {
   }
 
   /**
-   * Invoked on a request to set an unknown property [tag] for the specified widget [kind].
+   * Invoked on a request to set an unknown property with [tag] for a widget with [widgetTag]. This
+   * is a schema mismatch and the property is ignored.
    */
-  public open fun onUnknownProperty(
+  public open fun unknownProperty(
     widgetTag: WidgetTag,
     tag: PropertyTag,
   ) {
   }
 
-  /** Invoked on a request to process an unknown event [tag] for the specified widget [widgetTag]. */
-  public open fun onUnknownEvent(
+  /**
+   * Invoked on a request to process an unknown event with [tag] for a widget with [widgetTag]. This
+   * is a schema mismatch and the event is dropped.
+   */
+  public open fun unknownEvent(
     widgetTag: WidgetTag,
     tag: EventTag,
   ) {
   }
 
-  /** Invoked for an event whose node [id] is unknown. */
-  public open fun onUnknownEventNode(
+  /**
+   * Invoked when an event is received on a widget that no longer exists.
+   *
+   * This is a normal artifact of the asynchronous event processing used by Treehouse. For example,
+   * it will occur if a user is still scrolling a `LazyColumn` when it is removed from a layout. The
+   * scroll event is discarded and that's fine.
+   */
+  public open fun unknownEventNode(
     id: Id,
     tag: EventTag,
   ) {
@@ -338,7 +351,7 @@ public open class EventListener {
   }
 
   public companion object {
-    public val NONE: Factory = Factory { app, manifestUrl ->
+    public val NONE: Factory = Factory { _, _ ->
       EventListener()
     }
   }

redwood-treehouse-host/src/commonMain/kotlin/app/cash/redwood/treehouse/RealEventPublisher.kt

@@ -158,28 +158,28 @@ internal class RealEventPublisher(
 
   override val widgetProtocolMismatchHandler = object : ProtocolMismatchHandler {
     override fun onUnknownWidget(tag: WidgetTag) {
-      listener.onUnknownWidget(tag)
+      listener.unknownWidget(tag)
     }
 
     override fun onUnknownModifier(tag: ModifierTag) {
-      listener.onUnknownModifier(tag)
+      listener.unknownModifier(tag)
     }
 
     override fun onUnknownChildren(widgetTag: WidgetTag, tag: ChildrenTag) {
-      listener.onUnknownChildren(widgetTag, tag)
+      listener.unknownChildren(widgetTag, tag)
     }
 
     override fun onUnknownProperty(widgetTag: WidgetTag, tag: PropertyTag) {
-      listener.onUnknownProperty(widgetTag, tag)
+      listener.unknownProperty(widgetTag, tag)
     }
   }
 
   override fun onUnknownEvent(widgetTag: WidgetTag, tag: EventTag) {
-    listener.onUnknownEvent(widgetTag, tag)
+    listener.unknownEvent(widgetTag, tag)
   }
 
   override fun onUnknownEventNode(id: Id, tag: EventTag) {
-    listener.onUnknownEventNode(id, tag)
+    listener.unknownEventNode(id, tag)
   }
 
   override fun onUncaughtException(exception: Throwable) {