wip: do not build dialogs before container is attached, still needs tests at the very least

Author: rjrjr

workflow-ui/core-android/src/main/java/com/squareup/workflow1/ui/container/LayeredDialogSessions.kt

@@ -113,6 +113,10 @@ public class LayeredDialogSessions private constructor(
 
   private var sessions: List<DialogSession> = emptyList()
 
+  private var attached = false
+
+  private var earlyUpdate: Pair<List<Overlay>, ViewEnvironment>? = null
+
   public var allowEvents: Boolean = true
     private set(value) {
       val was = field
@@ -140,6 +144,12 @@ public class LayeredDialogSessions private constructor(
     viewEnvironment: ViewEnvironment,
     updateBase: (environment: ViewEnvironment) -> Unit
   ) {
+    if (!attached) {
+      earlyUpdate = Pair(overlays, viewEnvironment)
+      updateBase(viewEnvironment)
+      return
+    }
+
     // Set up a ViewEnvironment with the single DialogCollator instance that handles
     // this entire view hierarchy. See that class for details.
     val envWithDialogManager =
@@ -201,10 +211,15 @@ public class LayeredDialogSessions private constructor(
     savedStateParentKey: String,
     view: View
   ) {
+    attached = true
     stateRegistryAggregator.attachToParentRegistry(
       savedStateParentKey,
       WorkflowAndroidXSupport.stateRegistryOwnerFromViewTreeOrContext(view)
     )
+    earlyUpdate?.let { update ->
+      earlyUpdate = null
+      update(update.first, update.second) { /* Base was already updated. */ }
+    }
   }
 
   /**
@@ -213,6 +228,7 @@ public class LayeredDialogSessions private constructor(
    * Must be matched with a call to [onAttachedToWindow].
    */
   public fun onDetachedFromWindow() {
+    attached = false
     stateRegistryAggregator.detachFromParentRegistry()
   }