From 186ffa6182d1cf1c281fa6ffdd727acb9e8b3215 Mon Sep 17 00:00:00 2001
From: Sergei Tachenov <Sergei.Tachenov@jetbrains.com>
Date: Wed, 16 Jul 2025 11:59:08 +0300
Subject: [PATCH] IJPL-197188 Fix fallback Switcher hint popup update

PSI_ELEMENT.getData returns an outdated PSI element
if called in-place in the same EDT event the selection changes.
Fix by postponing the update using a state flow.

GitOrigin-RevId: 29ce5db2492e14974887b68b2f044bd2f18de8f9
---
 .../src/com/intellij/ide/actions/Switcher.kt  | 32 +++++++++++++++++--
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/ide/actions/Switcher.kt b/platform/platform-impl/src/com/intellij/ide/actions/Switcher.kt
index e8c1a6e1959c..25912fb25e00 100644
--- a/platform/platform-impl/src/com/intellij/ide/actions/Switcher.kt
+++ b/platform/platform-impl/src/com/intellij/ide/actions/Switcher.kt
@@ -21,9 +21,13 @@ import com.intellij.ide.util.gotoByName.QuickSearchComponent
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.actionSystem.*
 import com.intellij.openapi.actionSystem.ex.ActionUtil
+import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.application.EDT
 import com.intellij.openapi.application.ModalityState
 import com.intellij.openapi.application.ReadAction
+import com.intellij.openapi.application.UiDispatcherKind
+import com.intellij.openapi.application.ui
+import com.intellij.openapi.application.writeIntentReadAction
 import com.intellij.openapi.components.service
 import com.intellij.openapi.fileEditor.FileEditorManager
 import com.intellij.openapi.fileEditor.ex.IdeDocumentHistory
@@ -67,8 +71,12 @@ import com.intellij.util.ui.StartupUiUtil
 import com.intellij.util.ui.SwingTextTrimmer
 import com.intellij.util.ui.accessibility.ScreenReader
 import com.intellij.util.ui.components.BorderLayoutPanel
+import com.intellij.util.ui.launchOnShow
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import org.jetbrains.annotations.ApiStatus
 import org.jetbrains.annotations.Nls
 import org.jetbrains.annotations.NonNls
@@ -279,6 +287,7 @@ object Switcher : BaseSwitcherAction(null) {
         pinned = recent,
       )
       resetListModelAndUpdateNames(filesModel, filesToShow)
+      val selectedItemFlow = MutableStateFlow<SwitcherListItem?>(null)
       val filesSelectionListener = object : ListSelectionListener {
         override fun valueChanged(e: ListSelectionEvent) {
           if (e.valueIsAdjusting) {
@@ -286,9 +295,26 @@ object Switcher : BaseSwitcherAction(null) {
           }
 
           updatePathLabel()
-          val hint = hint
-          val popupUpdater = if (hint == null || !hint.isVisible) null else hint.getUserData(PopupUpdateProcessorBase::class.java)
-          popupUpdater?.updatePopup(CommonDataKeys.PSI_ELEMENT.getData(DataManager.getInstance().getDataContext(this@SwitcherPanel)))
+          selectedItemFlow.value = selectedList?.selectedValue
+        }
+      }
+      launchOnShow("Switcher hint popup updates") {
+        selectedItemFlow.collectLatest { selectedValue ->
+          // launchOnShow uses UI, but it won't do here: updatePopup needs a WIRA.
+          // Still, we'd like to avoid locking until the updatePopup call.
+          // At the same time, we'd like to keep this whole thing in a single EDT event,
+          // otherwise there's a chance that the hint popup may be hidden in between.
+          // So we can't just switch to Dispatchers.EDT, as that will dispatch on a separate event.
+          // Therefore, we use RELAX and take the lock only when necessary.
+          withContext(Dispatchers.ui(UiDispatcherKind.RELAX)) {
+            val hint = hint
+            val popupUpdater = if (hint == null || !hint.isVisible) null else hint.getUserData(PopupUpdateProcessorBase::class.java)
+            if (selectedValue != null && popupUpdater != null) {
+              writeIntentReadAction {
+                popupUpdater.updatePopup(CommonDataKeys.PSI_ELEMENT.getData(DataManager.getInstance().getDataContext(this@SwitcherPanel)))
+              }
+            }
+          }
         }
       }