[platform UI] IJPL-209442 Search Everywhere: show "No exact matches found. Here are similar results" hint in the search field when only semantic search results are listed

GitOrigin-RevId: 6eccd43bb3fb88a9a618df592974917a4926aa36

platform/searchEverywhere/frontend/src/ui/SePopupContentPane.kt

@@ -24,6 +24,7 @@ import com.intellij.openapi.ui.popup.JBPopupFactory
 import com.intellij.openapi.ui.popup.ListItemDescriptorAdapter
 import com.intellij.openapi.util.NlsContexts
 import com.intellij.openapi.util.registry.Registry
+import com.intellij.openapi.util.text.StringUtil
 import com.intellij.platform.searchEverywhere.*
 import com.intellij.platform.searchEverywhere.data.SeDataKeys
 import com.intellij.platform.searchEverywhere.frontend.AutoToggleAction
@@ -122,6 +123,8 @@ class SePopupContentPane(
     private set
   var popupExtendedSize: Dimension? = initPopupExtendedSize
 
+  private val semanticWarning = MutableStateFlow(false)
+
   init {
     layout = GridLayout()
 
@@ -265,6 +268,7 @@ class SePopupContentPane(
                 updateEmptyStatus()
               }
 
+              semanticWarning.value = resultListModel.isValidAndHasOnlySemantic
               updateViewMode()
               autoSelectIndex(searchContext.searchPattern, true)
             }
@@ -345,9 +349,12 @@ class SePopupContentPane(
     }
 
     launch {
-      vm.searchFieldHint.collect { hint ->
+      combine(vm.searchFieldHint, semanticWarning) { searchFieldHint, semanticWarning ->
+        searchFieldHint to semanticWarning
+      }.collect { (searchFieldHint, semanticWarning) ->
         withContext(Dispatchers.EDT) {
-          hint.let { (text, tooltip, isWarning) ->
+          if (searchFieldHint != null) {
+            val (text, tooltip, isWarning) = searchFieldHint
             if (isWarning) {
               hintHelper.setLoadingText(text, tooltip)
             }
@@ -355,6 +362,15 @@ class SePopupContentPane(
               hintHelper.setHint(text)
             }
           }
+          else if (semanticWarning) {
+            val noExactMatchesText = SemanticBundleProvider.getSemanticBundle()?.getMessage("search.everywhere.no.exact.matches")?.let {
+              StringUtil.trimTrailing(it, ':')
+            }
+            hintHelper.setHint(noExactMatchesText)
+          }
+          else {
+            hintHelper.setHint(null)
+          }
         }
       }
     }

platform/searchEverywhere/frontend/src/ui/SeResultListModel.kt

@@ -4,18 +4,22 @@ package com.intellij.platform.searchEverywhere.frontend.ui
 import com.intellij.ide.rpc.ThrottledAccumulatedItems
 import com.intellij.ide.rpc.ThrottledItems
 import com.intellij.ide.rpc.ThrottledOneItem
+import com.intellij.platform.searchEverywhere.SeItemDataKeys
+import com.intellij.platform.searchEverywhere.SeResultAddedEvent
 import com.intellij.platform.searchEverywhere.SeResultEvent
+import com.intellij.platform.searchEverywhere.SeResultReplacedEvent
 import com.intellij.platform.searchEverywhere.frontend.SeSearchStatePublisher
 import com.intellij.platform.searchEverywhere.frontend.vm.SeSearchContext
 import com.intellij.platform.searchEverywhere.providers.SeLog
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
-import org.jetbrains.annotations.ApiStatus
+import org.jetbrains.annotations.ApiStatus.Internal
 import javax.swing.DefaultListModel
 import javax.swing.ListSelectionModel
+import kotlin.text.toBoolean
 
-@ApiStatus.Internal
+@Internal
 class SeResultListModel(private val searchStatePublisher: SeSearchStatePublisher,
                         private val selectionModelProvider: () -> ListSelectionModel): DefaultListModel<SeResultListRow>() {
   val freezer: Freezer = Freezer { size }
@@ -26,16 +30,21 @@ class SeResultListModel(private val searchStatePublisher: SeSearchStatePublisher
 
   val pendingReplacementElementUuids: MutableSet<String> = mutableSetOf()
 
+  var isValidAndHasOnlySemantic: Boolean = false
+    private set
+
   fun reset() {
     SeLog.log(SeLog.THROTTLING) { "Will reset result list model" }
     freezer.reset()
     _isValidState.value = true
     pendingReplacementElementUuids.clear()
     removeAllElements()
+    isValidAndHasOnlySemantic = false
   }
 
   fun invalidate() {
     _isValidState.value = false
+    isValidAndHasOnlySemantic = false
   }
 
   fun removeLoadingItem() {
@@ -47,6 +56,8 @@ class SeResultListModel(private val searchStatePublisher: SeSearchStatePublisher
   fun addFromThrottledEvent(searchContext: SeSearchContext, throttledEvent: ThrottledItems<SeResultEvent>) {
     if (!isValid) reset()
 
+    val wasEmpty = isEmpty
+
     val resultListAdapter = SeResultListModelAdapter(this, selectionModelProvider())
     when (throttledEvent) {
       is ThrottledAccumulatedItems<SeResultEvent> -> {
@@ -83,6 +94,8 @@ class SeResultListModel(private val searchStatePublisher: SeSearchStatePublisher
         })
       }
     }
+
+    isValidAndHasOnlySemantic = (isValidAndHasOnlySemantic || (wasEmpty && !isEmpty)) && throttledEvent.allItemsAreSemantic()
   }
 
   class Freezer(private val listSize: () -> Int) {
@@ -109,4 +122,23 @@ class SeResultListModel(private val searchStatePublisher: SeSearchStatePublisher
       frozenCountToApply = 0
     }
   }
-}
+}
+
+private fun <T : SeResultEvent> ThrottledItems<T>.allItemsAreSemantic(): Boolean =
+  when (this) {
+    is ThrottledAccumulatedItems<T> -> items.all { it.isSemantic() }
+    is ThrottledOneItem<T> -> item.isSemantic()
+  }
+
+private fun SeResultEvent.isSemantic(): Boolean {
+  val itemData = when (this) {
+    is SeResultAddedEvent -> {
+      itemData
+    }
+    is SeResultReplacedEvent -> {
+      newItemData
+    }
+    else -> null
+  }
+  return itemData?.additionalInfo?.get(SeItemDataKeys.IS_SEMANTIC).toBoolean()
+}

platform/searchEverywhere/frontend/src/ui/SemanticBundleProvider.kt

@@ -0,0 +1,30 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.platform.searchEverywhere.frontend.ui
+
+import com.intellij.DynamicBundle
+import com.intellij.ide.plugins.PluginManagerCore
+import com.intellij.openapi.extensions.PluginId
+import org.jetbrains.annotations.ApiStatus
+
+@ApiStatus.Internal
+object SemanticBundleProvider {
+  fun getSemanticBundle(): DynamicBundle? {
+    val pluginId = PluginId.getId("com.intellij.ml.llm")
+    if (!PluginManagerCore.isPluginInstalled(pluginId)) {
+      return null
+    }
+
+    val descriptor = PluginManagerCore.getPlugin(pluginId) ?: return null
+    val classLoader = descriptor.pluginClassLoader
+
+    return try {
+      val clazz = classLoader?.loadClass(
+        "com.intellij.ml.llm.searchEverywhere.embeddings.SemanticSearchBundle"
+      )
+      val instanceField = clazz?.getDeclaredField("INSTANCE")
+      instanceField?.get(null) as DynamicBundle
+    } catch (_: Throwable) {
+      null
+    }
+  }
+}

platform/searchEverywhere/frontend/src/vm/SePopupVm.kt

@@ -66,8 +66,8 @@ class SePopupVm(
 
   data class SearchFieldHint(val text: String?, val tooltip: String?, val isWarning: Boolean)
 
-  private val _searchFieldHint = MutableStateFlow(SearchFieldHint("", null, false))
-  val searchFieldHint: StateFlow<SearchFieldHint> = _searchFieldHint
+  private val _searchFieldHint = MutableStateFlow<SearchFieldHint?>(null)
+  val searchFieldHint: StateFlow<SearchFieldHint?> = _searchFieldHint
 
   private var historyIterator: HistoryIterator = historyList.getIterator(currentTab.tabId)
     get() {
@@ -151,11 +151,10 @@ class SePopupVm(
           SearchFieldHint(IdeBundle.message("incomplete.mode.results.might.be.incomplete"), null, true)
         }
         else {
-          val text = if (currentTab.isCommandsSupported()) {
-            IdeBundle.message("searcheverywhere.textfield.hint", getTopHitAccelerator())
+          if (currentTab.isCommandsSupported()) {
+            SearchFieldHint(IdeBundle.message("searcheverywhere.textfield.hint", getTopHitAccelerator()), null, false)
           }
           else null
-          SearchFieldHint(text, null, false)
         }
       }.distinctUntilChanged().collect {
         _searchFieldHint.value = it