[terminal] IJPL-212254 Do not store terminal tabs in a separate list

Let's use tool window content manager as a single source of truth about opened tabs.

(cherry picked from commit a801410428988c3993472c89c1ef1dd2905053d0)

IJ-CR-214214

GitOrigin-RevId: 014c48801f8739b593e07b28a13cd16528aad070

plugins/terminal/frontend/src/com/intellij/terminal/frontend/toolwindow/TerminalToolWindowTab.kt

@@ -1,5 +1,6 @@
 package com.intellij.terminal.frontend.toolwindow
 
+import com.intellij.openapi.util.Key
 import com.intellij.terminal.frontend.view.TerminalView
 import com.intellij.ui.content.Content
 import org.jetbrains.annotations.ApiStatus
@@ -38,4 +39,8 @@ interface TerminalToolWindowTab {
    * Terminal process startup options that were specified in the [TerminalToolWindowTabBuilder].
    */
   val processOptions: TerminalRequestedProcessOptions
+
+  companion object {
+    val KEY: Key<TerminalToolWindowTab> = Key.create("TerminalToolWindowTab")
+  }
 }

plugins/terminal/frontend/src/com/intellij/terminal/frontend/toolwindow/impl/TerminalToolWindowTabsManagerImpl.kt

@@ -62,10 +62,8 @@ internal class TerminalToolWindowTabsManagerImpl(
   private val project: Project,
   private val coroutineScope: CoroutineScope,
 ) : TerminalToolWindowTabsManager {
-  private val mutableTabs: MutableList<TerminalToolWindowTab> = mutableListOf()
-
   override val tabs: List<TerminalToolWindowTab>
-    get() = mutableTabs.toList()
+    get() = getToolWindow().contentManager.contentsRecursively.mapNotNull { it.getUserData(TerminalToolWindowTab.KEY) }
 
   private var tabsRestoredDeferred: Deferred<Unit> = CompletableDeferred(Unit)
 
@@ -123,7 +121,6 @@ internal class TerminalToolWindowTabsManagerImpl(
     processOptions: TerminalRequestedProcessOptions,
   ): TerminalToolWindowTab {
     val tab = doCreateTab(view, closeOnProcessTermination, processOptions)
-    addToTabsList(tab)
     addTabToToolWindow(tab, contentManager, true)
     return tab
   }
@@ -159,7 +156,6 @@ internal class TerminalToolWindowTabsManagerImpl(
       closeOnProcessTermination = builder.closeOnProcessTermination,
       processOptions = builder.getRequestedProcessOptions()
     )
-    addToTabsList(tab)
     if (builder.shouldAddToToolWindow) {
       addTabToToolWindow(tab, builder.contentManager, builder.requestFocus)
       ReworkedTerminalUsageCollector.logTabOpened(
@@ -225,7 +221,9 @@ internal class TerminalToolWindowTabsManagerImpl(
       manager.removeContent(content, true)
     }
 
-    return TerminalToolWindowTabImpl(terminal, content, closeOnProcessTermination, processOptions)
+    val tab = TerminalToolWindowTabImpl(terminal, content, closeOnProcessTermination, processOptions)
+    content.putUserData(TerminalToolWindowTab.KEY, tab)
+    return tab
   }
 
   private fun addTabToToolWindow(
@@ -251,13 +249,6 @@ internal class TerminalToolWindowTabsManagerImpl(
     project.messageBus.syncPublisher(TerminalTabsManagerListener.TOPIC).tabAdded(tab)
   }
 
-  private fun addToTabsList(tab: TerminalToolWindowTab) {
-    mutableTabs.add(tab)
-    Disposer.register(tab.content) {
-      mutableTabs.remove(tab)
-    }
-  }
-
   private fun createTerminalViewAndStartSession(builder: TerminalToolWindowTabBuilderImpl): TerminalView {
     val viewOptions = TerminalViewBuilderOptions(
       processOptions = builder.getRequestedProcessOptions(),