[VIM-3577] Replace weak reference to focused editor to needed informa…

…tion

The `editorInFocus` used the weak reference in order to avoid editor leaks. However, if the user is unlucky, the GC may be called in between the console closing and switching focus to the new editor. In this case, the logic breaks and the Editor remains in the insert mode.
Now, we store only the required information about the last used editor.

src/main/java/com/maddyhome/idea/vim/listener/IJEditorFocusListener.kt

@@ -13,6 +13,7 @@ import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.editor.EditorKind
 import com.maddyhome.idea.vim.KeyHandler
+import com.maddyhome.idea.vim.LastUsedEditorInfo
 import com.maddyhome.idea.vim.VimPlugin
 import com.maddyhome.idea.vim.api.ExecutionContext
 import com.maddyhome.idea.vim.api.VimEditor
@@ -31,10 +32,9 @@ import com.maddyhome.idea.vim.state.mode.Mode
  */
 class IJEditorFocusListener : EditorListener {
   override fun focusGained(editor: VimEditor) {
-    val oldEditor = KeyHandler.getInstance().editorInFocus
-    if (oldEditor != null && oldEditor.ij == editor.ij) return
-
-    KeyHandler.getInstance().editorInFocus = editor
+    val oldEditorInfo = KeyHandler.getInstance().lastUsedEditorInfo
+    val currentEditorHashCode = editor.ij.hashCode()
+    if (oldEditorInfo.hash == currentEditorHashCode) return
 
     // We add Vim bindings to all opened editors, including editors used as UI controls rather than just project file
     // editors. This includes editors used as part of the UI, such as the VCS commit message, or used as read-only
@@ -57,15 +57,17 @@ class IJEditorFocusListener : EditorListener {
     // to know that a read-only editor that is hosting a console view with a running process can be treated as writable.
 
     val ijEditor = editor.ij
+    val isCurrentEditorTerminal = isTerminal(ijEditor)
 
+    KeyHandler.getInstance().lastUsedEditorInfo = LastUsedEditorInfo(currentEditorHashCode, isCurrentEditorTerminal)
 
     val switchToInsertMode = Runnable {
       val context: ExecutionContext = injector.executionContextManager.getEditorExecutionContext(editor)
       VimPlugin.getChange().insertBeforeCursor(editor, context)
     }
-    if (isTerminal(ijEditor) && !ijEditor.inInsertMode) {
+    if (isCurrentEditorTerminal && !ijEditor.inInsertMode) {
       switchToInsertMode.run()
-    } else if (ijEditor.isInsertMode && ((oldEditor != null && isTerminal(oldEditor.ij)) || !ijEditor.document.isWritable)) {
+    } else if (ijEditor.isInsertMode && (oldEditorInfo.isTerminal || !ijEditor.document.isWritable)) {
       val context: ExecutionContext = injector.executionContextManager.getEditorExecutionContext(editor)
       val mode = injector.vimState.mode
       when (mode) {

vim-engine/src/main/kotlin/com/maddyhome/idea/vim/KeyHandler.kt

@@ -36,7 +36,6 @@ import com.maddyhome.idea.vim.state.VimStateMachine
 import com.maddyhome.idea.vim.state.mode.Mode
 import com.maddyhome.idea.vim.state.mode.ReturnTo
 import com.maddyhome.idea.vim.state.mode.returnTo
-import java.lang.ref.WeakReference
 import javax.swing.KeyStroke
 
 /**
@@ -47,7 +46,6 @@ import javax.swing.KeyStroke
 // 1. avoid using handleKeyRecursionCount & shouldRecord
 // 2. maybe we can live without allowKeyMappings: Boolean & mappingCompleted: Boolean
 class KeyHandler {
-  private var editorInFocusReference: WeakReference<VimEditor>? = null
   private val keyConsumers: List<KeyConsumer> = listOf(ModalInputConsumer(), MappingProcessor, CommandCountConsumer(), DeleteCommandConsumer(), EditorResetConsumer(), CharArgumentConsumer(), RegisterConsumer(), DigraphConsumer(), CommandConsumer(), SelectRegisterConsumer(), ModeInputConsumer())
   private var handleKeyRecursionCount = 0
 
@@ -64,11 +62,7 @@ class KeyHandler {
   val keyStack: KeyStack = KeyStack()
   val modalEntryKeys: MutableList<KeyStroke> = ArrayList()
 
-  var editorInFocus: VimEditor?
-    get() = editorInFocusReference?.get()
-    set(value) {
-      editorInFocusReference = WeakReference(value)
-    }
+  var lastUsedEditorInfo: LastUsedEditorInfo = LastUsedEditorInfo(-1, false)
 
   /**
    * This is the main key handler for the Vim plugin. Every keystroke not handled directly by Idea is sent here for
@@ -482,3 +476,8 @@ sealed interface KeyProcessResult {
 }
 
 typealias KeyProcessing = (KeyHandlerState, VimEditor, ExecutionContext) -> Unit
+
+data class LastUsedEditorInfo(
+  val hash: Int,
+  val isTerminal: Boolean,
+)