fix(jetbrains): support copying session text

2026-09-21 05:52:35 +08:00 · 2026-06-02 10:31:45 -04:00
parent bee54755ff
commit 2a3975ea29
22 changed files with 658 additions and 36 deletions
@@ -0,0 +1,5 @@
+---
+"kilo-code": patch
+---
+
+Support coherent selection and copy behavior across JetBrains session transcript fragments.
@@ -22,6 +22,7 @@ import ai.kilocode.client.session.ui.account.SessionAccountOverlay
 import ai.kilocode.client.session.ui.SessionRootPanel
 import ai.kilocode.client.session.ui.SessionMessageListPanel
 import ai.kilocode.client.session.ui.header.SessionHeaderPanel
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.session.controller.EVENT_FLUSH_MS
@@ -38,6 +39,11 @@ import ai.kilocode.log.ChatLogSummary
 import com.intellij.util.ui.JBUI
 import ai.kilocode.log.KiloLog
 import com.intellij.ide.BrowserUtil
+import com.intellij.ide.TextCopyProvider
+import com.intellij.openapi.actionSystem.ActionUpdateThread
+import com.intellij.openapi.actionSystem.DataSink
+import com.intellij.openapi.actionSystem.PlatformDataKeys
+import com.intellij.openapi.actionSystem.UiDataProvider
 import com.intellij.ide.ui.LafManagerListener
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.application.ApplicationManager
@@ -79,7 +85,7 @@ class SessionUi(
    private val manager: SessionManager? = null,
    private val workspaces: KiloWorkspaceService = service(),
    private val migration: MigrationUiController = service<KiloMigrationService>(),
-) : JPanel(BorderLayout()), Disposable, SessionEditorStyleTarget {
+) : JPanel(BorderLayout()), Disposable, SessionEditorStyleTarget, UiDataProvider {

    companion object {
        private val LOG = KiloLog.create(SessionUi::class.java)
@@ -143,12 +149,22 @@ class SessionUi(
    private var empty: EmptySessionPanel? = null
    private var modalFocus: (() -> JComponent)? = null
    private var style = SessionEditorStyle.current()
+    private val selection = SessionSelection()
+    private val copy = object : TextCopyProvider() {
+        override fun getActionUpdateThread() = ActionUpdateThread.EDT
+
+        override fun getTextLinesToCopy(): Collection<String>? {
+            val text = selection.selectedText()?.takeIf { it.isNotEmpty() } ?: return null
+            return listOf(text)
+        }
+    }
    private var editorTheme = style.editorScheme
    private var colorTheme = UIManager.getLookAndFeel()
    private var disposed = false

    init {
        buildUi()
+        Disposer.register(this, selection)
        scroll.show(body(controller.model.state))
        bindUi()
        bindStyle()
@@ -178,6 +194,10 @@ class SessionUi(

    internal fun currentStyle() = style

+    override fun uiDataSnapshot(sink: DataSink) {
+        sink[PlatformDataKeys.COPY_PROVIDER] = copy
+    }
+
    @RequiresEdt
    internal fun canDisposeInactive(): Boolean = controller.model.state is SessionState.Idle

@@ -259,12 +279,18 @@ class SessionUi(
            reject = { id -> controller.rejectQuestion(id) },
            follow = { scroll.following() },
            scroll = { scroll.followBottom(it) },
+            selection = selection,
        )
        permission = PermissionView(
            reply = { id, dto -> controller.replyPermission(id, dto) },
+            selection = selection,
        )
-        login = LoginRequiredView(openProfile = { controller.openProfile() }, dismiss = { controller.dismissLoginRequired() })
-        messageBody = SessionMessageListPanel(controller.model, this, question, permission, login, ::openFile, ::openUrl)
+        login = LoginRequiredView(
+            openProfile = { controller.openProfile() },
+            dismiss = { controller.dismissLoginRequired() },
+            selection = selection,
+        )
+        messageBody = SessionMessageListPanel(controller.model, this, question, permission, login, ::openFile, ::openUrl, selection)
        header = SessionHeaderPanel(controller, this)

        scroll = SessionScroll(root, sessionContent, messageBody, blankBody)
@@ -524,6 +550,7 @@ class SessionUi(

    override fun applyStyle(style: SessionEditorStyle) {
        this.style = style
+        selection.applyStyle(style)
        editorTheme = style.editorScheme
        colorTheme = UIManager.getLookAndFeel()
        background = style.editorBackground
@@ -5,6 +5,7 @@ import ai.kilocode.client.session.model.SessionModelEvent
 import ai.kilocode.client.session.model.SessionState
 import ai.kilocode.client.session.model.ToolCallRef
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import ai.kilocode.client.session.views.LoginRequiredView
@@ -49,6 +50,7 @@ class SessionMessageListPanel(
    private val login: LoginRequiredView? = null,
    private val openFile: (String) -> Unit,
    private val openUrl: (String) -> Unit = {},
+    private val selection: SessionSelection? = null,
 ) : SessionLayoutPanel(
    JBUI.scale(SessionUiStyle.SessionLayout.GAP),
    JBUI.insets(
@@ -177,7 +179,7 @@ class SessionMessageListPanel(
    // ------ private event handlers ------

    private fun onTurnAdded(turn: ai.kilocode.client.session.model.Turn) {
-        val tv = TurnView(turn.id, openFile, style, openUrl)
+        val tv = TurnView(turn.id, openFile, style, openUrl, selection)
        turnViews[turn.id] = tv
        for (msgId in turn.messageIds) {
            val msg = model.message(msgId) ?: continue
@@ -233,7 +235,7 @@ class SessionMessageListPanel(
        removeAll()

        for (turn in model.turns()) {
-            val tv = TurnView(turn.id, openFile, style, openUrl)
+            val tv = TurnView(turn.id, openFile, style, openUrl, selection)
            turnViews[turn.id] = tv
            for (msgId in turn.messageIds) {
                val msg = model.message(msgId) ?: continue
@@ -0,0 +1,255 @@
+package ai.kilocode.client.session.ui.selection
+
+import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import com.intellij.openapi.Disposable
+import com.intellij.openapi.editor.colors.EditorColors
+import com.intellij.openapi.editor.event.SelectionEvent
+import com.intellij.openapi.editor.event.SelectionListener
+import com.intellij.openapi.editor.ex.EditorEx
+import com.intellij.openapi.util.Disposer
+import com.intellij.ui.EditorTextField
+import com.intellij.util.concurrency.annotations.RequiresEdt
+import java.awt.Color
+import java.awt.event.MouseAdapter
+import java.awt.event.MouseEvent
+import javax.swing.event.CaretEvent
+import javax.swing.event.CaretListener
+import javax.swing.text.JTextComponent
+
+class SessionSelection : Disposable {
+    private val items = linkedSetOf<Item>()
+    private var active: Item? = null
+    private var style: SessionEditorStyle? = null
+    private var clearing = false
+    private var disposed = false
+
+    @RequiresEdt
+    fun selectedText(): String? {
+        active?.selectedText()?.takeIf { it.isNotEmpty() }?.let { return it }
+        val item = items.toList().asReversed().firstOrNull { !it.selectedText().isNullOrEmpty() }
+        if (item == null) {
+            active = null
+            return null
+        }
+        active = item
+        clearExcept(item)
+        return item.selectedText()?.takeIf { it.isNotEmpty() }
+    }
+
+    @RequiresEdt
+    fun register(component: JTextComponent, parent: Disposable? = null): Disposable {
+        val item = TextItem(component)
+        add(item, parent)
+        return item
+    }
+
+    @RequiresEdt
+    fun register(field: EditorTextField, parent: Disposable? = null): Disposable {
+        val item = FieldItem(field)
+        add(item, parent)
+        return item
+    }
+
+    @RequiresEdt
+    fun register(editor: EditorEx, parent: Disposable? = null): Disposable {
+        val item = EditorItem(editor)
+        add(item, parent)
+        return item
+    }
+
+    @RequiresEdt
+    private fun clearExcept(item: Item) {
+        if (clearing) return
+        clearing = true
+        try {
+            for (entry in items) {
+                if (entry !== item) entry.clearSelection()
+            }
+        } finally {
+            clearing = false
+        }
+    }
+
+    @RequiresEdt
+    fun clear() {
+        if (clearing) return
+        clearing = true
+        try {
+            for (entry in items) entry.clearSelection()
+            active = null
+        } finally {
+            clearing = false
+        }
+    }
+
+    @RequiresEdt
+    fun applyStyle(style: SessionEditorStyle) {
+        this.style = style
+        for (item in items) item.applyStyle(style)
+    }
+
+    @RequiresEdt
+    override fun dispose() {
+        disposed = true
+        clear()
+        val copy = items.toList()
+        for (item in copy) item.dispose()
+        items.clear()
+        active = null
+    }
+
+    @RequiresEdt
+    private fun add(item: Item, parent: Disposable?) {
+        if (disposed) return
+        items.add(item)
+        style?.let(item::applyStyle)
+        parent?.let { Disposer.register(it, item) }
+    }
+
+    @RequiresEdt
+    private fun changed(item: Item) {
+        if (clearing || item.disposed) return
+        if (!items.contains(item)) return
+        if (!item.selectedText().isNullOrEmpty()) {
+            active = item
+            clearExcept(item)
+            return
+        }
+        if (active === item) active = null
+    }
+
+    @RequiresEdt
+    private fun started(item: Item) {
+        if (clearing || item.disposed) return
+        if (!items.contains(item)) return
+        active = item
+        clearExcept(item)
+    }
+
+    private interface Item : Disposable {
+        val disposed: Boolean
+        fun selectedText(): String?
+        fun clearSelection()
+        fun applyStyle(style: SessionEditorStyle)
+    }
+
+    private inner class TextItem(private val component: JTextComponent) : Item, CaretListener {
+        private val mouse = object : MouseAdapter() {
+            override fun mousePressed(e: MouseEvent) = started(this@TextItem)
+        }
+
+        override var disposed = false
+            private set
+
+        init {
+            component.caret.isSelectionVisible = true
+            component.caret.isVisible = false
+            component.isFocusable = true
+            component.isRequestFocusEnabled = true
+            component.addCaretListener(this)
+            component.addMouseListener(mouse)
+        }
+
+        override fun caretUpdate(e: CaretEvent) = changed(this)
+
+        override fun selectedText(): String? = component.selectedText
+
+        override fun clearSelection() {
+            val pos = component.selectionStart.coerceIn(0, component.document.length)
+            component.select(pos, pos)
+        }
+
+        override fun applyStyle(style: SessionEditorStyle) {
+            selectionColors(style, component.selectionColor, component.selectedTextColor).let {
+                component.selectionColor = it.first
+                component.selectedTextColor = it.second
+            }
+        }
+
+        override fun dispose() {
+            if (disposed) return
+            disposed = true
+            component.removeCaretListener(this)
+            component.removeMouseListener(mouse)
+            if (active === this) active = null
+            items.remove(this)
+        }
+    }
+
+    private inner class FieldItem(private val field: EditorTextField) : Item, SelectionListener {
+        private var editor: EditorEx? = null
+        private var reg: Disposable? = null
+        override var disposed = false
+            private set
+
+        init {
+            field.getEditor(false)?.let(::bind)
+            field.addSettingsProvider { ed -> bind(ed) }
+        }
+
+        override fun selectedText(): String? = editor?.selectionModel?.selectedText
+
+        override fun clearSelection() {
+            editor?.selectionModel?.removeSelection()
+        }
+
+        override fun applyStyle(style: SessionEditorStyle) {
+            editor?.let(style::applyToEditor)
+        }
+
+        override fun selectionChanged(e: SelectionEvent) = changed(this)
+
+        override fun dispose() {
+            if (disposed) return
+            disposed = true
+            reg?.let(Disposer::dispose)
+            reg = null
+            editor = null
+            if (active === this) active = null
+            items.remove(this)
+        }
+
+        private fun bind(editor: EditorEx) {
+            if (disposed || this.editor != null) return
+            this.editor = editor
+            val disposable = Disposer.newDisposable("Session selection editor")
+            reg = disposable
+            editor.selectionModel.addSelectionListener(this, disposable)
+            style?.let(::applyStyle)
+        }
+    }
+
+    private inner class EditorItem(private val editor: EditorEx) : Item, SelectionListener {
+        override var disposed = false
+            private set
+
+        init {
+            editor.selectionModel.addSelectionListener(this, this)
+        }
+
+        override fun selectionChanged(e: SelectionEvent) = changed(this)
+
+        override fun selectedText(): String? = editor.selectionModel.selectedText
+
+        override fun clearSelection() {
+            editor.selectionModel.removeSelection()
+        }
+
+        override fun applyStyle(style: SessionEditorStyle) {
+            style.applyToEditor(editor)
+        }
+
+        override fun dispose() {
+            if (disposed) return
+            disposed = true
+            if (active === this) active = null
+            items.remove(this)
+        }
+    }
+
+    private fun selectionColors(style: SessionEditorStyle, bg: Color?, fg: Color?): Pair<Color, Color> {
+        val scheme = style.editorScheme
+        return (scheme.getColor(EditorColors.SELECTION_BACKGROUND_COLOR) ?: bg ?: style.editorBackground) to
+            (scheme.getColor(EditorColors.SELECTION_FOREGROUND_COLOR) ?: fg ?: style.editorForeground)
+    }
+}
@@ -3,6 +3,7 @@ package ai.kilocode.client.session.views
 import ai.kilocode.client.plugin.KiloBundle
 import ai.kilocode.client.session.ui.SessionView
 import ai.kilocode.client.session.views.base.BaseQuestionView
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import com.intellij.util.concurrency.annotations.RequiresEdt
@@ -21,11 +22,12 @@ import javax.swing.JButton
 class LoginRequiredView(
    private val openProfile: () -> Unit,
    private val dismiss: () -> Unit,
+    selection: SessionSelection? = null,
 ) : BorderLayoutPanel(), SessionEditorStyleTarget, SessionView {

    override val sessionViewKind = SessionView.Kind.Default

-    private val card = BaseQuestionView()
+    private val card = BaseQuestionView(selection)

    private val ID_DISMISS = "dismiss"
    private val ID_OPEN = "open"
@@ -8,6 +8,7 @@ import ai.kilocode.client.session.model.ToolCallRef
 import ai.kilocode.client.session.model.ToolExecState
 import ai.kilocode.client.session.ui.SessionView
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.session.views.base.PartView
 import ai.kilocode.client.session.ui.style.SessionUiStyle
@@ -34,6 +35,7 @@ class MessageView(
    private val openFile: (String) -> Unit,
    private var style: SessionEditorStyle = SessionEditorStyle.current(),
    private val openUrl: (String) -> Unit = {},
+    private val selection: SessionSelection? = null,
 ) : ai.kilocode.client.session.ui.SessionLayoutPanel(
    JBUI.scale(SessionUiStyle.SessionLayout.GAP),
 ), Disposable, SessionEditorStyleTarget, SessionView {
@@ -174,9 +176,9 @@ class MessageView(
    }

    private fun view(content: Content) = if (msg.info.role == SessionUiStyle.View.Message.USER_ROLE) {
-        ViewFactory.createUser(content, openFile, openUrl)
+        ViewFactory.createUser(content, openFile, openUrl, selection)
    } else {
-        ViewFactory.create(content, openFile, openUrl)
+        ViewFactory.create(content, openFile, openUrl, selection)
    }

    /** Append a streaming delta to the renderer for [contentId]. */
@@ -5,12 +5,15 @@ import ai.kilocode.client.session.model.Content
 import ai.kilocode.client.session.model.Tool
 import ai.kilocode.client.session.model.ToolExecState
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.views.base.PartView
 import ai.kilocode.client.ui.md.MdViewFactory
 import com.intellij.openapi.util.Disposer
 import java.awt.BorderLayout

-class PlanExitView(tool: Tool, openFile: (String) -> Unit) : PartView() {
+class PlanExitView(tool: Tool, openFile: (String) -> Unit, selection: SessionSelection? = null) : PartView() {
+    constructor(tool: Tool, openFile: (String) -> Unit) : this(tool, openFile, null)
+
    companion object {
        fun canRender(tool: Tool): Boolean = tool.name == "plan_exit" && tool.state == ToolExecState.COMPLETED
    }
@@ -18,7 +21,7 @@ class PlanExitView(tool: Tool, openFile: (String) -> Unit) : PartView() {
    override val contentId: String = tool.id

    private var item = tool
-    private val md = MdViewFactory.create(SessionEditorStyle.current())
+    private val md = MdViewFactory.create(SessionEditorStyle.current(), selection)

    init {
        layout = BorderLayout()
@@ -6,6 +6,7 @@ import ai.kilocode.client.plugin.KiloBundle
 import ai.kilocode.client.session.model.Content
 import ai.kilocode.client.session.model.Reasoning
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import ai.kilocode.client.session.views.base.SecondarySessionPartView
 import ai.kilocode.client.ui.UiStyle
@@ -28,7 +29,8 @@ import javax.swing.Scrollable
 class ReasoningView(
    reasoning: Reasoning,
    openUrl: (String) -> Unit = {},
-    private val parts: ReasoningParts = reasoningParts(),
+    selection: SessionSelection? = null,
+    private val parts: ReasoningParts = reasoningParts(selection),
 ) :
    SecondarySessionPartView(parts.header, parts.scroll) {

@@ -133,8 +135,8 @@ class ReasoningParts(
    val icon: JBLabel,
 )

-private fun reasoningParts(): ReasoningParts {
-    val md = MdViewFactory.create(SessionEditorStyle.current())
+private fun reasoningParts(selection: SessionSelection? = null): ReasoningParts {
+    val md = MdViewFactory.create(SessionEditorStyle.current(), selection)
    val panel = TrackPanel().apply {
        isOpaque = true
        background = SessionUiStyle.View.surface()
@@ -3,6 +3,7 @@ package ai.kilocode.client.session.views
 import ai.kilocode.client.session.model.Content
 import ai.kilocode.client.session.model.Text
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.views.base.PartView
 import ai.kilocode.client.ui.md.MdView
 import ai.kilocode.client.ui.md.MdViewFactory
@@ -18,11 +19,12 @@ class TextView(
    text: Text,
    transparent: Boolean = false,
    openUrl: (String) -> Unit = {},
+    selection: SessionSelection? = null,
 ) : PartView() {

    override val contentId: String = text.id

-    val md: MdView = MdViewFactory.create(SessionEditorStyle.current())
+    val md: MdView = MdViewFactory.create(SessionEditorStyle.current(), selection)

    init {
        layout = BorderLayout()
@@ -8,6 +8,7 @@ import ai.kilocode.client.session.model.Tool
 import ai.kilocode.client.session.model.ToolExecState
 import ai.kilocode.client.session.model.ToolKind
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import ai.kilocode.client.session.views.base.SecondarySessionPartView
 import ai.kilocode.client.ui.UiStyle
@@ -32,7 +33,11 @@ import javax.swing.JPanel
 import javax.swing.ScrollPaneConstants

 /** Renders non-read tool calls with VS Code-inspired rows/cards. */
-class ToolView(tool: Tool, private val parts: ToolParts = toolParts(tool)) :
+class ToolView(
+    tool: Tool,
+    private val selection: SessionSelection? = null,
+    private val parts: ToolParts = toolParts(tool),
+) :
    SecondarySessionPartView(parts.header, parts.scroll) {

    override val contentId: String = tool.id
@@ -41,6 +46,7 @@ class ToolView(tool: Tool, private val parts: ToolParts = toolParts(tool)) :
    private var style = SessionEditorStyle.current()

    init {
+        selection?.register(parts.text, this)
        bindHeader(parts.glyph, parts.title, parts.sub, parts.state, parts.center, parts.controls, parts.slot)
        parts.text.text = preview(item)
        applyStyle(style)
@@ -147,6 +153,7 @@ class ToolView(tool: Tool, private val parts: ToolParts = toolParts(tool)) :
 class ReadToolView(
    tool: Tool,
    openFile: (String) -> Unit = {},
+    private val selection: SessionSelection? = null,
    private val parts: ToolParts = toolParts(tool, openFile),
 ) : SecondarySessionPartView(parts.header, parts.scroll, expandable = false) {

@@ -160,6 +167,7 @@ class ReadToolView(
    private var style = SessionEditorStyle.current()

    init {
+        selection?.register(parts.text, this)
        bindHeader(parts.glyph, parts.title, parts.sub, parts.state, parts.center, parts.controls, parts.slot)
        parts.text.text = preview(item)
        applyStyle(style)
@@ -322,7 +330,7 @@ private fun toolParts(tool: Tool, openFile: ((String) -> Unit)? = null): ToolPar
    val text = JBTextArea().apply {
        isEditable = false
        caret.isVisible = false
-        caret.isSelectionVisible = false
+        caret.isSelectionVisible = true
        lineWrap = true
        wrapStyleWord = true
        foreground = if (tool.state == ToolExecState.ERROR) UiStyle.Colors.errorLabelForeground() else UiStyle.Colors.fg()
@@ -3,6 +3,7 @@ package ai.kilocode.client.session.views
 import ai.kilocode.client.session.model.Message
 import ai.kilocode.client.session.ui.SessionLayoutPanel
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import com.intellij.openapi.Disposable
@@ -23,6 +24,7 @@ class TurnView(
    private val openFile: (String) -> Unit,
    private var style: SessionEditorStyle = SessionEditorStyle.current(),
    private val openUrl: (String) -> Unit = {},
+    private val selection: SessionSelection? = null,
 ) : SessionLayoutPanel(JBUI.scale(SessionUiStyle.SessionLayout.GAP)), Disposable, SessionEditorStyleTarget {

    constructor(id: String, openFile: (String) -> Unit) : this(id, openFile, SessionEditorStyle.current())
@@ -35,7 +37,7 @@ class TurnView(

    /** Add a new [MessageView] for [msg] at the end of this turn. */
    fun addMessage(msg: Message): MessageView {
-        val view = MessageView(msg, openFile, style, openUrl)
+        val view = MessageView(msg, openFile, style, openUrl, selection)
        messages[msg.info.id] = view
        add(view)
        revalidate()
@@ -3,6 +3,7 @@ package ai.kilocode.client.session.views
 import ai.kilocode.client.session.views.base.GenericView
 import ai.kilocode.client.session.views.base.PartView
 import ai.kilocode.client.session.views.question.QuestionResultView
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.model.Compaction
 import ai.kilocode.client.session.model.Content
 import ai.kilocode.client.session.model.Generic
@@ -21,32 +22,56 @@ import ai.kilocode.client.session.views.todo.TodoWriteView
 * 3. Add a branch here — the exhaustive `when` will surface the gap as a compile error.
 */
 object ViewFactory {
+    fun create(
+        content: Content,
+        openFile: (String) -> Unit,
+    ): PartView = create(content, openFile, openUrl = {}, selection = null)
+
+    fun create(
+        content: Content,
+        openFile: (String) -> Unit,
+        openUrl: (String) -> Unit,
+    ): PartView = create(content, openFile, openUrl, selection = null)
+
    fun create(
        content: Content,
        openFile: (String) -> Unit,
        openUrl: (String) -> Unit = {},
+        selection: SessionSelection? = null,
    ): PartView = when (content) {
-        is Text -> TextView(content, openUrl = openUrl)
-        is Reasoning -> ReasoningView(content, openUrl = openUrl)
+        is Text -> TextView(content, openUrl = openUrl, selection = selection)
+        is Reasoning -> ReasoningView(content, openUrl = openUrl, selection = selection)
        is Tool -> when {
            TodoWriteView.canRender(content) -> TodoWriteView(content)
-            PlanExitView.canRender(content) -> PlanExitView(content, openFile)
-            QuestionResultView.canRender(content) -> QuestionResultView(content)
-            ReadToolView.canRender(content) -> ReadToolView(content, openFile)
-            else -> ToolView(content)
+            PlanExitView.canRender(content) -> PlanExitView(content, openFile, selection)
+            QuestionResultView.canRender(content) -> QuestionResultView(content, selection)
+            ReadToolView.canRender(content) -> ReadToolView(content, openFile, selection = selection)
+            else -> ToolView(content, selection = selection)
        }
        is Compaction -> CompactionView(content)
        is StepFinish -> error("step-finish is timeline-only")
        is Generic -> GenericView(content)
    }

+    fun createUser(
+        content: Content,
+        openFile: (String) -> Unit,
+    ): PartView = createUser(content, openFile, openUrl = {}, selection = null)
+
+    fun createUser(
+        content: Content,
+        openFile: (String) -> Unit,
+        openUrl: (String) -> Unit,
+    ): PartView = createUser(content, openFile, openUrl, selection = null)
+
    fun createUser(
        content: Content,
        openFile: (String) -> Unit,
        openUrl: (String) -> Unit = {},
+        selection: SessionSelection? = null,
    ): PartView = when (content) {
-        is Text -> TextView(content, transparent = true, openUrl = openUrl)
-        else -> create(content, openFile, openUrl)
+        is Text -> TextView(content, transparent = true, openUrl = openUrl, selection = selection)
+        else -> create(content, openFile, openUrl, selection)
    }

    /**
@@ -1,6 +1,7 @@
 package ai.kilocode.client.session.views.base

 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import ai.kilocode.client.ui.RoundedContentPanel
@@ -37,7 +38,9 @@ import javax.swing.JPanel
 * Call [setTopPanel], [setHeaderIcon], [setHeader], [setDescription],
 * [setContent], [setActions], or [setActionEnabled] to configure the card.
 */
-class BaseQuestionView : RoundedContentPanel(
+class BaseQuestionView(
+    private val selection: SessionSelection? = null,
+) : RoundedContentPanel(
    UiStyle.Gap.lg(),
    UiStyle.Gap.pad(),
 ), SessionEditorStyleTarget {
@@ -352,6 +355,7 @@ class BaseQuestionView : RoundedContentPanel(
            alignmentX = Component.LEFT_ALIGNMENT
        }
        tracked.add(area to bold)
+        selection?.register(area)
        applyFont(area, bold)
        return area
    }
@@ -6,6 +6,7 @@ import ai.kilocode.client.session.model.PermissionFileDiff
 import ai.kilocode.client.session.model.PermissionRequestState
 import ai.kilocode.client.session.ui.SessionView
 import ai.kilocode.client.session.views.base.BaseQuestionView
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.session.ui.style.SessionUiStyle
@@ -17,6 +18,8 @@ import ai.kilocode.client.ui.layout.VAlign
 import ai.kilocode.client.ui.layout.align
 import ai.kilocode.rpc.dto.PermissionReplyDto
 import com.intellij.icons.AllIcons
+import com.intellij.openapi.Disposable
+import com.intellij.openapi.util.Disposer
 import com.intellij.ui.ColorUtil
 import com.intellij.ui.components.JBHtmlPane
 import com.intellij.ui.components.JBHtmlPaneConfiguration
@@ -42,18 +45,20 @@ import javax.swing.text.html.StyleSheet
 */
 class PermissionView(
    private val reply: (String, PermissionReplyDto) -> Unit,
+    private val selection: SessionSelection? = null,
 ) : BorderLayoutPanel(), SessionEditorStyleTarget, SessionView {
    override val sessionViewKind = SessionView.Kind.Default

    private var requestId: String? = null
    private var style = SessionEditorStyle.current()

-    private val card = BaseQuestionView()
+    private val card = BaseQuestionView(selection)

    private val body = Stack.vertical()

    // Track target panes for style updates
    private val panes = mutableListOf<JBHtmlPane>()
+    private val regs = mutableListOf<Disposable>()
    private val diffViews = mutableListOf<PermissionDiffView>()

    private val ID_DENY = "deny"
@@ -79,6 +84,7 @@ class PermissionView(
        card.setHeader(KiloBundle.message("session.permission.title"))

        body.removeAll()
+        disposeRegs()
        panes.clear()
        diffViews.clear()

@@ -102,6 +108,7 @@ class PermissionView(
    fun hideView() {
        requestId = null
        body.removeAll()
+        disposeRegs()
        panes.clear()
        diffViews.clear()
        isVisible = false
@@ -158,10 +165,11 @@ class PermissionView(
        },
    ).apply {
        isEditable = false
-        isOpaque = true
-        this.text = "<html><body><pre>${XmlStringUtil.escapeString(text)}</pre></body></html>"
-        applyTargetPane(this)
-    }
+            isOpaque = true
+            this.text = "<html><body><pre>${XmlStringUtil.escapeString(text)}</pre></body></html>"
+            applyTargetPane(this)
+            selection?.register(this)?.let(regs::add)
+        }

    private fun applyTargetPane(pane: JBHtmlPane) {
        pane.font = style.transcriptFont
@@ -244,6 +252,11 @@ class PermissionView(
        parent?.repaint()
    }

+    private fun disposeRegs() {
+        regs.forEach(Disposer::dispose)
+        regs.clear()
+    }
+
    // Test helpers
    internal fun runButtonForTest() = buttons(card).first { it.text == KiloBundle.message("session.permission.run") }
    internal fun denyButtonForTest() = buttons(card).first { it.text == KiloBundle.message("session.permission.deny") }
@@ -3,12 +3,15 @@ package ai.kilocode.client.session.views.question
 import ai.kilocode.client.plugin.KiloBundle
 import ai.kilocode.client.session.model.Content
 import ai.kilocode.client.session.model.Tool
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import ai.kilocode.client.session.views.base.PartView
 import ai.kilocode.client.session.views.ToolView
 import ai.kilocode.client.ui.UiStyle
 import com.intellij.icons.AllIcons
+import com.intellij.openapi.Disposable
+import com.intellij.openapi.util.Disposer
 import com.intellij.ui.components.JBLabel
 import com.intellij.ui.components.JBTextArea
 import com.intellij.util.ui.JBUI
@@ -25,13 +28,14 @@ import javax.swing.BoxLayout
 import javax.swing.JPanel
 import javax.swing.SwingUtilities

-class QuestionResultView(tool: Tool) : PartView() {
+class QuestionResultView(tool: Tool, private val selection: SessionSelection? = null) : PartView() {

    override val contentId: String = tool.id

    private var result = QuestionResultParser.parse(tool) ?: QuestionResult(emptyList(), emptyList())
    private var style = SessionEditorStyle.current()
    private val texts = mutableListOf<Pair<JBTextArea, Boolean>>()
+    private val regs = mutableListOf<Disposable>()

    private val root = object : JPanel(BorderLayout()) {
        override fun updateUI() {
@@ -143,6 +147,11 @@ class QuestionResultView(tool: Tool) : PartView() {
    fun titleFont(): Font = title.font
    fun subFont(): Font = sub.font

+    override fun dispose() {
+        disposeRegs()
+        texts.clear()
+    }
+
    override fun dumpLabel(): String = "QuestionResultView#$contentId(${labelText()})"

    companion object {
@@ -179,6 +188,7 @@ class QuestionResultView(tool: Tool) : PartView() {
    private fun syncBody() {
        val panel = pane ?: return
        panel.removeAll()
+        disposeRegs()
        texts.clear()

        for ((i, q) in result.questions.withIndex()) {
@@ -249,10 +259,16 @@ class QuestionResultView(tool: Tool) : PartView() {
            border = JBUI.Borders.empty()
        }
        texts.add(area to bold)
+        selection?.register(area)?.let(regs::add)
        setFont(area, bold)
        return area
    }

+    private fun disposeRegs() {
+        regs.forEach(Disposer::dispose)
+        regs.clear()
+    }
+
    private fun syncArrow() {
        arrow.icon = if (isExpanded()) AllIcons.General.ArrowDown else AllIcons.General.ArrowRight
    }
@@ -7,13 +7,16 @@ import ai.kilocode.client.session.model.QuestionOption
 import ai.kilocode.client.session.ui.SessionView
 import ai.kilocode.client.session.ui.editor.SessionEditorTextField
 import ai.kilocode.client.session.views.base.BaseQuestionView
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionEditorStyle
 import ai.kilocode.client.session.ui.style.SessionEditorStyleTarget
 import ai.kilocode.client.ui.HoverIcon
 import ai.kilocode.client.ui.UiStyle
 import ai.kilocode.rpc.dto.QuestionReplyDto
 import com.intellij.icons.AllIcons
+import com.intellij.openapi.Disposable
 import com.intellij.openapi.project.Project
+import com.intellij.openapi.util.Disposer
 import com.intellij.openapi.util.IconLoader
 import com.intellij.ui.components.JBCheckBox
 import com.intellij.ui.components.JBLabel
@@ -48,6 +51,7 @@ class QuestionView(
    private val reject: (String) -> Unit,
    private val follow: () -> Boolean = { true },
    private val scroll: (Boolean) -> Unit = {},
+    private val selection: SessionSelection? = null,
 ) : BorderLayoutPanel(), SessionEditorStyleTarget, SessionView {
    override val sessionViewKind = SessionView.Kind.Default

@@ -61,11 +65,12 @@ class QuestionView(
    private var customOpen = emptyList<Boolean>()
    private var style = SessionEditorStyle.current()
    private val texts = mutableListOf<Pair<JBTextArea, Boolean>>()
+    private val regs = mutableListOf<Disposable>()
    // The custom editor for the currently shown question; null when not shown.
    private var customEditor: SessionEditorTextField? = null
    private var customFocus: FocusAdapter? = null

-    private val card = BaseQuestionView()
+    private val card = BaseQuestionView(selection)

    private val summary = JBLabel()
    private val nav = JPanel().apply {
@@ -145,6 +150,7 @@ class QuestionView(
        customOpen = emptyList()
        customEditor = null
        customFocus = null
+        disposeRegs()
        texts.clear()
        body.removeAll()
        card.setActions(emptyList())
@@ -169,6 +175,7 @@ class QuestionView(
    @RequiresEdt
    private fun syncPage() {
        val q = question ?: return
+        disposeRegs()
        texts.clear()
        customEditor = null
        customFocus = null
@@ -693,10 +700,16 @@ class QuestionView(
            border = JBUI.Borders.empty()
        }
        texts.add(area to bold)
+        selection?.register(area)?.let(regs::add)
        setFont(area, bold)
        return area
    }

+    private fun disposeRegs() {
+        regs.forEach(Disposer::dispose)
+        regs.clear()
+    }
+
    private fun single(q: Question): Boolean = q.items.size == 1 && !q.items[0].multiple

    private fun review(q: Question): Boolean = !single(q) && idx == q.items.size
@@ -1,6 +1,7 @@
 package ai.kilocode.client.ui.md

 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import com.intellij.openapi.Disposable
 import java.awt.Color
 import java.awt.Font
@@ -15,6 +16,7 @@ interface MdView : Disposable {
    fun append(delta: String)
    fun clear()
    fun applyStyle(style: SessionEditorStyle)
+    fun setSelection(selection: SessionSelection?)
    fun resetStyles()
    fun addLinkListener(listener: LinkListener)
    fun removeLinkListener(listener: LinkListener)
@@ -1,11 +1,15 @@
 package ai.kilocode.client.ui.md

 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection

 object MdViewFactory {
-    fun create(style: SessionEditorStyle = SessionEditorStyle.current()): MdView = hybrid(style)
+    fun create(style: SessionEditorStyle = SessionEditorStyle.current(), selection: SessionSelection? = null): MdView =
+        hybrid(style, selection)

-    fun hybrid(style: SessionEditorStyle = SessionEditorStyle.current()): MdView = MdViewHybrid(style)
+    fun hybrid(style: SessionEditorStyle = SessionEditorStyle.current(), selection: SessionSelection? = null): MdView =
+        MdViewHybrid(style, selection)

-    fun html(style: SessionEditorStyle = SessionEditorStyle.current()): MdView = MdViewHtmlPane(style)
+    fun html(style: SessionEditorStyle = SessionEditorStyle.current(), selection: SessionSelection? = null): MdView =
+        MdViewHtmlPane(style, selection)
 }
@@ -1,7 +1,10 @@
 package ai.kilocode.client.ui.md

 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.log.KiloLog
+import com.intellij.openapi.Disposable
+import com.intellij.openapi.util.Disposer
 import com.intellij.ui.components.JBHtmlPane
 import com.intellij.ui.components.JBHtmlPaneConfiguration
 import com.intellij.ui.components.JBHtmlPaneStyleConfiguration
@@ -19,6 +22,7 @@ import javax.swing.text.html.StyleSheet
@Suppress("UnstableApiUsage")
 internal class MdViewHtmlPane(
    style: SessionEditorStyle = SessionEditorStyle.current(),
+    private var selection: SessionSelection? = null,
 ) : MdView {
    companion object {
        private val LOG = KiloLog.create(MdViewHtmlPane::class.java)
@@ -28,6 +32,7 @@ internal class MdViewHtmlPane(
    private val source = StringBuilder()
    private var rendered = ""
    private var style = style
+    private var reg: Disposable? = null
    private var disposed = false

    private val extensions = listOf(
@@ -78,6 +83,10 @@ internal class MdViewHtmlPane(
        }
    }

+    init {
+        syncSelection()
+    }
+
    override val component: JComponent get() = pane

    override var font: Font
@@ -195,10 +204,20 @@ internal class MdViewHtmlPane(
        if (disposed) return
        if (this.style == style) return
        this.style = style
+        selection?.applyStyle(style)
        if (opaqueState) pane.background = background
        markDirty()
    }

+    override fun setSelection(selection: SessionSelection?) {
+        if (disposed) return
+        if (this.selection === selection) return
+        reg?.let(Disposer::dispose)
+        reg = null
+        this.selection = selection
+        syncSelection()
+    }
+
    override fun resetStyles() {
        if (disposed) return
        fontOverride = null
@@ -266,9 +285,15 @@ internal class MdViewHtmlPane(
        listeners.clear()
        source.clear()
        rendered = ""
+        reg?.let(Disposer::dispose)
+        reg = null
        pane.text = ""
    }

+    private fun syncSelection() {
+        reg = selection?.register(pane)
+    }
+
    private fun dispatch(event: MdView.LinkEvent) {
        for (l in listeners) l.onLink(event)
    }
@@ -1,6 +1,7 @@
 package ai.kilocode.client.ui.md

 import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import ai.kilocode.client.session.ui.selection.SessionSelection
 import ai.kilocode.client.session.ui.style.SessionUiStyle
 import ai.kilocode.log.KiloLog
 import com.intellij.openapi.Disposable
@@ -42,6 +43,7 @@ import javax.swing.text.html.StyleSheet
@Suppress("UnstableApiUsage")
 internal class MdViewHybrid(
    style: SessionEditorStyle = SessionEditorStyle.current(),
+    private var selection: SessionSelection? = null,
 ) : MdView {
    companion object {
        private val LOG = KiloLog.create(MdViewHybrid::class.java)
@@ -274,9 +276,17 @@ internal class MdViewHybrid(
        if (disposed) return
        if (this.style == style) return
        this.style = style
+        selection?.applyStyle(style)
        syncStyle()
    }

+    override fun setSelection(selection: SessionSelection?) {
+        if (disposed) return
+        if (this.selection === selection) return
+        this.selection = selection
+        syncBlocks()
+    }
+
    override fun resetStyles() {
        if (disposed) return
        fontOverride = null
@@ -412,6 +422,7 @@ internal class MdViewHybrid(
            isOpaque = opts.opaque
            background = opts.background
            text = "<html><body>$body</body></html>"
+            block?.let { selection?.register(this, it) }
            addHyperlinkListener { e ->
                if (e.eventType != HyperlinkEvent.EventType.ACTIVATED) return@addHyperlinkListener
                val href = e.description ?: return@addHyperlinkListener
@@ -427,6 +438,7 @@ internal class MdViewHybrid(
        val field = runCatching {
            CodeField(file(lang), opts, text).also { ed ->
                block?.let { ed.setDisposedWith(it) }
+                block?.let { selection?.register(ed, it) }
            }
        }.getOrElse { err ->
            LOG.warn("kind=markdown codeEditor=true failed message=${err.message}", err)
@@ -502,6 +514,7 @@ internal class MdViewHybrid(
            SessionUiStyle.View.Code.VIEWPORT_TOP_PADDING,
            SessionUiStyle.View.Code.VIEWPORT_HORIZONTAL_PADDING,
        )
+        block?.let { selection?.register(this, it) }
    }

    private inner class CodeField(file: FileType, opts: MdStyle, value: String) :
@@ -0,0 +1,125 @@
+package ai.kilocode.client.session.ui
+
+import ai.kilocode.client.session.SessionUiTestBase
+import ai.kilocode.client.session.views.ToolView
+import ai.kilocode.rpc.dto.ChatEventDto
+import ai.kilocode.rpc.dto.PartDto
+import com.intellij.ide.CopyProvider
+import com.intellij.openapi.actionSystem.DataContext
+import com.intellij.openapi.actionSystem.DataKey
+import com.intellij.openapi.actionSystem.DataMap
+import com.intellij.openapi.actionSystem.DataProvider
+import com.intellij.openapi.actionSystem.DataSink
+import com.intellij.openapi.actionSystem.DataSnapshotProvider
+import com.intellij.openapi.actionSystem.PlatformDataKeys
+import com.intellij.openapi.actionSystem.UiDataProvider
+import com.intellij.openapi.ide.CopyPasteManager
+import java.awt.Container
+import java.awt.datatransfer.DataFlavor
+import javax.swing.text.JTextComponent
+
+@Suppress("UnstableApiUsage")
+class SessionSelectionCopyTest : SessionUiTestBase() {
+    fun `test session ui exposes copy provider when selection exists`() {
+        val area = showTool("alpha output")
+
+        select(area, "alpha")
+        val provider = copyProvider()
+
+        assertNotNull(provider)
+        assertTrue(provider!!.isCopyEnabled(DataContext.EMPTY_CONTEXT))
+    }
+
+    fun `test copy provider writes active selected text`() {
+        val area = showTool("alpha output")
+
+        select(area, "alpha")
+        copyProvider()!!.performCopy(DataContext.EMPTY_CONTEXT)
+
+        assertEquals("alpha", CopyPasteManager.getInstance().getContents(DataFlavor.stringFlavor))
+    }
+
+    fun `test selecting another transcript component changes copied text`() {
+        val one = showTool("alpha output", id = "tool_a")
+        val two = showTool("bravo output", id = "tool_b")
+
+        select(one, "alpha")
+        select(two, "bravo")
+        copyProvider()!!.performCopy(DataContext.EMPTY_CONTEXT)
+
+        assertNull(one.selectedText)
+        assertEquals("bravo", CopyPasteManager.getInstance().getContents(DataFlavor.stringFlavor))
+    }
+
+    private fun select(area: JTextComponent, text: String) {
+        val start = area.text.indexOf(text)
+        assertTrue(start >= 0)
+        area.select(start, start + text.length)
+    }
+
+    private fun showTool(text: String, id: String = "tool_msg"): JTextComponent {
+        if (controller().id == null) showMessages()
+        emit(ChatEventDto.MessageUpdated("ses_test", message(id)))
+        emit(ChatEventDto.PartUpdated(
+            "ses_test",
+            PartDto(
+                id = "part_$id",
+                sessionID = "ses_test",
+                messageID = id,
+                type = "tool",
+                tool = "bash",
+                state = "completed",
+                input = mapOf("command" to "printf"),
+                output = text,
+            ),
+        ))
+        for (view in toolViews(ui)) view.expand()
+        layout()
+        return textComponent(text)
+    }
+
+    private fun toolViews(root: Container): List<ToolView> {
+        val out = mutableListOf<ToolView>()
+        if (root is ToolView) out.add(root)
+        for (child in root.components) {
+            if (child is Container) out.addAll(toolViews(child))
+        }
+        return out
+    }
+
+    private fun copyProvider(): CopyProvider? {
+        val sink = CopySink()
+        (ui as UiDataProvider).uiDataSnapshot(sink)
+        return sink.copy
+    }
+
+    private fun textComponent(needle: String): JTextComponent = textComponents(ui)
+        .first { it.text.contains(needle) }
+
+    private fun textComponents(root: Container): List<JTextComponent> {
+        val out = mutableListOf<JTextComponent>()
+        if (root is JTextComponent) out.add(root)
+        for (child in root.components) {
+            if (child is Container) out.addAll(textComponents(child))
+        }
+        return out
+    }
+
+    private class CopySink : DataSink {
+        var copy: CopyProvider? = null
+
+        override fun <T : Any> set(key: DataKey<T>, data: T?) {
+            if (key == PlatformDataKeys.COPY_PROVIDER) copy = data as? CopyProvider
+        }
+
+        override fun <T : Any> setNull(key: DataKey<T>) {}
+
+        override fun <T : Any> lazyNull(key: DataKey<T>) {}
+
+        override fun <T : Any> lazyValue(key: DataKey<T>, data: (DataMap) -> T?) {}
+
+        override fun uiDataSnapshot(provider: UiDataProvider) = provider.uiDataSnapshot(this)
+        override fun dataSnapshot(provider: DataSnapshotProvider) = provider.dataSnapshot(this)
+        override fun uiDataSnapshot(provider: DataProvider) {}
+    }
+}
@@ -0,0 +1,72 @@
+package ai.kilocode.client.session.ui.selection
+
+import ai.kilocode.client.session.ui.style.SessionEditorStyle
+import com.intellij.openapi.util.Disposer
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+import com.intellij.ui.components.JBTextArea
+import java.awt.event.MouseEvent
+
+@Suppress("UnstableApiUsage")
+class SessionSelectionTest : BasePlatformTestCase() {
+    fun `test selecting second text component clears first`() {
+        val selection = SessionSelection()
+        val one = JBTextArea("first value")
+        val two = JBTextArea("second value")
+        selection.register(one)
+        selection.register(two)
+
+        one.select(0, 5)
+        two.select(0, 6)
+
+        assertNull(one.selectedText)
+        assertEquals("second", two.selectedText)
+        assertEquals("second", selection.selectedText())
+    }
+
+    fun `test clearing active selection disables copy text`() {
+        val selection = SessionSelection()
+        val area = JBTextArea("selected value")
+        selection.register(area)
+
+        area.select(0, 8)
+        area.select(0, 0)
+
+        assertNull(selection.selectedText())
+    }
+
+    fun `test starting mouse selection clears previous text component immediately`() {
+        val selection = SessionSelection()
+        val one = JBTextArea("first value")
+        val two = JBTextArea("second value")
+        selection.register(one)
+        selection.register(two)
+
+        one.select(0, 5)
+        val event = MouseEvent(two, MouseEvent.MOUSE_PRESSED, System.currentTimeMillis(), 0, 1, 1, 1, false)
+        for (listener in two.mouseListeners) listener.mousePressed(event)
+
+        assertNull(one.selectedText)
+        assertNull(selection.selectedText())
+    }
+
+    fun `test unregistering active selection clears active state`() {
+        val selection = SessionSelection()
+        val area = JBTextArea("selected value")
+        val reg = selection.register(area)
+
+        area.select(0, 8)
+        Disposer.dispose(reg)
+
+        assertNull(selection.selectedText())
+    }
+
+    fun `test applyStyle updates swing selection colors`() {
+        val selection = SessionSelection()
+        val area = JBTextArea("selected value")
+        selection.register(area)
+        selection.applyStyle(SessionEditorStyle.current())
+
+        assertNotNull(area.selectionColor)
+        assertNotNull(area.selectedTextColor)
+    }
+}