feat(jetbrains): render edit tool diff previews in session view

.changeset/jetbrains-diff-preview-fixes.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Improve JetBrains diff previews by hiding hunk headers and adding full-path tooltips to clickable file links.

.changeset/jetbrains-edit-diff-view.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Render edit tool results with a clickable file target and a highlighted, simplified diff view.

.changeset/jetbrains-edit-file-links.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Open edit tool file links directly when multiple files share the same name.

.changeset/jetbrains-multi-file-patch-view.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Render multi-file apply_patch edits as a "Patch" with a file-count tag and one section per file, each showing a clickable filename link and its own changes badge aligned with the diff.

.changeset/jetbrains-scroll-hover-fanout.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Smooth out chat scrolling in large JetBrains sessions by only refreshing hover state for the message under the pointer.

.changeset/jetbrains-session-scroll-perf.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Improve chat scrolling performance in large JetBrains sessions.

.changeset/jetbrains-wide-preview-popovers.md

@@ -0,0 +1,5 @@
+---
+"@kilocode/kilo-jetbrains": patch
+---
+
+Size edit and shell preview popovers to their content with a wider maximum width.

packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/scroll/SessionScroll.kt

@@ -346,7 +346,7 @@ internal class SessionScroll(
 
     @RequiresEdt
     private fun layoutScroll() {
-        root.validate()
+        component.validate()
     }
 
     @RequiresEdt

packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/SessionLayout.kt

@@ -8,6 +8,7 @@ import java.awt.Container
 import java.awt.Dimension
 import java.awt.Insets
 import java.awt.LayoutManager
+import java.util.IdentityHashMap
 
 /**
  * A vertical, width-aware layout manager for the session transcript.
@@ -33,8 +34,12 @@ class SessionLayout(
     private val basePad: Insets = JBUI.emptyInsets(),
 ) : LayoutManager {
 
+    private val cache = IdentityHashMap<Component, Measured>()
+
     override fun addLayoutComponent(name: String, comp: Component) = Unit
-    override fun removeLayoutComponent(comp: Component) = Unit
+    override fun removeLayoutComponent(comp: Component) {
+        cache.remove(comp)
+    }
 
     override fun preferredLayoutSize(parent: Container): Dimension {
         val ins = insets(parent)
@@ -46,9 +51,7 @@ class SessionLayout(
             if (!first) h += gap(comp)
             first = false
             val child = bounds(ins, w, comp)
-            // Pre-size to available width so HTML panes reflow before we measure
-            comp.setSize(child.width, comp.height.coerceAtLeast(1))
-            h += comp.preferredSize.height
+            h += measure(comp, child.width)
         }
         // w and h are already scaled px (child preferred heights + scaled gaps/insets) and
         // match what layoutContainer stacks, so return a plain Dimension. A JBDimension would
@@ -68,14 +71,36 @@ class SessionLayout(
             if (!first) y += gap(comp)
             first = false
             val child = bounds(ins, w, comp)
-            // Fix width first so HTML reflows, then read the resulting height
-            comp.setSize(child.width, comp.height.coerceAtLeast(1))
-            val h = comp.preferredSize.height
+            val h = measure(comp, child.width)
             comp.setBounds(child.left, y, child.width, h)
             y += h
         }
     }
 
+    /**
+     * Drop the cached measurement for [comp] so the next layout pass re-measures it.
+     *
+     * [measure] trusts `comp.isValid` as a freshness signal, which is safe only while `comp` is
+     * invalidated through this container. A child that is its own validate root (see
+     * [ai.kilocode.client.session.views.TurnView.isValidateRoot]) can be re-validated independently
+     * by `RepaintManager` — its `isValid` flips back to `true` before this layout re-measures it,
+     * so a content change that grows/shrinks its height would otherwise return a stale cached value.
+     * Callers that mutate such a child's content must forget it here so the cache stays honest.
+     */
+    fun forget(comp: Component) {
+        cache.remove(comp)
+    }
+
+    private fun measure(comp: Component, width: Int): Int {
+        val hit = cache[comp]
+        if (comp.isValid && hit?.width == width) return hit.height
+        // Pre-size to available width so HTML panes reflow before we measure.
+        comp.setSize(width, comp.height.coerceAtLeast(1))
+        val h = comp.preferredSize.height
+        cache[comp] = Measured(width, h)
+        return h
+    }
+
     private fun bounds(ins: Insets, width: Int, comp: Component): Bounds {
         val view = view(comp) ?: return Bounds(ins.left, width)
         if (view.sessionViewKind != SessionView.Kind.UserPrompt) return Bounds(ins.left, width)
@@ -103,6 +128,8 @@ class SessionLayout(
     private fun view(comp: Component): SessionView? = comp as? SessionView
 
     private data class Bounds(val left: Int, val width: Int)
+
+    private data class Measured(val width: Int, val height: Int)
 }
 
 /**

packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/SessionMessageListPanel.kt

@@ -96,34 +96,37 @@ class SessionMessageListPanel(
                 is SessionModelEvent.TurnRemoved -> onTurnRemoved(event.id)
 
                 is SessionModelEvent.ContentAdded -> {
-                    msgToView[event.messageId]?.upsertPart(event.content)
-                    msgToTurn[event.messageId]?.syncCopyToolbars()
-                    refresh()
+                    if (msgToView[event.messageId]?.upsertPartChanged(event.content) == true) {
+                        onContentChanged(event.messageId)
+                    }
                 }
 
                 is SessionModelEvent.ContentUpdated -> {
-                    msgToView[event.messageId]?.upsertPart(event.content)
-                    msgToTurn[event.messageId]?.syncCopyToolbars()
-                    refresh()
+                    if (msgToView[event.messageId]?.upsertPartChanged(event.content) == true) {
+                        onContentChanged(event.messageId)
+                    }
                 }
 
                 is SessionModelEvent.ContentRemoved -> {
-                    msgToView[event.messageId]?.removePart(event.contentId)
-                    msgToTurn[event.messageId]?.syncCopyToolbars()
-                    refresh()
+                    if (msgToView[event.messageId]?.removePartChanged(event.contentId) == true) {
+                        onContentChanged(event.messageId)
+                    }
                 }
 
                 is SessionModelEvent.ContentDelta -> {
                     if (event.created) return@addListener
+                    if (event.delta.isEmpty()) return@addListener
                     val handled = msgToView[event.messageId]?.appendDelta(event.contentId, event.delta) == true
                     if (handled) {
                         msgToTurn[event.messageId]?.syncCopyToolbars()
+                        forgetTurn(event.messageId)
                         return@addListener
                     }
                     val content = model.content(event.messageId, event.contentId)
                     if (content != null) {
-                        msgToView[event.messageId]?.upsertPart(content)
-                        msgToTurn[event.messageId]?.syncCopyToolbars()
+                        if (msgToView[event.messageId]?.upsertPartChanged(content) == true) {
+                            onContentChanged(event.messageId)
+                        }
                     }
                 }
 
@@ -132,6 +135,7 @@ class SessionMessageListPanel(
 
                 is SessionModelEvent.StateChanged -> {
                     syncActive(event.state)
+                    syncSettled(event.state)
                     syncReverted()
                     syncReverting(event.state)
                     anchorFooter()
@@ -222,6 +226,7 @@ class SessionMessageListPanel(
         tv.syncCopyToolbars()
         syncReverted()
         add(tv)
+        syncSettled()
         anchorFooter()
         refresh()
     }
@@ -234,8 +239,7 @@ class SessionMessageListPanel(
         // Remove messages no longer in this turn
         for (id in prev) {
             if (id !in next) {
-                tv.removeMessage(id)
-                unregister(id)
+                if (tv.removeMessageChanged(id)) unregister(id)
             }
         }
 
@@ -248,6 +252,7 @@ class SessionMessageListPanel(
         }
         tv.syncCopyToolbars()
         syncReverted()
+        syncSettled()
 
         refresh()
     }
@@ -257,6 +262,7 @@ class SessionMessageListPanel(
         for (msgId in tv.messageIds()) unregister(msgId)
         remove(tv)
         Disposer.dispose(tv)
+        syncSettled()
         anchorFooter()
         refresh()
     }
@@ -285,6 +291,7 @@ class SessionMessageListPanel(
         }
 
         syncActive(model.state)
+        syncSettled(model.state)
         syncReverted()
         syncReverting(model.state)
         banner?.update()
@@ -313,6 +320,7 @@ class SessionMessageListPanel(
         revertingMessage = null
         removeAll()
         syncActive(model.state)
+        syncSettled(model.state)
         syncReverting(model.state)
         banner?.update()
         anchorFooter()
@@ -375,6 +383,11 @@ class SessionMessageListPanel(
         for (mv in msgToView.values) mv.setHiddenQuestionTool(ref)
     }
 
+    private fun syncSettled(state: SessionState = model.state) {
+        val active = if (state.isBusy()) turnViews.values.lastOrNull() else null
+        for (view in turnViews.values) view.setSettled(view !== active)
+    }
+
     /**
      * Re-insert [question], [permission], [login], and [progress] as the last children
      * so active views always render after all turn views, and progress is last.
@@ -413,6 +426,25 @@ class SessionMessageListPanel(
         repaint()
     }
 
+    /**
+     * Handle a content mutation that changed an already-rendered message: sync the turn's copy
+     * toolbars, forget its cached height, then relayout. [forgetTurn] is essential when the update
+     * lands on a settled turn — a settled [TurnView] is its own validate root, so `RepaintManager`
+     * re-validates it independently and its `isValid` flag no longer signals the height change to
+     * [SessionLayout]'s measurement cache.
+     */
+    private fun onContentChanged(messageId: String) {
+        msgToTurn[messageId]?.syncCopyToolbars()
+        forgetTurn(messageId)
+        refresh()
+    }
+
+    /** Drop [SessionLayout]'s cached height for the turn holding [messageId] after its content changes. */
+    private fun forgetTurn(messageId: String) {
+        val tv = msgToTurn[messageId] ?: return
+        (layout as? SessionLayout)?.forget(tv)
+    }
+
     private fun hover(view: PartView, value: Boolean) {
         if (value) {
             val prev = hovered

packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/popup/HeaderPopup.kt

@@ -1,14 +1,20 @@
 package ai.kilocode.client.session.ui.popup
 
+import ai.kilocode.client.session.ui.style.SessionUiStyle
 import com.intellij.openapi.Disposable
+import com.intellij.ui.EditorTextField
+import com.intellij.ui.components.JBTextArea
 import com.intellij.util.ui.JBUI
 import java.awt.BorderLayout
 import java.awt.Color
+import java.awt.Component
 import java.awt.Container
 import java.awt.Dimension
+import java.awt.Insets
 import javax.swing.JComponent
 import javax.swing.JEditorPane
 import javax.swing.JPanel
+import javax.swing.JScrollPane
 
 class HeaderPopupRequest(
     val anchor: JComponent,
@@ -20,26 +26,48 @@ class HeaderPopupBody(
     component: JComponent,
     val disposable: Disposable,
     val background: Color,
+    maxWidth: Int = SessionUiStyle.View.Popup.MAX_WIDTH,
 ) {
-    val component: JComponent = HeaderPopupPanel(component)
+    val component: JComponent = HeaderPopupPanel(component, JBUI.scale(maxWidth))
 }
 
-private class HeaderPopupPanel(private val child: JComponent) : JPanel(BorderLayout()) {
+private class HeaderPopupPanel(
+    private val child: JComponent,
+    private val maxWidth: Int,
+) : JPanel(BorderLayout()) {
     init {
         // Transparent so the balloon fill shows uniformly behind nested popup content.
         isOpaque = false
         add(child, BorderLayout.CENTER)
     }
 
     override fun getPreferredSize(): Dimension {
-        val size = super.getPreferredSize()
-        val cap = JBUI.scale(350)
-        val width = size.width.takeIf { it > 0 }?.coerceAtMost(cap) ?: cap
+        val width = contentWidth(child).takeIf { it > 0 }?.coerceAtMost(maxWidth) ?: maxWidth
         fit(child, width)
-        val height = super.getPreferredSize().height.coerceAtMost(JBUI.scale(450))
+        val height = super.getPreferredSize().height.coerceAtMost(JBUI.scale(SessionUiStyle.View.Popup.MAX_HEIGHT))
         return Dimension(width, height)
     }
 
+    private fun contentWidth(item: Component): Int = when (item) {
+        is EditorTextField -> item.preferredSize.width
+        is JBTextArea -> item.preferredSize.width
+        is JEditorPane -> item.preferredSize.width
+        is JScrollPane -> {
+            val view = item.viewport?.view?.let(::contentWidth) ?: 0
+            view + horiz(item.insets) + horiz(item.viewportBorder?.getBorderInsets(item))
+        }
+        // JComponent is a Container, so leaf components (labels, buttons, icons) reach here with no
+        // children — fall back to their own preferred width instead of measuring an empty child set.
+        is Container -> {
+            val kids = item.components
+            if (kids.isEmpty()) (item as? JComponent)?.preferredSize?.width ?: 0
+            else (kids.maxOfOrNull(::contentWidth) ?: 0) + horiz((item as? JComponent)?.insets)
+        }
+        else -> 0
+    }
+
+    private fun horiz(insets: Insets?): Int = (insets?.left ?: 0) + (insets?.right ?: 0)
+
     private fun fit(item: JComponent, width: Int) {
         if (width <= 0) return
         // JBHtmlPane derives wrapped preferred height from the current width, not just HTML content.

packages/kilo-jetbrains/frontend/src/main/kotlin/ai/kilocode/client/session/ui/style/SessionUiStyle.kt

@@ -37,6 +37,12 @@ object SessionUiStyle {
             const val BODY_EXTRA_HEIGHT = 16
         }
 
+        object Popup {
+            const val MAX_WIDTH = 350
+            const val WIDE_MAX_WIDTH = MAX_WIDTH * 2
+            const val MAX_HEIGHT = 450
+        }
+
         internal const val BORDER_DELTA = 80
         internal const val HOVER_BORDER_ALPHA = 0.18f
         internal const val HOVER_FILL_ALPHA = 0.10f
@@ -169,6 +175,7 @@ object SessionUiStyle {
         object Tool {
             const val BODY_LINES = 15
             const val TASK_LINES = 10
+            const val DIFF_LINES = 20
             const val PREVIEW_LIMIT = 20_000
 
             fun pending(): Color = UiStyle.Colors.weak()