fix(chat): preserve native copying of selected text (#540)

- Allow native text selection in AI chat messages.\n- Leave active DOM text ranges to the platform clipboard.\n- Preserve canvas clipboard routing when no document text is selected.

CHANGELOG.md

@@ -55,6 +55,7 @@
 
 ### Fixed
 
+- Let desktop users select and copy AI chat text without replacing it with the selected canvas layers. (#538)
 - Restore visible above, below, and child drop feedback while dragging layers in the Layers panel.
 - Place editor-created instances beside nested source components in world space, including transformed source and destination parents.
 - Harden collaboration node synchronization against malformed remote source metadata and geometry while excluding derived text-renderer caches.

src/app/shell/keyboard/clipboard.ts

@@ -7,7 +7,7 @@ import {
   copySelectionToTauriClipboard,
   pasteFromTauriClipboard
 } from '@/app/editor/clipboard/system'
-import { isEditing } from '@/app/shell/keyboard/focus'
+import { hasDocumentTextSelection, isEditing } from '@/app/shell/keyboard/focus'
 import { isTauri } from '@/app/tauri/env'
 
 function cursorPosition(store: EditorStore) {
@@ -17,7 +17,7 @@ function cursorPosition(store: EditorStore) {
 
 export function bindEditorClipboard(store: EditorStore) {
   useEventListener(window, 'copy', (e: ClipboardEvent) => {
-    if (isEditing(e)) return
+    if (isEditing(e) || hasDocumentTextSelection()) return
     e.preventDefault()
     if (isTauri()) {
       void copySelectionToTauriClipboard(store)

src/app/shell/keyboard/focus.ts

@@ -10,6 +10,11 @@ export function isEditing(event: Event) {
   return event.composedPath().some(isEditableTarget)
 }
 
+export function hasDocumentTextSelection(): boolean {
+  const selection = window.getSelection()
+  return selection !== null && !selection.isCollapsed && selection.toString().length > 0
+}
+
 export function isInputElement(element: EventTarget | null | undefined): boolean {
   return (
     element instanceof HTMLInputElement ||

src/components/chat/ChatMessage.vue

@@ -52,7 +52,10 @@ function partKey(part: UIMessagePart<UIDataTypes, UITools>, index: number): stri
     v-test-id="`chat-message-${message.role}`"
     :class="message.role === 'user' ? 'flex justify-end' : ''"
   >
-    <div class="min-w-0 space-y-2" :class="message.role === 'user' ? 'max-w-[85%]' : ''">
+    <div
+      class="min-w-0 space-y-2 select-text"
+      :class="message.role === 'user' ? 'max-w-[85%]' : ''"
+    >
       <template v-if="message.role === 'assistant'">
         <template v-for="(part, i) in message.parts" :key="partKey(part, i)">
           <!-- Tool call -->

tests/e2e/clipboard/tauri-plugin-routing.spec.ts

@@ -36,6 +36,18 @@ function selectedCount(page: Page): Promise<number> {
   })
 }
 
+async function selectProbeText(page: Page, selector: string) {
+  await page.evaluate((probeSelector) => {
+    const probe = document.querySelector(probeSelector)
+    const selection = window.getSelection()
+    if (!probe || !selection) throw new Error(`Text selection probe not found: ${probeSelector}`)
+    const range = document.createRange()
+    range.selectNodeContents(probe)
+    selection.removeAllRanges()
+    selection.addRange(range)
+  }, selector)
+}
+
 async function dispatchClipboardEvent(
   page: Page,
   type: 'copy' | 'cut' | 'paste',
@@ -147,6 +159,33 @@ test('Tauri clipboard events from editable fields keep native text behavior', as
   expect(await pageChildren(page)).toHaveLength(1)
 })
 
+test('Tauri copy preserves selected document text instead of copying canvas layers', async ({
+  page
+}) => {
+  const { canvas, clipboard } = await createTauriEditorPage(page)
+  await canvas.drawRect(160, 160, 96, 72)
+  const before = clipboard.snapshot()
+
+  await page.evaluate(() => {
+    const probe = document.createElement('div')
+    probe.className = 'select-text'
+    probe.dataset.clipboardProbe = 'document-text'
+    probe.textContent = 'Assistant response'
+    document.body.append(probe)
+  })
+  await selectProbeText(page, '[data-clipboard-probe="document-text"]')
+  expect(
+    await page.evaluate(() => ({
+      collapsed: window.getSelection()?.isCollapsed,
+      text: window.getSelection()?.toString()
+    }))
+  ).toEqual({ collapsed: false, text: 'Assistant response' })
+  await dispatchClipboardEvent(page, 'copy', '[data-clipboard-probe="document-text"]')
+
+  expect(clipboard.snapshot()).toEqual(before)
+  expect(await selectedCount(page)).toBe(1)
+})
+
 test('Tauri context-menu copy uses plugin clipboard fallback instead of blocked browser command', async ({
   page
 }) => {