feat: Ctrl+O to expand paste placeholder (#18103)

packages/cli/src/ui/components/InputPrompt.tsx

@@ -17,6 +17,8 @@ import {
   logicalPosToOffset,
   PASTED_TEXT_PLACEHOLDER_REGEX,
   getTransformUnderCursor,
+  LARGE_PASTE_LINE_THRESHOLD,
+  LARGE_PASTE_CHAR_THRESHOLD,
 } from './shared/text-buffer.js';
 import {
   cpSlice,
@@ -59,6 +61,11 @@ import { getSafeLowColorBackground } from '../themes/color-utils.js';
 import { isLowColorDepth } from '../utils/terminalUtils.js';
 import { useShellFocusState } from '../contexts/ShellFocusContext.js';
 import { useUIState } from '../contexts/UIStateContext.js';
+import {
+  appEvents,
+  AppEvent,
+  TransientMessageType,
+} from '../../utils/events.js';
 import { useSettings } from '../contexts/SettingsContext.js';
 import { StreamingState } from '../types.js';
 import { useMouseClick } from '../hooks/useMouseClick.js';
@@ -122,6 +129,55 @@ export const calculatePromptWidths = (mainContentWidth: number) => {
   } as const;
 };
 
+/**
+ * Returns true if the given text exceeds the thresholds for being considered a "large paste".
+ */
+export function isLargePaste(text: string): boolean {
+  const pasteLineCount = text.split('\n').length;
+  return (
+    pasteLineCount > LARGE_PASTE_LINE_THRESHOLD ||
+    text.length > LARGE_PASTE_CHAR_THRESHOLD
+  );
+}
+
+/**
+ * Attempt to toggle expansion of a paste placeholder in the buffer.
+ * Returns true if a toggle action was performed or hint was shown, false otherwise.
+ */
+export function tryTogglePasteExpansion(buffer: TextBuffer): boolean {
+  if (!buffer.pastedContent || Object.keys(buffer.pastedContent).length === 0) {
+    return false;
+  }
+
+  const [row, col] = buffer.cursor;
+
+  // 1. Check if cursor is on or immediately after a collapsed placeholder
+  const transform = getTransformUnderCursor(
+    row,
+    col,
+    buffer.transformationsByLine,
+    { includeEdge: true },
+  );
+  if (transform?.type === 'paste' && transform.id) {
+    buffer.togglePasteExpansion(transform.id, row, col);
+    return true;
+  }
+
+  // 2. Check if cursor is inside an expanded paste region — collapse it
+  const expandedId = buffer.getExpandedPasteAtLine(row);
+  if (expandedId) {
+    buffer.togglePasteExpansion(expandedId, row, col);
+    return true;
+  }
+
+  // 3. Placeholders exist but cursor isn't on one — show hint
+  appEvents.emit(AppEvent.TransientMessage, {
+    message: 'Move cursor within placeholder to expand',
+    type: TransientMessageType.Hint,
+  });
+  return true;
+}
+
 export const InputPrompt: React.FC<InputPromptProps> = ({
   buffer,
   onSubmit,
@@ -402,6 +458,12 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
       } else {
         const textToInsert = await clipboardy.read();
         buffer.insert(textToInsert, { paste: true });
+        if (isLargePaste(textToInsert)) {
+          appEvents.emit(AppEvent.TransientMessage, {
+            message: 'Press Ctrl+O to expand pasted text',
+            type: TransientMessageType.Hint,
+          });
+        }
       }
     } catch (error) {
       debugLogger.error('Error handling paste:', error);
@@ -455,6 +517,7 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
           logicalPos.row,
           logicalPos.col,
           buffer.transformationsByLine,
+          { includeEdge: true },
         );
         if (transform?.type === 'paste' && transform.id) {
           buffer.togglePasteExpansion(
@@ -591,6 +654,12 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
         }
         // Ensure we never accidentally interpret paste as regular input.
         buffer.handleInput(key);
+        if (key.sequence && isLargePaste(key.sequence)) {
+          appEvents.emit(AppEvent.TransientMessage, {
+            message: 'Press Ctrl+O to expand pasted text',
+            type: TransientMessageType.Hint,
+          });
+        }
         return true;
       }
 
@@ -632,6 +701,12 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
         }
       }
 
+      // Ctrl+O to expand/collapse paste placeholders
+      if (keyMatchers[Command.EXPAND_PASTE](key)) {
+        const handled = tryTogglePasteExpansion(buffer);
+        if (handled) return true;
+      }
+
       if (
         key.sequence === '!' &&
         buffer.text === '' &&