feat(cli): improve CTRL+O experience for both standard and alternate screen buffer (ASB) modes (#19010)

Co-authored-by: jacob314 <jacob314@gmail.com>

packages/cli/src/ui/components/messages/ShellToolMessage.tsx

@@ -15,24 +15,21 @@ import {
   ToolStatusIndicator,
   ToolInfo,
   TrailingIndicator,
-  STATUS_INDICATOR_WIDTH,
   isThisShellFocusable as checkIsShellFocusable,
   isThisShellFocused as checkIsShellFocused,
   useFocusHint,
   FocusHint,
 } from './ToolShared.js';
 import type { ToolMessageProps } from './ToolMessage.js';
-import {
-  ACTIVE_SHELL_MAX_LINES,
-  COMPLETED_SHELL_MAX_LINES,
-} from '../../constants.js';
+import { ACTIVE_SHELL_MAX_LINES } from '../../constants.js';
 import { useAlternateBuffer } from '../../hooks/useAlternateBuffer.js';
-import { type Config, CoreToolCallStatus } from '@google/gemini-cli-core';
-
 import { useUIState } from '../../contexts/UIStateContext.js';
+import { type Config } from '@google/gemini-cli-core';
+import { calculateShellMaxLines } from '../../utils/toolLayoutUtils.js';
 
 export interface ShellToolMessageProps extends ToolMessageProps {
   config?: Config;
+  isExpandable?: boolean;
 }
 
 export const ShellToolMessage: React.FC<ShellToolMessageProps> = ({
@@ -61,9 +58,15 @@ export const ShellToolMessage: React.FC<ShellToolMessageProps> = ({
   borderColor,
 
   borderDimColor,
+  isExpandable,
 }) => {
-  const { activePtyId: activeShellPtyId, embeddedShellFocused } = useUIState();
+  const {
+    activePtyId: activeShellPtyId,
+    embeddedShellFocused,
+    constrainHeight,
+  } = useUIState();
   const isAlternateBuffer = useAlternateBuffer();
+
   const isThisShellFocused = checkIsShellFocused(
     name,
     status,
@@ -155,59 +158,23 @@ export const ShellToolMessage: React.FC<ShellToolMessageProps> = ({
           terminalWidth={terminalWidth}
           renderOutputAsMarkdown={renderOutputAsMarkdown}
           hasFocus={isThisShellFocused}
-          maxLines={getShellMaxLines(
+          maxLines={calculateShellMaxLines({
             status,
             isAlternateBuffer,
             isThisShellFocused,
             availableTerminalHeight,
-          )}
+            constrainHeight,
+            isExpandable,
+          })}
         />
         {isThisShellFocused && config && (
-          <Box paddingLeft={STATUS_INDICATOR_WIDTH} marginTop={1}>
-            <ShellInputPrompt
-              activeShellPtyId={activeShellPtyId ?? null}
-              focus={embeddedShellFocused}
-              scrollPageSize={availableTerminalHeight ?? ACTIVE_SHELL_MAX_LINES}
-            />
-          </Box>
+          <ShellInputPrompt
+            activeShellPtyId={activeShellPtyId ?? null}
+            focus={embeddedShellFocused}
+            scrollPageSize={availableTerminalHeight ?? ACTIVE_SHELL_MAX_LINES}
+          />
         )}
       </Box>
     </>
   );
 };
-
-/**
- * Calculates the maximum number of lines to display for shell output.
- *
- * For completed processes (Success, Error, Canceled), it returns COMPLETED_SHELL_MAX_LINES.
- * For active processes, it returns the available terminal height if in alternate buffer mode
- * and focused. Otherwise, it returns ACTIVE_SHELL_MAX_LINES.
- *
- * This function ensures a finite number of lines is always returned to prevent performance issues.
- */
-function getShellMaxLines(
-  status: CoreToolCallStatus,
-  isAlternateBuffer: boolean,
-  isThisShellFocused: boolean,
-  availableTerminalHeight: number | undefined,
-): number {
-  if (
-    status === CoreToolCallStatus.Success ||
-    status === CoreToolCallStatus.Error ||
-    status === CoreToolCallStatus.Cancelled
-  ) {
-    return COMPLETED_SHELL_MAX_LINES;
-  }
-
-  if (availableTerminalHeight === undefined) {
-    return ACTIVE_SHELL_MAX_LINES;
-  }
-
-  const maxLinesBasedOnHeight = Math.max(1, availableTerminalHeight - 2);
-
-  if (isAlternateBuffer && isThisShellFocused) {
-    return maxLinesBasedOnHeight;
-  }
-
-  return Math.min(maxLinesBasedOnHeight, ACTIVE_SHELL_MAX_LINES);
-}