feat: Implement background shell commands (#14849)

packages/cli/src/ui/AppContainer.tsx

@@ -99,6 +99,7 @@ import { computeTerminalTitle } from '../utils/windowTitle.js';
 import { useTextBuffer } from './components/shared/text-buffer.js';
 import { useLogger } from './hooks/useLogger.js';
 import { useGeminiStream } from './hooks/useGeminiStream.js';
+import { type BackgroundShell } from './hooks/shellCommandProcessor.js';
 import { useVim } from './hooks/vim.js';
 import { type LoadableSettingScope, SettingScope } from '../config/settings.js';
 import { type InitializationResult } from '../core/initializer.js';
@@ -138,6 +139,7 @@ import { terminalCapabilityManager } from './utils/terminalCapabilityManager.js'
 import { useInputHistoryStore } from './hooks/useInputHistoryStore.js';
 import { useBanner } from './hooks/useBanner.js';
 import { useHookDisplayState } from './hooks/useHookDisplayState.js';
+import { useBackgroundShellManager } from './hooks/useBackgroundShellManager.js';
 import {
   WARNING_PROMPT_DURATION_MS,
   QUEUE_ERROR_DISPLAY_DURATION_MS,
@@ -259,6 +261,10 @@ export const AppContainer = (props: AppContainerProps) => {
   );
   const [copyModeEnabled, setCopyModeEnabled] = useState(false);
   const [pendingRestorePrompt, setPendingRestorePrompt] = useState(false);
+  const toggleBackgroundShellRef = useRef<() => void>(() => {});
+  const isBackgroundShellVisibleRef = useRef<boolean>(false);
+  const backgroundShellsRef = useRef<Map<number, BackgroundShell>>(new Map());
+
   const [adminSettingsChanged, setAdminSettingsChanged] = useState(false);
 
   const [shellModeActive, setShellModeActive] = useState(false);
@@ -489,6 +495,12 @@ export const AppContainer = (props: AppContainerProps) => {
     registerCleanup(async () => {
       // Turn off mouse scroll.
       disableMouseEvents();
+
+      // Kill all background shells
+      for (const pid of backgroundShellsRef.current.keys()) {
+        ShellExecutionService.kill(pid);
+      }
+
       const ideClient = await IdeClient.getInstance();
       await ideClient.disconnect();
 
@@ -837,6 +849,10 @@ Logging in with Google... Restarting Gemini CLI to continue.
 
   const { toggleVimEnabled } = useVimMode();
 
+  const setIsBackgroundShellListOpenRef = useRef<(open: boolean) => void>(
+    () => {},
+  );
+
   const slashCommandActions = useMemo(
     () => ({
       openAuthDialog: () => setAuthState(AuthState.Updating),
@@ -860,6 +876,17 @@ Logging in with Google... Restarting Gemini CLI to continue.
       toggleDebugProfiler,
       dispatchExtensionStateUpdate,
       addConfirmUpdateExtensionRequest,
+      toggleBackgroundShell: () => {
+        toggleBackgroundShellRef.current();
+        if (!isBackgroundShellVisibleRef.current) {
+          setEmbeddedShellFocused(true);
+          if (backgroundShellsRef.current.size > 1) {
+            setIsBackgroundShellListOpenRef.current(true);
+          } else {
+            setIsBackgroundShellListOpenRef.current(false);
+          }
+        }
+      },
       setText: (text: string) => buffer.setText(text),
     }),
     [
@@ -1011,6 +1038,12 @@ Logging in with Google... Restarting Gemini CLI to continue.
     activePtyId,
     loopDetectionConfirmationRequest,
     lastOutputTime,
+    backgroundShellCount,
+    isBackgroundShellVisible,
+    toggleBackgroundShell,
+    backgroundCurrentShell,
+    backgroundShells,
+    dismissBackgroundShell,
     retryStatus,
   } = useGeminiStream(
     config.getGeminiClient(),
@@ -1033,7 +1066,30 @@ Logging in with Google... Restarting Gemini CLI to continue.
     embeddedShellFocused,
   );
 
+  toggleBackgroundShellRef.current = toggleBackgroundShell;
+  isBackgroundShellVisibleRef.current = isBackgroundShellVisible;
+  backgroundShellsRef.current = backgroundShells;
+
+  const {
+    activeBackgroundShellPid,
+    setIsBackgroundShellListOpen,
+    isBackgroundShellListOpen,
+    setActiveBackgroundShellPid,
+    backgroundShellHeight,
+  } = useBackgroundShellManager({
+    backgroundShells,
+    backgroundShellCount,
+    isBackgroundShellVisible,
+    activePtyId,
+    embeddedShellFocused,
+    setEmbeddedShellFocused,
+    terminalHeight,
+  });
+
+  setIsBackgroundShellListOpenRef.current = setIsBackgroundShellListOpen;
+
   const lastOutputTimeRef = useRef(0);
+
   useEffect(() => {
     lastOutputTimeRef.current = lastOutputTime;
   }, [lastOutputTime]);
@@ -1182,7 +1238,11 @@ Logging in with Google... Restarting Gemini CLI to continue.
   // Compute available terminal height based on controls measurement
   const availableTerminalHeight = Math.max(
     0,
-    terminalHeight - controlsHeight - staticExtraHeight - 2,
+    terminalHeight -
+      controlsHeight -
+      staticExtraHeight -
+      2 -
+      backgroundShellHeight,
   );
 
   config.setShellExecutionConfig({
@@ -1542,9 +1602,10 @@ Logging in with Google... Restarting Gemini CLI to continue.
         setConstrainHeight(false);
         return true;
       } else if (
-        keyMatchers[Command.UNFOCUS_SHELL_INPUT](key) &&
-        activePtyId &&
-        embeddedShellFocused
+        keyMatchers[Command.FOCUS_SHELL_INPUT](key) &&
+        (activePtyId ||
+          (isBackgroundShellVisible && backgroundShells.size > 0)) &&
+        buffer.text.length === 0
       ) {
         if (key.name === 'tab' && key.shift) {
           // Always change focus
@@ -1552,26 +1613,72 @@ Logging in with Google... Restarting Gemini CLI to continue.
           return true;
         }
 
+        if (embeddedShellFocused) {
+          handleWarning('Press Shift+Tab to focus out.');
+          return true;
+        }
+
         const now = Date.now();
         // If the shell hasn't produced output in the last 100ms, it's considered idle.
         const isIdle = now - lastOutputTimeRef.current >= 100;
-        if (isIdle) {
+        if (isIdle && !activePtyId) {
           if (tabFocusTimeoutRef.current) {
             clearTimeout(tabFocusTimeoutRef.current);
           }
-          tabFocusTimeoutRef.current = setTimeout(() => {
-            tabFocusTimeoutRef.current = null;
-            // If the shell produced output since the tab press, we assume it handled the tab
-            // (e.g. autocomplete) so we should not toggle focus.
-            if (lastOutputTimeRef.current > now) {
-              handleWarning('Press Shift+Tab to focus out.');
-              return;
+          toggleBackgroundShell();
+          if (!isBackgroundShellVisible) {
+            // We are about to show it, so focus it
+            setEmbeddedShellFocused(true);
+            if (backgroundShells.size > 1) {
+              setIsBackgroundShellListOpen(true);
             }
-            setEmbeddedShellFocused(false);
-          }, 100);
+          } else {
+            // We are about to hide it
+            tabFocusTimeoutRef.current = setTimeout(() => {
+              tabFocusTimeoutRef.current = null;
+              // If the shell produced output since the tab press, we assume it handled the tab
+              // (e.g. autocomplete) so we should not toggle focus.
+              if (lastOutputTimeRef.current > now) {
+                handleWarning('Press Shift+Tab to focus out.');
+                return;
+              }
+              setEmbeddedShellFocused(false);
+            }, 100);
+          }
           return true;
         }
-        handleWarning('Press Shift+Tab to focus out.');
+
+        // Not idle, just focus it
+        setEmbeddedShellFocused(true);
+        return true;
+      } else if (keyMatchers[Command.TOGGLE_BACKGROUND_SHELL](key)) {
+        if (activePtyId) {
+          backgroundCurrentShell();
+          // After backgrounding, we explicitly do NOT show or focus the background UI.
+        } else {
+          if (isBackgroundShellVisible && !embeddedShellFocused) {
+            setEmbeddedShellFocused(true);
+          } else {
+            toggleBackgroundShell();
+            // Toggle focus based on intent: if we were hiding, unfocus; if showing, focus.
+            if (!isBackgroundShellVisible && backgroundShells.size > 0) {
+              setEmbeddedShellFocused(true);
+              if (backgroundShells.size > 1) {
+                setIsBackgroundShellListOpen(true);
+              }
+            } else {
+              setEmbeddedShellFocused(false);
+            }
+          }
+        }
+        return true;
+      } else if (keyMatchers[Command.TOGGLE_BACKGROUND_SHELL_LIST](key)) {
+        if (backgroundShells.size > 0 && isBackgroundShellVisible) {
+          if (!embeddedShellFocused) {
+            setEmbeddedShellFocused(true);
+          }
+          setIsBackgroundShellListOpen(true);
+        }
         return true;
       }
       return false;
@@ -1595,11 +1702,18 @@ Logging in with Google... Restarting Gemini CLI to continue.
       setCopyModeEnabled,
       copyModeEnabled,
       isAlternateBuffer,
+      backgroundCurrentShell,
+      toggleBackgroundShell,
+      backgroundShells,
+      isBackgroundShellVisible,
+      setIsBackgroundShellListOpen,
+      lastOutputTimeRef,
+      tabFocusTimeoutRef,
       handleWarning,
     ],
   );
 
-  useKeypress(handleGlobalKeypress, { isActive: true });
+  useKeypress(handleGlobalKeypress, { isActive: true, priority: true });
 
   useEffect(() => {
     // Respect hideWindowTitle settings
@@ -1878,6 +1992,8 @@ Logging in with Google... Restarting Gemini CLI to continue.
       isRestarting,
       extensionsUpdateState,
       activePtyId,
+      backgroundShellCount,
+      isBackgroundShellVisible,
       embeddedShellFocused,
       showDebugProfiler,
       customDialog,
@@ -1887,6 +2003,10 @@ Logging in with Google... Restarting Gemini CLI to continue.
       bannerVisible,
       terminalBackgroundColor: config.getTerminalBackground(),
       settingsNonce,
+      backgroundShells,
+      activeBackgroundShellPid,
+      backgroundShellHeight,
+      isBackgroundShellListOpen,
       adminSettingsChanged,
       newAgents,
     }),
@@ -1977,6 +2097,8 @@ Logging in with Google... Restarting Gemini CLI to continue.
       currentModel,
       extensionsUpdateState,
       activePtyId,
+      backgroundShellCount,
+      isBackgroundShellVisible,
       historyManager,
       embeddedShellFocused,
       showDebugProfiler,
@@ -1989,6 +2111,10 @@ Logging in with Google... Restarting Gemini CLI to continue.
       bannerVisible,
       config,
       settingsNonce,
+      backgroundShellHeight,
+      isBackgroundShellListOpen,
+      activeBackgroundShellPid,
+      backgroundShells,
       adminSettingsChanged,
       newAgents,
     ],
@@ -2036,7 +2162,11 @@ Logging in with Google... Restarting Gemini CLI to continue.
       handleApiKeySubmit,
       handleApiKeyCancel,
       setBannerVisible,
+      handleWarning,
       setEmbeddedShellFocused,
+      dismissBackgroundShell,
+      setActiveBackgroundShellPid,
+      setIsBackgroundShellListOpen,
       setAuthContext,
       handleRestart: async () => {
         if (process.send) {
@@ -2108,7 +2238,11 @@ Logging in with Google... Restarting Gemini CLI to continue.
       handleApiKeySubmit,
       handleApiKeyCancel,
       setBannerVisible,
+      handleWarning,
       setEmbeddedShellFocused,
+      dismissBackgroundShell,
+      setActiveBackgroundShellPid,
+      setIsBackgroundShellListOpen,
       setAuthContext,
       newAgents,
       config,