From 62a39dadb752d9da06486a7593f6349fbd89f6b3 Mon Sep 17 00:00:00 2001
From: Deng Liu <deng@sesame.com>
Date: Sun, 8 Nov 2026 10:22:51 -0800
Subject: [PATCH] feat(zoom): route Increase/Decrease Font Size across editors,
 terminals and WebViews (#2172)

Increase, Decrease and Reset Font Size only reached the active CodeMirror editor, so they did nothing with focus in a terminal or plugin WebView. They now apply to the focused surface through a shared workbench service: an editor tab, a terminal tab (which refits), or a plugin WebView. Wheel zoom stays pointer-based.

Co-authored-by: dengliu <5108773+dengliu@users.noreply.github.com>
---
 src/editor/core/actions.ts                    | 33 ++++++++--
 .../plugins/__tests__/webViews.test.tsx       | 25 ++++++++
 src/features/plugins/views/WebView.tsx        |  7 ++-
 src/features/plugins/views/frame-bridge.js    | 10 ++-
 src/features/terminal/copyKeys.test.ts        | 33 ++++++++++
 src/features/terminal/session.test.ts         | 49 ++++++++++++++-
 src/features/terminal/session.ts              | 24 ++++++-
 src/features/viewers/markdown/zoom.test.tsx   | 62 +++++++++++++++++++
 src/workbench/contributions.ts                | 25 ++++++++
 9 files changed, 259 insertions(+), 9 deletions(-)

diff --git a/src/editor/core/actions.ts b/src/editor/core/actions.ts
index abc9389e1..fb82ead1b 100644
--- a/src/editor/core/actions.ts
+++ b/src/editor/core/actions.ts
@@ -6,6 +6,7 @@ import { foldEffect, syntaxTree, toggleFold } from "@codemirror/language";
 import { acceptCompletion, completionStatus } from "@codemirror/autocomplete";
 import { executeAction, registerActions, type Action } from "@/platform/actions";
 import { getContext } from "@/platform/context";
+import { resetSurfaceFontZoom, stepFocusedSurfaceFontZoom } from "@/workbench/contributions";
 import { editorController, useGotoLine, useTabs } from "./controller";
 import {
   addCaretsToLineEnds,
@@ -109,6 +110,27 @@ function withView(run: (view: EditorView, slot: EditorSlot) => unknown) {
   };
 }
 
+/** Routes keyboard font zoom to focus, then the active editor slot. */
+function stepSurfaceFontSize(delta: 1 | -1): void {
+  const activeEl = typeof document !== "undefined" ? (document.activeElement as HTMLElement | null) : null;
+  if (activeEl) {
+    if (stepFocusedSurfaceFontZoom(delta)) return;
+    const cmEl = activeEl.closest?.(".cm-editor") as HTMLElement | null;
+    if (cmEl) {
+      const cmView = EditorView.findFromDOM(cmEl);
+      if (cmView) {
+        stepFontZoom(cmView, delta);
+        return;
+      }
+    }
+  }
+
+  const slot = activeSlot();
+  if (!slot?.view) return;
+  stepFontZoom(slot.view, delta);
+  if (!slot.view.hasFocus && !getContext().popupOpen) slot.view.focus();
+}
+
 // --- extend / shrink selection ---------------------------------------------------
 
 /** One stack per selection range (by index): ⌥↑ / ⌥↓ work on every caret. */
@@ -872,6 +894,9 @@ export function registerEditorActions(): () => void {
       run: () => {
         for (const ed of useEditorRegistry.getState().editors)
           if (ed.view.state.field(fontZoom, false)) ed.view.dispatch({ effects: setFontZoom.of(0) });
+        if (typeof document !== "undefined") {
+          resetSurfaceFontZoom();
+        }
       },
     },
     {
@@ -879,16 +904,16 @@ export function registerEditorActions(): () => void {
       title: "Increase Font Size",
       category: "View",
       keywords: ["zoom", "font size"],
-      when: EDITOR_WHEN,
-      run: withView((view) => stepFontZoom(view, 1)),
+      when: "projectOpen",
+      run: () => stepSurfaceFontSize(1),
     },
     {
       id: "editor.decreaseFontSize",
       title: "Decrease Font Size",
       category: "View",
       keywords: ["zoom", "font size"],
-      when: EDITOR_WHEN,
-      run: withView((view) => stepFontZoom(view, -1)),
+      when: "projectOpen",
+      run: () => stepSurfaceFontSize(-1),
     },
     {
       id: "file.toggleReadOnly",
diff --git a/src/features/plugins/__tests__/webViews.test.tsx b/src/features/plugins/__tests__/webViews.test.tsx
index 84338837c..2674128da 100644
--- a/src/features/plugins/__tests__/webViews.test.tsx
+++ b/src/features/plugins/__tests__/webViews.test.tsx
@@ -102,6 +102,31 @@ describe("web view helpers", () => {
 });
 
 describe("frame bridge", () => {
+  it("accepts bounded zoom only from its parent with the bridge tag", () => {
+    const script = /<script>([\s\S]*)<\/script>/.exec(frameDocument("", { dark: true, vars: {} }))![1]!;
+    const parent = {};
+    const handlers = new Map<string, (e: { source: object; data: object }) => void>();
+    const root = document.createElement("html");
+    const frameWindow = {
+      parent,
+      addEventListener: (type: string, fn: (e: { source: object; data: object }) => void) => handlers.set(type, fn),
+    };
+    new Function("window", "document", script)(frameWindow, { documentElement: root });
+    const send = (source: object, data: object) => handlers.get("message")!({ source, data });
+    send({}, { tag: FRAME_TAG, fontZoomDelta: 1 });
+    send(parent, { tag: "other", fontZoomDelta: 1 });
+    send(parent, { tag: FRAME_TAG, fontZoomDelta: NaN });
+    send(parent, { tag: FRAME_TAG, fontZoomDelta: 100 });
+    expect(root.style.zoom).toBe("");
+    send(parent, { tag: FRAME_TAG, fontZoomDelta: 1 });
+    expect(root.style.zoom).toBe("1.08");
+    send(parent, { tag: FRAME_TAG, fontZoomDelta: -1 });
+    expect(root.style.zoom).toBe("");
+    send(parent, { tag: FRAME_TAG, fontZoomDelta: 1 });
+    send(parent, { tag: FRAME_TAG, fontZoomDelta: 0 });
+    expect(root.style.zoom).toBe("");
+  });
+
   it("asks the workbench for the document and edits it, and hears of changes made elsewhere", async () => {
     const script = /<script>([\s\S]*)<\/script>/.exec(frameDocument("", { dark: true, vars: {} }))![1]!;
     const sent: Array<{ call: number; op: string; args: unknown }> = [];
diff --git a/src/features/plugins/views/WebView.tsx b/src/features/plugins/views/WebView.tsx
index afa6ecf82..a32a8fd9b 100644
--- a/src/features/plugins/views/WebView.tsx
+++ b/src/features/plugins/views/WebView.tsx
@@ -20,7 +20,7 @@ import { tx } from "@/platform/i18n";
 import { useProject } from "@/platform/project";
 import { subscribeTheme, themeKey } from "@/platform/themeWatch";
 import { EmptyState, Spinner } from "@/ui";
-import { editorService } from "@/workbench/contributions";
+import { editorService, registerFontZoomSurface } from "@/workbench/contributions";
 import { ToolWindowCornerActions, useOwnToolWindowHeader } from "@/workbench/toolwindows/ToolWindows";
 import { pluginsBackend, type FileFilter } from "../backend";
 import { errorText, usePlugins } from "../store";
@@ -164,6 +164,10 @@ export function WebView({ pluginId, view, label, header = "default", document =
   const post = useCallback((message: object, transfer: Transferable[] = []) => {
     frame.current?.contentWindow?.postMessage({ tag: FRAME_TAG, ...message }, "*", transfer);
   }, []);
+  useEffect(() => {
+    const host = frame.current;
+    if (host) return registerFontZoomSurface(host, (delta) => post({ fontZoomDelta: delta }));
+  }, [page, post]);
   const postTheme = useCallback(() => {
     const t = frameTheme();
     if (ownHeader) {
@@ -360,6 +364,7 @@ export function WebView({ pluginId, view, label, header = "default", document =
     <iframe
       ref={frame}
       className={styles.frame}
+      data-plugin-webview={pluginId}
       title={label}
       sandbox="allow-scripts"
       allow={clipboard ? "clipboard-read; clipboard-write" : undefined}
diff --git a/src/features/plugins/views/frame-bridge.js b/src/features/plugins/views/frame-bridge.js
index 6e2b88c99..70b7d964b 100644
--- a/src/features/plugins/views/frame-bridge.js
+++ b/src/features/plugins/views/frame-bridge.js
@@ -60,12 +60,18 @@
 
   if (initialTheme) applyTheme(initialTheme);
 
+  const stepFrameFontZoom = (delta) => {
+    const cur = Math.round((parseFloat(root.style.zoom || "1") || 1) * 100);
+    const next = delta === 0 ? 100 : Math.max(60, Math.min(200, cur + delta * 8));
+    root.style.zoom = next === 100 ? "" : (next / 100).toFixed(2);
+  };
+
   // IDE shortcuts (Save, Close, Find Action…) pressed while the page has focus:
   // the ones the page left alone go to the workbench. Editing keys stay here.
   const EDITING_KEYS = new Set(["a", "c", "v", "x", "z", "y"]);
   window.addEventListener("keydown", (e) => {
     const fn = /^F\d{1,2}$/.test(e.key);
-    const mod = (e.metaKey || e.ctrlKey) && !EDITING_KEYS.has(e.key.toLowerCase());
+    const mod = (e.metaKey || e.ctrlKey || e.altKey) && !EDITING_KEYS.has(e.key.toLowerCase());
     if (e.isComposing || (!fn && !mod)) return;
     // After every handler of the page has seen it.
     setTimeout(() => {
@@ -78,6 +84,8 @@
     const m = e.data;
     if (e.source !== window.parent || !m || m.tag !== TAG) return;
     if (m.theme) applyTheme(m.theme);
+    else if (m.fontZoomDelta === -1 || m.fontZoomDelta === 0 || m.fontZoomDelta === 1)
+      stepFrameFontZoom(m.fontZoomDelta);
     else if (typeof m.reply === "number") {
       const p = pending.get(m.reply);
       pending.delete(m.reply);
diff --git a/src/features/terminal/copyKeys.test.ts b/src/features/terminal/copyKeys.test.ts
index cb48d8c93..3a8357db1 100644
--- a/src/features/terminal/copyKeys.test.ts
+++ b/src/features/terminal/copyKeys.test.ts
@@ -108,3 +108,36 @@ describe("terminal copy capture", () => {
     }
   });
 });
+
+it.each([
+  ["Ctrl+C", "c", "KeyC", true],
+  ["Ctrl+R", "r", "KeyR", false],
+  ["Shift+Enter", "Enter", "Enter", false],
+] as const)("keeps terminal handling for %s even when bound to font zoom", (stroke, key, code, selection) => {
+  mock.settings.terminal.overrideIdeShortcuts = true;
+  mock.session.hasSelection = selection;
+  useKeymap.setState({ preset: "intellij-windows", overrides: { "editor.increaseFontSize": [stroke] } });
+  const zoom = vi.fn();
+  const removeAction = registerAction({ id: "editor.increaseFontSize", title: "Increase Font Size", run: zoom });
+  const removeKeys = installTerminalKeys();
+  const removeDispatcher = installKeyboardDispatcher();
+  try {
+    window.dispatchEvent(
+      new KeyboardEvent("keydown", {
+        key,
+        code,
+        ctrlKey: stroke.startsWith("Ctrl"),
+        shiftKey: stroke.startsWith("Shift"),
+        cancelable: true,
+      }),
+    );
+    expect(zoom).not.toHaveBeenCalled();
+    if (selection) expect(mock.session.copySelection).toHaveBeenCalledOnce();
+    else expect(mock.session.send).toHaveBeenCalledWith(key === "r" ? "\x12" : "\x1b\r");
+  } finally {
+    removeDispatcher();
+    removeKeys();
+    removeAction();
+    useKeymap.setState({ overrides: {} });
+  }
+});
diff --git a/src/features/terminal/session.test.ts b/src/features/terminal/session.test.ts
index 9bf9e1d3a..d8305bc8e 100644
--- a/src/features/terminal/session.test.ts
+++ b/src/features/terminal/session.test.ts
@@ -1,3 +1,6 @@
+import { useProject } from "@/platform/project";
+import { workflowSettings } from "@/platform/workflowSettings";
+import { getSession, newTab, splitTab, syncTerminalProject, unbindTerminals, useTerminals } from "./store";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { FIT_INTERVAL_MS } from "./fit";
 import { findTerminalLinks, type TerminalLink } from "./links";
@@ -21,7 +24,8 @@ const workbench = vi.hoisted(() => ({
 }));
 
 vi.mock("@/platform/ipc", () => ({ call: ipc.call, commands: ipc.commands, isTauri: () => true }));
-vi.mock("@/workbench/contributions", () => ({
+vi.mock("@/workbench/contributions", async (importOriginal) => ({
+  ...(await importOriginal<object>()),
   editorService: () => ({ openFile: workbench.openFile }),
   notifications: () => ({ notify: workbench.notify }),
   OWNS_FILE_DROP: { "data-owner": true },
@@ -210,3 +214,46 @@ describe("terminal open", () => {
     container.remove();
   });
 });
+
+describe("terminal font zoom", () => {
+  afterEach(() => {
+    unbindTerminals();
+    localStorage.clear();
+    useProject.setState({ settings: null });
+  });
+
+  it("keeps the offset through settings, refit and moving splits; fresh splits and restores start at the base", () => {
+    const settings = (fontSize: number) => {
+      useProject.setState({ settings: { terminal: { useEditorFont: false, fontSize } } } as never);
+      for (const tab of useTerminals.getState().tabs)
+        getSession(tab.session)?.applySettings(workflowSettings().terminal);
+    };
+    settings(14);
+    syncTerminalProject("/font-zoom");
+    const a = newTab("/font-zoom");
+    const first = getSession(a.session)!;
+    const b = newTab("/font-zoom");
+    const second = getSession(b.session)!;
+    first.stepFontSize(2);
+    expect(first.term.options.fontSize).toBe(16);
+    expect(second.term.options.fontSize).toBe(14);
+    settings(18);
+    expect(first.term.options.fontSize).toBe(20);
+    first.refit();
+    expect(first.term.options.fontSize).toBe(20);
+    splitTab(a.id, "horizontal", true);
+    expect(getSession(a.session)).toBe(first);
+    expect(first.term.options.fontSize).toBe(20);
+    const split = splitTab(a.id, "vertical")!;
+    const splitTabInfo = useTerminals.getState().tabs.find((t) => t.id === split)!;
+    expect(getSession(splitTabInfo.session)!.term.options.fontSize).toBe(18);
+    first.stepFontSize(0);
+    expect(first.term.options.fontSize).toBe(18);
+    second.stepFontSize(3);
+    expect(second.term.options.fontSize).toBe(21);
+    expect(first.term.options.fontSize).toBe(18);
+    syncTerminalProject(null);
+    syncTerminalProject("/font-zoom");
+    for (const tab of useTerminals.getState().tabs) expect(getSession(tab.session)!.term.options.fontSize).toBe(18);
+  });
+});
diff --git a/src/features/terminal/session.ts b/src/features/terminal/session.ts
index 6217babde..8cfe922c9 100644
--- a/src/features/terminal/session.ts
+++ b/src/features/terminal/session.ts
@@ -9,7 +9,7 @@ import { SearchAddon, type ISearchOptions } from "@xterm/addon-search";
 import "@xterm/xterm/css/xterm.css";
 import { Channel } from "@tauri-apps/api/core";
 import { call, commands, isTauri, type TerminalId } from "@/platform/ipc";
-import { editorService, notifications } from "@/workbench/contributions";
+import { editorService, notifications, registerFontZoomSurface } from "@/workbench/contributions";
 import { fitScheduler, settledResize } from "./fit";
 import { installTerminalDrop } from "./drop";
 import { installTerminalPaste, pasteTerminalClipboard } from "./paste";
@@ -211,6 +211,8 @@ export class TerminalSession {
   /** Keystrokes typed while the PTY is still starting; sent as soon as it exists. */
   private pendingInput = "";
   private lastSize = { cols: 0, rows: 0 };
+  /** Per-tab font size offset (px) relative to `workflowSettings().terminal.fontSize`. */
+  private fontZoom = 0;
   /** Bumped on restart so late output from a previous PTY is ignored. */
   private generation = 0;
   /** WebKitGTK delivers one IME commit' worth of text more than once; see `ImeCommitGate`. */
@@ -308,6 +310,7 @@ export class TerminalSession {
       { dispose: installTerminalDrop(this.host, (text) => this.paste(text)) },
     );
     this.host.addEventListener("mousedown", this.onMiddleClick);
+    this.disposables.push({ dispose: registerFontZoomSurface(this.host, (delta) => this.stepFontSize(delta)) });
   }
 
   private onMiddleClick = (e: MouseEvent) => {
@@ -352,7 +355,8 @@ export class TerminalSession {
           () => this.scheduleFit(),
         );
     }
-    if (o.fontSize !== font.size) o.fontSize = font.size;
+    const targetSize = Math.max(8, Math.min(36, font.size + this.fontZoom));
+    if (o.fontSize !== targetSize) o.fontSize = targetSize;
     if (o.lineHeight !== font.lineHeight) o.lineHeight = font.lineHeight;
     if (o.letterSpacing !== font.letterSpacing) o.letterSpacing = font.letterSpacing;
     if (o.fontWeight !== font.weight) o.fontWeight = font.weight;
@@ -363,6 +367,22 @@ export class TerminalSession {
     this.scheduleFit();
   }
 
+  /** Steps this terminal tab's font size by `delta` px (or resets to 0 when `delta === 0`). */
+  stepFontSize(delta: number) {
+    const base = fontFor(workflowSettings().terminal).size;
+    if (delta === 0) {
+      this.fontZoom = 0;
+    } else {
+      const nextSize = Math.max(8, Math.min(36, base + this.fontZoom + delta));
+      this.fontZoom = nextSize - base;
+    }
+    const targetSize = Math.max(8, Math.min(36, base + this.fontZoom));
+    if (this.term.options.fontSize !== targetSize) {
+      this.term.options.fontSize = targetSize;
+      this.refit();
+    }
+  }
+
   get state(): SessionSnapshot {
     return this.snapshot;
   }
diff --git a/src/features/viewers/markdown/zoom.test.tsx b/src/features/viewers/markdown/zoom.test.tsx
index b8d83f8d5..65264e698 100644
--- a/src/features/viewers/markdown/zoom.test.tsx
+++ b/src/features/viewers/markdown/zoom.test.tsx
@@ -1,3 +1,4 @@
+import { registerFontZoomSurface } from "@/workbench/contributions";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { act, cleanup, render, screen } from "@testing-library/react";
 import { EditorState } from "@codemirror/state";
@@ -114,6 +115,67 @@ describe("editor font size actions", () => {
     expect(view.dom.style.getPropertyValue("--openidea-editor-font-size")).toContain("+ 2px");
   });
 
+  it("routes font size actions by focus even when another surface is hovered", async () => {
+    const md = open(mdCtx);
+    activate(md);
+    // Works even when editorFocus is false (e.g. a tool window has focus).
+    useContextKeys.setState({ projectOpen: true, textEditorActive: false, editorFocus: false, popupOpen: false });
+
+    const termHost = document.createElement("div");
+    termHost.setAttribute("data-terminal-session", "s1");
+    const termInput = document.createElement("textarea");
+    termHost.appendChild(termInput);
+    document.body.appendChild(termHost);
+    const termZooms: number[] = [];
+    const releaseTerminal = registerFontZoomSurface(termHost, (delta) => termZooms.push(delta));
+
+    const iframe = document.createElement("iframe");
+    iframe.setAttribute("data-plugin-webview", "dengliu.kubernetes");
+    document.body.appendChild(iframe);
+    const posted: unknown[] = [];
+    Object.defineProperty(iframe, "contentWindow", {
+      value: { postMessage: (msg: unknown) => posted.push(msg) },
+      configurable: true,
+    });
+
+    const releaseFrame = registerFontZoomSurface(iframe, (delta) =>
+      iframe.contentWindow?.postMessage({ tag: "openidea-view", fontZoomDelta: delta }, "*"),
+    );
+
+    try {
+      termInput.focus();
+      await executeAction("editor.increaseFontSize");
+      await executeAction("editor.decreaseFontSize");
+      expect(termZooms).toEqual([1, -1]);
+      expect(zoom(md)).toBe(0);
+
+      // The pointer must not redirect a keyboard action away from terminal focus.
+      const qsa = vi.spyOn(document, "querySelectorAll").mockImplementation(((sel: string) => {
+        if (sel === ":hover") return [iframe] as unknown as NodeListOf<Element>;
+        return Document.prototype.querySelectorAll.call(document, sel);
+      }) as typeof document.querySelectorAll);
+      await executeAction("editor.increaseFontSize");
+      expect(posted).toEqual([]);
+      expect(termZooms).toEqual([1, -1, 1]);
+      iframe.focus();
+      await executeAction("editor.increaseFontSize");
+      expect(posted).toEqual([{ tag: "openidea-view", fontZoomDelta: 1 }]);
+      qsa.mockRestore();
+
+      await executeAction("editor.resetFontSize");
+      expect(termZooms).toEqual([1, -1, 1, 0]);
+      expect(posted).toEqual([
+        { tag: "openidea-view", fontZoomDelta: 1 },
+        { tag: "openidea-view", fontZoomDelta: 0 },
+      ]);
+    } finally {
+      releaseTerminal();
+      releaseFrame();
+      termHost.remove();
+      iframe.remove();
+    }
+  });
+
   it("leaves ⌘= / ⌘- to fold and unfold", () => {
     for (const km of [intellijMacos, intellijWindows]) {
       expect(km["editor.increaseFontSize"]).toEqual(["Alt+Shift+."]);
diff --git a/src/workbench/contributions.ts b/src/workbench/contributions.ts
index bf0668dfb..9b42a9a24 100644
--- a/src/workbench/contributions.ts
+++ b/src/workbench/contributions.ts
@@ -1706,3 +1706,28 @@ export function registerDocumentIndexSync(sync: (path: string) => Promise<void>)
 export async function synchronizeDocumentIndexes(path: string): Promise<void> {
   await Promise.all([...documentIndexSync].map((sync) => sync(path)));
 }
+
+/** Font zoom for non-CodeMirror surfaces, owned and released by their features. */
+const fontZoomSurfaces = new Map<Element, (delta: number) => void>();
+
+export function registerFontZoomSurface(host: Element, step: (delta: number) => void): () => void {
+  fontZoomSurfaces.set(host, step);
+  return () => {
+    fontZoomSurfaces.delete(host);
+  };
+}
+
+export function stepFocusedSurfaceFontZoom(delta: number): boolean {
+  const focused = document.activeElement;
+  for (const [host, step] of fontZoomSurfaces) {
+    if (focused && host.contains(focused)) {
+      step(delta);
+      return true;
+    }
+  }
+  return false;
+}
+
+export function resetSurfaceFontZoom(): void {
+  for (const step of fontZoomSurfaces.values()) step(0);
+}