Use platform-native app shortcuts on macOS (#521)

desktop/src/app/AppShell.tsx

@@ -52,6 +52,7 @@ import { useDeferredStartup } from "@/shared/hooks/useDeferredStartup";
 import { joinChannel } from "@/shared/api/tauri";
 import type { Channel, RelayEvent, SearchHit } from "@/shared/api/types";
 import { ChannelNavigationProvider } from "@/shared/context/ChannelNavigationContext";
+import { hasPrimaryShortcutModifier } from "@/shared/lib/platform";
 import { Button } from "@/shared/ui/button";
 import {
   SidebarInset,
@@ -398,7 +399,7 @@ export function AppShell() {
     }
 
     function handleKeyDown(event: KeyboardEvent) {
-      if (!(event.metaKey || event.ctrlKey) || event.altKey) {
+      if (!hasPrimaryShortcutModifier(event) || event.altKey) {
         return;
       }
 
@@ -444,7 +445,7 @@ export function AppShell() {
     function handleKeyDown(event: KeyboardEvent) {
       const isSettingsShortcut =
         (event.key === "," || event.code === "Comma") &&
-        (event.metaKey || event.ctrlKey) &&
+        hasPrimaryShortcutModifier(event) &&
         !event.altKey &&
         !event.shiftKey;
 

desktop/src/app/navigation/useBackForwardControls.ts

@@ -5,6 +5,7 @@ import {
   useRouterState,
 } from "@tanstack/react-router";
 
+import { isMacPlatform } from "@/shared/lib/platform";
 import { trimMapToSize } from "@/shared/lib/trimMapToSize";
 
 type RouterHistoryState = {
@@ -26,10 +27,6 @@ function isEditableTarget(target: EventTarget | null): boolean {
   );
 }
 
-function isMacPlatform() {
-  return window.navigator.platform.toLowerCase().includes("mac");
-}
-
 export function useBackForwardControls() {
   const router = useRouter();
   const canGoBack = useCanGoBack();

desktop/src/app/useWebviewZoomShortcuts.ts

@@ -1,6 +1,8 @@
 import * as React from "react";
 import { getCurrentWebview } from "@tauri-apps/api/webview";
 
+import { hasPrimaryShortcutModifier } from "@/shared/lib/platform";
+
 const DEFAULT_ZOOM_FACTOR = 1;
 const MIN_ZOOM_FACTOR = 0.2;
 const MAX_ZOOM_FACTOR = 10;
@@ -9,7 +11,7 @@ const ZOOM_STEP = 0.2;
 type ZoomAction = "increase" | "decrease" | "reset";
 
 function getZoomAction(event: KeyboardEvent): ZoomAction | null {
-  if (!(event.metaKey || event.ctrlKey) || event.altKey) {
+  if (!hasPrimaryShortcutModifier(event) || event.altKey) {
     return null;
   }
 

desktop/src/features/messages/lib/useRichTextEditor.ts

@@ -5,8 +5,10 @@ import { useEditor, type Editor } from "@tiptap/react";
 import StarterKit from "@tiptap/starter-kit";
 import Placeholder from "@tiptap/extension-placeholder";
 import Link from "@tiptap/extension-link";
-import { Extension } from "@tiptap/core";
-import { TextSelection } from "@tiptap/pm/state";
+import { Extension, type KeyboardShortcutCommand } from "@tiptap/core";
+import { Selection, TextSelection } from "@tiptap/pm/state";
+
+import { isMacPlatform } from "@/shared/lib/platform";
 
 import {
   MentionHighlightExtension,
@@ -73,6 +75,55 @@ export function useRichTextEditor({
           // below with custom options (autolink, openOnClick, etc.).
           link: false,
         }),
+        // macOS text fields traditionally support a small set of Emacs-style
+        // Control shortcuts. ProseMirror already handles Ctrl-A/E/H/D on macOS;
+        // these fill in the common movement and kill-line gaps for the composer.
+        Extension.create({
+          name: "macEmacsTextShortcuts",
+          addKeyboardShortcuts() {
+            const shortcuts: Record<string, KeyboardShortcutCommand> = {};
+            if (!isMacPlatform()) {
+              return shortcuts;
+            }
+
+            return {
+              "Ctrl-b": ({ editor: ed }) => {
+                const { empty, from } = ed.state.selection;
+                if (!empty || from <= 0) return false;
+                return ed.commands.setTextSelection(from - 1);
+              },
+              "Ctrl-f": ({ editor: ed }) => {
+                const { empty, from } = ed.state.selection;
+                if (!empty || from >= ed.state.doc.content.size) return false;
+                return ed.commands.setTextSelection(from + 1);
+              },
+              "Ctrl-k": ({ editor: ed }) => {
+                const { state, view } = ed;
+                const { $from, empty, from, to } = state.selection;
+
+                if (!empty) {
+                  return ed.commands.deleteSelection();
+                }
+
+                const blockEnd = $from.end();
+                if (from < blockEnd) {
+                  return ed.commands.deleteRange({ from, to: blockEnd });
+                }
+
+                const nextSelection = Selection.findFrom(
+                  state.doc.resolve(to),
+                  1,
+                  true,
+                );
+                if (!nextSelection) return false;
+
+                const transaction = state.tr.delete(to, nextSelection.from);
+                view.dispatch(transaction.scrollIntoView());
+                return true;
+              },
+            };
+          },
+        }),
         // Shift+Enter inside lists/blockquotes: split the node instead of
         // inserting a hard break so continuation lines keep their formatting.
         Extension.create({

desktop/src/features/search/useChannelFind.ts

@@ -2,6 +2,7 @@ import * as React from "react";
 
 import { useSearchMessagesQuery } from "@/features/search/hooks";
 import type { TimelineMessage } from "@/features/messages/types";
+import { hasPrimaryShortcutModifier } from "@/shared/lib/platform";
 
 const MIN_QUERY_LENGTH = 2;
 const DEBOUNCE_MS = 300;
@@ -119,11 +120,11 @@ export function useChannelFind({ channelId, messages }: UseChannelFindOptions) {
     );
   }, [matchedIds.length]);
 
-  // Register CMD+F keyboard shortcut.
+  // Register platform-standard find shortcut (⌘F on macOS, Ctrl+F elsewhere).
   React.useEffect(() => {
     function handleKeyDown(event: KeyboardEvent) {
       if (
-        (event.metaKey || event.ctrlKey) &&
+        hasPrimaryShortcutModifier(event) &&
         !event.altKey &&
         !event.shiftKey &&
         event.key.toLowerCase() === "f"

desktop/src/shared/lib/keyboard-shortcuts.ts

@@ -1,3 +1,5 @@
+import { isMacPlatform } from "@/shared/lib/platform";
+
 export type ShortcutCategory =
   | "Navigation"
   | "Messages"
@@ -220,10 +222,6 @@ export function getShortcutsByCategory(): Map<
   return map;
 }
 
-function isMac(): boolean {
-  return /mac|iphone|ipad|ipod/i.test(navigator.platform);
-}
-
 export function getPlatformKeys(shortcut: KeyboardShortcut): string {
-  return isMac() ? shortcut.keys : shortcut.keysWindows;
+  return isMacPlatform() ? shortcut.keys : shortcut.keysWindows;
 }

desktop/src/shared/lib/platform.ts

@@ -0,0 +1,31 @@
+type ModifierKeyboardEvent = Pick<
+  KeyboardEvent,
+  "altKey" | "ctrlKey" | "metaKey" | "shiftKey"
+>;
+
+/** Returns true on macOS/iOS-style Apple platforms. */
+export function isMacPlatform(): boolean {
+  if (typeof navigator === "undefined") {
+    return false;
+  }
+
+  return /mac|iphone|ipad|ipod/i.test(navigator.platform);
+}
+
+/**
+ * The platform's normal application-shortcut modifier:
+ * - macOS: Command (Meta)
+ * - Windows/Linux: Control
+ *
+ * On macOS this intentionally rejects Control so native Emacs-style text
+ * editing shortcuts (Ctrl-A/E/B/F/K/etc.) are left available to text fields.
+ */
+export function hasPrimaryShortcutModifier(
+  event: ModifierKeyboardEvent,
+): boolean {
+  if (isMacPlatform()) {
+    return event.metaKey && !event.ctrlKey;
+  }
+
+  return event.ctrlKey && !event.metaKey;
+}

desktop/src/shared/ui/sidebar.tsx

@@ -4,6 +4,7 @@ import { cva, type VariantProps } from "class-variance-authority";
 import { PanelLeftClose, PanelLeftOpen } from "lucide-react";
 
 import { cn } from "@/shared/lib/cn";
+import { hasPrimaryShortcutModifier } from "@/shared/lib/platform";
 import { useIsMobile } from "@/shared/hooks/use-mobile";
 import { Button } from "@/shared/ui/button";
 import { Input } from "@/shared/ui/input";
@@ -105,7 +106,7 @@ const SidebarProvider = React.forwardRef<
       const handleKeyDown = (event: KeyboardEvent) => {
         if (
           event.key === SIDEBAR_KEYBOARD_SHORTCUT &&
-          (event.metaKey || event.ctrlKey)
+          hasPrimaryShortcutModifier(event)
         ) {
           event.preventDefault();
           toggleSidebar();