feat: add view mode in Excalidraw (#2840)

Co-authored-by: Lipis <lipiridis@gmail.com>

src/actions/actionToggleViewMode.tsx

@@ -0,0 +1,22 @@
+import { CODES, KEYS } from "../keys";
+import { register } from "./register";
+import { trackEvent } from "../analytics";
+
+export const actionToggleViewMode = register({
+  name: "viewMode",
+  perform(elements, appState) {
+    trackEvent("view", "mode", "view");
+    return {
+      appState: {
+        ...appState,
+        viewModeEnabled: !this.checked!(appState),
+        selectedElementIds: {},
+      },
+      commitToHistory: false,
+    };
+  },
+  checked: (appState) => appState.viewModeEnabled,
+  contextItemLabel: "labels.viewMode",
+  keyTest: (event) =>
+    !event[KEYS.CTRL_OR_CMD] && event.altKey && event.code === CODES.R,
+});