app: Drop persistent docs position.

This was very complicated, particularly between versions and tabs and windows, for something that offers only a minor convenience.

This also makes it simpler to navigate to a particular page interactively by just setting the iframe URL, which is useful for interactive help from the block editor.

src/app/App.tsx

@@ -17,7 +17,7 @@ import StatusBar from '../status-bar/StatusBar';
 import Toolbar from '../toolbar/Toolbar';
 import Tour from '../tour/Tour';
 import { isMacOS } from '../utils/os';
-import { useAppLastDocsPageSetting } from './hooks';
+import { docsDefaultPage } from './constants';
 import { useI18n } from './i18n';
 
 const Editor = React.lazy(async () => {
@@ -48,7 +48,6 @@ const Terminal = React.lazy(async () => {
 
 const Docs: React.FunctionComponent = () => {
     const { setIsSettingShowDocsEnabled } = useSettingIsShowDocsEnabled();
-    const { initialDocsPage, setLastDocsPage } = useAppLastDocsPageSetting();
 
     return (
         <iframe
@@ -80,10 +79,8 @@ const Docs: React.FunctionComponent = () => {
                 if (document.body.classList.contains(Classes.DARK)) {
                     contentWindow.document.documentElement.classList.add(Classes.DARK);
                 }
-
-                setLastDocsPage(contentWindow.location.href);
             }}
-            src={initialDocsPage}
+            src={docsDefaultPage}
             allowFullScreen={true}
             width="100%"
             height="100%"

src/app/hooks.ts

@@ -1,55 +0,0 @@
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2022 The Pybricks Authors
-
-import { useEffect, useMemo } from 'react';
-import { useLocalStorage, useSessionStorage } from 'usehooks-ts';
-import { docsDefaultPage, docsPathPrefix, httpServerHeadersVersion } from './constants';
-
-const defaultPage = `${docsDefaultPage}?v$${httpServerHeadersVersion}`;
-
-export function useAppLastDocsPageSetting() {
-    const key = 'app.setting.lastDocsPage';
-
-    // last visited page is stored in local storage so that new windows get the
-    // last visited page
-    const [lastPageGlobalSetting, setLastPageGlobalSetting] = useLocalStorage(
-        key,
-        defaultPage,
-    );
-
-    // it is also stored in session storage in case two windows are open at the
-    // same time so that one window doesn't affect the other
-    const [lastPageSessionSetting, setLastPageSessionSetting] = useSessionStorage(
-        key,
-        lastPageGlobalSetting,
-    );
-
-    // mirror session storage value to local storage
-    useEffect(() => {
-        setLastPageGlobalSetting(lastPageSessionSetting);
-    }, [lastPageSessionSetting, setLastPageGlobalSetting]);
-
-    // the way the docs control works, we only provide the initial page, then
-    // it manages navigation after that, so we only want the initial of this
-    // value when the app first starts
-    const initialDocsPage = useMemo(
-        () => {
-            try {
-                const url = new URL(lastPageSessionSetting);
-
-                // in case someone is hacking the storage value directly
-                if (!url.pathname.startsWith(`/${docsPathPrefix}`)) {
-                    throw new Error('invalid or outdated path');
-                }
-
-                return lastPageSessionSetting;
-            } catch {
-                return defaultPage;
-            }
-        },
-        // eslint-disable-next-line react-hooks/exhaustive-deps
-        [], // no deps so that we only get the initial value
-    );
-
-    return { initialDocsPage, setLastDocsPage: setLastPageSessionSetting };
-}