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mirror of https://github.com/laurent22/joplin.git synced 2024-12-21 09:38:01 +02:00
joplin/packages/app-mobile/components/NoteBodyViewer/hooks/useSource.ts

303 lines
11 KiB
TypeScript

import { useEffect, useState, useMemo, useRef } from 'react';
import shim from '@joplin/lib/shim';
import Setting from '@joplin/lib/models/Setting';
const { themeStyle } = require('../../global-style.js');
import markupLanguageUtils from '@joplin/lib/markupLanguageUtils';
import useEditPopup from './useEditPopup';
import Logger from '@joplin/utils/Logger';
const { assetsToHeaders } = require('@joplin/renderer');
const logger = Logger.create('NoteBodyViewer/useSource');
interface UseSourceResult {
// [html] can be null if the note is still being rendered.
html: string|null;
injectedJs: string[];
}
function usePrevious(value: any, initialValue: any = null): any {
const ref = useRef(initialValue);
useEffect(() => {
ref.current = value;
});
return ref.current;
}
const onlyCheckboxHasChangedHack = (previousBody: string, newBody: string) => {
if (previousBody.length !== newBody.length) return false;
for (let i = 0; i < previousBody.length; i++) {
const c1 = previousBody.charAt(i);
const c2 = newBody.charAt(i);
if (c1 !== c2) {
if (c1 === ' ' && (c2 === 'x' || c2 === 'X')) continue;
if (c2 === ' ' && (c1 === 'x' || c1 === 'X')) continue;
return false;
}
}
return true;
};
export default function useSource(
noteBody: string,
noteMarkupLanguage: number,
themeId: number,
highlightedKeywords: string[],
noteResources: any,
paddingBottom: number,
noteHash: string,
initialScroll: number|null,
): UseSourceResult {
const [html, setHtml] = useState<string>('');
const [injectedJs, setInjectedJs] = useState<string[]>([]);
const [resourceLoadedTime, setResourceLoadedTime] = useState(0);
const [isFirstRender, setIsFirstRender] = useState(true);
const paddingTop = '.8em';
const rendererTheme = useMemo(() => {
return {
bodyPaddingTop: paddingTop, // Extra top padding on the rendered MD so it doesn't touch the border
bodyPaddingBottom: paddingBottom, // Extra bottom padding to make it possible to scroll past the action button (so that it doesn't overlap the text)
...themeStyle(themeId),
};
}, [themeId, paddingBottom]);
const markupToHtml = useMemo(() => {
return markupLanguageUtils.newMarkupToHtml();
// eslint-disable-next-line @seiyab/react-hooks/exhaustive-deps -- Old code before rule was applied
}, [isFirstRender]);
// To address https://github.com/laurent22/joplin/issues/433
//
// If a checkbox in a note is ticked, the body changes, which normally would
// trigger a re-render of this component, which has the unfortunate side
// effect of making the view scroll back to the top. This re-rendering
// however is uncessary since the component is already visually updated via
// JS. So here, if the note has not changed, we prevent the component from
// updating. This fixes the above issue. A drawback of this is if the note
// is updated via sync, this change will not be displayed immediately.
//
// 2022-05-03: However we sometimes need the HTML to be updated, even when
// only the body has changed - for example when attaching a resource, or
// when adding text via speech recognition. So the logic has been narrowed
// down so that updates are skipped only when checkbox has been changed.
// Checkboxes still work as expected, without making the note scroll, and
// other text added to the note is displayed correctly.
//
// IMPORTANT: KEEP noteBody AS THE FIRST dependency in the array as the
// below logic rely on this.
const effectDependencies = [noteBody, resourceLoadedTime, noteMarkupLanguage, themeId, rendererTheme, highlightedKeywords, noteResources, noteHash, isFirstRender, markupToHtml];
const previousDeps = usePrevious(effectDependencies, []);
const changedDeps = effectDependencies.reduce((accum: any, dependency: any, index: any) => {
if (dependency !== previousDeps[index]) {
return { ...accum, [index]: true };
}
return accum;
}, {});
const onlyNoteBodyHasChanged = Object.keys(changedDeps).length === 1 && changedDeps[0];
const onlyCheckboxesHaveChanged = previousDeps[0] && changedDeps[0] && onlyCheckboxHasChangedHack(previousDeps[0], noteBody);
const { createEditPopupSyntax, destroyEditPopupSyntax, editPopupCss } = useEditPopup(themeId);
useEffect(() => {
if (onlyNoteBodyHasChanged && onlyCheckboxesHaveChanged) {
logger.info('Only a checkbox has changed - not updating HTML');
return () => {};
}
let cancelled = false;
async function renderNote() {
const theme = themeStyle(themeId);
const bodyToRender = noteBody || '';
const mdOptions = {
onResourceLoaded: () => {
setResourceLoadedTime(Date.now());
},
highlightedKeywords: highlightedKeywords,
resources: noteResources,
codeTheme: theme.codeThemeCss,
postMessageSyntax: 'window.joplinPostMessage_',
enableLongPress: true,
// Show an 'edit' popup over SVG images
editPopupFiletypes: ['image/svg+xml'],
createEditPopupSyntax,
destroyEditPopupSyntax,
};
// Whenever a resource state changes, for example when it goes from "not downloaded" to "downloaded", the "noteResources"
// props changes, thus triggering a render. The **content** of this noteResources array however is not changed because
// it doesn't contain info about the resource download state. Because of that, if we were to use the markupToHtml() cache
// it wouldn't re-render at all. We don't need this cache in any way because this hook is only triggered when we know
// something has changed.
markupToHtml.clearCache(noteMarkupLanguage);
const result = await markupToHtml.render(
noteMarkupLanguage,
bodyToRender,
rendererTheme,
mdOptions,
);
if (cancelled) return;
let html = result.html;
const resourceDownloadMode = Setting.value('sync.resourceDownloadMode');
// On iOS, the root container has slow inertial scroll, which feels very different from
// the native scroll in other apps. This is not the case, however, when a child (e.g. a div)
// scrolls the content instead.
// Use a div to scroll on iOS instead of the main container:
const scrollRenderedMdContainer = shim.mobilePlatform() === 'ios';
const js = [];
js.push('try {');
js.push(shim.injectedJs('webviewLib'));
// Note that this postMessage function accepts two arguments, for compatibility with the desktop version, but
// the ReactNativeWebView actually supports only one, so the second arg is ignored (and currently not needed for the mobile app).
js.push('window.joplinPostMessage_ = (msg, args) => { return window.ReactNativeWebView.postMessage(msg); };');
js.push('webviewLib.initialize({ postMessage: msg => { return window.ReactNativeWebView.postMessage(msg); } });');
js.push(`
const scrollingElement =
${scrollRenderedMdContainer ? 'document.querySelector("#rendered-md")' : 'document.scrollingElement'};
let lastScrollTop;
const onMainContentScroll = () => {
const newScrollTop = scrollingElement.scrollTop;
if (lastScrollTop !== newScrollTop) {
const eventData = { scrollTop: newScrollTop };
window.ReactNativeWebView.postMessage('onscroll:' + JSON.stringify(eventData));
}
};
// Listen for events on both scrollingElement and window
// - On Android, scrollingElement.addEventListener('scroll', callback) doesn't call callback on
// scroll. However, window.addEventListener('scroll', callback) does.
// - iOS needs a listener to be added to scrollingElement -- events aren't received when
// the listener is added to window with window.addEventListener('scroll', ...).
scrollingElement.addEventListener('scroll', onMainContentScroll);
window.addEventListener('scroll', onMainContentScroll);
const scrollContentToPosition = (position) => {
scrollingElement.scrollTop = position;
};
`);
js.push(`
const readyStateCheckInterval = setInterval(function() {
if (document.readyState === "complete") {
clearInterval(readyStateCheckInterval);
if ("${resourceDownloadMode}" === "manual") webviewLib.setupResourceManualDownload();
const hash = "${noteHash}";
const initialScroll = ${JSON.stringify(initialScroll)};
// Don't scroll to a hash if we're given initial scroll (initial scroll
// overrides scrolling to a hash).
if ((initialScroll ?? null) !== null) {
scrollContentToPosition(initialScroll);
} else if (hash) {
// Gives it a bit of time before scrolling to the anchor
// so that images are loaded.
setTimeout(() => {
const e = document.getElementById(hash);
if (!e) {
console.warn('Cannot find hash', hash);
return;
}
e.scrollIntoView();
}, 500);
}
}
}, 10);
`);
js.push('} catch (e) {');
js.push(' console.error(e);');
js.push(' window.ReactNativeWebView.postMessage("error:" + e.message + ": " + JSON.stringify(e))');
js.push(' true;');
js.push('}');
js.push('true;');
// iOS doesn't automatically adjust the WebView's font size to match users'
// accessibility settings. To do this, we need to tell it to match the system font.
// See https://github.com/ionic-team/capacitor/issues/2748#issuecomment-612923135
const iOSSpecificCss = `
@media screen {
:root body {
font: -apple-system-body;
}
}
:root > body {
padding: 0;
}
`;
const scrollRenderedMdContainerCss = `
body > #rendered-md {
width: 100vw;
overflow: auto;
height: calc(100vh - ${paddingBottom}px - ${paddingTop});
padding-bottom: ${paddingBottom}px;
padding-top: ${paddingTop};
}
`;
const defaultCss = `
code {
white-space: pre-wrap;
overflow-x: hidden;
}
`;
html =
`
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
${defaultCss}
${shim.mobilePlatform() === 'ios' ? iOSSpecificCss : ''}
${scrollRenderedMdContainer ? scrollRenderedMdContainerCss : ''}
${editPopupCss}
</style>
${assetsToHeaders(result.pluginAssets, { asHtml: true })}
</head>
<body>
${html}
</body>
</html>
`;
setHtml(html);
setInjectedJs(js);
}
// When mounted, we need to render the webview in two stages;
// - First without any source, so that all webview props are setup properly
// - Secondly with the source to actually render the note
// This is necessary to prevent a race condition that could cause an ERR_ACCESS_DENIED error
// https://github.com/react-native-webview/react-native-webview/issues/656#issuecomment-551312436
if (isFirstRender) {
setIsFirstRender(false);
setHtml('');
setInjectedJs([]);
} else {
void renderNote();
}
return () => {
cancelled = true;
};
// eslint-disable-next-line @seiyab/react-hooks/exhaustive-deps -- Old code before rule was applied
}, effectDependencies);
return { html, injectedJs };
}