feat: pdf embed view component

packages/frontend/component/src/utils/index.ts

@@ -1,3 +1,4 @@
+export * from './observe-intersection';
 export * from './observe-resize';
 export { startScopedViewTransition } from './view-transition';
 export * from './with-unit';

packages/frontend/component/src/utils/observe-intersection.ts

@@ -0,0 +1,83 @@
+type ObserveIntersection = {
+  callback: (entity: IntersectionObserverEntry) => void;
+  dispose: () => void;
+};
+
+let _intersectionObserver: IntersectionObserver | null = null;
+const elementsMap = new WeakMap<Element, Array<ObserveIntersection>>();
+
+// for debugging
+if (typeof window !== 'undefined') {
+  (window as any)._intersectionObserverElementsMap = elementsMap;
+}
+
+/**
+ * @internal get or initialize the IntersectionObserver instance
+ */
+const getIntersectionObserver = () =>
+  (_intersectionObserver ??= new IntersectionObserver(
+    entries => {
+      entries.forEach(entry => {
+        const listeners = elementsMap.get(entry.target) ?? [];
+        listeners.forEach(({ callback }) => callback(entry));
+      });
+    },
+    {
+      rootMargin: '20px 20px 20px 20px',
+      threshold: 0.233,
+    }
+  ));
+
+/**
+ * @internal remove element's specific listener
+ */
+const removeListener = (element: Element, listener: ObserveIntersection) => {
+  if (!element) return;
+  const listeners = elementsMap.get(element) ?? [];
+  const observer = getIntersectionObserver();
+  // remove the listener from the element
+  if (listeners.includes(listener)) {
+    elementsMap.set(
+      element,
+      listeners.filter(l => l !== listener)
+    );
+  }
+  // if no more listeners, unobserve the element
+  if (elementsMap.get(element)?.length === 0) {
+    observer.unobserve(element);
+    elementsMap.delete(element);
+  }
+};
+
+/**
+ * A function to observe the intersection of an element use global IntersectionObserver.
+ *
+ * ```ts
+ * useEffect(() => {
+ *  const dispose1 = observeIntersection(elRef1.current, (entry) => {});
+ *  const dispose2 = observeIntersection(elRef2.current, (entry) => {});
+ *
+ *  return () => {
+ *   dispose1();
+ *   dispose2();
+ *  };
+ * }, [])
+ * ```
+ * @return A function to dispose the observer.
+ */
+export const observeIntersection = (
+  element: Element,
+  callback: ObserveIntersection['callback']
+) => {
+  const observer = getIntersectionObserver();
+  if (!elementsMap.has(element)) {
+    observer.observe(element);
+  }
+  const prevListeners = elementsMap.get(element) ?? [];
+  const listener = { callback, dispose: () => {} };
+  listener.dispose = () => removeListener(element, listener);
+
+  elementsMap.set(element, [...prevListeners, listener]);
+
+  return listener.dispose;
+};

packages/frontend/core/src/components/attachment-viewer/index.tsx

@@ -2,7 +2,7 @@ import { ViewBody, ViewHeader } from '@affine/core/modules/workbench';
 import type { AttachmentBlockModel } from '@blocksuite/affine/blocks';
 
 import { AttachmentPreviewErrorBoundary, Error } from './error';
-import { PDFViewer } from './pdf-viewer';
+import { PDFViewer, type PDFViewerProps } from './pdf-viewer';
 import * as styles from './styles.css';
 import { Titlebar } from './titlebar';
 import { buildAttachmentProps } from './utils';
@@ -18,13 +18,7 @@ export const AttachmentViewer = ({ model }: AttachmentViewerProps) => {
   return (
     <div className={styles.viewerContainer}>
       <Titlebar {...props} />
-      {model.type.endsWith('pdf') ? (
-        <AttachmentPreviewErrorBoundary>
-          <PDFViewer {...props} />
-        </AttachmentPreviewErrorBoundary>
-      ) : (
-        <Error {...props} />
-      )}
+      <AttachmentViewerInner {...props} />
     </div>
   );
 };
@@ -39,14 +33,18 @@ export const AttachmentViewerView = ({ model }: AttachmentViewerProps) => {
         <Titlebar {...props} />
       </ViewHeader>
       <ViewBody>
-        {model.type.endsWith('pdf') ? (
-          <AttachmentPreviewErrorBoundary>
-            <PDFViewer {...props} />
-          </AttachmentPreviewErrorBoundary>
-        ) : (
-          <Error {...props} />
-        )}
+        <AttachmentViewerInner {...props} />
       </ViewBody>
     </>
   );
 };
+
+const AttachmentViewerInner = (props: PDFViewerProps) => {
+  return props.model.type.endsWith('pdf') ? (
+    <AttachmentPreviewErrorBoundary>
+      <PDFViewer {...props} />
+    </AttachmentPreviewErrorBoundary>
+  ) : (
+    <Error {...props} />
+  );
+};

packages/frontend/core/src/components/attachment-viewer/pdf-viewer-embedded-inner.tsx

@@ -0,0 +1,249 @@
+import { IconButton, observeIntersection } from '@affine/component';
+import {
+  type PDF,
+  type PDFPage,
+  PDFService,
+  PDFStatus,
+} from '@affine/core/modules/pdf';
+import { LoadingSvg, PDFPageCanvas } from '@affine/core/modules/pdf/views';
+import { PeekViewService } from '@affine/core/modules/peek-view';
+import { stopPropagation } from '@affine/core/utils';
+import {
+  ArrowDownSmallIcon,
+  ArrowUpSmallIcon,
+  AttachmentIcon,
+  CenterPeekIcon,
+} from '@blocksuite/icons/rc';
+import { LiveData, useLiveData, useService } from '@toeverything/infra';
+import clsx from 'clsx';
+import { debounce } from 'lodash-es';
+import {
+  type MouseEvent,
+  useCallback,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+} from 'react';
+
+import type { PDFViewerProps } from './pdf-viewer';
+import * as styles from './styles.css';
+import * as embeddedStyles from './styles.embedded.css';
+
+type PDFViewerEmbeddedInnerProps = PDFViewerProps;
+
+export function PDFViewerEmbeddedInner({ model }: PDFViewerEmbeddedInnerProps) {
+  const peekView = useService(PeekViewService).peekView;
+  const pdfService = useService(PDFService);
+  const [pdfEntity, setPdfEntity] = useState<{
+    pdf: PDF;
+    release: () => void;
+  } | null>(null);
+  const [pageEntity, setPageEntity] = useState<{
+    page: PDFPage;
+    release: () => void;
+  } | null>(null);
+
+  const meta = useLiveData(
+    useMemo(() => {
+      return pdfEntity
+        ? pdfEntity.pdf.state$.map(s => {
+            return s.status === PDFStatus.Opened
+              ? s.meta
+              : { pageCount: 0, width: 0, height: 0 };
+          })
+        : new LiveData({ pageCount: 0, width: 0, height: 0 });
+    }, [pdfEntity])
+  );
+  const img = useLiveData(
+    useMemo(() => {
+      return pageEntity ? pageEntity.page.bitmap$ : null;
+    }, [pageEntity])
+  );
+
+  const [isLoading, setIsLoading] = useState(true);
+  const [cursor, setCursor] = useState(0);
+  const viewerRef = useRef<HTMLDivElement>(null);
+  const [visibility, setVisibility] = useState(false);
+  const canvasRef = useRef<HTMLCanvasElement>(null);
+
+  const peek = useCallback(() => {
+    const target = model.doc.getBlock(model.id);
+    if (!target) return;
+    peekView.open({ element: target }).catch(console.error);
+  }, [peekView, model]);
+
+  const navigator = useMemo(() => {
+    const p = cursor - 1;
+    const n = cursor + 1;
+
+    return {
+      prev: {
+        disabled: p < 0,
+        onClick: (e: MouseEvent) => {
+          e.stopPropagation();
+          setCursor(p);
+        },
+      },
+      next: {
+        disabled: n >= meta.pageCount,
+        onClick: (e: MouseEvent) => {
+          e.stopPropagation();
+          setCursor(n);
+        },
+      },
+      peek: {
+        onClick: (e: MouseEvent) => {
+          e.stopPropagation();
+          peek();
+        },
+      },
+    };
+  }, [cursor, meta, peek]);
+
+  useEffect(() => {
+    const canvas = canvasRef.current;
+    if (!canvas) return;
+    if (!img) return;
+    const ctx = canvas.getContext('2d');
+    if (!ctx) return;
+    const { width, height } = meta;
+    if (width * height === 0) return;
+
+    setIsLoading(false);
+
+    canvas.width = width * 2;
+    canvas.height = height * 2;
+    ctx.clearRect(0, 0, canvas.width, canvas.height);
+    ctx.drawImage(img, 0, 0);
+  }, [img, meta]);
+
+  useEffect(() => {
+    if (!visibility) return;
+    if (!pageEntity) return;
+
+    const { width, height } = meta;
+    if (width * height === 0) return;
+
+    pageEntity.page.render({ width, height, scale: 2 });
+
+    return () => {
+      pageEntity.page.render.unsubscribe();
+    };
+  }, [visibility, pageEntity, meta]);
+
+  useEffect(() => {
+    if (!visibility) return;
+    if (!pdfEntity) return;
+
+    const { width, height } = meta;
+    if (width * height === 0) return;
+
+    const pageEntity = pdfEntity.pdf.page(cursor, `${width}:${height}:2`);
+
+    setPageEntity(pageEntity);
+
+    return () => {
+      pageEntity.release();
+      setPageEntity(null);
+    };
+  }, [visibility, pdfEntity, cursor, meta]);
+
+  useEffect(() => {
+    if (!visibility) return;
+
+    const pdfEntity = pdfService.get(model);
+
+    setPdfEntity(pdfEntity);
+
+    return () => {
+      pdfEntity.release();
+      setPdfEntity(null);
+    };
+  }, [model, pdfService, visibility]);
+
+  useEffect(() => {
+    const viewer = viewerRef.current;
+    if (!viewer) return;
+
+    return observeIntersection(
+      viewer,
+      debounce(
+        entry => {
+          setVisibility(entry.isIntersecting);
+        },
+        377,
+        {
+          trailing: true,
+        }
+      )
+    );
+  }, []);
+
+  return (
+    <div ref={viewerRef} className={embeddedStyles.pdfContainer}>
+      <main className={embeddedStyles.pdfViewer}>
+        <div
+          className={styles.pdfPage}
+          style={{
+            position: 'relative',
+            display: 'flex',
+            justifyContent: 'center',
+            alignItems: 'center',
+            width: '100%',
+            minHeight: '759px',
+          }}
+        >
+          <PDFPageCanvas ref={canvasRef} />
+          <LoadingSvg
+            style={{
+              position: 'absolute',
+              visibility: isLoading ? 'visible' : 'hidden',
+            }}
+          />
+        </div>
+
+        <div className={embeddedStyles.pdfControls}>
+          <IconButton
+            size={16}
+            icon={<ArrowUpSmallIcon />}
+            className={embeddedStyles.pdfControlButton}
+            onDoubleClick={stopPropagation}
+            {...navigator.prev}
+          />
+          <IconButton
+            size={16}
+            icon={<ArrowDownSmallIcon />}
+            className={embeddedStyles.pdfControlButton}
+            onDoubleClick={stopPropagation}
+            {...navigator.next}
+          />
+          <IconButton
+            size={16}
+            icon={<CenterPeekIcon />}
+            className={embeddedStyles.pdfControlButton}
+            onDoubleClick={stopPropagation}
+            {...navigator.peek}
+          />
+        </div>
+      </main>
+      <footer className={embeddedStyles.pdfFooter}>
+        <div
+          className={clsx([embeddedStyles.pdfFooterItem, { truncate: true }])}
+        >
+          <AttachmentIcon />
+          <span className={embeddedStyles.pdfTitle}>{model.name}</span>
+        </div>
+        <div
+          className={clsx([
+            embeddedStyles.pdfFooterItem,
+            embeddedStyles.pdfPageCount,
+          ])}
+        >
+          <span>{meta.pageCount > 0 ? cursor + 1 : '-'}</span>/
+          <span>{meta.pageCount > 0 ? meta.pageCount : '-'}</span>
+        </div>
+      </footer>
+    </div>
+  );
+}