1.0.0

bin/wwwroot/_content/Blazor.Bootstrap/blazor.bootstrap.pdf.js

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+import * as pdfJS from './pdfjs-4.0.379.min.mjs';
+import * as pdfWorker from './pdfjs-4.0.379.worker.min.mjs';
+
+if (pdfJS != null && pdfWorker != null) {
+    pdfJS.GlobalWorkerOptions.workerSrc = pdfWorker;
+}
+
+function getCanvas(item) {
+    if (isDomSupported() && typeof item === 'string') {
+        item = document.getElementById(item);
+    } else if (item && item.length) {
+        // support for array based queries
+        item = item[0];
+    }
+
+    if (item && item.canvas !== undefined && item.canvas) {
+        // support for any object associated to a canvas (including a context2d)
+        item = item.canvas;
+    }
+
+    return item;
+}
+
+const getPdf = (key) => {
+    const canvas = getCanvas(key);
+    return Object.values(pdfInstances).filter((c) => c.canvas === canvas).pop();
+};
+
+const pdfInstances = {};
+
+class Pdf {
+    static instances = pdfInstances;
+    static getPdf = getPdf;
+
+    constructor(item) {
+        const canvas = getCanvas(item);
+        //const existingPdf = getPdf(canvas);
+
+        this.id = canvas.id;
+        this.canvas = canvas;
+        this.ctx = canvas.getContext('2d');
+        this.pdfDoc = null;
+        this.pageNum = 1;
+        this.pagesCount = 0;
+        this.pageRendering = false;
+        this.pageNumPending = null;
+        this.scale = 1;
+        this.rotation = 0;
+
+        pdfInstances[this.id] = this;
+    }
+}
+
+export function firstPage(dotNetHelper, elementId) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null || pdf.pageNum === 1)
+        return;
+
+    if (pdf.pageNum > 1)
+        pdf.pageNum = 1;
+
+    queueRenderPage(pdf, pdf.pageNum);
+
+    setPdfViewerMetaData(dotNetHelper, pdf);
+}
+
+export function gotoPage(dotNetHelper, elementId, gotoPageNum) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null || gotoPageNum < 1 || gotoPageNum > pdf.pagesCount)
+        return;
+
+    pdf.pageNum = gotoPageNum;
+
+    queueRenderPage(pdf, pdf.pageNum);
+
+    setPdfViewerMetaData(dotNetHelper, pdf);
+}
+
+export function lastPage(dotNetHelper, elementId) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null || (pdf.pageNum === 1 && pdf.pageNum === pdf.pagesCount))
+        return;
+
+    if (pdf.pageNum < pdf.pagesCount)
+        pdf.pageNum = pdf.pagesCount;
+
+    queueRenderPage(pdf, pdf.pageNum);
+
+    setPdfViewerMetaData(dotNetHelper, pdf);
+}
+
+export function nextPage(dotNetHelper, elementId) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null || pdf.pageNum === pdf.pagesCount)
+        return;
+
+    if (pdf.pageNum < pdf.pagesCount)
+        pdf.pageNum += 1;
+
+    queueRenderPage(pdf, pdf.pageNum);
+
+    setPdfViewerMetaData(dotNetHelper, pdf);
+}
+
+export function previousPage(dotNetHelper, elementId) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null || pdf.pageNum === 0 || pdf.pageNum === 1)
+        return;
+
+    if (pdf.pageNum > 0)
+        pdf.pageNum -= 1;
+
+    queueRenderPage(pdf, pdf.pageNum);
+
+    setPdfViewerMetaData(dotNetHelper, pdf);
+}
+
+export async function print(dotNetHelper, elementId, url) {
+    const pdfDoc = await pdfJS.getDocument(url).promise;
+    const pageRange = [1, 2, 3, 4]; // TODO: update this
+
+    const iframeEl = document.createElement('iframe');
+    iframeEl.style = 'display:none';
+    document.body.appendChild(iframeEl);
+
+    for (const pageNumber of pageRange) {
+        const page = await pdfDoc.getPage(pageNumber);
+        
+        const viewport = page.getViewport({ scale: 1.5 });
+        const canvas = document.createElement("canvas");
+        canvas.height = viewport.height;
+        canvas.width = viewport.width;
+
+        //canvas.style.height = `${viewport.height * 2}px`;
+        //canvas.style.width = `${viewport.width * 2}px`;
+
+        const ctx = canvas.getContext('2d');
+
+        const renderContext = {
+            //intent: 'print',
+            canvasContext: ctx,
+            viewport: viewport
+        };
+        await page.render(renderContext).promise;
+        
+        const iframeDoc = iframeEl.contentWindow.document;
+        iframeDoc.body.appendChild(canvas);
+    }
+
+    setTimeout(() => {
+        iframeEl.contentWindow.print();
+        iframeEl.remove();
+    },
+    1000);
+}
+
+export function rotate(dotNetHelper, elementId, rotation) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null || Number.isNaN(rotation) || rotation % 90 !== 0)
+        return;
+
+    pdf.rotation = rotation;
+
+    queueRenderPage(pdf, pdf.pageNum);
+}
+
+export function zoomInOut(dotNetHelper, elementId, scale) {
+    const pdf = getPdf(elementId);
+
+    if (pdf == null)
+        return;
+
+    if (!Number.isNaN(scale))
+        pdf.scale = scale;
+
+    queueRenderPage(pdf, pdf.pageNum);
+}
+
+// resize
+// print
+// download
+// zoomreset
+
+/*
+firstPageButton.disabled = this.pageNumber <= 1;
+lastPageButton.disabled = this.pageNumber >= this.pagesCount;
+pageRotateCwButton.disabled = this.pagesCount === 0;
+pageRotateCcwButton.disabled = this.pagesCount === 0;
+*/
+
+export function initialize(dotNetHelper, elementId, scale, rotation, url) {
+    const pdf = new Pdf(elementId);
+    pdf.scale = scale;
+    pdf.rotation = rotation;
+
+    pdfJS.getDocument(url).promise.then(function (doc) {
+        pdf.pdfDoc = doc;
+        pdf.pagesCount = doc.numPages;
+        renderPage(pdf, pdf.pageNum);
+        dotNetHelper.invokeMethodAsync('DocumentLoaded', { pagesCount: pdf.pagesCount, pageNumber: pdf.pageNum });
+    });
+}
+
+function isDomSupported() {
+    return typeof window !== 'undefined' && typeof document !== 'undefined';
+}
+
+/**
+ * If another page rendering in progress, waits until the rendering is
+ * finished. Otherwise, executes rendering immediately.
+ */
+function queueRenderPage(pdf, num) {
+    if (pdf.pageRendering) {
+        pdf.pageNumPending = num;
+    } else {
+        renderPage(pdf, num);
+    }
+}
+
+/**
+ * Get page info from document, resize canvas accordingly, and render page.
+ * @param num Page number.
+ */
+function renderPage(pdf, num) {
+    pdf.pageRendering = true;
+
+    // Using promise to fetch the page
+    pdf.pdfDoc.getPage(num).then((page) => {
+        const viewport = page.getViewport({ scale: pdf.scale, rotation: pdf.rotation });
+        pdf.canvas.height = viewport.height;
+        pdf.canvas.width = viewport.width;
+
+        // Render PDF page into canvas context
+        const renderContext = {
+            canvasContext: pdf.ctx,
+            viewport: viewport
+        };
+
+        const renderTask = page.render(renderContext);
+
+        // Wait for rendering to finish
+        renderTask.promise.then(() => {
+                pdf.pageRendering = false;
+                if (pdf.pageNumPending !== null) {
+                    // New page rendering is pending
+                    renderPage(pdf, pdf.pageNumPending);
+                    pdf.pageNumPending = null;
+                }
+            })
+            .catch((error) => {
+                // TODO: track exception
+            });
+    });
+}
+
+function setPdfViewerMetaData(dotNetHelper, pdf) {
+    if (dotNetHelper == null)
+        return;
+
+    dotNetHelper.invokeMethodAsync('SetPdfViewerMetaData', { pagesCount: pdf.pagesCount, pageNumber: pdf.pageNum });
+}