add zoom

app/pub/scripts/anviewer.js

@@ -0,0 +1,65 @@
+var pdfjsLib = window['pdfjs-dist/build/pdf'];
+
+
+function renderPage() {
+    pageRendering = true;
+    // Using promise to fetch the page
+    pdfDoc.getPage(pageNum).then(function(page, ) {
+
+    var canvas = document.getElementById('the-canvas');  
+    var context = canvas.getContext('2d');
+      var viewport = page.getViewport({scale: scale});
+      canvas.height = viewport.height;
+      canvas.width = viewport.width;
+  
+      // Render PDF page into canvas context
+      var renderContext = {
+        canvasContext: context,
+        viewport: viewport
+      };
+      var renderTask = page.render(renderContext);
+  
+      // Wait for rendering to finish
+      renderTask.promise.then(function() {
+        pageRendering = false;
+        if (pageNumPending !== null) {
+          // New page rendering is pending
+          renderPage(pageNumPending);
+          pageNumPending = null;
+        }
+      });
+    });
+
+    document.getElementById('pdfprogress').innerHTML = 'Приятного чтения ↓';
+}  
+
+
+function pdfzoomin(){
+
+    scale += 0.5;
+    renderPage();
+
+}
+
+function pdfzoomout(){
+
+    scale -= 0.5;
+    renderPage();
+
+}
+
+
+
+pdfjsLib.getDocument(url).promise.then(function(pdfDoc_) {
+    
+    document.getElementById('pdfprogress').innerHTML = 'Идет подготовка страницы ...';
+
+    pdfDoc = pdfDoc_;
+    renderPage();
+  });
+
+
+
+
+
+