image navigation fix

WebGde/WebContent/WebGde-Widgets/ImageViewerWidget/modules/imageViewer/imageViewer.js

@@ -67,13 +67,13 @@ export class ImageViewer {
         let filename = document.getElementById("imageFileName");
         filename.textContent = imageName.length > 30 ? imageName.substring(0, 30) : imageName;
         filename.title = imageName
-
         let pages = document.getElementById("pageDetails");
         pages.textContent = "Page 1 of " + document.getElementById(imageID).getAttribute("num-of-pages");
-
+       
         switch (imageID) {
             case this.currentImageID:
                 this.setCurrentImage(null, imageToDisplay);
+            
                 break;
             case this.nextImageID:
                 this.setNextImage(imageToDisplay);
@@ -116,10 +116,8 @@ export class ImageViewer {
             document.getElementById("nextPageBtn").style.visibility = "visible";
             this.nextPageButton.addEventListener("click", () => { this.nextPageFunction(this.currentImageObject) });
             this.previousPageButton.addEventListener("click", () => { this.previousPageFunction(this.currentImageObject) });
-            sessionStorage.setItem("current_page", 1);
             sessionStorage.setItem("total_pages", numOfPages);
         } else {
-            sessionStorage.setItem("current_page", 1);
             sessionStorage.setItem("total_pages", 1);
             document.getElementById("previousPageBtn").style.visibility = "hidden";
             document.getElementById("nextPageBtn").style.visibility = "hidden";
@@ -484,13 +482,13 @@ export class ImageViewer {
             document.getElementById("previousPageBtn").style.visibility = "visible";
 
             if (fileDocument !== null && fileDocument instanceof PDFDocument) {
-                pageNum++;
+                pageNum=pageNum+1;
                 this.currentImageObject.queueRenderPage(pageNum);
             }
 
             if (fileDocument !== null && fileDocument instanceof TiffDocument) {
                 document.getElementById(fileDocument.filenameWithoutExt + `${pageNum}`).style = "display: none";
-                pageNum++;
+                pageNum=pageNum+1;
                 document.getElementById(fileDocument.filenameWithoutExt + `${pageNum}`).style.display = "block";
             }
             sessionStorage.setItem("current_page", pageNum);
@@ -511,13 +509,13 @@ export class ImageViewer {
             document.getElementById("nextPageBtn").style.visibility = "visible";
 
             if (fileDocument !== null && fileDocument instanceof PDFDocument) {
-                pageNum--;
+                pageNum =pageNum-1;
                 fileDocument.queueRenderPage(pageNum);
             }
 
             if (fileDocument !== null && fileDocument instanceof TiffDocument) {
                 document.getElementById(fileDocument.filenameWithoutExt + `${pageNum}`).style = "display: none";
-                pageNum--;
+                pageNum =pageNum-1;
                 document.getElementById(fileDocument.filenameWithoutExt + `${pageNum}`).style.display = "block";
             }
             sessionStorage.setItem("current_page", pageNum);