function updateLargeViewer() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  const DWObjectLargeViewer = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainerLargeViewer');
  if (DWObject) {
    DWObject.CopyToClipboard(DWObject.CurrentImageIndexInBuffer); // Copy the current image in the thumbnail to clipboard in DIB format.
    DWObjectLargeViewer.LoadDibFromClipboard(); // Load the image from Clipboard into the large viewer.
  }
}

function downloadImage() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    DWObject.HTTPPort = 80;                
    DWObject.HTTPDownload("www.dynamsoft.com", "img.png", () => {}, (errorCode: number, errorString: string) => {});
  }
}

function uploadImage() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    DWObject.HTTPPort = 80;  
    DWObject.IfSSL = false;
    DWObject.HTTPUploadThroughPost("www.dynamsoft.com", DWObject.CurrentImageIndexInBuffer, "upload", "tmp.jpg", () => {}, (errorCode: number, errorString: string) => {});
  }
}

function saveImage() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    DWObject.ConvertToGrayScale(DWObject.CurrentImageIndexInBuffer);
    DWObject.SaveAsJPEG("DynamicWebTWAIN.jpg", DWObject.CurrentImageIndexInBuffer);
    DWObject.SaveAllAsMultiPageTIFF("DynamicWebTWAIN.tiff", () => {}, (errorCode: number, errorString: string) => {});
    DWObject.SaveAllAsPDF("DynamicWebTWAIN.pdf", () => {}, (errorCode: number, errorString: string) => {});
  }
}

function acquireImage() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    DWObject.SelectSourceByIndex(0); // Use method SelectSourceByIndex to avoid the 'Select Source' dialog
    DWObject.OpenSource();
    DWObject.IfDisableSourceAfterAcquire = true; // Scanner source will be disabled/closed automatically after the scan.
    DWObject.AcquireImage({}, () => {}, (errorCode: number, errorString: string) => {DWObject.CloseSource(); });
  }
}

function loadPDF() {
    const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
    if (DWObject) {
		DWObject.Addon.PDF.SetResolution(200);
		DWObject.Addon.PDF.SetConvertMode(1);
        DWObject.IfShowFileDialog = true;
        DWObject.LoadImageEx(" ", 5);
    }
}

function dwtOnReady() {
    const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');    // Get the Dynamic Web TWAIN object that is embeded in the div with id 'dwtcontrolContainer'
    if (DWObject) {
      let count = DWObject.SourceCount;
      if (count === 0) {
        DWObject.CloseSourceManager();
        DWObject.ImageCaptureDriverType = 0;
        DWObject.OpenSourceManager();
        count = DWObject.SourceCount;
      }
  }
}

function editImage() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    if (DWObject.HowManyImagesInBuffer > 0)
        DWObject.RotateLeft(DWObject.CurrentImageIndexInBuffer);

    if (DWObject.HowManyImagesInBuffer > 0)
        DWObject.RotateRight(DWObject.CurrentImageIndexInBuffer);

    if (DWObject.HowManyImagesInBuffer > 0)
        DWObject.Mirror(DWObject.CurrentImageIndexInBuffer);
    
    if (DWObject.HowManyImagesInBuffer > 0)
        DWObject.Flip(DWObject.CurrentImageIndexInBuffer);
  }
}

function registerEvent() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    // The event OnPostTransfer fires after each image is scanned and transferred
    DWObject.RegisterEvent("OnPostTransfer", function () {});

    // The event OnPostLoad fires after the images from a local directory have been loaded into the control
    DWObject.RegisterEvent("OnPostLoad", function () {});

    // The event OnMouseClick fires when the mouse clicks on an image on Dynamic Web TWAIN viewer
    DWObject.RegisterEvent("OnMouseClick", function () {});

    // The event OnTopImageInTheViewChanged fires when the top image currently displayed in the viewer changes
    DWObject.RegisterEvent("OnTopImageInTheViewChanged", function (index: number) {
        DWObject.CurrentImageIndexInBuffer = index;
    });
  }
}

function showImageEditor() {
  const DWObject = Dynamsoft.WebTwainEnv.GetWebTwain('dwtcontrolContainer');
  if (DWObject) {
    DWObject.ShowImageEditor();
  }
}