feat: add onNewImage callback prop

* Add a callback call on new image updates

* Prevent js to break if metaData is not provided

Author: galelis

src/CornerstoneViewport/CornerstoneViewport.js

@@ -48,6 +48,7 @@ class CornerstoneViewport extends Component {
     frameRate: PropTypes.number, // Between 1 and ?
     //
     setViewportActive: PropTypes.func, // Called when viewport should be set to active?
+    onNewImage: PropTypes.func,
     viewportOverlayComponent: PropTypes.oneOfType([
       PropTypes.string,
       PropTypes.func,
@@ -595,14 +596,22 @@ class CornerstoneViewport extends Component {
   };
 
   onNewImage = event => {
-    const newImageId = event.detail.image.imageId;
-    const newImageIdIndex = this.props.imageIds.indexOf(newImageId);
+    const { imageId } = event.detail.image;
+    const { sopInstanceUid } =
+      cornerstone.metaData.get('generalImageModule', imageId) || {};
+    const currentImageIdIndex = this.props.imageIds.indexOf(imageId);
 
     // TODO: Should we grab and set some imageId specific metadata here?
     // Could prevent cornerstone dependencies in child components.
     this.setState({
-      imageIdIndex: newImageIdIndex,
+      imageIdIndex: currentImageIdIndex,
     });
+
+    if (this.props.onNewImage) {
+      this.props.onNewImage({
+        sopInstanceUid,
+      });
+    }
   };
 
   onImageLoaded = () => {

src/metadataProvider.js

@@ -32,6 +32,7 @@ function wadoRsMetaDataProvider(type, imageId) {
 
   if (type === 'generalImageModule') {
     return {
+      sopInstanceUid: getValue(metaData['00080018']),
       instanceNumber: getNumberValue(metaData['00200013']),
       lossyImageCompression: getValue(metaData['00282110']),
       lossyImageCompressionRatio: getValue(metaData['00282112']),