1 files changed, 14 insertions, 9 deletions

diff --git a/src/client/views/nodes/PDFBox.tsx b/src/client/views/nodes/PDFBox.tsx
index a3c818c91..b9ccd79e4 100644
--- a/src/client/views/nodes/PDFBox.tsx
+++ b/src/client/views/nodes/PDFBox.tsx
@@ -30,20 +30,24 @@ export class PDFBox extends DocComponent<FieldViewProps, PdfDocument>(PdfDocumen
 
     @observable private _alt = false;
     @observable private _scrollY: number = 0;
+    private _reactionDisposer?: IReactionDisposer;
+    _targetDiv: any = undefined;
+
+    componentDidMount: () => void = () => {
+        if (this._reactionDisposer) this._reactionDisposer();
+        this._reactionDisposer = reaction(() => this.props.Document.scrollY, () =>
+            this._targetDiv && this._targetDiv.scrollTo({ top: NumCast(this.Document.scrollY), behavior: "smooth" })
+        );
+    }
 
     loaded = (nw: number, nh: number) => {
         if (this.props.Document) {
+            if (this.props.Document.nativeWidth && this.props.Document.nativeHeight) return;
             let doc = this.props.Document.proto ? this.props.Document.proto : this.props.Document;
-            let oldnw = NumCast(doc.nativeWidth);
+            let oldaspect = NumCast(doc.nativeHeight) / NumCast(doc.nativeWidth, 1);
             doc.nativeWidth = nw;
-            if (!doc.nativeHeight) {
-                doc.nativeHeight = nh;
-            }
-            else {
-                let oldnh = NumCast(doc.nativeHeight);
-                let aspect = oldnh / oldnw;
-                doc.nativeHeight = nw * aspect;
-            }
+            if (doc.nativeHeight) doc.nativeHeight = nw * oldaspect;
+            else doc.nativeHeight = nh;
             let ccv = this.props.ContainingCollectionView;
             if (ccv) {
                 ccv.props.Document.pdfHeight = nh;
@@ -55,6 +59,7 @@ export class PDFBox extends DocComponent<FieldViewProps, PdfDocument>(PdfDocumen
     @action
     onScroll = (e: React.UIEvent<HTMLDivElement>) => {
         if (e.currentTarget) {
+            this._targetDiv = e.currentTarget;
             this._scrollY = e.currentTarget.scrollTop;
             // e.currentTarget.scrollTo({ top: 1000, behavior: "smooth" });
             let ccv = this.props.ContainingCollectionView;