fix(StackViewport): weird interaction between scroll() and setImageIdIndex()

common/reviews/api/core.api.md

@@ -2094,7 +2094,7 @@ interface IStackViewport extends IViewport {
     // (undocumented)
     setDefaultProperties(ViewportProperties: StackViewportProperties, imageId?: string): void;
     // (undocumented)
-    setImageIdIndex(imageIdIndex: number): Promise<string>;
+    setImageIdIndex(imageIdIndex: number, overwriteScrollIndex?: boolean): Promise<string>;
     // (undocumented)
     setProperties({ voiRange, invert, interpolationType, rotation, colormap, }: StackViewportProperties, suppressEvents?: boolean): void;
     // (undocumented)
@@ -3138,7 +3138,7 @@ export class StackViewport extends Viewport implements IStackViewport, IImagesLo
     // (undocumented)
     setDefaultProperties(ViewportProperties: StackViewportProperties, imageId?: string): void;
     // (undocumented)
-    setImageIdIndex(imageIdIndex: number): Promise<string>;
+    setImageIdIndex(imageIdIndex: number, overwriteScrollIndex?: any): Promise<string>;
     // (undocumented)
     protected setInterpolationType: (interpolationType: InterpolationType) => void;
     // (undocumented)

packages/core/src/RenderingEngine/StackViewport.ts

@@ -2445,8 +2445,12 @@ class StackViewport extends Viewport implements IStackViewport, IImagesLoader {
   /**
    * Loads the image based on the provided imageIdIndex
    * @param imageIdIndex - number represents imageId index
+   * @param overwriteScrollIndex - can be used to also set the start position of scroll() to this index
    */
-  private async _setImageIdIndex(imageIdIndex: number): Promise<string> {
+  private async _setImageIdIndex(
+    imageIdIndex: number,
+    overwriteScrollIndex?: boolean
+  ): Promise<string> {
     if (imageIdIndex >= this.imageIds.length) {
       throw new Error(
         `ImageIdIndex provided ${imageIdIndex} is invalid, the stack only has ${this.imageIds.length} elements`
@@ -2455,6 +2459,9 @@ class StackViewport extends Viewport implements IStackViewport, IImagesLoader {
 
     // Update the state of the viewport to the new imageIdIndex;
     this.currentImageIdIndex = imageIdIndex;
+    if (overwriteScrollIndex) {
+      this.targetImageIdIndex = this.currentImageIdIndex;
+    }
     this.hasPixelSpacing = true;
     this.viewportStatus = ViewportStatus.PRE_RENDER;
 
@@ -2583,8 +2590,12 @@ class StackViewport extends Viewport implements IStackViewport, IImagesLoader {
    *
    * @param imageIdIndex - number represents imageId index in the list of
    * provided imageIds in setStack
+   * @param overwriteScrollIndex - can be used to also set the start position of scroll() to this index
    */
-  public setImageIdIndex(imageIdIndex: number): Promise<string> {
+  public setImageIdIndex(
+    imageIdIndex: number,
+    overwriteScrollIndex?
+  ): Promise<string> {
     this._throwIfDestroyed();
 
     // If we are already on this imageId index, stop here
@@ -2593,7 +2604,10 @@ class StackViewport extends Viewport implements IStackViewport, IImagesLoader {
     }
 
     // Otherwise, get the imageId and attempt to display it
-    const imageIdPromise = this._setImageIdIndex(imageIdIndex);
+    const imageIdPromise = this._setImageIdIndex(
+      imageIdIndex,
+      overwriteScrollIndex
+    );
 
     return imageIdPromise;
   }

packages/core/src/types/IStackViewport.ts

@@ -158,7 +158,10 @@ export default interface IStackViewport extends IViewport {
    * Loads the image based on the provided imageIdIndex. It is an Async function which
    * returns a promise that resolves to the imageId.
    */
-  setImageIdIndex(imageIdIndex: number): Promise<string>;
+  setImageIdIndex(
+    imageIdIndex: number,
+    overwriteScrollIndex?: boolean
+  ): Promise<string>;
   /**
    * Calibrates the image with new metadata that has been added for imageId. To calibrate
    * a viewport, you should add your calibration data manually to