Add useScrollIntoView hook

extensions/ql-vscode/src/view/results/AlertTable.tsx

@@ -14,13 +14,13 @@ import {
   SarifInterpretationData,
 } from "../../common/interface-types";
 import { parseSarifLocation, isNoLocation } from "../../common/sarif-utils";
-import { ScrollIntoViewHelper } from "./scroll-into-view-helper";
 import { sendTelemetry } from "../common/telemetry";
 import { AlertTableHeader } from "./AlertTableHeader";
 import { AlertTableNoResults } from "./AlertTableNoResults";
 import { AlertTableTruncatedMessage } from "./AlertTableTruncatedMessage";
 import { AlertTableResultRow } from "./AlertTableResultRow";
 import { useCallback, useEffect, useRef, useState } from "react";
+import { useScrollIntoView } from "./useScrollIntoView";
 
 type AlertTableProps = ResultTableProps & {
   resultSet: InterpretedResultSet<SarifInterpretationData>;
@@ -29,17 +29,14 @@ type AlertTableProps = ResultTableProps & {
 export function AlertTable(props: AlertTableProps) {
   const { databaseUri, resultSet } = props;
 
-  const scroller = useRef<ScrollIntoViewHelper | undefined>(undefined);
-  if (scroller.current === undefined) {
-    scroller.current = new ScrollIntoViewHelper();
-  }
-  useEffect(() => scroller.current?.update());
-
   const [expanded, setExpanded] = useState<Set<string>>(new Set<string>());
   const [selectedItem, setSelectedItem] = useState<Keys.ResultKey | undefined>(
     undefined,
   );
 
+  const selectedItemRef = useRef<any>();
+  useScrollIntoView(selectedItem, selectedItemRef);
+
   /**
    * Given a list of `keys`, toggle the first, and if we 'open' the
    * first item, open all the rest as well. This mimics vscode's file
@@ -162,7 +159,6 @@ export function AlertTable(props: AlertTableProps) {
           newExpanded.delete(Keys.keyToString(selectedItem));
         }
       }
-      scroller.current?.scrollIntoViewOnNextUpdate();
       setExpanded(newExpanded);
       setSelectedItem(key);
     },
@@ -203,11 +199,11 @@ export function AlertTable(props: AlertTableProps) {
               resultIndex={resultIndex}
               expanded={expanded}
               selectedItem={selectedItem}
+              selectedItemRef={selectedItemRef}
               databaseUri={databaseUri}
               sourceLocationPrefix={sourceLocationPrefix}
               updateSelectionCallback={updateSelectionCallback}
               toggleExpanded={toggle}
-              scroller={scroller.current}
             />
           ),
         )}

extensions/ql-vscode/src/view/results/AlertTablePathNodeRow.tsx

@@ -3,7 +3,6 @@ import * as Sarif from "sarif";
 import * as Keys from "./result-keys";
 import { SarifLocation } from "./locations/SarifLocation";
 import { selectableZebraStripe } from "./result-table-utils";
-import { ScrollIntoViewHelper } from "./scroll-into-view-helper";
 import { useCallback, useMemo } from "react";
 
 interface Props {
@@ -12,12 +11,12 @@ interface Props {
   pathIndex: number;
   resultIndex: number;
   selectedItem: undefined | Keys.ResultKey;
+  selectedItemRef: React.RefObject<any>;
   databaseUri: string;
   sourceLocationPrefix: string;
   updateSelectionCallback: (
     resultKey: Keys.PathNode | Keys.Result | undefined,
   ) => void;
-  scroller?: ScrollIntoViewHelper;
 }
 
 export function AlertTablePathNodeRow(props: Props) {
@@ -27,10 +26,10 @@ export function AlertTablePathNodeRow(props: Props) {
     pathIndex,
     resultIndex,
     selectedItem,
+    selectedItemRef,
     databaseUri,
     sourceLocationPrefix,
     updateSelectionCallback,
-    scroller,
   } = props;
 
   const pathNodeKey: Keys.PathNode = useMemo(
@@ -51,7 +50,7 @@ export function AlertTablePathNodeRow(props: Props) {
   const zebraIndex = resultIndex + stepIndex;
   return (
     <tr
-      ref={scroller?.ref(isSelected)}
+      ref={isSelected ? selectedItemRef : undefined}
       className={isSelected ? "vscode-codeql__selected-path-node" : undefined}
     >
       <td className="vscode-codeql__icon-cell">

extensions/ql-vscode/src/view/results/AlertTablePathRow.tsx

@@ -2,7 +2,6 @@ import * as React from "react";
 import * as Sarif from "sarif";
 import * as Keys from "./result-keys";
 import { selectableZebraStripe } from "./result-table-utils";
-import { ScrollIntoViewHelper } from "./scroll-into-view-helper";
 import { AlertTablePathNodeRow } from "./AlertTablePathNodeRow";
 import { AlertTableDropdownIndicatorCell } from "./AlertTableDropdownIndicatorCell";
 import { useCallback, useMemo } from "react";
@@ -13,13 +12,13 @@ interface Props {
   resultIndex: number;
   currentPathExpanded: boolean;
   selectedItem: undefined | Keys.ResultKey;
+  selectedItemRef: React.RefObject<any>;
   databaseUri: string;
   sourceLocationPrefix: string;
   updateSelectionCallback: (
     resultKey: Keys.PathNode | Keys.Result | undefined,
   ) => void;
   toggleExpanded: (e: React.MouseEvent, keys: Keys.ResultKey[]) => void;
-  scroller?: ScrollIntoViewHelper;
 }
 
 export function AlertTablePathRow(props: Props) {
@@ -29,8 +28,8 @@ export function AlertTablePathRow(props: Props) {
     resultIndex,
     currentPathExpanded,
     selectedItem,
+    selectedItemRef,
     toggleExpanded,
-    scroller,
   } = props;
 
   const pathKey = useMemo(
@@ -50,7 +49,7 @@ export function AlertTablePathRow(props: Props) {
   return (
     <>
       <tr
-        ref={scroller?.ref(isPathSpecificallySelected)}
+        ref={isPathSpecificallySelected ? selectedItemRef : undefined}
         {...selectableZebraStripe(isPathSpecificallySelected, resultIndex)}
       >
         <td className="vscode-codeql__icon-cell">

extensions/ql-vscode/src/view/results/AlertTableResultRow.tsx

@@ -2,7 +2,6 @@ import * as React from "react";
 import * as Sarif from "sarif";
 import * as Keys from "./result-keys";
 import { info, listUnordered } from "./octicons";
-import { ScrollIntoViewHelper } from "./scroll-into-view-helper";
 import { selectableZebraStripe } from "./result-table-utils";
 import { AlertTableDropdownIndicatorCell } from "./AlertTableDropdownIndicatorCell";
 import { useCallback, useMemo } from "react";
@@ -15,13 +14,13 @@ interface Props {
   resultIndex: number;
   expanded: Set<string>;
   selectedItem: undefined | Keys.ResultKey;
+  selectedItemRef: React.RefObject<any>;
   databaseUri: string;
   sourceLocationPrefix: string;
   updateSelectionCallback: (
     resultKey: Keys.PathNode | Keys.Result | undefined,
   ) => void;
   toggleExpanded: (e: React.MouseEvent, keys: Keys.ResultKey[]) => void;
-  scroller?: ScrollIntoViewHelper;
 }
 
 export function AlertTableResultRow(props: Props) {
@@ -30,11 +29,11 @@ export function AlertTableResultRow(props: Props) {
     resultIndex,
     expanded,
     selectedItem,
+    selectedItemRef,
     databaseUri,
     sourceLocationPrefix,
     updateSelectionCallback,
     toggleExpanded,
-    scroller,
   } = props;
 
   const resultKey: Keys.Result = useMemo(
@@ -81,7 +80,7 @@ export function AlertTableResultRow(props: Props) {
   return (
     <>
       <tr
-        ref={scroller?.ref(resultRowIsSelected)}
+        ref={resultRowIsSelected ? selectedItemRef : undefined}
         {...selectableZebraStripe(resultRowIsSelected, resultIndex)}
       >
         {result.codeFlows === undefined ? (

extensions/ql-vscode/src/view/results/RawTable.tsx

@@ -13,10 +13,10 @@ import RawTableRow from "./RawTableRow";
 import { ResultRow } from "../../common/bqrs-cli-types";
 import { onNavigation } from "./ResultsApp";
 import { tryGetResolvableLocation } from "../../common/bqrs-utils";
-import { ScrollIntoViewHelper } from "./scroll-into-view-helper";
 import { sendTelemetry } from "../common/telemetry";
 import { assertNever } from "../../common/helpers-pure";
 import { EmptyQueryResultsMessage } from "./EmptyQueryResultsMessage";
+import { useScrollIntoView } from "./useScrollIntoView";
 
 type RawTableProps = {
   databaseUri: string;
@@ -38,11 +38,8 @@ export function RawTable({
 }: RawTableProps) {
   const [selectedItem, setSelectedItem] = useState<TableItem | undefined>();
 
-  const scroller = useRef<ScrollIntoViewHelper | undefined>(undefined);
+  const selectedItemRef = useRef<any>();
-  if (scroller.current === undefined) {
+  useScrollIntoView(selectedItem, selectedItemRef);
-    scroller.current = new ScrollIntoViewHelper();
-  }
-  useEffect(() => scroller.current?.update());
 
   const setSelection = useCallback((row: number, column: number): void => {
     setSelectedItem({ row, column });
@@ -76,11 +73,10 @@ export function RawTable({
             jumpToLocation(location, databaseUri);
           }
         }
-        scroller.current?.scrollIntoViewOnNextUpdate();
         return { row: nextRow, column: nextColumn };
       });
     },
-    [databaseUri, resultSet, scroller],
+    [databaseUri, resultSet],
   );
 
   const handleNavigationEvent = useCallback(
@@ -140,7 +136,7 @@ export function RawTable({
         selectedItem?.row === rowIndex ? selectedItem?.column : undefined
       }
       onSelected={setSelection}
-      scroller={scroller.current}
+      selectedItemRef={selectedItemRef}
     />
   ));
 

extensions/ql-vscode/src/view/results/RawTableRow.tsx

@@ -2,7 +2,6 @@ import * as React from "react";
 import { ResultRow } from "../../common/bqrs-cli-types";
 import { selectedRowClassName, zebraStripe } from "./result-table-utils";
 import RawTableValue from "./RawTableValue";
-import { ScrollIntoViewHelper } from "./scroll-into-view-helper";
 
 interface Props {
   rowIndex: number;
@@ -10,8 +9,8 @@ interface Props {
   databaseUri: string;
   className?: string;
   selectedColumn?: number;
+  selectedItemRef?: React.Ref<any>;
   onSelected?: (row: number, column: number) => void;
-  scroller?: ScrollIntoViewHelper;
 }
 
 export default function RawTableRow(props: Props) {
@@ -26,7 +25,7 @@ export default function RawTableRow(props: Props) {
         const isSelected = props.selectedColumn === columnIndex;
         return (
           <td
-            ref={props.scroller?.ref(isSelected)}
+            ref={isSelected ? props.selectedItemRef : undefined}
             key={columnIndex}
             {...(isSelected ? { className: selectedRowClassName } : {})}
           >

extensions/ql-vscode/src/view/results/scroll-into-view-helper.ts

@@ -1,55 +0,0 @@
-import { createRef } from "react";
-
-/**
- * Some book-keeping needed to scroll a specific HTML element into view in a React component.
- */
-export class ScrollIntoViewHelper {
-  private selectedElementRef = createRef<HTMLElement | any>(); // need 'any' to work around typing bug in React
-  private shouldScrollIntoView = true;
-
-  /**
-   * If `isSelected` is true, gets the `ref={}` attribute to use for an element that we might want to scroll into view.
-   */
-  public ref(isSelected: boolean) {
-    return isSelected ? this.selectedElementRef : undefined;
-  }
-
-  /**
-   * Causes the element whose `ref={}` was set to be scrolled into view after the next render.
-   */
-  public scrollIntoViewOnNextUpdate() {
-    this.shouldScrollIntoView = true;
-  }
-
-  /**
-   * Should be called from `componentDidUpdate` and `componentDidMount`.
-   *
-   * Scrolls the component into view if requested.
-   */
-  public update() {
-    if (!this.shouldScrollIntoView) {
-      return;
-    }
-    this.shouldScrollIntoView = false;
-    const element = this.selectedElementRef.current as HTMLElement | null;
-    if (element == null) {
-      return;
-    }
-    const rect = element.getBoundingClientRect();
-    // The selected item's bounding box might be on screen, but hidden underneath the sticky header
-    // which overlaps the table view. As a workaround we hardcode a fixed distance from the top which
-    // we consider to be obscured. It does not have to exact, as it's just a threshold for when to scroll.
-    const heightOfStickyHeader = 30;
-    if (rect.top < heightOfStickyHeader || rect.bottom > window.innerHeight) {
-      element.scrollIntoView({
-        block: "center", // vertically align to center
-      });
-    }
-    if (rect.left < 0 || rect.right > window.innerWidth) {
-      element.scrollIntoView({
-        block: "nearest",
-        inline: "nearest", // horizontally align as little as possible
-      });
-    }
-  }
-}

extensions/ql-vscode/src/view/results/useScrollIntoView.tsx

@@ -0,0 +1,29 @@
+import { RefObject, useEffect } from "react";
+
+export function useScrollIntoView<T>(
+  selectedElement: T | undefined,
+  selectedElementRef: RefObject<any>,
+) {
+  useEffect(() => {
+    const element = selectedElementRef.current as HTMLElement | undefined;
+    if (!element) {
+      return;
+    }
+    const rect = element.getBoundingClientRect();
+    // The selected item's bounding box might be on screen, but hidden underneath the sticky header
+    // which overlaps the table view. As a workaround we hardcode a fixed distance from the top which
+    // we consider to be obscured. It does not have to exact, as it's just a threshold for when to scroll.
+    const heightOfStickyHeader = 30;
+    if (rect.top < heightOfStickyHeader || rect.bottom > window.innerHeight) {
+      element.scrollIntoView({
+        block: "center", // vertically align to center
+      });
+    }
+    if (rect.left < 0 || rect.right > window.innerWidth) {
+      element.scrollIntoView({
+        block: "nearest",
+        inline: "nearest", // horizontally align as little as possible
+      });
+    }
+  }, [selectedElement, selectedElementRef]);
+}