fix: widget persistence (#535)

Ensure that that user widgets are not remounted when the cursor moves, so that their component state persists.

lean4-infoview/src/infoview/info.tsx

@@ -131,6 +131,13 @@ function GoalInfoDisplay(props: GoalInfoDisplayProps) {
 
  const [selectedLocs, setSelectedLocs] = React.useState<GoalsLocation[]>([])
 
+ // https://react.dev/learn/you-might-not-need-an-effect#adjusting-some-state-when-a-prop-changes
+ const [prevPos, setPrevPos] = React.useState<DocumentPosition>(pos)
+ if (!DocumentPosition.isEqual(pos, prevPos)) {
+ setPrevPos(pos)
+ setSelectedLocs([])
+ }
+
  const locs: Locations = React.useMemo(
  () => ({
  isSelected: (l: GoalsLocation) => selectedLocs.some(v => GoalsLocation.isEqual(v, l)),
@@ -218,13 +225,7 @@ const InfoDisplayContent = React.memo((props: InfoDisplayContentProps) => {
  </a>
  </div>
  )}
- <GoalInfoDisplay
- key={DocumentPosition.toString(pos)}
- pos={pos}
- goals={goals}
- termGoal={termGoal}
- userWidgets={userWidgets}
- />
+ <GoalInfoDisplay pos={pos} goals={goals} termGoal={termGoal} userWidgets={userWidgets} />
  <div style={{ display: hasMessages ? 'block' : 'none' }} key="messages">
  <Details initiallyOpen key="messages">
  <>Messages ({messages.length})</>