finalizeTree method

Implementation

void finalizeTree() {
  Timeline.startSync('Finalize tree', arguments: timelineWhitelistArguments);
  try {
    lockState(() {
      _inactiveElements._unmountAll(); // this unregisters the GlobalKeys
    });
    assert(() {
      try {
        GlobalKey._debugVerifyIllFatedPopulation();
        if (_debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans != null &&
            _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.isNotEmpty) {
          final Set<GlobalKey> keys = HashSet<GlobalKey>();
          for (Element element in _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.keys) {
            if (element._debugLifecycleState != _ElementLifecycle.defunct)
              keys.addAll(_debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans[element]);
          }
          if (keys.isNotEmpty) {
            final Map<String, int> keyStringCount = HashMap<String, int>();
            for (String key in keys.map<String>((GlobalKey key) => key.toString())) {
              if (keyStringCount.containsKey(key)) {
                keyStringCount[key] += 1;
              } else {
                keyStringCount[key] = 1;
              }
            }
            final List<String> keyLabels = <String>[];
            keyStringCount.forEach((String key, int count) {
              if (count == 1) {
                keyLabels.add(key);
              } else {
                keyLabels.add('$key ($count different affected keys had this toString representation)');
              }
            });
            final Iterable<Element> elements = _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans.keys;
            final Map<String, int> elementStringCount = HashMap<String, int>();
            for (String element in elements.map<String>((Element element) => element.toString())) {
              if (elementStringCount.containsKey(element)) {
                elementStringCount[element] += 1;
              } else {
                elementStringCount[element] = 1;
              }
            }
            final List<String> elementLabels = <String>[];
            elementStringCount.forEach((String element, int count) {
              if (count == 1) {
                elementLabels.add(element);
              } else {
                elementLabels.add('$element ($count different affected elements had this toString representation)');
              }
            });
            assert(keyLabels.isNotEmpty);
            final String the = keys.length == 1 ? ' the' : '';
            final String s = keys.length == 1 ? '' : 's';
            final String were = keys.length == 1 ? 'was' : 'were';
            final String their = keys.length == 1 ? 'its' : 'their';
            final String respective = elementLabels.length == 1 ? '' : ' respective';
            final String those = keys.length == 1 ? 'that' : 'those';
            final String s2 = elementLabels.length == 1 ? '' : 's';
            final String those2 = elementLabels.length == 1 ? 'that' : 'those';
            final String they = elementLabels.length == 1 ? 'it' : 'they';
            final String think = elementLabels.length == 1 ? 'thinks' : 'think';
            final String are = elementLabels.length == 1 ? 'is' : 'are';
            throw FlutterError(
              'Duplicate GlobalKey$s detected in widget tree.\n'
              'The following GlobalKey$s $were specified multiple times in the widget tree. This will lead to '
              'parts of the widget tree being truncated unexpectedly, because the second time a key is seen, '
              'the previous instance is moved to the new location. The key$s $were:\n'
              '- ${keyLabels.join("\n  ")}\n'
              'This was determined by noticing that after$the widget$s with the above global key$s $were moved '
              'out of $their$respective previous parent$s2, $those2 previous parent$s2 never updated during this frame, meaning '
              'that $they either did not update at all or updated before the widget$s $were moved, in either case '
              'implying that $they still $think that $they should have a child with $those global key$s.\n'
              'The specific parent$s2 that did not update after having one or more children forcibly removed '
              'due to GlobalKey reparenting $are:\n'
              '- ${elementLabels.join("\n  ")}\n'
              'A GlobalKey can only be specified on one widget at a time in the widget tree.'
            );
          }
        }
      } finally {
        _debugElementsThatWillNeedToBeRebuiltDueToGlobalKeyShenanigans?.clear();
      }
      return true;
    }());
  } catch (e, stack) {
    _debugReportException('while finalizing the widget tree', e, stack);
  } finally {
    Timeline.finishSync();
  }
}