function delivered()

in src/Clients/Web/winjs/js/winjs.js [42235:42327]
83 lines of code
27 McCabe index (conditional complexity)

                    function delivered(index) {
                        if (that._realizePass !== currentPass) {
                            return;
                        }

                        if (index >= firstInView && index <= lastInView) {
                            if (--inViewCounter === 0) {
                                appendItemsToDom(firstInView, lastInView);
                                removeGaps(firstInView, lastInView, begin, end);

                                if (that._firstLayoutPass) {
                                    scheduleReadySignal(firstInView, lastInView, that._frontOffscreenJob, direction === "right" ? "left" : "right", true);

                                    var entranceAnimation = Scheduler.schedulePromiseHigh(null, "WinJS.UI.ListView.entranceAnimation").then(function () {
                                        if (that._listView._isZombie()) { return; }
                                        that._listView._writeProfilerMark("entranceAnimation,StartTM");
                                        var promise = that._listView._animateListEntrance(!that._firstEntranceAnimated);
                                        that._firstEntranceAnimated = true;
                                        return promise;
                                    });

                                    that._runningAnimations = Promise.join([that._runningAnimations, entranceAnimation]);
                                    that._runningAnimations.done(function () {
                                        that._listView._writeProfilerMark("entranceAnimation,StopTM");
                                        if (that._realizePass === currentPass) {
                                            that._runningAnimations = null;
                                            entranceAnimationSignal.complete();
                                        }
                                    });
                                    that._firstLayoutPass = false;

                                    if (that._listView._isCurrentZoomView) {
                                        Scheduler.requestDrain(that._onscreenJob.priority);
                                    }
                                } else {
                                    // during scrolling ready for onscreen items after front off screen items
                                    scheduleReadySignal(firstInView, lastInView, that._frontOffscreenJob, direction);
                                    entranceAnimationSignal.complete();
                                }

                                that._updateHeaders(that._listView._canvas, firstInView, lastInView + 1).done(function () {
                                    viewportItemsRealized.complete();
                                });
                            }
                        } else if (index < firstInView) {
                            --leftOffscreenCount;
                            if (leftOffscreenCount % inView === 0) {
                                appendItemsToDom(begin, firstInView - 1);
                            }
                            if (!leftOffscreenCount) {
                                that._updateHeaders(that._listView._canvas, begin, firstInView).done(function () {
                                    if (direction !== "right") {
                                        frontItemsRealized.complete();
                                    }
                                });
                                scheduleReadySignal(begin, firstInView - 1, direction !== "right" ? that._frontOffscreenJob : that._backOffscreenJob, "left");
                            }
                        } else if (index > lastInView) {
                            --rightOffscreenCount;
                            if (rightOffscreenCount % inView === 0) {
                                appendItemsToDom(lastInView + 1, end - 1);
                            }
                            if (!rightOffscreenCount) {
                                that._updateHeaders(that._listView._canvas, lastInView + 1, end).then(function () {
                                    if (direction === "right") {
                                        frontItemsRealized.complete();
                                    }
                                });
                                scheduleReadySignal(lastInView + 1, end - 1, direction === "right" ? that._frontOffscreenJob : that._backOffscreenJob, "right");
                            }
                        }
                        counter--;

                        if (counter === 0) {
                            that._renderCompletePromise = Promise.join(renderCompletePromises).then(null, function (e) {
                                var error = Array.isArray(e) && e.some(function (item) { return item && !(item instanceof Error && item.name === "Canceled"); });
                                if (error) {
                                    // rethrow
                                    return Promise.wrapError(e);
                                }
                            });

                            (that._headerRenderPromises || Promise.wrap()).done(function () {
                                Scheduler.schedule(function VirtualizeContentsView_async_delivered() {
                                    if (that._listView._isZombie()) {
                                        workCompleteSignal.cancel();
                                    } else {
                                        workCompleteSignal.complete();
                                    }
                                }, Math.min(that._onscreenJob.priority, that._backOffscreenJob.priority), null, "WinJS.UI.ListView._allItemsRealized");
                            });
                        }
                    }