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refactor(repeat): cleanup repeat
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@bigopon
bigopon committed Mar 15, 2019
1 parent 632b939 commit 0b9e6f7
Showing 1 changed file with 34 additions and 37 deletions.
71 changes: 34 additions & 37 deletions src/virtual-repeat.ts
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Expand Up @@ -214,7 +214,7 @@ export class VirtualRepeat extends AbstractRepeater {
_prevItemsCount: number;

/**@internal */
scrollContainer: HTMLElement;
containerEl: HTMLElement;

/**@internal */
private scrollListener: () => any;
Expand Down Expand Up @@ -339,7 +339,7 @@ export class VirtualRepeat extends AbstractRepeater {
const scrollListener = this.scrollListener = () => {
this._onScroll();
};
const scrollContainer = this.scrollContainer = templateStrategy.getScrollContainer(element);
const containerEl = this.containerEl = templateStrategy.getScrollContainer(element);
const [topBufferEl, bottomBufferEl] = templateStrategy.createBuffers(element);

this.topBufferEl = topBufferEl;
Expand All @@ -359,14 +359,14 @@ export class VirtualRepeat extends AbstractRepeater {
const firstElement = templateStrategy.getFirstElement(topBufferEl, bottomBufferEl);
this.distanceToTop = firstElement === null ? 0 : getElementDistanceToTopOfDocument(firstElement);

if (hasOverflowScroll(scrollContainer)) {
if (hasOverflowScroll(containerEl)) {
this._fixedHeightContainer = true;
scrollContainer.addEventListener('scroll', scrollListener);
containerEl.addEventListener('scroll', scrollListener);
} else {
DOM.addEventListener('scroll', scrollListener, false);
}
if (this.items.length < this.elementsInView && this.isLastIndex === undefined) {
this._getMore(true);
this._getMore(/*force?*/true);
}
}

Expand All @@ -377,34 +377,34 @@ export class VirtualRepeat extends AbstractRepeater {

/**@override */
detached(): void {
const scrollCt = this.scrollContainer;
const scrollCt = this.containerEl;
const scrollListener = this.scrollListener;
if (hasOverflowScroll(scrollCt)) {
scrollCt.removeEventListener('scroll', scrollListener);
} else {
DOM.removeEventListener('scroll', scrollListener, false);
}
this.isLastIndex = undefined;
this._fixedHeightContainer = false;
this._isAttached
= this._fixedHeightContainer = false;
this._unsubscribeCollection();
this._resetCalculation();
this._isAttached = false;
this._prevItemsCount = 0;
this.templateStrategy.removeBuffers(this.element, this.topBufferEl, this.bottomBufferEl);
this.topBufferEl = this.bottomBufferEl = this.scrollContainer = this.scrollListener = null;
this.distanceToTop = 0;
this.topBufferEl = this.bottomBufferEl = this.containerEl = this.scrollListener = null;
this.removeAllViews(/*return to cache?*/true, /*skip animation?*/false);
this._unsubscribeCollection();
const $clearInterval = PLATFORM.global.clearInterval;
$clearInterval(this._calcDistanceToTopInterval);
$clearInterval(this._sizeInterval);
this._sizeInterval = this._calcDistanceToTopInterval = 0;
this._prevItemsCount
= this.distanceToTop
= this._sizeInterval
= this._calcDistanceToTopInterval = 0;
}

/**@override */
unbind(): void {
this.scope = null;
this.items = null;
this._prevItemsCount = 0;
}

/**
Expand Down Expand Up @@ -439,7 +439,7 @@ export class VirtualRepeat extends AbstractRepeater {
throw new Error('Value is not iterateable for virtual repeat.');
}

const scroller = this.scrollContainer;
const scroller = this.containerEl;
if (shouldCalculateSize) {
const currentItemCount = items.length;
if (currentItemCount > 0 && this.viewCount() === 0) {
Expand All @@ -462,9 +462,10 @@ export class VirtualRepeat extends AbstractRepeater {
strategy.instanceChanged(this, items, this._first);

if (shouldCalculateSize) {
const firstIndex = this._first;
const currentItemCount = items.length;
// Reset rebinding
this._lastRebind = this._first;
this._lastRebind = firstIndex;

if (reducingItems && previousLastViewIndex > currentItemCount - 1) {
// Do we need to set scrolltop so that we appear at the bottom of the list to match scrolling as far as we could?
Expand All @@ -474,7 +475,7 @@ export class VirtualRepeat extends AbstractRepeater {
}
if (!reducingItems) {
// If we're expanding our items, then we need to reset our previous first for the next go around of scroll handling
this._previousFirst = this._first;
this._previousFirst = firstIndex;
// Simulating the down scroll event to load up data appropriately
this._scrollingDown = true;
this._scrollingUp = false;
Expand Down Expand Up @@ -527,7 +528,7 @@ export class VirtualRepeat extends AbstractRepeater {
*/
getScroller(): HTMLElement {
return this._fixedHeightContainer
? this.scrollContainer
? this.containerEl
: document.documentElement;
}

Expand Down Expand Up @@ -594,13 +595,8 @@ export class VirtualRepeat extends AbstractRepeater {
return;
}
const topBufferEl = this.topBufferEl;
const scrollerEl = this.scrollContainer;
const scrollerEl = this.containerEl;
const itemHeight = this.itemHeight;
// If offset parent of top buffer is the scroll container
// its actual offsetTop is just the offset top itself
// If not, then the offset top is calculated based on the parent offsetTop as well
const topBufferDistance = getDistanceToParent(topBufferEl, scrollerEl);
const isFixedHeightContainer = this._fixedHeightContainer;
/**
* Real scroll top calculated based on current scroll top of scroller and top buffer {height + distance to top}
* as there could be elements before top buffer and it affects real scroll top of the selected repeat
Expand All @@ -609,15 +605,18 @@ export class VirtualRepeat extends AbstractRepeater {
* - not document: the scroll top of this repeat is calculated based on current scroller.scrollTop and the distance to top of `top buffer`
* - document: the scroll top is the substraction of `pageYOffset` and distance to top of current buffer element (logic needs revised)
*/
const scrollTop = isFixedHeightContainer
? scrollerEl.scrollTop
: (pageYOffset - this.distanceToTop);
const realScrollTop = Math$max(
0,
isFixedHeightContainer
? scrollTop - Math$abs(topBufferDistance)
: scrollTop
);
let realScrollTop = 0;
const isFixedHeightContainer = this._fixedHeightContainer;
if (isFixedHeightContainer) {
// If offset parent of top buffer is the scroll container
// its actual offsetTop is just the offset top itself
// If not, then the offset top is calculated based on the parent offsetTop as well
const topBufferDistance = getDistanceToParent(topBufferEl, scrollerEl);
const scrollerScrollTop = scrollerEl.scrollTop;
realScrollTop = Math$max(0, scrollerScrollTop - Math$abs(topBufferDistance));
} else {
realScrollTop = pageYOffset - this.distanceToTop;
}
const elementsInView = this.elementsInView;

// Calculate the index of first view
Expand Down Expand Up @@ -695,9 +694,7 @@ export class VirtualRepeat extends AbstractRepeater {
}
}
this._previousFirst = firstIndex;
this._isScrolling
= this._scrollingUp
= this._scrollingDown = false;
this._isScrolling = false;
}

/**@internal*/
Expand Down Expand Up @@ -930,7 +927,7 @@ export class VirtualRepeat extends AbstractRepeater {
this._prevItemsCount = itemsLength;
const itemHeight = this.itemHeight;
const scrollContainerHeight = this._fixedHeightContainer
? calcScrollHeight(this.scrollContainer)
? calcScrollHeight(this.containerEl)
: document.documentElement.clientHeight;
const elementsInView = this.elementsInView = Math$ceil(scrollContainerHeight / itemHeight) + 1;
const viewsCount = this._viewsLength = elementsInView * 2;
Expand Down

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