Fix minimumViewTime

Reviewed By: blairvanderhoof

Differential Revision: D4723575

fbshipit-source-id: a120eef4079a808bd3dead08df93989e1db3d96a
This commit is contained in:
Spencer Ahrens 2017-03-16 16:36:57 -07:00 committed by Facebook Github Bot
parent 63fa621df1
commit b1a63f0088
2 changed files with 8 additions and 8 deletions

View File

@ -49,7 +49,7 @@ export type ViewabilityConfig = {|
* layout.
*
* An item is said to be in a "viewable" state when any of the following
* is true for longer than `minViewTime` milliseconds (after an interaction if `waitForInteraction`
* is true for longer than `minimumViewTime` milliseconds (after an interaction if `waitForInteraction`
* is true):
*
* - Occupying >= `viewAreaCoveragePercentThreshold` of the view area XOR fraction of the item
@ -145,7 +145,7 @@ class ViewabilityHelper {
renderRange?: {first: number, last: number}, // Optional optimization to reduce the scan size
): void {
const updateTime = Date.now();
if (this._lastUpdateTime === 0 && getFrameMetrics(0)) {
if (this._lastUpdateTime === 0 && itemCount > 0 && getFrameMetrics(0)) {
// Only count updates after the first item is rendered and has a frame.
this._lastUpdateTime = updateTime;
}
@ -171,13 +171,13 @@ class ViewabilityHelper {
}
this._viewableIndices = viewableIndices;
this._lastUpdateTime = updateTime;
if (this._config.minViewTime && updateElapsed < this._config.minViewTime) {
if (this._config.minimumViewTime && updateElapsed < this._config.minimumViewTime) {
const handle = setTimeout(
() => {
this._timers.delete(handle);
this._onUpdateSync(viewableIndices, onViewableItemsChanged, createViewToken);
},
this._config.minViewTime,
this._config.minimumViewTime,
);
this._timers.add(handle);
} else {

View File

@ -249,9 +249,9 @@ describe('onUpdate', function() {
);
it(
'minViewTime delays callback',
'minimumViewTime delays callback',
function() {
const helper = new ViewabilityHelper({minViewTime: 350, viewAreaCoveragePercentThreshold: 0});
const helper = new ViewabilityHelper({minimumViewTime: 350, viewAreaCoveragePercentThreshold: 0});
rowFrames = {
a: {y: 0, height: 200},
b: {y: 200, height: 200},
@ -279,9 +279,9 @@ describe('onUpdate', function() {
);
it(
'minViewTime skips briefly visible items',
'minimumViewTime skips briefly visible items',
function() {
const helper = new ViewabilityHelper({minViewTime: 350, viewAreaCoveragePercentThreshold: 0});
const helper = new ViewabilityHelper({minimumViewTime: 350, viewAreaCoveragePercentThreshold: 0});
rowFrames = {
a: {y: 0, height: 250},
b: {y: 250, height: 200},