react-native-flip
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Flow
/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
* @format
*/
;
export type FillRateInfo = Info;
declare class Info {
any_blank_count: number,
any_blank_ms: number,
any_blank_speed_sum: number,
mostly_blank_count: number,
mostly_blank_ms: number,
pixels_blank: number,
pixels_sampled: number,
pixels_scrolled: number,
total_time_spent: number,
sample_count: number,
}
type FrameMetrics = {
inLayout?: boolean,
length: number,
offset: number,
...
};
const DEBUG = false;
let _listeners: Array<(Info) => void> = [];
let _minSampleCount = 10;
let _sampleRate = DEBUG ? 1 : null;
/**
* A helper class for detecting when the maximem fill rate of `VirtualizedList` is exceeded.
* By default the sampling rate is set to zero and this will do nothing. If you want to collect
* samples (e.g. to log them), make sure to call `FillRateHelper.setSampleRate(0.0-1.0)`.
*
* Listeners and sample rate are global for all `VirtualizedList`s - typical usage will combine with
* `SceneTracker.getActiveScene` to determine the context of the events.
*/
declare class FillRateHelper {
_anyBlankStartTime: any,
_enabled: any,
_getFrameMetrics: (index: number) => ?FrameMetrics,
_info: any,
_mostlyBlankStartTime: any,
_samplesStartTime: any,
static addListener(callback: (FillRateInfo) => void): {
remove: () => void,
...
},
static setSampleRate(sampleRate: number): any,
static setMinSampleCount(minSampleCount: number): any,
constructor(getFrameMetrics: (index: number) => ?FrameMetrics): any,
activate(): any,
deactivateAndFlush(): any,
computeBlankness(props: {
data: any,
getItemCount: (data: any) => number,
initialNumToRender: number,
...
}, state: {
first: number,
last: number,
...
}, scrollMetrics: {
dOffset: number,
offset: number,
velocity: number,
visibleLength: number,
...
}): number,
enabled(): boolean,
_resetData(): any,
}
export default FillRateHelper;