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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 | 1x 1x 1x 1x 1x 5x 5x 5x 5x 5x 1x 1x 10x 5x 5x 5x 5x 5x 5x 5x | import React from "react";
import { canUseDOM } from "exenv-es6";
import { Breakpoints, defaultBreakpoints, identifyBreakpoint } from "./breakpoints";
export interface BreakpointTrackerProps {
/**
* The render method
*/
render: (activeBreakpoint: number | void) => React.ReactNode;
}
export interface BreakpointTrackerState {
/**
* The active breakpoint as an index of the Breakpoints array
*/
activeBreakpoint: number | void;
}
export default class BreakpointTracker extends React.Component<
BreakpointTrackerProps,
BreakpointTrackerState
> {
/**
* The array of breakpoint values
*/
public static breakpoints: Breakpoints = defaultBreakpoints;
/**
* Track if we have an open animation frame request
*/
private openRequestAnimationFrame: boolean;
/**
* Constructor for the BreakpointTracker component.
*/
constructor(props: BreakpointTrackerProps) {
super(props);
this.state = {
activeBreakpoint: null,
};
}
/**
* React life-cycle method
*/
public componentDidMount(): void {
// We are doing this work in a lifecycle method instead of the constructor to ensure that
// server rendered instances with conditional DOM rendering by breakpoint will be re-rendered.
// ReactDOM.hydrate() will call the constructor again, but it does not trigger a re-render. It will only bind event handlers.
// The only way to ensure the correct DOM is consistently rendered on the client is to perform this work here.
Eif (canUseDOM()) {
this.updateBreakpoint();
window.addEventListener("resize", this.requestFrame);
}
}
/**
* React life-cycle method
*/
public componentWillUnmount(): void {
Eif (canUseDOM()) {
window.removeEventListener("resize", this.requestFrame);
}
}
/**
* React render method
*/
public render(): React.ReactNode {
return this.props.render(this.state.activeBreakpoint);
}
/**
* Updates the active breakpoint
*/
private updateBreakpoint = (): void => {
const windowWidth: number = window.innerWidth;
const breakpoint: number | void = identifyBreakpoint(
windowWidth,
BreakpointTracker.breakpoints
);
Eif (this.state.activeBreakpoint !== breakpoint) {
this.setState({
activeBreakpoint: breakpoint,
});
}
this.openRequestAnimationFrame = false;
};
/**
* Request's an animation frame if there are currently no open animation frame requests
*/
private requestFrame = (): void => {
if (!this.openRequestAnimationFrame) {
this.openRequestAnimationFrame = true;
window.requestAnimationFrame(this.updateBreakpoint);
}
};
}
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