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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
import React, { useState, useEffect } from 'react';
import { Paper, Typography } from '@material-ui/core';
import { makeStyles } from "@material-ui/core/styles";
const useStyles = makeStyles(theme => ({
root: {
textAlign: 'center',
padding: theme.spacing(5),
background: theme.palette.primary.main,
marginTop: theme.spacing(20),
},
}));
const Timer = ({ registerResult }) => {
const classes = useStyles();
const SPACE = 32;
const maxCountdown = 15000;
const [time, setTime] = useState('00:00:00');
const [mode, setMode] = useState('idle');
const [repeater, setRepeater] = useState(0);
useEffect(()=> {
clearInterval(repeater);
const timestamp = Date.now();
if (mode === 'countdown') setRepeater(setInterval(() => {
const timeDelta = maxCountdown - (Date.now() - timestamp);
if (timeDelta <= 0) setMode('over');
setTime(convertTimeToString(timeDelta));
}, 10));
if (mode === 'running') setRepeater(setInterval(() => {
setTime(convertTimeToString(Date.now() - timestamp));
}, 10));
if (mode === 'over') {
setTime('00:00:00');
}
}, [mode]);
const handleKeyPress = event => {
event.preventDefault();
if (event.keyCode === SPACE && mode === 'idle' ) setMode('countdown');
};
const handleKeyUp = event => {
clearInterval(repeater);
if (event.keyCode === SPACE) {
if (mode === 'running') {
registerResult(time);
setMode('idle');
} else if (mode === 'over') {
setMode('idle');
} else {
setMode('running');
}
}
};
useEffect(() => {
window.addEventListener('keyup', handleKeyUp);
window.addEventListener('keypress', handleKeyPress);
return () => {
window.removeEventListener('keyup', handleKeyUp);
window.removeEventListener('keypress', handleKeyPress);
};
});
const composeHelperText = () => {
switch (mode) {
case 'running': return '_';
case 'countdown': return 'Release SPACE to begin';
case 'over': return 'You are too late!';
default: return 'Hold SPACE to start countdown';
}
};
const helperColor = () => {
switch (mode) {
case 'running': return 'primary';
case 'over': return 'secondary';
default: return 'textSecondary';
}
};
return (
<Paper elevation={3} className={classes.root}>
<Typography variant="h1"> {time} </Typography>
<Typography variant="h5" color={helperColor()}>
{composeHelperText()}
</Typography>
</Paper>
);
};
const convertTimeToString = timeDelta => {
let resultTime = '';
const minute = Math.floor(timeDelta / 60000);
if (minute < 10) resultTime += '0';
resultTime += minute + ':';
let second = Math.floor(timeDelta / 1000);
if (second < 10) resultTime += '0';
if (second > 59) second %= 60;
resultTime += second + ':';
const mill = Math.floor((timeDelta % 1000) / 10);
if (mill < 10) resultTime += '0';
resultTime += mill;
return resultTime;
};
export default Timer;
|
