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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
import * as _ from 'lodash';
import * as React from 'react';
import { ColorOption } from '../style/theme';
import { util } from '../util/util';
import { Input } from './ui/input';
export enum ScalingInputPhase {
FixedFontSize,
ScalingFontSize,
}
export interface ScalingSettings {
percentageToReduceFontSizePerCharacter: number;
constantPxToIncreaseWidthPerCharacter: number;
}
export interface ScalingInputProps {
textLengthThreshold: number;
maxFontSizePx: number;
value: string;
emptyInputWidthCh: number;
onChange: (event: React.ChangeEvent<HTMLInputElement>) => void;
onFontSizeChange: (fontSizePx: number) => void;
fontColor?: ColorOption;
placeholder?: string;
maxLength?: number;
scalingSettings: ScalingSettings;
isDisabled: boolean;
}
export interface ScalingInputState {
inputWidthPxAtPhaseChange?: number;
}
export interface ScalingInputSnapshot {
inputWidthPx: number;
}
// These are magic numbers that were determined experimentally.
const defaultScalingSettings: ScalingSettings = {
percentageToReduceFontSizePerCharacter: 0.125,
constantPxToIncreaseWidthPerCharacter: 4,
};
export class ScalingInput extends React.Component<ScalingInputProps, ScalingInputState> {
public static defaultProps = {
onChange: util.boundNoop,
onFontSizeChange: util.boundNoop,
maxLength: 7,
scalingSettings: defaultScalingSettings,
isDisabled: false,
};
public state: ScalingInputState = {
inputWidthPxAtPhaseChange: undefined,
};
private readonly _inputRef = React.createRef<HTMLInputElement>();
public static getPhase(textLengthThreshold: number, value: string): ScalingInputPhase {
if (value.length <= textLengthThreshold) {
return ScalingInputPhase.FixedFontSize;
}
return ScalingInputPhase.ScalingFontSize;
}
public static getPhaseFromProps(props: ScalingInputProps): ScalingInputPhase {
const { value, textLengthThreshold } = props;
return ScalingInput.getPhase(textLengthThreshold, value);
}
public static calculateFontSize(
textLengthThreshold: number,
maxFontSizePx: number,
phase: ScalingInputPhase,
value: string,
percentageToReduceFontSizePerCharacter: number,
): number {
if (phase !== ScalingInputPhase.ScalingFontSize) {
return maxFontSizePx;
}
const charactersOverMax = value.length - textLengthThreshold;
const scalingFactor = (1 - percentageToReduceFontSizePerCharacter) ** charactersOverMax;
const fontSize = scalingFactor * maxFontSizePx;
return fontSize;
}
public static calculateFontSizeFromProps(props: ScalingInputProps, phase: ScalingInputPhase): number {
const { textLengthThreshold, value, maxFontSizePx, scalingSettings } = props;
return ScalingInput.calculateFontSize(
textLengthThreshold,
maxFontSizePx,
phase,
value,
scalingSettings.percentageToReduceFontSizePerCharacter,
);
}
public getSnapshotBeforeUpdate(): ScalingInputSnapshot {
return {
inputWidthPx: this._getInputWidthInPx(),
};
}
public componentDidUpdate(
prevProps: ScalingInputProps,
prevState: ScalingInputState,
snapshot: ScalingInputSnapshot,
): void {
const prevPhase = ScalingInput.getPhaseFromProps(prevProps);
const curPhase = ScalingInput.getPhaseFromProps(this.props);
// if we went from fixed to scaling, save the width from the transition
if (prevPhase !== ScalingInputPhase.ScalingFontSize && curPhase === ScalingInputPhase.ScalingFontSize) {
this.setState({
inputWidthPxAtPhaseChange: snapshot.inputWidthPx,
});
}
// if we went from scaling to fixed, revert back to scaling using `ch`
if (prevPhase === ScalingInputPhase.ScalingFontSize && curPhase !== ScalingInputPhase.ScalingFontSize) {
this.setState({
inputWidthPxAtPhaseChange: undefined,
});
}
const prevFontSize = ScalingInput.calculateFontSizeFromProps(prevProps, prevPhase);
const curFontSize = ScalingInput.calculateFontSizeFromProps(this.props, curPhase);
// If font size has changed, notify.
if (prevFontSize !== curFontSize) {
this.props.onFontSizeChange(curFontSize);
}
}
public render(): React.ReactNode {
const { isDisabled, fontColor, onChange, placeholder, value, maxLength } = this.props;
const phase = ScalingInput.getPhaseFromProps(this.props);
return (
<Input
ref={this._inputRef as any}
fontColor={fontColor}
onChange={onChange}
value={value}
placeholder={placeholder}
fontSize={`${this._calculateFontSize(phase)}px`}
width={this._calculateWidth(phase)}
maxLength={maxLength}
disabled={isDisabled}
/>
);
}
private readonly _calculateWidth = (phase: ScalingInputPhase): string => {
const { value, textLengthThreshold, scalingSettings } = this.props;
if (_.isEmpty(value)) {
return `${this.props.emptyInputWidthCh}ch`;
}
switch (phase) {
case ScalingInputPhase.FixedFontSize:
return `${value.length}ch`;
case ScalingInputPhase.ScalingFontSize:
const { inputWidthPxAtPhaseChange } = this.state;
if (!_.isUndefined(inputWidthPxAtPhaseChange)) {
const charactersOverMax = value.length - textLengthThreshold;
const scalingAmount = scalingSettings.constantPxToIncreaseWidthPerCharacter * charactersOverMax;
const width = inputWidthPxAtPhaseChange + scalingAmount;
return `${width}px`;
}
return `${textLengthThreshold}ch`;
}
};
private readonly _calculateFontSize = (phase: ScalingInputPhase): number => {
return ScalingInput.calculateFontSizeFromProps(this.props, phase);
};
private readonly _getInputWidthInPx = (): number => {
const ref = this._inputRef.current;
if (!ref) {
return 0;
}
return ref.getBoundingClientRect().width;
};
}
|
