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Themes and darkMode ๐ŸŒ—

This boilerplate handle dark themes and theme overrides


What is the default configuration โ“โ€‹

By default, the boilerplate comes with a default theme and a default dark theme. The default theme is build around the different files at the root of src/Theme, by default:

  • Common.js
  • Fonts.js
  • Gutters.js
  • Images.js
  • Layout.js
  • Variables.js

the default dark theme is located in src/Theme/themes/default_dark.

The Boilerplate Theme system is based on layers overriding.
In other words, the default theme is the "base theme" of the application. On the top of it, if the darkMode is on, the base theme is overrided by style classes or variables of the default dark theme.

Moreover, if we add a new theme into src/Theme/themes, for example : custom. The theme system will override the default theme classes by the ones of custom theme. If the dark mode is activated, the theme system will try to get a custom_dark directory if exists, and override the theme too.

So, the merge of style and variables classes look like this :

default theme <- custom theme <- custom dark theme (if darkMode = true and theme exist)

The name of the current theme and if the dark mode is on are stored in redux and persisted in the device. At a given point of the time the state can look like this :

{
theme: 'custom',
darkMode: true, // can be null|true|false
}

The darkMode values can be :

  • null (by default) : the darkMode is automatically set depending of the scheme of the device
  • true : force the theme to be dark
  • false : force the theme to be light

There are two Actions availabled to set a new theme :

  • DefaultTheme allow to set the theme from parameters only if the state.theme is null (used in the initialisation of the app to set the default theme if this is the first time the app is openned or if the data were cleared)
  • ChangeTheme allow to set a given theme (see example bellow)

Create a new theme ๐Ÿงฉโ€‹

Basic exampleโ€‹

To create a new theme, create a new directory into src/Theme/themes with the name of your theme. For example custom. Add files with the same names of the default theme files. For example, if custom theme has to override the primary color, simply create a new file called Variables into src/Theme/themes/custom with the following :

src/Theme/themes/custom/Variables.js
const Colors = {
primary: 'yellow',
}

export default {
Colors,
}

๐Ÿšจ After adding a new override file, don't forget to export it into the root file of the custom directory with the following :

src/Theme/themes/custom/index.js
export { default as Variables } from './Variables'

๐Ÿšจ Each time a new theme is create, import it into the root of themes directory with the name of the theme :

src/Theme/themes/index.js
import * as default_dark from './default_dark'
import * as custom from './custom' // <-- add this line

export default {
default_dark,
custom, // <-- add this line
}

That's it ! now you can use the ChangeTheme action to set the theme in a container for example:

src/Containers/Example/index.js
import React, { useState } from 'react'
import { useDispatch, useSelector } from 'react-redux'
import { View, Button } from 'react-native'
import { useTheme } from '@/Hooks'
import { changeTheme } from '@/Store/Theme'

const IndexExampleContainer = () => {
const { Common, Fonts, Gutters, Layout } = useTheme()
const dispatch = useDispatch()

const changeTheme = ({ theme, darkMode }) => {
dispatch(changeTheme({ theme, darkMode }))
}

return (
<View style={[Layout.fill, Layout.colCenter, Gutters.smallHPadding]}>
<View
style={[
Layout.row,
Layout.rowHCenter,
Gutters.smallHPadding,
Gutters.largeVMargin,
Common.backgroundPrimary,
]}
>
<Button onPress={() => changeTheme({ theme: 'custom' })} title="set theme custom" />
<Button onPress={() => changeTheme({ theme: 'default' })} title="set theme default" />
</View>
</View>
)
}
export default IndexExampleContainer

Extended example with dark themeโ€‹

After adding a new theme, to handle the dark theme of it, the same way the new theme was created, the dark will be. ๐Ÿ˜Ž
So, the first step is to create the src/Theme/themes/custom_dark directory. This theme will override the default and the custom theme by :

  • adding a new color
  • override the React Navigation primary color
  • apply the new color by adding a border on the backgroundPrimary class.

Let's create the following files :

src/Theme/themes/custom_dark/Variables.js
const Colors = {
orange: 'orange', // adding a new color โœ…
}

const NavigationColors = {
primary: 'red', // override the React Navigation primary color โœ…
}

export default {
Colors,
NavigationColors,
}

And,

src/Theme/themes/custom_dark/Common.js
import { StyleSheet } from 'react-native'

export default function ({ Colors }) {
return StyleSheet.create({
backgroundPrimary: {
backgroundColor: Colors.primary,
borderColor: Colors.orange, // apply the new color by adding a border on the `backgroundPrimary` class โœ…
},
})
}

๐Ÿšจ After adding a new override file, don't forget to export it into the root file of the custom_dark directory with the following :

src/Theme/themes/custom_dark/index.js
export { default as Variables } from './Variables'
export { default as Common } from './Common'

๐Ÿšจ Each time a new theme is create, import it into the root of themes directory with the name of the theme :

src/Theme/themes/index.js
import * as default_dark from './default_dark'
import * as custom from './custom'
import * as custom_dark from './custom_dark' // <- add this line

export default {
default_dark,
custom,
custom_dark, // <- add this line
}

You can add extra buttons to the ExampleContainer below to test it :

src/Containers/Example/index.js
...
const ExampleContainer = () => {
...
return (
<View style={[Layout.fill, Layout.colCenter, Gutters.smallHPadding]}>
<View
style={[
Layout.row,
Layout.rowHCenter,
Gutters.smallHPadding,
Gutters.largeVMargin,
Common.backgroundPrimary,
]}
>
<Button onPress={() => changeTheme({ theme: 'custom' })} title="set theme custom" />
<Button onPress={() => changeTheme({ theme: 'default' })} title="set theme default" />
<Button onPress={() => changeTheme({ darkMode: null })} title="Dark auto" /> {/* <- add this line */}
<Button onPress={() => changeTheme({ darkMode: true })} title="set to Dark" /> {/* <- add this line */}
<Button onPress={() => changeTheme({ darkMode: false })} title="set to Light" /> {/* <- add this line */}
</View>
</View>
)
}

That's it ! you can now enjoy multi theming and dark mode ! ๐Ÿ‘