README.md

@trousers/theme

@trousers/theme provides tools for theming your application.

Theming is achieved via React's Context API. Use the ThemeProvider to send your theme down the react tree and give all usages of useStyles and useGlobals access to your theme. You can even choose to nest themes and present a section of your app in a different way.

It looks a little something like this:

import { ThemeProvider } from 'trousers';

const lightTheme = {
    primaryColor: 'white',
    secondaryColor: 'blue',
    disabledColor: 'grey',
};

const darkTheme = {
    primaryColor: 'black',
    secondaryColor: 'purple',
    disabledColor: 'grey',
};

const MyApp = () => {
    return (
        <ThemeProvider theme={lightTheme}>
            <h1>Hello World</h1>
            <p>Rest of my app lives here and has access to the light theme!</p>
            <ThemeProvider theme={darkTheme}>
                <p>This subtree will have access to the dark theme!</p>
            </ThemeProvider>
        </ThemeProvider>
    );
};

When a Trousers component is mounted within a new theme context, it will render new styles and apply them to the component.

You can define how your component handles themes like this:

const buttonStyles = props => styleCollector('button').element`
        background-color: ${theme => theme.secondaryColor};
    `.modifier(props.primary)`
        background-color: ${theme => theme.primaryColor};
    `.modifier(props.disabled)`
        background-color: ${theme => theme.disabledColor};
    `;

Now your component will render different styles based on the context it is mounted in.

API

<ThemeProvider />

Responsible for pushing the supplied theme into React's Context API.

Props:

• theme: Object

Example:

import React from 'react';
import { ThemeProvider } from '@trousers/theme';

const theme = {
    primaryColor: 'red',
    secondaryColor: 'blue',
};

const App = () => (
    <ThemeProvider theme={theme}>
        {* Every child node will have access to the theme *}
    </ThemeProvider>
);

useTheme

A handy utility hook which pulls the theme from context. Useful when you want to use the CSS prop with object notation.

/** @jsx jsx */
import React from 'react';
import { jsx } from '@trousers/core';
import { ThemeProvider, useTheme } from '@trousers/theme';

const theme = {
    primaryColor: 'red',
    secondaryColor: 'blue',
};

const Foo = () => {
  const theme = useTheme();

  return (
    <div css={{
      color: theme.primaryColor;
    }}>
      Foo bar
    </div>
  );
}

const App = () => (
    <ThemeProvider theme={theme}>
      <Foo />
    </ThemeProvider>
);