TextFlow

TextFlow is a package for easily doing text heavy layouts on platforms that don't have a typesetting engine (like React Native). It allows you to flow text around block elements, measure text sizing without platform support and fit text into arbitary shapes. It also has markup support for styling such as different fonts, weights, kerning, tracking and colours.

Usage

Measuring Text

import { Text as FlowText, Markup } from "@times-components/text-flow";

const text = new FlowText.Text({
  font: "TimesModern-Regular",
  width: 660,
  size: 18,
  lineHeight: 30,
  markup: [new Markup.MarkupString("Hello World!")]
});

const width = text.measuredWidth;
const height = text.measuredHeight;

Make sure you set the same font, size and line-height as what you will be rendering the text with.

Getting the layout of a paragraph

import { Text as FlowText, Layout, Markup } from "@times-components/text-flow";

const textStyle = {
  font: "TimesModern-Regular",
  size: 18,
  lineHeight: 30
};

const flow = new Layout.TextFlow({
  width: 660,
  flow: [
    // First Paragraph
    new FlowText.Text({
      ...textStyle,
      markup: [new Markup.MarkupString("<SOME PARAGRAPH>")]
    }),
    // Second Paragraph
    new FlowText.Text({
      ...textStyle,
      markup: [new Markup.MarkupString("<SOME OTHER PARAGRAPH>")]
    })
  ]
});

Paragraphs with markup

import { Text as FlowText, Layout, Markup } from "@times-components/text-flow";

const flow = new FlowText.Text({
  font: "TimesModern-Regular",
  width: 660,
  size: 18,
  lineHeight: 30,
  markup: [
    new Markup.MarkupString("Hello "),
    new Markup.Bold({
      children: [new Markup.MarkupString("Bold ")]
    }),
    new Markup.Italic({
      children: [new Markup.MarkupString("and Italic")]
    }),
    new Markup.Link({
      href: <Text onPress={() => {}}>, Linked world</Text>,
      children: [new Markup.MarkupString(", Linked world")]
    })
  ]
});

Types of markup supported:

• Bold
• Italic
• Link

No Markup API is currently provided for line tracking and character kerning, default values from the font are used.

Adding new Markup:

New markup classes should be put in src/Markup, use Bold or Italic as an example. You inherit from StyledText and modify the styling in the characters methods. All Markup nodes must implement the characters() method that returns an array of Character instances for the typesetter.

Arbitary text flowing

Currently only flowing around blocks is supported, text exclusion paths are possible but no API is provided.

import { Text as FlowText, Layout, Markup } from "@times-components/text-flow"

const flow = new Layout.TextFlow({
    font: 'TimesModern-Regular',
    width: 660,
    size: 18,
    lineHeight: 30,
    flow: [
        new Layout.InlineBlock({
            width: screenWidth * 0.35,
            height: 300,
            getComponent() {
                return <View>
                    <Image uri={} />
                </View>
            }
        }),
        new FlowText.Text({
            font: 'TimesModern-Regular',
            size: 18,
            lineHeight: 30,
            markup: [
                new Markup.MarkupString("Hello world...")
            ]
        }),
        new Layout.Block({
            width: 660,
            height: 100,
            getComponent() {
                return <View/>
            }
        })
    ]
})

The TextFlow class will automatically pull up as much text from the following paragraphs as it can until it runs out of text or the height of the paragraphs next to the inline exceeds the height of the dimensions set.

Rendering

TextFlow does not know how to do any rendering on it's own, it only does layout, you must implement a bridge to whichever platform you are using for rendering. An example of such a bridge can be found in @times-components/article-skeleton in article-skeleton.js and article-body-row.js.

TextFlow and Text both have a block property after layout is done, which for flow contains the layout classes or an array of Line for Text in the children property.

Each block or line contains the properties x, y, measuredWidth, measuredHeight, this should be all you need for positioning text in your rendering. The layout can be refreshed after changing the markup or flow properties by calling the layout method on either class.

Line and Word contain a property called idealSpans, this will contain so-called ideal spans which only break when styling changes. For example when rendering with React Native using these will minimise the number of <Text/> views you need to render.

Line and Word also have children, with everything containing the layout properties all the way down to the character level. It is not recommended to render characters individually but it is possible.

Contributing

Please read CONTRIBUTING.md before contributing to this package

Running the code

Please see our main README.md to get the project running locally

Development

The code can be formatted and linted in accordance with the agreed standards.

yarn fmt
yarn lint

Testing

Testing can be done on each platform individually

yarn test:android
yarn test:ios
yarn test:web

Or the tests for all platforms can be run

yarn test:all

Visit the official

Visit the official storybook to see examples of inline components in articles.

Future