Masthead component

The vf-masthead (masthead) is a full-width container that can take a text, theme colour, an image, and create a 'block' for the text to lay atop.

Usage

The vf-masthead component can be used on the home page of group sites to help inform the visitor of the groups name, location, and additional information.

| ✅ Do's | 🚫 Do Not's | | --------------------------------------- | ------------------------------------------ | | Use this on the homepage of group sites | On every subsquent page | | Use the title block with a theme colour | Use a title block, theme colour, and image |

Background Colours

By Default, the vf-masthead is black text on a light grey background except if it is the title block variant where the text will be white on a black background with an overall light grey background.

This can be effected by either having a component specific class that effects the colours.

Theme Variants available are:

• vf-masthead-theme--primary
• vf-masthead-theme--secondary
• vf-masthead-theme--tertiary

There is also a variant that allows for a background image - vf-masthead--has-image as well as a variant that allows for the text to be in a block of white (with the text being black) - vf-masthead--with-title-block.

notes:

If you are overriding the background or foreground (text) colour make sure you are:

• using a colour from the Visual Framework
• testing to be sure that the contrast ratio meets accessibility guidelines

Background Image Size

The maximum dimensions for a background image is 1224px wide with a height of 150px. As more and more displays are what we term 'retina' they need to be twice the width and height to look crisp.

Images that are used for mastheads need to have dimensions of 2448px by 300px.

Text Colour

When using a background image we have to determine the best text colour to meet the contrast ratio from our accessibility guidelines.

We do this using JavaScript and the background image filename.

In choosing the image for masthead the image filename needs to have it's most dominate colour added as a hexadecimal code.

masthead-background-image--00EF00.png

To find the dominant colour in the background image you can use a colour picker in graphics software to find the hex code.

This then allows the code to look for this hexidecimal colour code and mathematically works out the correct text colour to use. The CSS custom property --local-theme-fg-color is then applied in the style tag of the component.

<style>
<div
  class="vf-masthead vf-masthead--has-image"
  style="background-image: var(--vf-masthead__bg-image);
         --local-theme-fg-color:#FFFFFF;"
  data-vf-js-masthead
>
</style>

If JavaScript is disabled, or if it doesn't load with the page. The masthead will default to the background colour.

Browser Support

CSS Custom Properties do not work in older versions of Internet Explorer. We provide a default look for the masthead for these browser which is a white foreground colour (for text) on a green background.

However, this can be overriden if needed using the Sass variables.

Install

This component is distributed with npm. After installing npm, you can install the vf-masthead with this command.

$ yarn add --dev @visual-framework/vf-masthead

Sass/CSS

The source files included are written in Sass(scss). You can point your Sass include-path at your node_modules directory and import it like this.

@import "@visual-framework/vf-masthead/index.scss";

Make sure you import Sass requirements along with the modules. You can use a project boilerplate or the vf-sass-starter

Help

• Read the Visual Framework troubleshooting
• Open a ticket
• Chat on Slack