Managing Focus

To improve the authoring experience and accessibility for keyboard users, the widget should react sensibly when receiving focus.

focus(): Handle when the widget receives focus

A simple way of handling focus is delegating the focus to a child element.

In our example, we implement focus() on the element such that the textarea is focused when the widget is focused:

@customElement("cool-widget")
export default class CoolWidget extends LitElementWw {

  @property({attribute: true})
  value: string

  @property({attribute: true})
  placeholder: string

  @query("textarea")
  textarea: HTMLTextAreaElement

  focus(options: FocusOptions) {
    this.textarea?.focus(options)
  }

  static get styles() {
    return css`
      :host(:is([contenteditable=true], [contenteditable=""])) .placeholder {
        display: none;
      }

      :host(.ww-beforeprint) textarea {
        border: 2px solid black;
        border-radius: 2px;
      }
    `
  }

  render() {
    return html`
    <input part="action" class="placeholder" @change=${e => this.placeholder = e.target.value}></input>
    <textarea @change=${e => this.value = e.target.value} placeholder=${this.placeholder}>
      ${this.value}
    </textarea>`
  }
}