polygerrit-ui/app/elements/core/gr-key-binding-display/gr-key-binding-display.ts

/**
 * @license
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import {html} from 'lit-html';
import {GrLitElement} from '../../lit/gr-lit-element';
import {customElement, property} from 'lit-element';
import {cssTemplate} from './gr-key-binding-display.css';
import {sharedStyles} from '../../../styles/shared-styles';

declare global {
  interface HTMLElementTagNameMap {
    'gr-key-binding-display': GrKeyBindingDisplay;
  }
}

@customElement('gr-key-binding-display')
export class GrKeyBindingDisplay extends GrLitElement {
  static get styles() {
    return [sharedStyles, cssTemplate];
  }

  render() {
    const items = this.binding.map((binding, index) => [
      index > 0 ? html` or ` : html``,
      this._computeModifiers(binding).map(
        modifier => html`<span class="key modifier">${modifier}</span> `
      ),
      html`<span class="key">${this._computeKey(binding)}</span>`,
    ]);
    return html`${items}`;
  }

  @property({type: Array})
  binding: string[][] = [];

  _computeModifiers(binding: string[]) {
    return binding.slice(0, binding.length - 1);
  }

  _computeKey(binding: string[]) {
    return binding[binding.length - 1];
  }
}