element-web/src/components/views/audio_messages/AudioPlayer.tsx

/*
Copyright 2021 The Matrix.org Foundation C.I.C.

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 { Playback, PlaybackState } from "../../../voice/Playback";
import React, { createRef, ReactNode, RefObject } from "react";
import { UPDATE_EVENT } from "../../../stores/AsyncStore";
import PlaybackWaveform from "./PlaybackWaveform";
import PlayPauseButton from "./PlayPauseButton";
import { replaceableComponent } from "../../../utils/replaceableComponent";
import { formatBytes } from "../../../utils/FormattingUtils";
import DurationClock from "./DurationClock";
import { Key } from "../../../Keyboard";

interface IProps {
    // Playback instance to render. Cannot change during component lifecycle: create
    // an all-new component instead.
    playback: Playback;
}

interface IState {
    playbackPhase: PlaybackState;
}

@replaceableComponent("views.audio_messages.AudioPlayer")
export default class AudioPlayer extends React.PureComponent<IProps, IState> {
    private playPauseRef: RefObject<PlayPauseButton> = createRef();

    constructor(props: IProps) {
        super(props);

        this.state = {
            playbackPhase: PlaybackState.Decoding, // default assumption
        };

        // We don't need to de-register: the class handles this for us internally
        this.props.playback.on(UPDATE_EVENT, this.onPlaybackUpdate);

        // Don't wait for the promise to complete - it will emit a progress update when it
        // is done, and it's not meant to take long anyhow.
        // noinspection JSIgnoredPromiseFromCall
        this.props.playback.prepare();
    }

    private onPlaybackUpdate = (ev: PlaybackState) => {
        this.setState({ playbackPhase: ev });
    };

    private onKeyPress = (ev: React.KeyboardEvent) => {
        if (ev.key === Key.SPACE) {
            ev.stopPropagation();
            this.playPauseRef.current?.toggle();
        }
    };

    protected renderFileSize(): string {
        const bytes = this.props.playback.sizeBytes;
        if (!bytes) return null;

        // Not translated as these are units, and therefore universal
        return `(${formatBytes(bytes)})`;
    }

    public render(): ReactNode {
        // tabIndex=0 to ensure that the whole component becomes a tab stop, where we handle keyboard
        // events for accessibility
        return <div className='mx_AudioPlayer_container' tabIndex={0} onKeyPress={this.onKeyPress}>
            <div className='mx_AudioPlayer_primaryContainer'>
                <PlayPauseButton
                    playback={this.props.playback}
                    playbackPhase={this.state.playbackPhase}
                    tabIndex={-1} // prevent tabbing into the button
                    ref={this.playPauseRef}
                />
                <div className='mx_AudioPlayer_byline'>
                    <DurationClock playback={this.props.playback} />
                    &nbsp; {/* easiest way to introduce a gap between the components */}
                    { this.renderFileSize() }
                </div>
            </div>
            <PlaybackWaveform playback={this.props.playback} />
        </div>
    }
}