element-web/src/components/views/rooms/LinkPreviewWidget.js

/*
Copyright 2016 OpenMarket Ltd
Copyright 2019 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 React, {createRef} from 'react';
import PropTypes from 'prop-types';
import createReactClass from 'create-react-class';
import { linkifyElement } from '../../../HtmlUtils';
import SettingsStore from "../../../settings/SettingsStore";
import { _t } from "../../../languageHandler";

const sdk = require('../../../index');
const MatrixClientPeg = require('../../../MatrixClientPeg');
const ImageUtils = require('../../../ImageUtils');
const Modal = require('../../../Modal');

module.exports = createReactClass({
    displayName: 'LinkPreviewWidget',

    propTypes: {
        link: PropTypes.string.isRequired, // the URL being previewed
        mxEvent: PropTypes.object.isRequired, // the Event associated with the preview
        onCancelClick: PropTypes.func, // called when the preview's cancel ('hide') button is clicked
        onHeightChanged: PropTypes.func, // called when the preview's contents has loaded
    },

    getInitialState: function() {
        return {
            preview: null,
        };
    },

    componentWillMount: function() {
        this.unmounted = false;
        MatrixClientPeg.get().getUrlPreview(this.props.link, this.props.mxEvent.getTs()).then((res)=>{
            if (this.unmounted) {
                return;
            }
            this.setState(
                { preview: res },
                this.props.onHeightChanged,
            );
        }, (error)=>{
            console.error("Failed to get URL preview: " + error);
        });

        this._description = createRef();
    },

    componentDidMount: function() {
        if (this._description.current) {
            linkifyElement(this._description.current);
        }
    },

    componentDidUpdate: function() {
        if (this._description.current) {
            linkifyElement(this._description.current);
        }
    },

    componentWillUnmount: function() {
        this.unmounted = true;
    },

    onImageClick: function(ev) {
        const p = this.state.preview;
        if (ev.button != 0 || ev.metaKey) return;
        ev.preventDefault();
        const ImageView = sdk.getComponent("elements.ImageView");

        let src = p["og:image"];
        if (src && src.startsWith("mxc://")) {
            src = MatrixClientPeg.get().mxcUrlToHttp(src);
        }

        const params = {
            src: src,
            width: p["og:image:width"],
            height: p["og:image:height"],
            name: p["og:title"] || p["og:description"] || this.props.link,
            fileSize: p["matrix:image:size"],
            link: this.props.link,
        };

        Modal.createDialog(ImageView, params, "mx_Dialog_lightbox");
    },

    render: function() {
        const p = this.state.preview;
        if (!p || Object.keys(p).length === 0) {
            return <div />;
        }

        // FIXME: do we want to factor out all image displaying between this and MImageBody - especially for lightboxing?
        let image = p["og:image"];
        if (!SettingsStore.getValue("showImages")) {
            image = null; // Don't render a button to show the image, just hide it outright
        }
        const imageMaxWidth = 100; const imageMaxHeight = 100;
        if (image && image.startsWith("mxc://")) {
            image = MatrixClientPeg.get().mxcUrlToHttp(image, imageMaxWidth, imageMaxHeight);
        }

        let thumbHeight = imageMaxHeight;
        if (p["og:image:width"] && p["og:image:height"]) {
            thumbHeight = ImageUtils.thumbHeight(p["og:image:width"], p["og:image:height"], imageMaxWidth, imageMaxHeight);
        }

        let img;
        if (image) {
            img = <div className="mx_LinkPreviewWidget_image" style={{ height: thumbHeight }}>
                    <img style={{ maxWidth: imageMaxWidth, maxHeight: imageMaxHeight }} src={image} onClick={this.onImageClick} />
                  </div>;
        }

        const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
        return (
            <div className="mx_LinkPreviewWidget" >
                { img }
                <div className="mx_LinkPreviewWidget_caption">
                    <div className="mx_LinkPreviewWidget_title"><a href={this.props.link} target="_blank" rel="noopener">{ p["og:title"] }</a></div>
                    <div className="mx_LinkPreviewWidget_siteName">{ p["og:site_name"] ? (" - " + p["og:site_name"]) : null }</div>
                    <div className="mx_LinkPreviewWidget_description" ref={this._description}>
                        { p["og:description"] }
                    </div>
                </div>
                <AccessibleButton className="mx_LinkPreviewWidget_cancel" onClick={this.props.onCancelClick} aria-label={_t("Close preview")}>
                    <img className="mx_filterFlipColor" alt="" role="presentation"
                        src={require("../../../../res/img/cancel.svg")} width="18" height="18" />
                </AccessibleButton>
            </div>
        );
    },
});