githubmirror/zulip

web/src/lightbox.js
670 строк24 KB
roanster007
lightbox: Fix the panzoom access for non image.
27 ноя 2023, 21:15
27 ноя 2023, 21:156397df8
import $ from "jquery";
import panzoom from "panzoom";

import render_lightbox_overlay from "../templates/lightbox_overlay.hbs";

import * as blueslip from "./blueslip";
import * as message_store from "./message_store";
import * as overlays from "./overlays";
import * as people from "./people";
import * as popovers from "./popovers";
import * as rows from "./rows";
import * as util from "./util";

let is_open = false;
// the asset map is a map of all retrieved images and YouTube videos that are
// memoized instead of being looked up multiple times.
const asset_map = new Map();

export class PanZoomControl {
    // Class for both initializing and controlling the
    // the pan/zoom functionality.
    constructor(container) {
        this.container = container;
        this.panzoom = panzoom(this.container, {
            smoothScroll: false,
            // Ideally we'd set `bounds` here, but that feature is
            // currently broken upstream.  See
            // https://github.com/anvaka/panzoom/issues/112.
            maxZoom: 64,
            minZoom: 1 / 16,
            filterKey() {
                // Disable the library's built in keybindings
                return true;
            },
        });
        // The following events are necessary to prevent the click event
        // firing where the user "unclicks" at the end of the drag, which
        // was causing accidental overlay closes in some situations.
        this.panzoom.on("pan", () => {
            // Marks this overlay as needing to stay open.
            $("#lightbox_overlay").data("noclose", true);

            // Enable the panzoom reset button.
            $("#lightbox_overlay .lightbox-zoom-reset").removeClass("disabled");
        });

        this.panzoom.on("panend", (e) => {
            // Check if the image has been panned out of view.
            this.constrainImage(e);

            // Don't remove the noclose attribute on this overlay until after paint,
            // otherwise it will be removed too early and close the lightbox
            // unintentionally.
            setTimeout(() => {
                $("#lightbox_overlay").data("noclose", false);
            }, 0);
        });

        this.panzoom.on("zoom", (e) => {
            // Check if the image has been zoomed out of view.
            // We are using the zoom event instead of zoomend because the zoomend
            // event does not fire when using the scroll wheel or pinch to zoom.
            // https://github.com/anvaka/panzoom/issues/250
            this.constrainImage(e);

            // Enable the panzoom reset button.
            $("#lightbox_overlay .lightbox-zoom-reset").removeClass("disabled");
        });

        // key bindings
        document.addEventListener("keydown", (e) => {
            if (!overlays.lightbox_open()) {
                return;
            }
            switch (e.key) {
                case "Z":
                case "+":
                    this.zoomIn();
                    break;
                case "z":
                case "-":
                    this.zoomOut();
                    break;
                case "v":
                    overlays.close_overlay("lightbox");
                    break;
            }
            e.preventDefault();
            e.stopPropagation();
        });
    }

    constrainImage(e) {
        if (!this.isActive()) {
            return;
        }

        // Instead of using panzoom's built in bounds option which was buggy
        // at the time of this writing, we act on pan/zoom events and move the
        // image back in to view if it is moved beyond the image-preview container.
        // See https://github.com/anvaka/panzoom/issues/112 for upstream discussion.

        const {scale, x, y} = e.getTransform();
        const image_width = $(".zoom-element > img")[0].clientWidth * scale;
        const image_height = $(".zoom-element > img")[0].clientHeight * scale;
        const zoom_element_width = $(".zoom-element")[0].clientWidth * scale;
        const zoom_element_height = $(".zoom-element")[0].clientHeight * scale;
        const max_translate_x = $(".image-preview")[0].clientWidth;
        const max_translate_y = $(".image-preview")[0].clientHeight;

        // When the image is dragged out of the image-preview container
        // (max_translate) it will be "snapped" back so that the number
        // of pixels set below will remain visible in the dimension it was dragged.
        const return_buffer = 50 * scale;
        // Move the image if it gets within this many pixels of the edge.
        const border = 20;

        const zoom_border_width = (zoom_element_width - image_width) / 2 + image_width;
        const zoom_border_height = (zoom_element_height - image_height) / 2 + image_height;
        const modified_x = x + zoom_border_width;
        const modified_y = y + zoom_border_height;

        if (modified_x < 0 + border) {
            // Image has been dragged beyond the LEFT of the view.
            const move_by = modified_x * -1;
            e.moveBy(move_by + return_buffer, 0, false);
        } else if (modified_x - image_width > max_translate_x - border) {
            // Image has been dragged beyond the RIGHT of the view.
            const move_by = modified_x - max_translate_x - image_width;
            e.moveBy(-move_by - return_buffer, 0, false);
        }

        if (modified_y < 0 + border) {
            // Image has been dragged beyond the TOP of the view.
            const move_by = modified_y * -1;
            e.moveBy(0, move_by + return_buffer, false);
        } else if (modified_y - image_height > max_translate_y - border) {
            // Image has been dragged beyond the BOTTOM of the view.
            const move_by = modified_y - max_translate_y - image_height;
            e.moveBy(0, -move_by - return_buffer, false);
        }
    }

    reset() {
        // To reset the panzoom state, we want to:
        // Reset zoom to the initial state.
        this.panzoom.zoomAbs(0, 0, 1);
        // Re-center the image.
        this.panzoom.moveTo(0, 0);
        // Always ensure that the overlay is available for click to close.
        // This way we don't rely on the above events firing panend,
        // of which there is some anecdotal evidence that suggests they
        // might be prone to race conditions.
        $("#lightbox_overlay").data("noclose", false);
        // Disable the lightbox reset button to reflect the state that
        // the image has not been panned or zoomed.
        $("#lightbox_overlay .lightbox-zoom-reset").addClass("disabled");
    }

    zoomIn() {
        if (!this.isActive()) {
            return;
        }

        const w = $(".image-preview").width();
        const h = $(".image-preview").height();
        this.panzoom.smoothZoom(w / 2, h / 2, Math.SQRT2);
    }

    zoomOut() {
        if (!this.isActive()) {
            return;
        }

        const w = $(".image-preview").width();
        const h = $(".image-preview").height();
        this.panzoom.smoothZoom(w / 2, h / 2, Math.SQRT1_2);
    }

    isActive() {
        return $(".image-preview .zoom-element img").length > 0;
    }
}

export function clear_for_testing() {
    is_open = false;
    asset_map.clear();
}

export function render_lightbox_media_list(preview_source) {
    if (!is_open) {
        const media_list = Array.prototype.slice.call(
            $(
                ".focused-message-list .message_inline_image img, .focused-message-list .message_inline_video video",
            ),
        );
        const $media_list = $("#lightbox_overlay .image-list").empty();

        for (const media of media_list) {
            const unverified_src = media.getAttribute("src");
            const src = util.is_valid_url(unverified_src) ? unverified_src : "";
            const className = preview_source === src ? "image selected" : "image";
            const is_video = media.tagName === "VIDEO";

            let $node;
            if (is_video) {
                $node = $("<div>")
                    .addClass(className)
                    .addClass("lightbox_video")
                    .attr("data-src", src);

                const $video = $("<video>");
                $video.attr("src", src);
                $video.attr("controls", false);

                $node.html($video);
            } else {
                $node = $("<div>")
                    .addClass(className)
                    .attr("data-src", src)
                    .css({backgroundImage: "url(" + src + ")"});
            }

            $media_list.append($node);

            // We parse the data for each image to show in the list,
            // while we still have its original DOM element handy, so
            // that navigating within the list only needs the `src`
            // attribute used to construct the node object above.
            parse_media_data(media);
        }
    }
}

function display_image(payload) {
    render_lightbox_media_list(payload.preview);

    $(".player-container, .video-player").hide();
    $(".image-preview, .media-actions, .media-description, .download, .lightbox-zoom-reset").show();

    const $img_container = $("#lightbox_overlay .image-preview > .zoom-element");
    const img = new Image();
    img.src = payload.source;
    $img_container.html(img).show();

    const filename = payload.url?.split("/").pop();
    $(".media-description .title")
        .text(payload.title || "N/A")
        .attr("aria-label", payload.title || "N/A")
        .prop("data-filename", filename || "N/A");
    $(".media-description .user").text(payload.user).prop("title", payload.user);

    $(".media-actions .open").attr("href", payload.source);

    const url = new URL(payload.source, window.location.href);
    const same_origin = url.origin === window.location.origin;
    if (same_origin && url.pathname.startsWith("/user_uploads/")) {
        // Switch to the "download" handler, so S3 URLs set their Content-Disposition
        url.pathname = "/user_uploads/download/" + url.pathname.slice("/user_uploads/".length);
        $(".media-actions .download").attr("href", url.href);
    } else if (same_origin) {
        $(".media-actions .download").attr("href", payload.source);
    } else {
        // If it's not same-origin, and we don't know how to tell the remote service to put a
        // content-disposition on it, the download can't possibly download, just show -- so hide the
        // element.
        $(".media-actions .download").hide();
    }
}

function display_video(payload) {
    render_lightbox_media_list(payload.preview);

    $(
        "#lightbox_overlay .image-preview, .media-description, .download, .lightbox-zoom-reset, .video-player",
    ).hide();
    $(".player-container").show();

    if (payload.type === "inline-video") {
        $(".player-container").hide();
        $(".video-player, .media-description").show();
        const $video = $("<video>");
        $video.attr("src", payload.source);
        $video.attr("controls", true);
        $(".video-player").html($video);
        $(".media-actions .open").attr("href", payload.source);

        const filename = payload.url?.split("/").pop();
        $(".media-description .title")
            .text(payload.title || "N/A")
            .attr("aria-label", payload.title || "N/A")
            .prop("data-filename", filename || "N/A");
        $(".media-description .user").text(payload.user).prop("title", payload.user);
        return;
    }

    let source;
    switch (payload.type) {
        case "youtube-video":
            source = "https://www.youtube.com/embed/" + payload.source;
            break;
        case "vimeo-video":
            source = "https://player.vimeo.com/video/" + payload.source;
            break;
        case "embed-video":
            // Use data: to load the player in a unique origin for security.
            source =
                "data:text/html," +
                window.encodeURIComponent(
                    "<!DOCTYPE html><style>iframe{position:absolute;left:0;top:0;width:100%;height:100%;box-sizing:border-box}</style>" +
                        payload.source,
                );
            break;
    }

    const $iframe = $("<iframe>");
    $iframe.attr(
        "sandbox",
        "allow-forms allow-modals allow-orientation-lock allow-pointer-lock allow-popups allow-popups-to-escape-sandbox allow-presentation allow-same-origin allow-scripts",
    );
    $iframe.attr("src", source);
    $iframe.attr("frameborder", 0);
    $iframe.attr("allowfullscreen", true);

    $("#lightbox_overlay .player-container").html($iframe);
    $(".media-actions .open").attr("href", payload.url);
}

export function build_open_media_function(on_close) {
    if (on_close === undefined) {
        on_close = function () {
            remove_video_players();
            is_open = false;
            document.activeElement.blur();
        };
    }

    return function ($media) {
        // if the asset_map already contains the metadata required to display the
        // asset, just recall that metadata.
        let $preview_src = $media.attr("src");
        let payload = asset_map.get($preview_src);
        if (payload === undefined) {
            if ($preview_src.endsWith("&size=full")) {
                // while fetching an image for canvas, `src` attribute supplies
                // full-sized image instead of thumbnail, so we have to replace
                // `size=full` with `size=thumbnail`.
                //
                // TODO: This is a hack to work around the fact that for
                // the lightbox canvas, the `src` is the data-fullsize-src
                // for the image, not the original thumbnail used to open
                // the lightbox.  A better fix will be to check a
                // `data-thumbnail-src` attribute that we add to the
                // canvas elements.
                $preview_src = $preview_src.slice(0, -"full".length) + "thumbnail";
                payload = asset_map.get($preview_src);
            }
            if (payload === undefined) {
                payload = parse_media_data($media);
            }
        }

        if (payload.type.match("-video")) {
            display_video(payload);
        } else if (payload.type === "image") {
            display_image(payload);
        }

        if (is_open) {
            return;
        }

        overlays.open_overlay({
            name: "lightbox",
            $overlay: $("#lightbox_overlay"),
            on_close,
        });

        popovers.hide_all();
        is_open = true;
    };
}

export function show_from_selected_message() {
    const $message_selected = $(".selected_message");
    let $message = $message_selected;
    // This is a function to satisfy eslint unicorn/no-array-callback-reference
    const media_classes = () => ".message_inline_image img, .message_inline_image video";
    let $media = $message.find(media_classes());
    let $prev_traverse = false;

    // First, we walk upwards/backwards, starting with the current
    // message, looking for an media to preview.
    //
    // Care must be taken, since both recipient_row elements and
    // message_row objects have siblings of different types, such as
    // date elements.
    while ($media.length === 0) {
        if ($message.prev().length === 0) {
            const $prev_message_group = $message.parent().prevAll(".recipient_row").first();
            if ($prev_message_group.length === 0) {
                $prev_traverse = true;
                $message = $message_selected;
                break;
            } else {
                $message = $prev_message_group.find(".message_row").last();
                $media = $message.find(media_classes());
                continue;
            }
        }
        $message = $message.prev();
        $media = $message.find(media_classes());
    }

    if ($prev_traverse) {
        while ($media.length === 0) {
            if ($message.next().length === 0) {
                const $next_message_group = $message.parent().nextAll(".recipient_row").first();
                if ($next_message_group.length === 0) {
                    break;
                } else {
                    $message = $next_message_group.find(".message_row").first();
                    $media = $message.find(media_classes());
                    continue;
                }
            }
            $message = $message.next();
            $media = $message.find(media_classes());
        }
    }

    if ($media.length !== 0) {
        const open_media = build_open_media_function();
        open_media($media);
    }
}

// retrieve the metadata from the DOM and store into the asset_map.
export function parse_media_data(media) {
    const $media = $(media);
    const preview_src = $media.attr("src");

    if (asset_map.has(preview_src)) {
        // check if media's data is already present in asset_map.
        return asset_map.get(preview_src);
    }

    // if wrapped in the .youtube-video class, it will be length = 1, and therefore
    // cast to true.
    const is_youtube_video = Boolean($media.closest(".youtube-video").length);
    const is_vimeo_video = Boolean($media.closest(".vimeo-video").length);
    const is_embed_video = Boolean($media.closest(".embed-video").length);
    const is_inline_video = Boolean($media.closest(".message_inline_video").length);

    // check if media is descendent of #compose .preview_content
    const is_compose_preview_media = $media.closest("#compose .preview_content").length === 1;

    const $parent = $media.parent();
    let type;
    let source;
    const url = $parent.attr("href");
    if (is_inline_video) {
        type = "inline-video";
        // Render video from original source to reduce load on our own servers.
        const original_video_url = $media.attr("data-video-original-url");
        // `data-video-original-url` is only defined for external URLs in
        // organizations which have camo enabled.
        if (!original_video_url) {
            source = preview_src;
        } else {
            source = encodeURI(original_video_url);
        }
    } else if (is_youtube_video) {
        type = "youtube-video";
        source = $parent.attr("data-id");
    } else if (is_vimeo_video) {
        type = "vimeo-video";
        source = $parent.attr("data-id");
    } else if (is_embed_video) {
        type = "embed-video";
        source = $parent.attr("data-id");
    } else {
        type = "image";
        if ($media.attr("data-src-fullsize")) {
            source = $media.attr("data-src-fullsize");
        } else {
            source = preview_src;
        }
    }
    let sender_full_name;
    if (is_compose_preview_media) {
        sender_full_name = people.my_full_name();
    } else {
        const $message = $parent.closest("[zid]");
        const zid = rows.id($message);
        const message = message_store.get(zid);
        if (message === undefined) {
            blueslip.error("Lightbox for unknown message", {zid});
        } else {
            sender_full_name = message.sender_full_name;
        }
    }
    const payload = {
        user: sender_full_name,
        title: $parent.attr("aria-label") || $parent.attr("href"),
        type,
        preview: util.is_valid_url(preview_src) ? preview_src : "",
        source: util.is_valid_url(source) ? source : "",
        url: util.is_valid_url(url) ? url : "",
    };

    asset_map.set(preview_src, payload);
    return payload;
}

export function prev() {
    $(".image-list .image.selected").prev().trigger("click");
}

export function next() {
    $(".image-list .image.selected").next().trigger("click");
}

function remove_video_players() {
    // Remove video players from the DOM. Used when closing lightbox
    // so that videos doesn't keep playing in the background.
    $(".player-container iframe").remove();
    $("#lightbox_overlay .video-player").html("");
}

// this is a block of events that are required for the lightbox to work.
export function initialize() {
    // Renders the DOM for the lightbox.
    const rendered_lightbox_overlay = render_lightbox_overlay();
    $("body").append(rendered_lightbox_overlay);

    // Bind the pan/zoom control the newly created element.
    const pan_zoom_control = new PanZoomControl(
        $("#lightbox_overlay .image-preview > .zoom-element")[0],
    );

    const reset_lightbox_state = function () {
        remove_video_players();
        is_open = false;
        document.activeElement.blur();
        if (pan_zoom_control.isActive()) {
            pan_zoom_control.reset();
        }
    };

    const open_image = build_open_media_function(reset_lightbox_state);
    const open_video = build_open_media_function();

    $("#main_div, #compose .preview_content").on(
        "click",
        ".message_inline_image:not(.message_inline_video) a",
        function (e) {
            // prevent the link from opening in a new page.
            e.preventDefault();
            // prevent the message compose dialog from happening.
            e.stopPropagation();
            const $img = $(this).find("img");
            open_image($img);
        },
    );

    $("#main_div, #compose .preview_content").on("click", ".message_inline_video", (e) => {
        e.preventDefault();
        e.stopPropagation();

        const $video = $(e.currentTarget).find("video");
        open_video($video);
    });

    $("#lightbox_overlay .download").on("click", function () {
        this.blur();
    });

    $("#lightbox_overlay").on("click", ".image-list .image", function () {
        const $media_list = $(this).parent();
        let $original_media_element;
        const is_video = $(this).hasClass("lightbox_video");
        if (is_video) {
            $original_media_element = $(
                `.message_row video[src='${CSS.escape($(this).attr("data-src"))}']`,
            );
        } else {
            $original_media_element = $(
                `.message_row img[src='${CSS.escape($(this).attr("data-src"))}']`,
            );
        }

        open_image($original_media_element);

        if (!$(".image-list .image.selected").hasClass("lightbox_video") || !is_video) {
            pan_zoom_control.reset();
        }

        $(".image-list .image.selected").removeClass("selected");
        $(this).addClass("selected");

        const parentOffset = this.parentNode.clientWidth + this.parentNode.scrollLeft;
        // this is the left and right of the image compared to its parent.
        const coords = {
            left: this.offsetLeft,
            right: this.offsetLeft + this.clientWidth,
        };

        if (coords.right > parentOffset) {
            // add 2px margin
            $media_list.animate(
                {
                    scrollLeft: coords.right - this.parentNode.clientWidth + 2,
                },
                100,
            );
        } else if (coords.left < this.parentNode.scrollLeft) {
            // subtract 2px margin
            $media_list.animate({scrollLeft: coords.left - 2}, 100);
        }
    });

    $("#lightbox_overlay").on("click", ".center .arrow", function () {
        const direction = $(this).attr("data-direction");

        if (direction === "next") {
            next();
        } else if (direction === "prev") {
            prev();
        }
    });

    $("#lightbox_overlay").on("click", ".lightbox-zoom-reset", () => {
        if (!$("#lightbox_overlay .lightbox-zoom-reset").hasClass("disabled")) {
            const $img = $("#lightbox_overlay").find(".image-preview img");
            open_image($img);
            pan_zoom_control.reset();
        }
    });

    $("#lightbox_overlay .player-container").on("click", function () {
        if ($(this).is(".player-container")) {
            reset_lightbox_state();
            overlays.close_active();
        }
    });

    $("#lightbox_overlay").on("click", ".media-info-wrapper, .center", (e) => {
        if ($(e.target).is(".media-info-wrapper, .center")) {
            reset_lightbox_state();
            overlays.close_overlay("lightbox");
        }
    });

    $("#lightbox_overlay .image-preview").on("click", (e) => {
        // Ensure that the click isn't on the image itself, and that
        // the window isn't marked as disabled to click to close.
        if (!$(e.target).is("img") && !$("#lightbox_overlay").data("noclose")) {
            reset_lightbox_state();
            overlays.close_overlay("lightbox");
        }
    });

    $("#lightbox_overlay .video-player").on("click", (e) => {
        // Close lightbox when clicked outside video.
        if (!$(e.target).is("video")) {
            overlays.close_overlay("lightbox");
        }
    });
}