zulip/web/src/message_list_hover.ts

import $ from "jquery";
import assert from "minimalistic-assert";

import render_edit_content_button from "../templates/edit_content_button.hbs";

import * as message_edit from "./message_edit";
import * as message_lists from "./message_lists";
import * as rows from "./rows";
import * as thumbnail from "./thumbnail";
import {user_settings} from "./user_settings";

let $current_message_hover: JQuery | undefined;
export function message_unhover(): void {
    if ($current_message_hover === undefined) {
        return;
    }
    $current_message_hover.find("span.edit_content").empty();
    $current_message_hover = undefined;
}

export function message_hover($message_row: JQuery): void {
    const id = rows.id($message_row);
    assert(message_lists.current !== undefined);
    const message = message_lists.current.get(id);
    assert(message !== undefined);

    if ($current_message_hover && rows.id($current_message_hover) === id) {
        return;
    } else if (message.locally_echoed) {
        return;
    }

    message_unhover();
    $current_message_hover = $message_row;

    if (!message.sent_by_me) {
        // The actions and reactions icon hover logic is handled entirely by CSS
        return;
    }

    // But the message edit hover icon is determined by whether the message is still editable
    const is_content_editable = message_edit.is_content_editable(message);
    const can_move_message = message_edit.can_move_message(message);
    const args = {
        is_content_editable,
        can_move_message,
    };
    const $edit_content = $message_row.find(".edit_content");
    $edit_content.html(render_edit_content_button(args));

    if (args.is_content_editable) {
        $edit_content.attr("data-tooltip-template-id", "edit-content-tooltip-template");
    } else if (args.can_move_message) {
        $edit_content.attr("data-tooltip-template-id", "move-message-tooltip-template");
    }
}

export function initialize(): void {
    $("#main_div").on("mouseover", ".message-list .message_row", function (this: HTMLElement) {
        const $row = $(this).closest(".message_row");
        message_hover($row);
    });

    $("#main_div").on("mouseleave", ".message-list .message_row", () => {
        message_unhover();
    });

    $("#main_div").on("mouseover", ".sender_info_hover", function (this: HTMLElement) {
        const $row = $(this).closest(".message_row");
        $row.addClass("sender_info_hovered");
    });

    $("#main_div").on("mouseout", ".sender_info_hover", function (this: HTMLElement) {
        const $row = $(this).closest(".message_row");
        $row.removeClass("sender_info_hovered");
    });

    $("#main_div").on(
        "mouseover",
        '.message-list div.message_inline_image img[data-animated="true"]',
        function (this: HTMLElement) {
            if (user_settings.web_animate_image_previews !== "on_hover") {
                return;
            }
            const $img = $(this);
            $img.closest(".message_inline_image").removeClass(
                "message_inline_animated_image_still",
            );
            $img.attr(
                "src",
                $img.attr("src")!.replace(/\/[^/]+$/, "/" + thumbnail.animated_format.name),
            );
        },
    );

    $("#main_div").on(
        "mouseout",
        '.message-list div.message_inline_image img[data-animated="true"]',
        function (this: HTMLElement) {
            if (user_settings.web_animate_image_previews !== "on_hover") {
                return;
            }
            const $img = $(this);
            $img.closest(".message_inline_image").addClass("message_inline_animated_image_still");
            $img.attr(
                "src",
                $img.attr("src")!.replace(/\/[^/]+$/, "/" + thumbnail.preferred_format.name),
            );
        },
    );

    function handle_video_preview_mouseenter($elem: JQuery): void {
        // Set image height and css vars for play button position, if not done already
        const setPosition = !$elem.data("entered-before");
        if (setPosition) {
            const imgW = $elem.find("img")[0]!.width;
            const imgH = $elem.find("img")[0]!.height;
            // Ensure height doesn't change on mouse enter
            $elem.css("height", `${imgH}px`);
            // variables to set play button position
            const marginLeft = (imgW - 30) / 2;
            const marginTop = (imgH - 26) / 2;
            $elem.css("--margin-left", `${marginLeft}px`).css("--margin-top", `${marginTop}px`);
            $elem.data("entered-before", true);
        }
        $elem.addClass("fa fa-play");
    }

    $("#main_div").on("mouseenter", ".youtube-video a", function (this: HTMLElement) {
        handle_video_preview_mouseenter($(this));
    });

    $("#main_div").on("mouseleave", ".youtube-video a", function () {
        $(this).removeClass("fa fa-play");
    });

    $("#main_div").on("mouseenter", ".embed-video a", function (this: HTMLElement) {
        handle_video_preview_mouseenter($(this));
    });

    $("#main_div").on("mouseleave", ".embed-video a", function () {
        $(this).removeClass("fa fa-play");
    });

    $("body").on("mouseover", ".message_edit_content", function () {
        $(this).closest(".message_row").find(".copy_message").show();
    });

    $("body").on("mouseout", ".message_edit_content", function () {
        $(this).closest(".message_row").find(".copy_message").hide();
    });

    $("body").on("mouseenter", ".copy_message", function () {
        $(this).show();
    });
}