zulip/static/js/lightbox.js

559 lines
20 KiB
JavaScript

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";
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: 100,
minZoom: 0.1,
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) {
// 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() {
const w = $(".image-preview").width();
const h = $(".image-preview").height();
this.panzoom.smoothZoom(w / 2, h / 2, 1.5);
}
zoomOut() {
const w = $(".image-preview").width();
const h = $(".image-preview").height();
this.panzoom.smoothZoom(w / 2, h / 2, 0.5);
}
isActive() {
return $(".image-preview .zoom-element img").length > 0;
}
}
export function clear_for_testing() {
is_open = false;
asset_map.clear();
}
export function render_lightbox_list_images(preview_source) {
if (!is_open) {
const images = Array.prototype.slice.call($(".focused_table .message_inline_image img"));
const $image_list = $("#lightbox_overlay .image-list").html("");
for (const img of images) {
const src = img.getAttribute("src");
const className = preview_source === src ? "image selected" : "image";
const $node = $("<div>", {
class: className,
"data-src": src,
}).css({backgroundImage: "url(" + src + ")"});
$image_list.append($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_image_data(img);
}
}
}
function display_image(payload) {
render_lightbox_list_images(payload.preview);
$(".player-container").hide();
$(".image-preview, .image-actions, .image-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();
$(".image-description .title")
.text(payload.title || "N/A")
.attr("aria-label", payload.title || "N/A")
.prop("data-filename", filename || "N/A");
$(".image-description .user").text(payload.user).prop("title", payload.user);
$(".image-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);
$(".image-actions .download").attr("href", url.href);
} else if (same_origin) {
$(".image-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.
$(".image-actions .download").hide();
}
}
function display_video(payload) {
render_lightbox_list_images(payload.preview);
$(
"#lightbox_overlay .image-preview, .image-description, .download, .lightbox-zoom-reset",
).hide();
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).show();
$(".image-actions .open").attr("href", payload.url);
}
export function build_open_image_function(on_close) {
if (on_close === undefined) {
on_close = function () {
$(".player-container iframe").remove();
is_open = false;
document.activeElement.blur();
};
}
return function ($image) {
// if the asset_map already contains the metadata required to display the
// asset, just recall that metadata.
let $preview_src = $image.attr("src");
let payload = asset_map.get($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_image_data($image);
}
}
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;
let $image = $message.find(".message_inline_image img");
let $prev_traverse = false;
while ($image.length === 0) {
if ($message.prev().length === 0) {
$message = $message.parent().prev();
if ($message.length === 0) {
$prev_traverse = true;
$message = $message_selected;
break;
} else {
$message = $message.find(".last_message");
continue;
}
}
$message = $message.prev();
$image = $message.find(".message_inline_image img");
}
if ($prev_traverse) {
while ($image.length === 0) {
if ($message.next().length === 0) {
$message = $message.parent().next();
if ($message.length === 0) {
break;
} else {
$message = $message.children().first();
continue;
}
}
$message = $message.next();
$image = $message.find(".message_inline_image img");
}
}
if ($image.length !== 0) {
const open_image = build_open_image_function();
open_image($image);
}
}
// retrieve the metadata from the DOM and store into the asset_map.
export function parse_image_data(image) {
const $image = $(image);
const preview_src = $image.attr("src");
if (asset_map.has(preview_src)) {
// check if image's data is already present in asset_map.
return asset_map.get(preview_src);
}
// if wrapped in the .youtube-video class, it will be length = 1, and therefore
// cast to true.
const is_youtube_video = Boolean($image.closest(".youtube-video").length);
const is_vimeo_video = Boolean($image.closest(".vimeo-video").length);
const is_embed_video = Boolean($image.closest(".embed-video").length);
// check if image is descendent of #compose .preview_content
const is_compose_preview_image = $image.closest("#compose .preview_content").length === 1;
const $parent = $image.parent();
let type;
let source;
const url = $parent.attr("href");
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 = $parent.attr("data-id");
} else {
type = "image";
if ($image.attr("data-src-fullsize")) {
source = $image.attr("data-src-fullsize");
} else {
source = preview_src;
}
}
let sender_full_name;
if (is_compose_preview_image) {
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: preview_src,
source,
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");
}
// 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 () {
$(".player-container iframe").remove();
is_open = false;
document.activeElement.blur();
if (pan_zoom_control.isActive()) {
pan_zoom_control.reset();
}
};
const open_image = build_open_image_function(reset_lightbox_state);
$("#main_div, #compose .preview_content").on("click", ".message_inline_image 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);
});
$("#lightbox_overlay .download").on("click", function () {
this.blur();
});
$("#lightbox_overlay").on("click", ".image-list .image", function () {
const $image_list = $(this).parent();
const $original_image = $(
`.message_row img[src='${CSS.escape($(this).attr("data-src"))}']`,
);
open_image($original_image);
$(".image-list .image.selected").removeClass("selected");
$(this).addClass("selected");
pan_zoom_control.reset();
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
$image_list.animate(
{
scrollLeft: coords.right - this.parentNode.clientWidth + 2,
},
100,
);
} else if (coords.left < this.parentNode.scrollLeft) {
// subtract 2px margin
$image_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();
}
});
$("#lightbox_overlay").on("click", ".image-info-wrapper, .center", (e) => {
if ($(e.target).is(".image-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");
}
});
}