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Fix GIF rendering issue 

Remove the GIF parsing code from this repo and instead add a dependency on gifuct-js.
This commit is contained in:
JC Brand 2023-07-28 17:47:16 +02:00
parent e31d4c7bac
commit 61192f91d9
9 changed files with 113 additions and 597 deletions
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4
dev.html
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@ -40,8 +40,8 @@
muc_show_logs_before_join: true,
notify_all_room_messages: ['discuss@conference.conversejs.org'],
view_mode: 'fullscreen',
websocket_url: 'wss://conversejs.org/xmpp-websocket',
// websocket_url: 'ws://chat.example.org:5380/xmpp-websocket',
// websocket_url: 'wss://conversejs.org/xmpp-websocket',
websocket_url: 'ws://chat.example.org:5380/xmpp-websocket',
whitelisted_plugins: ['converse-debug'],
// connection_options: { worker: '/dist/shared-connection-worker.js' }
});

14
package-lock.json generated
View File

@ -20,6 +20,7 @@
"dayjs": "^1.11.8",
"dompurify": "^2.3.1",
"favico.js-slevomat": "^0.3.11",
"gifuct-js": "^2.1.2",
"jed": "1.1.1",
"lit": "^2.4.0",
"localforage-webextensionstorage-driver": "^3.0.0",
@ -5612,6 +5613,14 @@
"safe-buffer": "^5.1.1"
}
},
"node_modules/gifuct-js": {
"version": "2.1.2",
"resolved": "https://registry.npmjs.org/gifuct-js/-/gifuct-js-2.1.2.tgz",
"integrity": "sha512-rI2asw77u0mGgwhV3qA+OEgYqaDn5UNqgs+Bx0FGwSpuqfYn+Ir6RQY5ENNQ8SbIiG/m5gVa7CD5RriO4f4Lsg==",
"dependencies": {
"js-binary-schema-parser": "^2.0.3"
}
},
"node_modules/glob": {
"version": "7.2.3",
"resolved": "https://registry.npmjs.org/glob/-/glob-7.2.3.tgz",
@ -6632,6 +6641,11 @@
"integrity": "sha512-umpJ0/k8X0MvD1ds0P9SfowREz2LenHsQaxSohMZ5OMNEU2r0tf8pdeEFTHMFxWVxKNyU9rTtK3CWzUCTKJUeQ==",
"peer": true
},
"node_modules/js-binary-schema-parser": {
"version": "2.0.3",
"resolved": "https://registry.npmjs.org/js-binary-schema-parser/-/js-binary-schema-parser-2.0.3.tgz",
"integrity": "sha512-xezGJmOb4lk/M1ZZLTR/jaBHQ4gG/lqQnJqdIv4721DMggsa1bDVlHXNeHYogaIEHD9vCRv0fcL4hMA+Coarkg=="
},
"node_modules/js-tokens": {
"version": "4.0.0",
"resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",

1
package.json
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@ -119,6 +119,7 @@
"dayjs": "^1.11.8",
"dompurify": "^2.3.1",
"favico.js-slevomat": "^0.3.11",
"gifuct-js": "^2.1.2",
"jed": "1.1.1",
"lit": "^2.4.0",
"localforage-webextensionstorage-driver": "^3.0.0",

3
src/shared/components/gif.js
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@ -28,6 +28,7 @@ export default class ConverseGIFElement extends CustomElement {
constructor () {
super();
this.src = null;
this.autoplay = false;
this.noloop = false;
this.fallback = 'url';
@ -90,8 +91,6 @@ export default class ConverseGIFElement extends CustomElement {
onControlsClicked (ev) {
ev.preventDefault();
if (this.supergif.playing) {
this.supergif.pause();
} else if (this.supergif.frames.length > 0) {

8
src/shared/components/image.js
View File

@ -16,6 +16,14 @@ export default class Image extends CustomElement {
}
}
constructor () {
super();
this.src = null;
this.href = null;
this.onImgClick = null;
this.onImgLoad = null;
}
render () {
if (isGIFURL(this.src) && shouldRenderMediaFromURL(this.src, 'image')) {
return tplGif(filterQueryParamsFromURL(this.src), true);

351
src/shared/gif/index.js
View File

@ -1,22 +1,10 @@
/**
* @copyright Shachaf Ben-Kiki, JC Brand
* @description
* Started as a fork of Shachaf Ben-Kiki's jsgif library
* https://github.com/shachaf/jsgif
* @license MIT License
*/
import Stream from './stream.js';
import { getOpenPromise } from '@converse/openpromise';
import { parseGIF } from './utils.js';
const DELAY_FACTOR = 10;
import { parseGIF, decompressFrames } from 'gifuct-js';
export default class ConverseGif {
/**
* Creates a new ConverseGif instance
* @param { HTMLElement } el
* @param { import('lit').LitElement } el
* @param { Object } [options]
* @param { Number } [options.width] - The width, in pixels, of the canvas
* @param { Number } [options.height] - The height, in pixels, of the canvas
@ -30,7 +18,8 @@ export default class ConverseGif {
* @param { Number } [options.progress_bar_height=5]
*/
constructor (el, opts) {
this.options = Object.assign({
this.options = Object.assign(
{
width: null,
height: null,
autoplay: true,
@ -38,7 +27,7 @@ export default class ConverseGif {
show_progress_bar: true,
progress_bg_color: 'rgba(0,0,0,0.4)',
progress_color: 'rgba(255,0,22,.8)',
progress_bar_height: 5
progress_bar_height: 5,
},
opts
);
@ -51,21 +40,15 @@ export default class ConverseGif {
this.offscreenCanvas = document.createElement('canvas');
this.ctx_scaled = false;
this.disposal_method = null;
this.disposal_restore_from_idx = null;
this.frame = null;
this.frame_offsets = []; // elements have .x and .y properties
this.frames = [];
this.last_disposal_method = null;
this.last_img = null;
this.load_error = null;
this.playing = this.options.autoplay;
this.transparency = null;
this.frame_delay = null;
this.frame_idx = 0;
this.iteration_count = 0;
this.start = null;
this.hovering = null;
this.frameImageData = null;
this.initialize();
}
@ -75,7 +58,7 @@ export default class ConverseGif {
this.setSizes(this.options.width, this.options.height);
}
const data = await this.fetchGIF(this.gif_el.src);
requestAnimationFrame(() => this.startParsing(data));
requestAnimationFrame(() => this.handleGIFResponse(data));
}
initPlayer () {
@ -90,7 +73,7 @@ export default class ConverseGif {
this.putFrame(this.frame_idx);
if (this.options.autoplay) {
const delay = (this.frames[this.frame_idx]?.delay ?? 0) * DELAY_FACTOR;
const delay = (this.frames[this.frame_idx]?.delay ?? 0);
setTimeout(() => this.play(), delay);
}
}
@ -137,8 +120,8 @@ export default class ConverseGif {
* `putFrame(0)` needs to be called *before* this method, otherwise the
* animation will incorrectly start from frame #1 (this is done in `initPlayer`).
*
* @param { DOMHighRestTimestamp } timestamp - The timestamp as returned by `requestAnimationFrame`
* @param { DOMHighRestTimestamp } previous_timestamp - The timestamp from the previous iteration of this method.
* @param { DOMHighResTimeStamp } timestamp - The timestamp as returned by `requestAnimationFrame`
* @param { DOMHighResTimeStamp } previous_timestamp - The timestamp from the previous iteration of this method.
* We need this in order to calculate whether we have waited long enough to
* show the next frame.
* @param { Number } frame_delay - The delay (in 1/100th of a second)
@ -148,10 +131,10 @@ export default class ConverseGif {
if (!this.playing) {
return;
}
if ((timestamp - previous_timestamp) < frame_delay) {
if (timestamp - previous_timestamp < frame_delay) {
this.hovering ? this.drawPauseIcon() : this.putFrame(this.frame_idx);
// We need to wait longer
requestAnimationFrame(ts => this.onAnimationFrame(ts, previous_timestamp, frame_delay));
requestAnimationFrame((ts) => this.onAnimationFrame(ts, previous_timestamp, frame_delay));
return;
}
const next_frame = this.getNextFrameNo();
@ -160,8 +143,8 @@ export default class ConverseGif {
}
this.frame_idx = next_frame;
this.putFrame(this.frame_idx);
const delay = (this.frames[this.frame_idx]?.delay || 8) * DELAY_FACTOR;
requestAnimationFrame(ts => this.onAnimationFrame(ts, timestamp, delay));
const delay = (this.frames[this.frame_idx]?.delay || 8);
requestAnimationFrame((ts) => this.onAnimationFrame(ts, timestamp, delay));
}
setSizes (w, h) {
@ -175,19 +158,6 @@ export default class ConverseGif {
this.offscreenCanvas.getContext('2d').setTransform(1, 0, 0, 1, 0, 0);
}
setFrameOffset (frame, offset) {
if (!this.frame_offsets[frame]) {
this.frame_offsets[frame] = offset;
return;
}
if (typeof offset.x !== 'undefined') {
this.frame_offsets[frame].x = offset.x;
}
if (typeof offset.y !== 'undefined') {
this.frame_offsets[frame].y = offset.y;
}
}
doShowProgress (pos, length, draw) {
if (draw && this.options.show_progress_bar) {
let height = this.options.progress_bar_height;
@ -207,32 +177,20 @@ export default class ConverseGif {
/**
* Starts parsing the GIF stream data by calling `parseGIF` and passing in
* a map of handler functions.
* @param { String } data - The GIF file data, as returned by the server
* @param {ArrayBuffer} data - The GIF file data, as returned by the server
*/
startParsing (data) {
const stream = new Stream(data);
/**
* @typedef { Object } GIFParserHandlers
* A map of callback functions passed `parseGIF`. These functions are
* called as various parts of the GIF file format are parsed.
* @property { Function } hdr - Callback to handle the GIF header data
* @property { Function } gce - Callback to handle the GIF Graphic Control Extension data
* @property { Function } com - Callback to handle the comment extension block
* @property { Function } img - Callback to handle image data
* @property { Function } eof - Callback once the end of file has been reached
*/
const handler = {
'hdr': this.withProgress(stream, header => this.handleHeader(header)),
'gce': this.withProgress(stream, gce => this.handleGCE(gce)),
'com': this.withProgress(stream, ),
'img': this.withProgress(stream, img => this.doImg(img), true),
'eof': () => this.handleEOF(stream)
};
handleGIFResponse (data) {
try {
parseGIF(stream, handler);
const gif = parseGIF(data);
this.hdr = gif.header;
this.lsd = gif.lsd;
this.setSizes(this.options.width ?? this.lsd.width, this.options.height ?? this.lsd.height);
this.frames = decompressFrames(gif, true);
} catch (err) {
this.showError('parse');
this.showError();
}
this.initPlayer();
!this.options.autoplay && this.drawPlayIcon();
}
drawError () {
@ -240,23 +198,23 @@ export default class ConverseGif {
this.ctx.fillRect(
0,
0,
this.options.width ? this.options.width : this.hdr.width,
this.options.height ? this.options.height : this.hdr.height
this.options.width ? this.options.width : this.lsd.width,
this.options.height ? this.options.height : this.lsd.height
);
this.ctx.strokeStyle = 'red';
this.ctx.lineWidth = 3;
this.ctx.moveTo(0, 0);
this.ctx.lineTo(
this.options.width ? this.options.width : this.hdr.width,
this.options.height ? this.options.height : this.hdr.height
this.options.width ? this.options.width : this.lsd.width,
this.options.height ? this.options.height : this.lsd.height
);
this.ctx.moveTo(0, this.options.height ? this.options.height : this.hdr.height);
this.ctx.lineTo(this.options.width ? this.options.width : this.hdr.width, 0);
this.ctx.moveTo(0, this.options.height ? this.options.height : this.lsd.height);
this.ctx.lineTo(this.options.width ? this.options.width : this.lsd.width, 0);
this.ctx.stroke();
}
showError (errtype) {
this.load_error = errtype;
showError () {
this.load_error = true;
this.hdr = {
width: this.gif_el.width,
height: this.gif_el.height,
@ -266,164 +224,49 @@ export default class ConverseGif {
this.el.requestUpdate();
}
handleHeader (header) {
this.hdr = header;
this.setSizes(
this.options.width ?? this.hdr.width,
this.options.height ?? this.hdr.height
);
}
/**
* Handler for GIF Graphic Control Extension (GCE) data
*/
handleGCE (gce) {
this.pushFrame();
this.clear();
this.frame_delay = gce.delayTime;
this.transparency = gce.transparencyGiven ? gce.transparencyIndex : null;
this.disposal_method = gce.disposalMethod;
}
/**
* Handler for when the end of the GIF's file has been reached
*/
handleEOF (stream) {
this.pushFrame();
this.doDecodeProgress(stream, false);
this.initPlayer();
!this.options.autoplay && this.drawPlayIcon();
}
pushFrame () {
if (!this.frame) return;
this.frames.push({
data: this.frame.getImageData(0, 0, this.hdr.width, this.hdr.height),
delay: this.frame_delay
});
this.frame_offsets.push({ x: 0, y: 0 });
}
doImg (img) {
this.frame = this.frame || this.offscreenCanvas.getContext('2d');
const currIdx = this.frames.length;
//ct = color table, gct = global color table
const ct = img.lctFlag ? img.lct : this.hdr.gct; // TODO: What if neither exists?
/*
* Disposal method indicates the way in which the graphic is to
* be treated after being displayed.
*
* Values : 0 - No disposal specified. The decoder is
* not required to take any action.
* 1 - Do not dispose. The graphic is to be left
* in place.
* 2 - Restore to background color. The area used by the
* graphic must be restored to the background color.
* 3 - Restore to previous. The decoder is required to
* restore the area overwritten by the graphic with
* what was there prior to rendering the graphic.
*
* Importantly, "previous" means the frame state
* after the last disposal of method 0, 1, or 2.
*/
if (currIdx > 0) {
if (this.last_disposal_method === 3) {
// Restore to previous
// If we disposed every frame including first frame up to this point, then we have
// no composited frame to restore to. In this case, restore to background instead.
if (this.disposal_restore_from_idx !== null) {
this.frame.putImageData(this.frames[this.disposal_restore_from_idx].data, 0, 0);
} else {
this.frame.clearRect(
this.last_img.leftPos,
this.last_img.topPos,
this.last_img.width,
this.last_img.height
);
}
} else {
this.disposal_restore_from_idx = currIdx - 1;
}
if (this.last_disposal_method === 2) {
// Restore to background color
// Browser implementations historically restore to transparent; we do the same.
// http://www.wizards-toolkit.org/discourse-server/viewtopic.php?f=1&t=21172#p86079
this.frame.clearRect(
this.last_img.leftPos,
this.last_img.topPos,
this.last_img.width,
this.last_img.height
);
}
}
// else, Undefined/Do not dispose.
// frame contains final pixel data from the last frame; do nothing
//Get existing pixels for img region after applying disposal method
const imgData = this.frame.getImageData(img.leftPos, img.topPos, img.width, img.height);
//apply color table colors
img.pixels.forEach((pixel, i) => {
// imgData.data === [R,G,B,A,R,G,B,A,...]
if (pixel !== this.transparency) {
imgData.data[i * 4 + 0] = ct[pixel][0];
imgData.data[i * 4 + 1] = ct[pixel][1];
imgData.data[i * 4 + 2] = ct[pixel][2];
imgData.data[i * 4 + 3] = 255; // Opaque.
}
});
this.frame.putImageData(imgData, img.leftPos, img.topPos);
if (!this.ctx_scaled) {
this.ctx.scale(this.getCanvasScale(), this.getCanvasScale());
this.ctx_scaled = true;
}
if (!this.last_img) {
// This is the first received image, so we draw it
this.ctx.drawImage(this.offscreenCanvas, 0, 0);
}
this.last_img = img;
}
/**
* Draws a gif frame at a specific index inside the canvas.
* @param { Number } i - The frame index
* @param {number|string} i - The frame index
*/
putFrame (i, show_pause_on_hover=true) {
if (!this.frames.length) return
putFrame (i, show_pause_on_hover = true) {
if (!this.frames.length) return;
i = parseInt(i, 10);
i = parseInt(i.toString(), 10);
if (i > this.frames.length - 1 || i < 0) {
i = 0;
}
const offset = this.frame_offsets[i];
this.offscreenCanvas.getContext('2d').putImageData(this.frames[i].data, offset.x, offset.y);
const frame = this.frames[i];
const dims = frame.dims;
if (
!this.frameImageData ||
dims.width != this.frameImageData.width ||
dims.height != this.frameImageData.height
) {
this.offscreenCanvas.width = dims.width;
this.offscreenCanvas.height = dims.height;
this.frameImageData = this.offscreenCanvas.getContext('2d').createImageData(dims.width, dims.height);
}
// set the patch data as an override
this.frameImageData.data.set(frame.patch);
this.offscreenCanvas.getContext('2d').putImageData(this.frameImageData, 0, 0);
this.ctx.globalCompositeOperation = 'copy';
this.ctx.drawImage(this.offscreenCanvas, 0, 0);
this.ctx.drawImage(this.offscreenCanvas, dims.left, dims.top);
if (show_pause_on_hover && this.hovering) {
this.drawPauseIcon();
}
}
clear () {
this.transparency = null;
this.last_disposal_method = this.disposal_method;
this.disposal_method = null;
this.frame = null;
}
/**
* Start playing the gif
*/
play () {
this.playing = true;
requestAnimationFrame(ts => this.onAnimationFrame(ts, 0, 0));
requestAnimationFrame((ts) => this.onAnimationFrame(ts, 0, 0));
}
/**
@ -431,7 +274,7 @@ export default class ConverseGif {
*/
pause () {
this.playing = false;
requestAnimationFrame(() => this.drawPlayIcon())
requestAnimationFrame(() => this.drawPlayIcon());
}
drawPauseIcon () {
@ -447,40 +290,32 @@ export default class ConverseGif {
this.ctx.fillStyle = 'rgb(0, 0, 0, 0.25)';
this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
const icon_size = this.canvas.height*0.1;
const icon_size = this.canvas.height * 0.1;
// Draw bars
this.ctx.lineWidth = this.canvas.height*0.04;
this.ctx.lineWidth = this.canvas.height * 0.04;
this.ctx.beginPath();
this.ctx.moveTo(this.canvas.width/2-icon_size/2, this.canvas.height/2-icon_size);
this.ctx.lineTo(this.canvas.width/2-icon_size/2, this.canvas.height/2+icon_size);
this.ctx.moveTo(this.canvas.width / 2 - icon_size / 2, this.canvas.height / 2 - icon_size);
this.ctx.lineTo(this.canvas.width / 2 - icon_size / 2, this.canvas.height / 2 + icon_size);
this.ctx.fillStyle = 'rgb(200, 200, 200, 0.75)';
this.ctx.stroke();
this.ctx.beginPath();
this.ctx.moveTo(this.canvas.width/2+icon_size/2, this.canvas.height/2-icon_size);
this.ctx.lineTo(this.canvas.width/2+icon_size/2, this.canvas.height/2+icon_size);
this.ctx.moveTo(this.canvas.width / 2 + icon_size / 2, this.canvas.height / 2 - icon_size);
this.ctx.lineTo(this.canvas.width / 2 + icon_size / 2, this.canvas.height / 2 + icon_size);
this.ctx.fillStyle = 'rgb(200, 200, 200, 0.75)';
this.ctx.stroke();
// Draw circle
this.ctx.lineWidth = this.canvas.height*0.02;
this.ctx.lineWidth = this.canvas.height * 0.02;
this.ctx.strokeStyle = 'rgb(200, 200, 200, 0.75)';
this.ctx.beginPath();
this.ctx.arc(
this.canvas.width/2,
this.canvas.height/2,
icon_size*1.5,
0,
2*Math.PI
);
this.ctx.arc(this.canvas.width / 2, this.canvas.height / 2, icon_size * 1.5, 0, 2 * Math.PI);
this.ctx.stroke();
}
drawPlayIcon () {
if (this.playing) {
return;
}
if (this.playing) return;
// Clear the potential pause button by re-rendering the current frame
this.putFrame(this.frame_idx, false);
@ -492,52 +327,28 @@ export default class ConverseGif {
this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
// Draw triangle
const triangle_size = this.canvas.height*0.1;
const triangle_size = this.canvas.height * 0.1;
const region = new Path2D();
region.moveTo(this.canvas.width/2+triangle_size, this.canvas.height/2); // start at the pointy end
region.lineTo(this.canvas.width/2-triangle_size/2, this.canvas.height/2+triangle_size);
region.lineTo(this.canvas.width/2-triangle_size/2, this.canvas.height/2-triangle_size);
region.moveTo(this.canvas.width / 2 + triangle_size, this.canvas.height / 2); // start at the pointy end
region.lineTo(this.canvas.width / 2 - triangle_size / 2, this.canvas.height / 2 + triangle_size);
region.lineTo(this.canvas.width / 2 - triangle_size / 2, this.canvas.height / 2 - triangle_size);
region.closePath();
this.ctx.fillStyle = 'rgb(200, 200, 200, 0.75)';
this.ctx.fill(region);
// Draw circle
const circle_size = triangle_size*1.5;
this.ctx.lineWidth = this.canvas.height*0.02;
const circle_size = triangle_size * 1.5;
this.ctx.lineWidth = this.canvas.height * 0.02;
this.ctx.strokeStyle = 'rgb(200, 200, 200, 0.75)';
this.ctx.beginPath();
this.ctx.arc(
this.canvas.width/2,
this.canvas.height/2,
circle_size,
0,
2*Math.PI
);
this.ctx.arc(this.canvas.width / 2, this.canvas.height / 2, circle_size, 0, 2 * Math.PI);
this.ctx.stroke();
}
doDecodeProgress (stream, draw) {
this.doShowProgress(stream.pos, stream.data.length, draw);
}
/**
* @param{boolean=} draw Whether to draw progress bar or not;
* this is not idempotent because of translucency.
* Note that this means that the text will be unsynchronized
* with the progress bar on non-frames;
* but those are typically so small (GCE etc.) that it doesn't really matter
*/
withProgress (stream, fn, draw) {
return block => {
fn?.(block);
this.doDecodeProgress(stream, draw);
};
}
getCanvasScale () {
let scale;
if (this.options.max_width && this.hdr && this.hdr.width > this.options.max_width) {
scale = this.options.max_width / this.hdr.width;
if (this.options.max_width && this.hdr && this.lsd.width > this.options.max_width) {
scale = this.options.max_width / this.lsd.width;
} else {
scale = 1;
}
@ -547,22 +358,24 @@ export default class ConverseGif {
/**
* Makes an HTTP request to fetch a GIF
* @param { String } url
* @returns { Promise<String> } Returns a promise which resolves with the response data.
* @returns { Promise<ArrayBuffer> } Returns a promise which resolves with the response data.
*/
fetchGIF (url) {
const promise = getOpenPromise();
const h = new XMLHttpRequest();
h.open('GET', url, true);
h.responseType = 'arraybuffer';
h?.overrideMimeType('text/plain; charset=x-user-defined');
h.onload = () => {
if (h.status != 200) {
this.showError('xhr - response');
this.showError();
return promise.reject();
}
promise.resolve(h.response);
};
h.onprogress = (e) => (e.lengthComputable && this.doShowProgress(e.loaded, e.total, true));
h.onerror = () => this.showError('xhr');
h.onprogress = (e) => e.lengthComputable && this.doShowProgress(e.loaded, e.total, true);
h.onerror = () => this.showError();
h.send();
return promise;
}

319
src/shared/gif/utils.js
View File

@ -1,319 +0,0 @@
/**
* @copyright Shachaf Ben-Kiki and the Converse.js contributors
* @description
* Started as a fork of Shachaf Ben-Kiki's jsgif library
* https://github.com/shachaf/jsgif
* @license MIT License
*/
function bitsToNum (ba) {
return ba.reduce(function (s, n) {
return s * 2 + n;
}, 0);
}
function byteToBitArr (bite) {
const a = [];
for (let i = 7; i >= 0; i--) {
a.push( !! (bite & (1 << i)));
}
return a;
}
function lzwDecode (minCodeSize, data) {
// TODO: Now that the GIF parser is a bit different, maybe this should get an array of bytes instead of a String?
let pos = 0; // Maybe this streaming thing should be merged with the Stream?
function readCode (size) {
let code = 0;
for (let i = 0; i < size; i++) {
if (data.charCodeAt(pos >> 3) & (1 << (pos & 7))) {
code |= 1 << i;
}
pos++;
}
return code;
}
const output = [];
const clearCode = 1 << minCodeSize;
const eoiCode = clearCode + 1;
let codeSize = minCodeSize + 1;
let dict = [];
const clear = function () {
dict = [];
codeSize = minCodeSize + 1;
for (let i = 0; i < clearCode; i++) {
dict[i] = [i];
}
dict[clearCode] = [];
dict[eoiCode] = null;
};
let code = clearCode;
let last;
clear();
while (true) { // eslint-disable-line no-constant-condition
last = code;
code = readCode(codeSize);
if (code === clearCode) {
clear();
continue;
}
if (code === eoiCode) break;
if (code < dict.length) {
if (last !== clearCode) {
dict.push(dict[last].concat(dict[code][0]));
}
}
else {
if (code !== dict.length) throw new Error('Invalid LZW code.');
dict.push(dict[last].concat(dict[last][0]));
}
output.push.apply(output, dict[code]);
if (dict.length === (1 << codeSize) && codeSize < 12) {
// If we're at the last code and codeSize is 12, the next code will be a clearCode, and it'll be 12 bits long.
codeSize++;
}
}
// I don't know if this is technically an error, but some GIFs do it.
//if (Math.ceil(pos / 8) !== data.length) throw new Error('Extraneous LZW bytes.');
return output;
}
function readSubBlocks (st) {
let size, data;
data = '';
do {
size = st.readByte();
data += st.read(size);
} while (size !== 0);
return data;
}
/**
* Parses GIF image color table information
* @param { Stream } st
* @param { Number } entries
*/
function parseCT (st, entries) { // Each entry is 3 bytes, for RGB.
const ct = [];
for (let i = 0; i < entries; i++) {
ct.push(st.readBytes(3));
}
return ct;
}
/**
* Parses GIF image information
* @param { Stream } st
* @param { ByteStream } img
* @param { Function } [callback]
*/
function parseImg (st, img, callback) {
function deinterlace (pixels, width) {
// Of course this defeats the purpose of interlacing. And it's *probably*
// the least efficient way it's ever been implemented. But nevertheless...
const newPixels = new Array(pixels.length);
const rows = pixels.length / width;
function cpRow (toRow, fromRow) {
const fromPixels = pixels.slice(fromRow * width, (fromRow + 1) * width);
newPixels.splice.apply(newPixels, [toRow * width, width].concat(fromPixels));
}
// See appendix E.
const offsets = [0, 4, 2, 1];
const steps = [8, 8, 4, 2];
let fromRow = 0;
for (let pass = 0; pass < 4; pass++) {
for (let toRow = offsets[pass]; toRow < rows; toRow += steps[pass]) {
cpRow(toRow, fromRow)
fromRow++;
}
}
return newPixels;
}
img.leftPos = st.readUnsigned();
img.topPos = st.readUnsigned();
img.width = st.readUnsigned();
img.height = st.readUnsigned();
const bits = byteToBitArr(st.readByte());
img.lctFlag = bits.shift();
img.interlaced = bits.shift();
img.sorted = bits.shift();
img.reserved = bits.splice(0, 2);
img.lctSize = bitsToNum(bits.splice(0, 3));
if (img.lctFlag) {
img.lct = parseCT(st, 1 << (img.lctSize + 1));
}
img.lzwMinCodeSize = st.readByte();
const lzwData = readSubBlocks(st);
img.pixels = lzwDecode(img.lzwMinCodeSize, lzwData);
if (img.interlaced) { // Move
img.pixels = deinterlace(img.pixels, img.width);
}
callback?.(img);
}
/**
* Parses GIF header information
* @param { Stream } st
* @param { Function } [callback]
*/
function parseHeader (st, callback) {
const hdr = {};
hdr.sig = st.read(3);
hdr.ver = st.read(3);
if (hdr.sig !== 'GIF') {
throw new Error('Not a GIF file.');
}
hdr.width = st.readUnsigned();
hdr.height = st.readUnsigned();
const bits = byteToBitArr(st.readByte());
hdr.gctFlag = bits.shift();
hdr.colorRes = bitsToNum(bits.splice(0, 3));
hdr.sorted = bits.shift();
hdr.gctSize = bitsToNum(bits.splice(0, 3));
hdr.bgColor = st.readByte();
hdr.pixelAspectRatio = st.readByte(); // if not 0, aspectRatio = (pixelAspectRatio + 15) / 64
if (hdr.gctFlag) {
hdr.gct = parseCT(st, 1 << (hdr.gctSize + 1));
}
callback?.(hdr);
}
function parseExt (st, block, handler) {
function parseGCExt (block) {
st.readByte(); // blocksize, always 4
const bits = byteToBitArr(st.readByte());
block.reserved = bits.splice(0, 3); // Reserved; should be 000.
block.disposalMethod = bitsToNum(bits.splice(0, 3));
block.userInput = bits.shift();
block.transparencyGiven = bits.shift();
block.delayTime = st.readUnsigned();
block.transparencyIndex = st.readByte();
block.terminator = st.readByte();
handler?.gce(block);
}
function parseComExt (block) {
block.comment = readSubBlocks(st);
handler.com && handler.com(block);
}
function parsePTExt (block) {
// No one *ever* uses this. If you use it, deal with parsing it yourself.
st.readByte(); // blocksize, always 12
block.ptHeader = st.readBytes(12);
block.ptData = readSubBlocks(st);
handler.pte && handler.pte(block);
}
function parseAppExt (block) {
function parseNetscapeExt (block) {
st.readByte(); // blocksize, always 3
block.unknown = st.readByte(); // ??? Always 1? What is this?
block.iterations = st.readUnsigned();
block.terminator = st.readByte();
handler.app && handler.app.NETSCAPE && handler.app.NETSCAPE(block);
}
function parseUnknownAppExt (block) {
block.appData = readSubBlocks(st);
// FIXME: This won't work if a handler wants to match on any identifier.
handler.app && handler.app[block.identifier] && handler.app[block.identifier](block);
}
st.readByte(); // blocksize, always 11
block.identifier = st.read(8);
block.authCode = st.read(3);
switch (block.identifier) {
case 'NETSCAPE':
parseNetscapeExt(block);
break;
default:
parseUnknownAppExt(block);
break;
}
}
function parseUnknownExt (block) {
block.data = readSubBlocks(st);
handler.unknown && handler.unknown(block);
}
block.label = st.readByte();
switch (block.label) {
case 0xF9:
block.extType = 'gce';
parseGCExt(block);
break;
case 0xFE:
block.extType = 'com';
parseComExt(block);
break;
case 0x01:
block.extType = 'pte';
parsePTExt(block);
break;
case 0xFF:
block.extType = 'app';
parseAppExt(block);
break;
default:
block.extType = 'unknown';
parseUnknownExt(block);
break;
}
}
/**
* @param { Stream } st
* @param { GIFParserHandlers } handler
*/
function parseBlock (st, handler) {
const block = {}
block.sentinel = st.readByte();
switch (String.fromCharCode(block.sentinel)) { // For ease of matching
case '!':
block.type = 'ext';
parseExt(st, block, handler);
break;
case ',':
block.type = 'img';
parseImg(st, block, handler?.img);
break;
case ';':
block.type = 'eof';
handler?.eof(block);
break;
default:
throw new Error('Unknown block: 0x' + block.sentinel.toString(16)); // TODO: Pad this with a 0.
}
if (block.type !== 'eof') setTimeout(() => parseBlock(st, handler), 0);
}
/**
* Takes a Stream and parses it for GIF data, calling the relevant handler
* methods on the passed in `handler` object.
* @param { Stream } st
* @param { GIFParserHandlers } handler
*/
export function parseGIF (st, handler={}) {
parseHeader(st, handler?.hdr);
setTimeout(() => parseBlock(st, handler), 0);
}

5
src/shared/rich-text.js
View File

@ -283,11 +283,6 @@ export class RichText extends String {
/**
* Parse the text and add template references for rendering the "rich" parts.
*
* @param { RichText } text
* @param { Boolean } show_images - Should URLs of images be rendered as `<img>` tags?
* @param { Function } onImgLoad
* @param { Function } onImgClick
**/
async addTemplates () {
/**

5
tsconfig.json
View File

@ -11,6 +11,11 @@
"target": "es2016",
"module": "esnext",
"lib": [
"ES2020",
"dom"
],
"allowJs": true,
"checkJs": true,