stable-diffusion-webui/javascript/extraNetworksClusterizeList.js

894 lines
30 KiB
JavaScript

// Collators used for sorting.
const INT_COLLATOR = new Intl.Collator([], { numeric: true });
const STR_COLLATOR = new Intl.Collator("en", { numeric: true, sensitivity: "base" });
const isString = x => typeof x === "string" || x instanceof String;
const isStringLogError = x => {
if (isString(x)) {
return true;
}
console.error("expected string, got:", typeof x);
return false;
};
const isNull = x => typeof x === "null" || x === null;
const isUndefined = x => typeof x === "undefined" || x === undefined;
// checks both null and undefined for simplicity sake.
const isNullOrUndefined = x => isNull(x) || isUndefined(x);
const isNullOrUndefinedLogError = x => {
if (isNullOrUndefined(x)) {
return true;
}
console.error("Variable is null/undefined.");
return false;
};
const isElement = x => x instanceof Element;
const isElementLogError = x => {
if (isElement(x)) {
return true;
}
console.error("expected element type, got:", typeof x);
return false;
}
const getElementByIdLogError = x => {
let elem = gradioApp().getElementById(x);
isElementLogError(elem);
return elem;
};
const querySelectorLogError = x => {
let elem = gradioApp().querySelector(x);
isElementLogError(elem);
return elem;
}
const getComputedPropertyDims = (elem, prop) => {
/** Returns the top/left/bottom/right float dimensions of an element for the specified property. */
const style = window.getComputedStyle(elem, null);
return {
top: parseFloat(style.getPropertyValue(`${prop}-top`)),
left: parseFloat(style.getPropertyValue(`${prop}-left`)),
bottom: parseFloat(style.getPropertyValue(`${prop}-bottom`)),
right: parseFloat(style.getPropertyValue(`${prop}-right`)),
};
}
const getComputedMarginDims = elem => {
const dims = getComputedPropertyDims(elem, "margin");
return {
width: dims.left + dims.right,
height: dims.top + dims.bottom,
};
}
const getComputedPaddingDims = elem => {
const dims = getComputedPropertyDims(elem, "padding");
return {
width: dims.left + dims.right,
height: dims.top + dims.bottom,
};
}
const getComputedBorderDims = elem => {
// computed border will always start with the pixel width so thankfully
// the parseFloat() conversion will just give us the width and ignore the rest.
// Otherwise we'd have to use border-<pos>-width instead.
const dims = getComputedPropertyDims(elem, "border");
return {
width: dims.left + dims.right,
height: dims.top + dims.bottom,
};
}
const getComputedDims = elem => {
/** Returns the full width and height of an element including its margin, padding, and border. */
const width = elem.scrollWidth;
const height = elem.scrollHeight;
const margin = getComputedMarginDims(elem);
const padding = getComputedPaddingDims(elem);
const border = getComputedBorderDims(elem);
return {
width: width + margin.width + padding.width + border.width,
height: height + margin.height + padding.height + border.height,
}
}
function compress(string) {
/** Compresses a string into a base64 encoded GZipped string. */
const cs = new CompressionStream('gzip');
const writer = cs.writable.getWriter();
const blobToBase64 = blob => new Promise((resolve, _) => {
const reader = new FileReader();
reader.onloadend = () => resolve(reader.result.split(',')[1]);
reader.readAsDataURL(blob);
});
const byteArray = new TextEncoder().encode(string);
writer.write(byteArray);
writer.close();
return new Response(cs.readable).blob().then(blobToBase64);
};
function decompress(base64string) {
/** Decompresses a base64 encoded GZipped string. */
const ds = new DecompressionStream('gzip');
const writer = ds.writable.getWriter();
const bytes = Uint8Array.from(atob(base64string), c => c.charCodeAt(0));
writer.write(bytes);
writer.close();
return new Response(ds.readable).arrayBuffer().then(function (arrayBuffer) {
return new TextDecoder().decode(arrayBuffer);
});
}
const parseHtml = function (str) {
const tmp = document.implementation.createHTMLDocument('');
tmp.body.innerHTML = str;
return [...tmp.body.childNodes];
}
const getComputedValue = function (container, css_property) {
return parseInt(
window.getComputedStyle(container, null)
.getPropertyValue(css_property)
.split("px")[0]
);
};
const calcColsPerRow = function (parent, child) {
/** Calculates the number of columns of children that can fit in a parent's visible width. */
const parent_inner_width = parent.offsetWidth - getComputedPaddingDims(parent).width;
return parseInt(parent_inner_width / getComputedDims(child).width);
}
const calcRowsPerCol = function (parent, child) {
/** Calculates the number of rows of children that can fit in a parent's visible height. */
const parent_inner_height = parent.offsetHeight - getComputedPaddingDims(parent).height;
return parseInt(parent_inner_height / getComputedDims(child).height);
}
class ExtraNetworksClusterize {
/** Base class for a clusterize list. Cannot be used directly. */
constructor(
{
data_id,
scroll_id,
content_id,
txt_search_elem,
rows_in_block = 10,
blocks_in_cluster = 4,
show_no_data_row = true,
callbacks = {},
} = {
rows_in_block: 10,
blocks_in_cluster: 4,
show_no_data_row: true,
callbacks: {},
}
) {
// Do not continue if any of the required parameters are invalid.
if (!isStringLogError(data_id)) { return; }
if (!isStringLogError(scroll_id)) { return; }
if (!isStringLogError(content_id)) { return; }
if (!isElementLogError(txt_search_elem)) { return; }
this.data_id = data_id;
this.scroll_id = scroll_id;
this.content_id = content_id;
this.txt_search_elem = txt_search_elem;
this.rows_in_block = rows_in_block;
this.blocks_in_cluster = blocks_in_cluster;
this.show_no_data_row = show_no_data_row;
this.callbacks = callbacks;
this.clusterize = null;
this.data_elem = null;
this.scroll_elem = null;
this.content_elem = null;
this.resize_observer = null;
this.resize_observer_timer = null;
this.resize_observer_timeout_ms = 250;
this.element_observer = null;
this.data_update_timer = null
this.data_update_timeout_ms = 1000;
this.enabled = false;
this.encoded_str = "";
this.no_data_text = "Directory is empty.";
this.no_data_class = "nocards";
this.n_rows = 1;
this.n_cols = 1;
this.data_obj = {};
this.data_obj_keys_sorted = [];
this.sort_fn = this.sortByDivId;
this.sort_reverse = false;
Promise.all([
waitForElement(`#${this.data_id}`).then((elem) => this.data_elem = elem),
waitForElement(`#${this.scroll_id}`).then((elem) => this.scroll_elem = elem),
waitForElement(`#${this.content_id}`).then((elem) => this.content_elem = elem),
]).then(() => {
this.setupElementObservers();
this.setupResizeHandlers();
});
}
enable(enabled) {
if (enabled === undefined || enabled === null) {
this.enabled = true;
} else if (typeof enabled !== "boolean") {
console.error("Invalid type. Expected boolean, got", typeof enabled);
} else {
this.enabled = enabled;
}
}
load() {
return new Promise(resolve => {
waitForElement(`#${this.data_id}`)
.then((elem) => this.data_elem = elem)
.then(() => this.parseJson(this.data_elem.dataset.json))
.then(() => { return resolve(); });
});
}
parseJson(encoded_str) { /** promise */
return new Promise(resolve => {
// Skip parsing if the string hasnt actually updated.
if (this.encoded_str === encoded_str) {
return resolve();
}
Promise.resolve(encoded_str)
.then(v => decompress(v))
.then(v => JSON.parse(v))
.then(v => this.updateJson(v))
.then(() => this.encoded_str = encoded_str)
.then(() => this.init())
.then(() => this.repair())
.then(() => this.applyFilter())
.then(() => { return resolve(); });
});
}
updateJson(json) { /** promise */
/** Must be overridden by inherited class. */
console.error("Base class method called. Must be overridden by child.");
return new Promise(resolve => {return resolve();});
}
sortByDivId() {
// Sort data_obj keys (div_id) as numbers.
this.data_obj_keys_sorted = Object.keys(this.data_obj).sort((a, b) => INT_COLLATOR.compare(a, b));
}
applySort() {
this.sort_fn()
if (this.sort_reverse) {
this.data_obj_keys_sorted = this.data_obj_keys_sorted.reverse();
}
}
applyFilter() {
/** Must be implemented by subclasses. */
this.applySort();
this.updateRows();
}
filterRows(obj) {
var results = [];
for (const div_id of this.data_obj_keys_sorted) {
if (obj[div_id].active) {
results.push(obj[div_id].element.outerHTML);
}
}
return results;
}
updateDivContent(div_id, content) {
/** Updates an element in the dataset. Does not call update_rows(). */
if (!(div_id in this.data_obj)) {
console.error("div_id not in data_obj:", div_id);
} else if (typeof content === "object") {
this.data_obj[div_id].element = parseHtml(content.outerHTML)[0];
return true;
} else if (typeof content === "string") {
this.data_obj[div_id].element = parseHtml(content)[0];
return true;
} else {
console.error("Invalid content:", div_id, content);
}
return false;
}
updateRows() {
// If we don't have any entries in the dataset, then just clear the list and return.
if (this.data_obj_keys_sorted.length === 0 || Object.keys(this.data_obj).length === 0) {
return;
}
this.refresh(true);
// Rebuild with `force=false` so we only rebuild if dimensions change.
this.rebuild(false);
}
getMaxRowWidth() {
// impliment in subclasses
return;
}
recalculateDims() {
let rebuild_required = false;
let clear_before_return = false;
if (!this.enabled) {
// Inactive list is not displayed on screen. Would error if trying to resize.
return false;
}
if (Object.keys(this.data_obj).length === 0 || this.data_obj_keys_sorted.length === 0) {
// If there is no data then just skip.
return false;
}
// If no rows exist, we need to add one so we can calculate rows/cols.
// We remove this row before returning.
if (this.rowCount() === 0){// || this.content_elem.innerHTML === "") {
this.clear();
this.update([this.data_obj[this.data_obj_keys_sorted[0]].element.outerHTML]);
clear_before_return = true;
}
const child = this.content_elem.querySelector(":not(.clusterize-extra-row)");
if (isNullOrUndefined(child)) {
if (clear_before_return) {
this.clear();
return rebuild_required;
}
}
// Calculate the visible rows and colums for the clusterize-content area.
let n_cols = calcColsPerRow(this.content_elem, child);
let n_rows = calcRowsPerCol(this.scroll_elem, child);
n_cols = (isNaN(n_cols) || n_cols <= 0) ? 1 : n_cols;
n_rows = (isNaN(n_rows) || n_rows <= 0) ? 1 : n_rows;
// Add two extra rows to account for partial row visibility on top and bottom
// of the content element view region.
n_rows += 2;
if (n_cols != this.n_cols || n_rows != this.n_rows) {
// Sizes have changed. Update the instance values.
this.n_cols = n_cols;
this.n_rows = n_rows;
this.rows_in_block = this.n_rows;
rebuild_required = true;
}
// If we added a temporary row earlier, remove before returning.
if (clear_before_return) {
this.clear();
}
return rebuild_required;
}
waitForElements() {
return new Promise(resolve => {
Promise.all([
waitForElement(`#${this.data_id}`),
waitForElement(`#${this.scroll_id}`),
waitForElement(`#${this.content_id}`),
]).then(() => {
return resolve();
});
});
}
repair() {
/** Fixes element association in DOM. Returns true if element was replaced in DOM. */
// If association for elements is broken, replace them with instance version.
if (!this.scroll_elem.isConnected || !this.content_elem.isConnected) {
gradioApp().getElementById(this.scroll_id).replaceWith(this.scroll_elem);
// Fix resize observers since they are bound to each element individually.
if (!isNullOrUndefined(this.resize_observer)) {
this.resize_observer.disconnect();
this.resize_observer.observe(this.scroll_elem);
this.resize_observer.observe(this.content_elem);
}
// Make sure to refresh forcefully after updating the dom.
this.refresh(true);
return true;
}
return false;
}
rebuild(force) {
// Only accept boolean values for `force` parameter. Default to false.
if (force !== true) {
force = false;
}
if (isNullOrUndefined(this.clusterize)) {
// If we have already initialized, don't do it again.
this.init();
} else if (this.recalculateDims() || force) {
this.destroy();
this.clusterize = null;
this.init();
} else {
this.update();
}
}
init(rows) {
if (!isNullOrUndefined(this.clusterize)) {
// If we have already initialized, don't do it again.
return;
}
if (isNullOrUndefined(rows) && isNullOrUndefined(this.data_obj)) {
// data hasnt been loaded yet and we arent provided any. skip.
return;
}
if (isNullOrUndefined(rows)) {
rows = this.data_obj;
} else if (Array.isArray(rows) && !(rows.every(row => isString(row)))) {
console.error("Invalid data type for rows. Expected array[string].");
return;
}
this.clusterize = new Clusterize(
{
rows: this.filterRows(rows),
scrollId: this.scroll_id,
contentId: this.content_id,
rows_in_block: this.rows_in_block,
blocks_in_cluster: this.blocks_in_cluster,
show_no_data_row: this.show_no_data_row,
no_data_text: this.no_data_text,
no_data_class: this.no_data_class,
callbacks: this.callbacks,
}
);
}
onResize(elem_id) {
this.updateRows();
}
onElementAdded(elem_id) {
switch(elem_id) {
case this.data_id:
waitForElement(`#${this.data_id}`).then((elem) => this.data_elem = elem);
break;
case this.scroll_id:
this.repair();
break;
case this.content_id:
this.repair();
break;
default:
break;
}
}
onElementRemoved(elem_id) {
switch(elem_id) {
case this.data_id:
waitForElement(`#${this.data_id}`).then((elem) => this.data_elem = elem);
break;
case this.scroll_id:
this.repair();
break;
case this.content_id:
this.repair();
break;
default:
break;
}
}
onElementUpdated(elem_id) {
switch(elem_id) {
case this.data_id:
waitForElement(`#${this.data_id}`).then((elem) => this.data_elem = elem);
break;
case this.scroll_id:
this.repair();
break;
case this.content_id:
this.repair();
break;
default:
break;
}
}
onDataChanged(data) {
this.parseJson(data);
}
setupElementObservers() {
this.element_observer = new MutationObserver((mutations) => {
// don't waste time if this object isn't enabled.
if (!this.enabled) {
return;
}
let data_elem = gradioApp().getElementById(this.data_id);
if (data_elem && data_elem !== this.data_elem) {
this.onElementUpdated(data_elem.id);
} else if (data_elem && data_elem.dataset.json !== this.encoded_str) {
// we don't want to get blasted with data updates so just wait for
// the data to settle down before updating.
clearTimeout(this.data_update_timer);
this.data_update_timer = setTimeout(() => {
this.onDataChanged(data_elem.dataset.json);
}, this.data_update_timeout_ms);
}
let scroll_elem = gradioApp().getElementById(this.scroll_id);
if (scroll_elem && scroll_elem !== this.scroll_elem) {
this.onElementUpdated(scroll_elem.id);
}
let content_elem = gradioApp().getElementById(this.content_id);
if (content_elem && content_elem !== this.content_elem) {
this.onElementUpdated(content_elem.id);
}
});
this.element_observer.observe(gradioApp(), {subtree: true, childList: true, attributes: true});
}
setupResizeHandlers() {
// Handle element resizes. Delay of `resize_observer_timeout_ms` after resize
// before firing an event as a way of "debouncing" resizes.
this.resize_observer = new ResizeObserver((entries) => {
for (const entry of entries) {
if (entry.target.id === this.scroll_id || entry.target.id === this.content_id) {
clearTimeout(this.resize_observer_timer);
this.resize_observer_timer = setTimeout(() => this.onResize(entry.id), this.resize_observer_timeout_ms);
}
}
});
this.resize_observer.observe(this.scroll_elem);
this.resize_observer.observe(this.content_elem);
}
/* ==== Clusterize.Js FUNCTION WRAPPERS ==== */
refresh(force) {
/** Refreshes the clusterize instance so that it can recalculate its dims. */
if (isNullOrUndefined(this.clusterize)) {
return;
}
// Only allow boolean variables. default to false.
if (force !== true) {
force = false;
}
this.clusterize.refresh(force);
}
rowCount() {
/** Gets the total (not only visible) row count in the clusterize instance. */
return this.clusterize.getRowsAmount();
}
clear() {
/** Removes all rows. */
this.clusterize.clear();
}
update(rows) {
/** Adds rows from a list of element strings. */
if (rows === undefined || rows === null) {
// If not passed, use the default method of getting rows.
rows = this.filterRows(this.data_obj);
} else if (!Array.isArray(rows) || !(rows.every(row => typeof row === "string"))) {
console.error("Invalid data type for rows. Expected array[string].");
return;
}
this.clusterize.update(rows);
}
destroy() {
/** Destroys a clusterize instance and removes its rows from the page. */
// If `true` isnt passed, then clusterize dumps every row to the DOM.
// This kills performance so we never want to do this.
this.clusterize.destroy(true);
}
}
class ExtraNetworksClusterizeTreeList extends ExtraNetworksClusterize {
constructor(...args) {
super(...args);
}
getBoxShadow(depth) {
// Generates style for a multi-level box shadow for vertical indentation lines.
let res = "";
var style = getComputedStyle(document.body);
let bg = style.getPropertyValue("--body-background-fill");
let fg = style.getPropertyValue("--border-color-primary");
let text_size = style.getPropertyValue("--button-large-text-size");
for (let i = 1; i <= depth; i++) {
res += `calc((${i} * ${text_size}) - (${text_size} * 0.6)) 0 0 ${bg} inset,`;
res += `calc((${i} * ${text_size}) - (${text_size} * 0.4)) 0 0 ${fg} inset`;
res += (i + 1 > depth) ? "" : ", ";
}
return res;
}
updateJson(json) {
return new Promise(resolve => {
var style = getComputedStyle(document.body);
//let spacing_sm = style.getPropertyValue("--spacing-sm");
let text_size = style.getPropertyValue("--button-large-text-size");
for (const [k, v] of Object.entries(json)) {
let div_id = k;
let parsed_html = parseHtml(v)[0];
// parent_id = -1 if item is at root level
let parent_id = "parentId" in parsed_html.dataset ? parsed_html.dataset.parentId : -1;
let expanded = "expanded" in parsed_html.dataset;
let depth = Number(parsed_html.dataset.depth);
parsed_html.style.paddingLeft = `calc(${depth} * ${text_size})`;
parsed_html.style.boxShadow = this.getBoxShadow(depth);
// Add the updated html to the data object.
this.data_obj[div_id] = {
element: parsed_html,
active: parent_id === -1, // always show root
expanded: expanded || (parent_id === -1), // always expand root
parent: parent_id,
children: [], // populated later
};
}
// Build list of children for each element in dataset.
for (const [k, v] of Object.entries(this.data_obj)) {
if (v.parent === -1) {
continue;
} else if (!(v.parent in this.data_obj)) {
console.error("parent not in data:", v.parent);
} else {
this.data_obj[v.parent].children.push(k);
}
}
// Handle expanding of rows on initial load
for (const [k, v] of Object.entries(this.data_obj)) {
if (v.parent === -1) {
// Always show root level.
this.data_obj[k].active = true;
} else if (this.data_obj[v.parent].expanded && this.data_obj[v.parent].active) {
// Parent is both active and expanded. show child
this.data_obj[k].active = true;
} else {
this.data_obj[k].active = false;
}
}
return resolve();
});
}
removeChildRows(div_id) {
for (const child_id of this.data_obj[div_id].children) {
this.data_obj[child_id].active = false;
this.data_obj[child_id].expanded = false;
delete this.data_obj[child_id].element.dataset.expanded;
this.removeChildRows(child_id);
}
}
addChildRows(div_id) {
for (const child_id of this.data_obj[div_id].children) {
this.data_obj[child_id].active = true;
if (this.data_obj[child_id].expanded) {
this.addChildRows(child_id);
}
}
}
getMaxRowWidth() {
if (!this.enabled) {
// Inactive list is not displayed on screen. Can't calculate size.
return false;
}
if (this.rowCount() === 0) {
// If there is no data then just skip.
return false;
}
let max_width = 0;
for (let i = 0; i < this.content_elem.children.length; i += this.n_cols) {
let row_width = 0;
for (let j = 0; j < this.n_cols; j++) {
const child = this.content_elem.children[i + j];
const child_style = window.getComputedStyle(child, null);
const prev_style = child.style.cssText;
const n_cols = child_style.getPropertyValue("grid-template-columns").split(" ").length;
child.style.gridTemplateColumns = `repeat(${n_cols}, max-content)`;
row_width += getComputedDims(child).width;
// Re-apply previous style.
child.style.cssText = prev_style;
}
max_width = Math.max(max_width, row_width);
}
if (max_width <= 0) {
return;
}
// Add the container's padding to the result.
max_width += getComputedPaddingDims(this.content_elem).width;
// Add the scrollbar's width to the result. Will add 0 if scrollbar isnt present.
max_width += this.scroll_elem.offsetWidth - this.scroll_elem.clientWidth;
return max_width;
}
}
class ExtraNetworksClusterizeCardsList extends ExtraNetworksClusterize {
constructor(...args) {
super(...args);
this.sort_mode_str = "path";
this.sort_dir_str = "ascending";
this.filter_str = "";
}
updateJson(json) {
return new Promise(resolve => {
for (const [k, v] of Object.entries(json)) {
let div_id = k;
let parsed_html = parseHtml(v)[0];
// Add the updated html to the data object.
this.data_obj[div_id] = {
element: parsed_html,
active: true,
};
}
return resolve();
});
}
filterRows(obj) {
let filtered_rows = super.filterRows(obj);
let res = [];
for (let i = 0; i < filtered_rows.length; i += this.n_cols) {
res.push(filtered_rows.slice(i, i + this.n_cols).join(""));
}
return res;
}
sortByName() {
this.data_obj_keys_sorted = Object.keys(this.data_obj).sort((a, b) => {
return STR_COLLATOR.compare(
this.data_obj[a].element.dataset.sortName,
this.data_obj[b].element.dataset.sortName,
);
});
}
sortByPath() {
this.data_obj_keys_sorted = Object.keys(this.data_obj).sort((a, b) => {
return STR_COLLATOR.compare(
this.data_obj[a].element.dataset.sortPath,
this.data_obj[b].element.dataset.sortPath,
);
});
}
sortByCreated() {
this.data_obj_keys_sorted = Object.keys(this.data_obj).sort((a, b) => {
return INT_COLLATOR.compare(
this.data_obj[a].element.dataset.sortCreated,
this.data_obj[b].element.dataset.sortCreated,
);
});
}
sortByModified() {
this.data_obj_keys_sorted = Object.keys(this.data_obj).sort((a, b) => {
return INT_COLLATOR.compare(
this.data_obj[a].element.dataset.sortModified,
this.data_obj[b].element.dataset.sortModified,
);
});
}
setSortMode(btn_sort_mode) {
this.sort_mode_str = btn_sort_mode.dataset.sortMode.toLowerCase();
}
setSortDir(btn_sort_dir) {
this.sort_dir_str = btn_sort_dir.dataset.sortDir.toLowerCase();
}
applySort() {
this.sort_reverse = this.sort_dir_str === "descending";
switch (this.sort_mode_str) {
case "name":
this.sort_fn = this.sortByName;
break;
case "path":
this.sort_fn = this.sortByPath;
break;
case "created":
this.sort_fn = this.sortByCreated;
break;
case "modified":
this.sort_fn = this.sortByModified;
break;
default:
this.sort_fn = this.sortByDivId;
break;
}
super.applySort();
}
applyFilter(filter_str) {
if (filter_str !== undefined && filter_str !== null) {
this.filter_str = filter_str.toLowerCase();
} else {
this.filter_str = this.txt_search_elem.value.toLowerCase();
}
for (const [k, v] of Object.entries(this.data_obj)) {
let search_only = v.element.querySelector(".search_only");
let text = Array.prototype.map.call(v.element.querySelectorAll(".search_terms"), function (t) {
return t.textContent.toLowerCase();
}).join(" ");
let visible = text.indexOf(this.filter_str) != -1;
if (search_only && this.filter_str.length < 4) {
visible = false;
}
this.data_obj[k].active = visible;
}
this.applySort();
this.updateRows();
}
getMaxRowWidth() {
if (!this.enabled) {
// Inactive list is not displayed on screen. Can't calculate size.
return false;
}
if (this.rowCount() === 0) {
// If there is no data then just skip.
return false;
}
let max_width = 0;
for (let i = 0; i < this.content_elem.children.length; i += this.n_cols) {
let row_width = 0;
for (let j = 0; j < this.n_cols; j++) {
row_width += getComputedDims(this.content_elem.children[i + j]).width;
}
max_width = Math.max(max_width, row_width);
}
if (max_width <= 0) {
return;
}
// Add the container's padding to the result.
max_width += getComputedPaddingDims(this.content_elem).width;
// Add the scrollbar's width to the result. Will add 0 if scrollbar isnt present.
max_width += this.scroll_elem.offsetWidth - this.scroll_elem.clientWidth;
return max_width;
}
}