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firefox/devtools/client/shared/sourceeditor/css-autocompleter.js
Daniel Baumann 5e9a113729
Adding upstream version 140.0.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-25 09:37:52 +02:00

1358 lines
46 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const {
cssTokenizer,
cssTokenizerWithLineColumn,
} = require("resource://devtools/shared/css/parsing-utils.js");
/**
* Here is what this file (+ css-parsing-utils.js) do.
*
* The main objective here is to provide as much suggestions to the user editing
* a stylesheet in Style Editor. The possible things that can be suggested are:
* - CSS property names
* - CSS property values
* - CSS Selectors
* - Some other known CSS keywords
*
* Gecko provides a list of both property names and their corresponding values.
* We take out a list of matching selectors using the Inspector actor's
* `getSuggestionsForQuery` method. Now the only thing is to parse the CSS being
* edited by the user, figure out what token or word is being written and last
* but the most difficult, what is being edited.
*
* The file 'css-parsing-utils' helps to convert the CSS into meaningful tokens,
* each having a certain type associated with it. These tokens help us to figure
* out the currently edited word and to write a CSS state machine to figure out
* what the user is currently editing (e.g. a selector or a property or a value,
* or even fine grained information like an id in the selector).
*
* The `resolveState` method iterated over the tokens spitted out by the
* tokenizer, using switch cases, follows a state machine logic and finally
* figures out these informations:
* - The state of the CSS at the cursor (one out of CSS_STATES)
* - The current token that is being edited `completing`
* - If the state is "selector", the selector state (one of SELECTOR_STATES)
* - If the state is "selector", the current selector till the cursor
* - If the state is "value", the corresponding property name
*
* In case of "value" and "property" states, we simply use the information
* provided by Gecko to filter out the possible suggestions.
* For "selector" state, we request the Inspector actor to query the page DOM
* and filter out the possible suggestions.
* For "media" and "keyframes" state, the only possible suggestions for now are
* "media" and "keyframes" respectively, although "media" can have suggestions
* like "max-width", "orientation" etc. Similarly "value" state can also have
* much better logical suggestions if we fine grain identify a sub state just
* like we do for the "selector" state.
*/
class CSSCompleter {
// Autocompletion types.
// These can be read _a lot_ in a hotpath, so keep those as individual constants using
// a Symbol as a value so the lookup is faster.
static CSS_STATE_NULL = Symbol("state_null");
// foo { bar|: … };
static CSS_STATE_PROPERTY = Symbol("state_property");
// foo {bar: baz|};
static CSS_STATE_VALUE = Symbol("state_value");
// f| {bar: baz};
static CSS_STATE_SELECTOR = Symbol("state_selector");
// @med| , or , @media scr| { };
static CSS_STATE_MEDIA = Symbol("state_media");
// @keyf|;
static CSS_STATE_KEYFRAMES = Symbol("state_keyframes");
// @keyframs foobar { t|;
static CSS_STATE_FRAME = Symbol("state_frame");
static CSS_SELECTOR_STATE_NULL = Symbol("selector_state_null");
// #f|
static CSS_SELECTOR_STATE_ID = Symbol("selector_state_id");
// #foo.b|
static CSS_SELECTOR_STATE_CLASS = Symbol("selector_state_class");
// fo|
static CSS_SELECTOR_STATE_TAG = Symbol("selector_state_tag");
// foo:|
static CSS_SELECTOR_STATE_PSEUDO = Symbol("selector_state_pseudo");
// foo[b|
static CSS_SELECTOR_STATE_ATTRIBUTE = Symbol("selector_state_attribute");
// foo[bar=b|
static CSS_SELECTOR_STATE_VALUE = Symbol("selector_state_value");
static SELECTOR_STATE_STRING_BY_SYMBOL = new Map([
[CSSCompleter.CSS_SELECTOR_STATE_NULL, "null"],
[CSSCompleter.CSS_SELECTOR_STATE_ID, "id"],
[CSSCompleter.CSS_SELECTOR_STATE_CLASS, "class"],
[CSSCompleter.CSS_SELECTOR_STATE_TAG, "tag"],
[CSSCompleter.CSS_SELECTOR_STATE_PSEUDO, "pseudo"],
[CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE, "attribute"],
[CSSCompleter.CSS_SELECTOR_STATE_VALUE, "value"],
]);
/**
* @constructor
* @param options {Object} An options object containing the following options:
* - walker {Object} The object used for query selecting from the current
* target's DOM.
* - maxEntries {Number} Maximum selectors suggestions to display.
* - cssProperties {Object} The database of CSS properties.
*/
constructor(options = {}) {
this.walker = options.walker;
this.maxEntries = options.maxEntries || 15;
this.cssProperties = options.cssProperties;
this.propertyNames = this.cssProperties.getNames().sort();
// Array containing the [line, ch, scopeStack] for the locations where the
// CSS state is "null"
this.nullStates = [];
}
/**
* Returns a list of suggestions based on the caret position.
*
* @param source {String} String of the source code.
* @param cursor {Object} Cursor location with line and ch properties.
*
* @returns [{object}] A sorted list of objects containing the following
* peroperties:
* - label {String} Full keyword for the suggestion
* - preLabel {String} Already entered part of the label
*/
complete(source, cursor) {
// Getting the context from the caret position.
if (!this.resolveState({ source, line: cursor.line, column: cursor.ch })) {
// We couldn't resolve the context, we won't be able to complete.
return Promise.resolve([]);
}
// Properly suggest based on the state.
switch (this.state) {
case CSSCompleter.CSS_STATE_PROPERTY:
return this.completeProperties(this.completing);
case CSSCompleter.CSS_STATE_VALUE:
return this.completeValues(this.propertyName, this.completing);
case CSSCompleter.CSS_STATE_SELECTOR:
return this.suggestSelectors();
case CSSCompleter.CSS_STATE_MEDIA:
case CSSCompleter.CSS_STATE_KEYFRAMES:
if ("media".startsWith(this.completing)) {
return Promise.resolve([
{
label: "media",
preLabel: this.completing,
text: "media",
},
]);
} else if ("keyframes".startsWith(this.completing)) {
return Promise.resolve([
{
label: "keyframes",
preLabel: this.completing,
text: "keyframes",
},
]);
}
}
return Promise.resolve([]);
}
/**
* Resolves the state of CSS given a source and a cursor location, or an array of tokens.
* This method implements a custom written CSS state machine. The various switch
* statements provide the transition rules for the state. It also finds out various
* information about the nearby CSS like the property name being completed, the complete
* selector, etc.
*
* @param options {Object}
* @param sourceTokens {Array<InspectorCSSToken>} Optional array of the tokens representing
* a CSS source. When this is defined, `source`, `line` and `column`
* shouldn't be passed.
* @param options.source {String} Optional string of the source code. When this is defined,
* `sourceTokens` shouldn't be passed.
* @param options.line {Number} Cursor line. Mandatory when source is passed.
* @param options.column {Number} Cursor column. Mandatory when source is passed
*
* @returns CSS_STATE
* One of CSS_STATE enum or null if the state cannot be resolved.
*/
// eslint-disable-next-line complexity
resolveState({ sourceTokens, source, line, column }) {
if (sourceTokens && source) {
throw new Error(
"This function only accepts sourceTokens or source, not both"
);
}
// _state can be one of CSS_STATES;
let _state = CSSCompleter.CSS_STATE_NULL;
let selector = "";
let selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
let propertyName = null;
let scopeStack = [];
let selectors = [];
// If we need to retrieve the tokens, fetch the closest null state line/ch from cached
// null state locations to save some cycle.
const matchedStateIndex = !sourceTokens
? this.findNearestNullState(line)
: -1;
if (matchedStateIndex > -1) {
const state = this.nullStates[matchedStateIndex];
line -= state[0];
if (line == 0) {
column -= state[1];
}
source = source.split("\n").slice(state[0]);
source[0] = source[0].slice(state[1]);
source = source.join("\n");
scopeStack = [...state[2]];
this.nullStates.length = matchedStateIndex + 1;
} else {
this.nullStates = [];
}
const tokens = sourceTokens || cssTokenizerWithLineColumn(source);
const tokIndex = tokens.length - 1;
if (
!sourceTokens &&
tokIndex >= 0 &&
(tokens[tokIndex].loc.end.line < line ||
(tokens[tokIndex].loc.end.line === line &&
tokens[tokIndex].loc.end.column < column))
) {
// If the last token ends before the cursor location, we didn't
// tokenize it correctly. This special case can happen if the
// final token is a comment.
return null;
}
let cursor = 0;
// This will maintain a stack of paired elements like { & }, @m & }, : & ;
// etc
let token = null;
let selectorBeforeNot = null;
while (cursor <= tokIndex && (token = tokens[cursor++])) {
switch (_state) {
case CSSCompleter.CSS_STATE_PROPERTY:
// From CSS_STATE_PROPERTY, we can either go to CSS_STATE_VALUE
// state when we hit the first ':' or CSS_STATE_SELECTOR if "}" is
// reached.
if (token.tokenType === "Colon") {
scopeStack.push(":");
if (tokens[cursor - 2].tokenType != "WhiteSpace") {
propertyName = tokens[cursor - 2].text;
} else {
propertyName = tokens[cursor - 3].text;
}
_state = CSSCompleter.CSS_STATE_VALUE;
}
if (token.tokenType === "CloseCurlyBracket") {
if (/[{f]/.test(scopeStack.at(-1))) {
const popped = scopeStack.pop();
if (popped == "f") {
_state = CSSCompleter.CSS_STATE_FRAME;
} else {
selector = "";
selectors = [];
_state = CSSCompleter.CSS_STATE_NULL;
}
}
}
break;
case CSSCompleter.CSS_STATE_VALUE:
// From CSS_STATE_VALUE, we can go to one of CSS_STATE_PROPERTY,
// CSS_STATE_FRAME, CSS_STATE_SELECTOR and CSS_STATE_NULL
if (token.tokenType === "Semicolon") {
if (/[:]/.test(scopeStack.at(-1))) {
scopeStack.pop();
_state = CSSCompleter.CSS_STATE_PROPERTY;
}
}
if (token.tokenType === "CloseCurlyBracket") {
if (scopeStack.at(-1) == ":") {
scopeStack.pop();
}
if (/[{f]/.test(scopeStack.at(-1))) {
const popped = scopeStack.pop();
if (popped == "f") {
_state = CSSCompleter.CSS_STATE_FRAME;
} else {
selector = "";
selectors = [];
_state = CSSCompleter.CSS_STATE_NULL;
}
}
}
break;
case CSSCompleter.CSS_STATE_SELECTOR:
// From CSS_STATE_SELECTOR, we can only go to CSS_STATE_PROPERTY
// when we hit "{"
if (token.tokenType === "CurlyBracketBlock") {
scopeStack.push("{");
_state = CSSCompleter.CSS_STATE_PROPERTY;
selectors.push(selector);
selector = "";
break;
}
switch (selectorState) {
case CSSCompleter.CSS_SELECTOR_STATE_ID:
case CSSCompleter.CSS_SELECTOR_STATE_CLASS:
case CSSCompleter.CSS_SELECTOR_STATE_TAG:
switch (token.tokenType) {
case "Hash":
case "IDHash":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ID;
selector += token.text;
break;
case "Delim":
if (token.text == ".") {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_CLASS;
selector += ".";
if (
cursor <= tokIndex &&
tokens[cursor].tokenType == "Ident"
) {
token = tokens[cursor++];
selector += token.text;
}
} else if (token.text == "#") {
// Lonely # char, that doesn't produce a Hash nor IDHash
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ID;
selector += "#";
} else if (
token.text == "+" ||
token.text == "~" ||
token.text == ">"
) {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selector += token.text;
}
break;
case "Comma":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selectors.push(selector);
selector = "";
break;
case "Colon":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_PSEUDO;
selector += ":";
if (cursor > tokIndex) {
break;
}
token = tokens[cursor++];
switch (token.tokenType) {
case "Function":
if (token.value == "not") {
selectorBeforeNot = selector;
selector = "";
scopeStack.push("(");
} else {
selector += token.text;
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
break;
case "Ident":
selector += token.text;
break;
}
break;
case "SquareBracketBlock":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE;
scopeStack.push("[");
selector += "[";
break;
case "CloseParenthesis":
if (scopeStack.at(-1) == "(") {
scopeStack.pop();
selector = selectorBeforeNot + "not(" + selector + ")";
selectorBeforeNot = null;
} else {
selector += ")";
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
break;
case "WhiteSpace":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selector && (selector += " ");
break;
}
break;
case CSSCompleter.CSS_SELECTOR_STATE_NULL:
// From CSS_SELECTOR_STATE_NULL state, we can go to one of
// CSS_SELECTOR_STATE_ID, CSS_SELECTOR_STATE_CLASS or
// CSS_SELECTOR_STATE_TAG
switch (token.tokenType) {
case "Hash":
case "IDHash":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ID;
selector += token.text;
break;
case "Ident":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_TAG;
selector += token.text;
break;
case "Delim":
if (token.text == ".") {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_CLASS;
selector += ".";
if (
cursor <= tokIndex &&
tokens[cursor].tokenType == "Ident"
) {
token = tokens[cursor++];
selector += token.text;
}
} else if (token.text == "#") {
// Lonely # char, that doesn't produce a Hash nor IDHash
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ID;
selector += "#";
} else if (token.text == "*") {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_TAG;
selector += "*";
} else if (
token.text == "+" ||
token.text == "~" ||
token.text == ">"
) {
selector += token.text;
}
break;
case "Comma":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selectors.push(selector);
selector = "";
break;
case "Colon":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_PSEUDO;
selector += ":";
if (cursor > tokIndex) {
break;
}
token = tokens[cursor++];
switch (token.tokenType) {
case "Function":
if (token.value == "not") {
selectorBeforeNot = selector;
selector = "";
scopeStack.push("(");
} else {
selector += token.text;
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
break;
case "Ident":
selector += token.text;
break;
}
break;
case "SquareBracketBlock":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE;
scopeStack.push("[");
selector += "[";
break;
case "CloseParenthesis":
if (scopeStack.at(-1) == "(") {
scopeStack.pop();
selector = selectorBeforeNot + "not(" + selector + ")";
selectorBeforeNot = null;
} else {
selector += ")";
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
break;
case "WhiteSpace":
selector && (selector += " ");
break;
}
break;
case CSSCompleter.CSS_SELECTOR_STATE_PSEUDO:
switch (token.tokenType) {
case "Delim":
if (
token.text == "+" ||
token.text == "~" ||
token.text == ">"
) {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selector += token.text;
}
break;
case "Comma":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selectors.push(selector);
selector = "";
break;
case "Colon":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_PSEUDO;
selector += ":";
if (cursor > tokIndex) {
break;
}
token = tokens[cursor++];
switch (token.tokenType) {
case "Function":
if (token.value == "not") {
selectorBeforeNot = selector;
selector = "";
scopeStack.push("(");
} else {
selector += token.text;
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
break;
case "Ident":
selector += token.text;
break;
}
break;
case "SquareBracketBlock":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE;
scopeStack.push("[");
selector += "[";
break;
case "WhiteSpace":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selector && (selector += " ");
break;
}
break;
case CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE:
switch (token.tokenType) {
case "IncludeMatch":
case "DashMatch":
case "PrefixMatch":
case "IncludeSuffixMatchMatch":
case "SubstringMatch":
selector += token.text;
token = tokens[cursor++];
break;
case "Delim":
if (token.text == "=") {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_VALUE;
selector += token.text;
}
break;
case "CloseSquareBracket":
if (scopeStack.at(-1) == "[") {
scopeStack.pop();
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selector += "]";
break;
case "Ident":
selector += token.text;
break;
case "QuotedString":
selector += token.value;
break;
case "WhiteSpace":
selector && (selector += " ");
break;
}
break;
case CSSCompleter.CSS_SELECTOR_STATE_VALUE:
switch (token.tokenType) {
case "Ident":
selector += token.text;
break;
case "QuotedString":
selector += token.value;
break;
case "CloseSquareBracket":
if (scopeStack.at(-1) == "[") {
scopeStack.pop();
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
selector += "]";
break;
case "WhiteSpace":
selector && (selector += " ");
break;
}
break;
}
break;
case CSSCompleter.CSS_STATE_NULL:
// From CSS_STATE_NULL state, we can go to either CSS_STATE_MEDIA or
// CSS_STATE_SELECTOR.
switch (token.tokenType) {
case "Hash":
case "IDHash":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ID;
selector = token.text;
_state = CSSCompleter.CSS_STATE_SELECTOR;
break;
case "Ident":
selectorState = CSSCompleter.CSS_SELECTOR_STATE_TAG;
selector = token.text;
_state = CSSCompleter.CSS_STATE_SELECTOR;
break;
case "Delim":
if (token.text == ".") {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_CLASS;
selector = ".";
_state = CSSCompleter.CSS_STATE_SELECTOR;
if (cursor <= tokIndex && tokens[cursor].tokenType == "Ident") {
token = tokens[cursor++];
selector += token.text;
}
} else if (token.text == "#") {
// Lonely # char, that doesn't produce a Hash nor IDHash
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ID;
selector = "#";
_state = CSSCompleter.CSS_STATE_SELECTOR;
} else if (token.text == "*") {
selectorState = CSSCompleter.CSS_SELECTOR_STATE_TAG;
selector = "*";
_state = CSSCompleter.CSS_STATE_SELECTOR;
}
break;
case "Colon":
_state = CSSCompleter.CSS_STATE_SELECTOR;
selectorState = CSSCompleter.CSS_SELECTOR_STATE_PSEUDO;
selector += ":";
if (cursor > tokIndex) {
break;
}
token = tokens[cursor++];
switch (token.tokenType) {
case "Function":
if (token.value == "not") {
selectorBeforeNot = selector;
selector = "";
scopeStack.push("(");
} else {
selector += token.text;
}
selectorState = CSSCompleter.CSS_SELECTOR_STATE_NULL;
break;
case "Ident":
selector += token.text;
break;
}
break;
case "CloseSquareBracket":
_state = CSSCompleter.CSS_STATE_SELECTOR;
selectorState = CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE;
scopeStack.push("[");
selector += "[";
break;
case "CurlyBracketBlock":
if (scopeStack.at(-1) == "@m") {
scopeStack.pop();
}
break;
case "AtKeyword":
// XXX: We should probably handle other at-rules (@container, @property, …)
_state = token.value.startsWith("m")
? CSSCompleter.CSS_STATE_MEDIA
: CSSCompleter.CSS_STATE_KEYFRAMES;
break;
}
break;
case CSSCompleter.CSS_STATE_MEDIA:
// From CSS_STATE_MEDIA, we can only go to CSS_STATE_NULL state when
// we hit the first '{'
if (token.tokenType == "CurlyBracketBlock") {
scopeStack.push("@m");
_state = CSSCompleter.CSS_STATE_NULL;
}
break;
case CSSCompleter.CSS_STATE_KEYFRAMES:
// From CSS_STATE_KEYFRAMES, we can only go to CSS_STATE_FRAME state
// when we hit the first '{'
if (token.tokenType == "CurlyBracketBlock") {
scopeStack.push("@k");
_state = CSSCompleter.CSS_STATE_FRAME;
}
break;
case CSSCompleter.CSS_STATE_FRAME:
// From CSS_STATE_FRAME, we can either go to CSS_STATE_PROPERTY
// state when we hit the first '{' or to CSS_STATE_SELECTOR when we
// hit '}'
if (token.tokenType == "CurlyBracketBlock") {
scopeStack.push("f");
_state = CSSCompleter.CSS_STATE_PROPERTY;
} else if (token.tokenType == "CloseCurlyBracket") {
if (scopeStack.at(-1) == "@k") {
scopeStack.pop();
}
_state = CSSCompleter.CSS_STATE_NULL;
}
break;
}
if (_state == CSSCompleter.CSS_STATE_NULL) {
if (!this.nullStates.length) {
this.nullStates.push([
token.loc.end.line,
token.loc.end.column,
[...scopeStack],
]);
continue;
}
let tokenLine = token.loc.end.line;
const tokenCh = token.loc.end.column;
if (tokenLine == 0) {
continue;
}
if (matchedStateIndex > -1) {
tokenLine += this.nullStates[matchedStateIndex][0];
}
this.nullStates.push([tokenLine, tokenCh, [...scopeStack]]);
}
}
// ^ while loop end
this.state = _state;
this.propertyName =
_state == CSSCompleter.CSS_STATE_VALUE ? propertyName : null;
this.selectorState =
_state == CSSCompleter.CSS_STATE_SELECTOR ? selectorState : null;
this.selectorBeforeNot =
selectorBeforeNot == null ? null : selectorBeforeNot;
if (token) {
// If the source text is passed, we need to remove the part of the computed selector
// after the caret (when sourceTokens are passed, the last token is already sliced,
// so we'll get the expected value)
if (!sourceTokens) {
selector = selector.slice(
0,
selector.length + token.loc.end.column - column
);
}
this.selector = selector;
} else {
this.selector = "";
}
this.selectors = selectors;
if (token && token.tokenType != "WhiteSpace") {
let text;
if (
token.tokenType === "IDHash" ||
token.tokenType === "Hash" ||
token.tokenType === "AtKeyword" ||
token.tokenType === "Function" ||
token.tokenType === "QuotedString"
) {
text = token.value;
} else {
text = token.text;
}
this.completing = (
sourceTokens
? text
: // If the source text is passed, we need to remove the text after the caret
// (when sourceTokens are passed, the last token is already sliced, so we'll
// get the expected value)
text.slice(0, column - token.loc.start.column)
).replace(/^[.#]$/, "");
} else {
this.completing = "";
}
// Special case the situation when the user just entered ":" after typing a
// property name.
if (this.completing == ":" && _state == CSSCompleter.CSS_STATE_VALUE) {
this.completing = "";
}
// Special check for !important; case.
if (
token &&
tokens[cursor - 2] &&
tokens[cursor - 2].text == "!" &&
this.completing == "important".slice(0, this.completing.length)
) {
this.completing = "!" + this.completing;
}
return _state;
}
/**
* Queries the DOM Walker actor for suggestions regarding the selector being
* completed
*/
suggestSelectors() {
const walker = this.walker;
if (!walker) {
return Promise.resolve([]);
}
let query = this.selector;
// Even though the selector matched atleast one node, there is still
// possibility of suggestions.
switch (this.selectorState) {
case CSSCompleter.CSS_SELECTOR_STATE_NULL:
if (this.completing === ",") {
return Promise.resolve([]);
}
query += "*";
break;
case CSSCompleter.CSS_SELECTOR_STATE_TAG:
query = query.slice(0, query.length - this.completing.length);
break;
case CSSCompleter.CSS_SELECTOR_STATE_ID:
case CSSCompleter.CSS_SELECTOR_STATE_CLASS:
case CSSCompleter.CSS_SELECTOR_STATE_PSEUDO:
if (/^[.:#]$/.test(this.completing)) {
query = query.slice(0, query.length - this.completing.length);
this.completing = "";
} else {
query = query.slice(0, query.length - this.completing.length - 1);
}
break;
}
if (
/[\s+>~]$/.test(query) &&
this.selectorState != CSSCompleter.CSS_SELECTOR_STATE_ATTRIBUTE &&
this.selectorState != CSSCompleter.CSS_SELECTOR_STATE_VALUE
) {
query += "*";
}
// Set the values that this request was supposed to suggest to.
this._currentQuery = query;
return walker
.getSuggestionsForQuery(
query,
this.completing,
CSSCompleter.SELECTOR_STATE_STRING_BY_SYMBOL.get(this.selectorState)
)
.then(result => this.prepareSelectorResults(result));
}
/**
* Prepares the selector suggestions returned by the walker actor.
*/
prepareSelectorResults(result) {
if (this._currentQuery != result.query) {
return [];
}
const { suggestions } = result;
const query = this.selector;
const completion = [];
// @backward-compat { version 140 } The shape of the returned value from getSuggestionsForQuery
// changed in 140. This variable should be removed and considered as true when 140 hits release
const suggestionNewShape =
this.walker.traits.getSuggestionsForQueryWithoutCount;
for (const suggestion of suggestions) {
let value = suggestion[0];
const state = suggestionNewShape ? suggestion[1] : suggestion[2];
switch (this.selectorState) {
case CSSCompleter.CSS_SELECTOR_STATE_ID:
case CSSCompleter.CSS_SELECTOR_STATE_CLASS:
case CSSCompleter.CSS_SELECTOR_STATE_PSEUDO:
if (/^[.:#]$/.test(this.completing)) {
value =
query.slice(0, query.length - this.completing.length) + value;
} else {
value =
query.slice(0, query.length - this.completing.length - 1) + value;
}
break;
case CSSCompleter.CSS_SELECTOR_STATE_TAG:
value = query.slice(0, query.length - this.completing.length) + value;
break;
case CSSCompleter.CSS_SELECTOR_STATE_NULL:
value = query + value;
break;
default:
value = query.slice(0, query.length - this.completing.length) + value;
}
const item = {
label: value,
preLabel: query,
text: value,
};
// In case the query's state is tag and the item's state is id or class
// adjust the preLabel
if (
this.selectorState === CSSCompleter.CSS_SELECTOR_STATE_TAG &&
state === CSSCompleter.CSS_SELECTOR_STATE_CLASS
) {
item.preLabel = "." + item.preLabel;
}
if (
this.selectorState === CSSCompleter.CSS_SELECTOR_STATE_TAG &&
state === CSSCompleter.CSS_SELECTOR_STATE_ID
) {
item.preLabel = "#" + item.preLabel;
}
completion.push(item);
if (completion.length > this.maxEntries - 1) {
break;
}
}
return completion;
}
/**
* Returns CSS property name suggestions based on the input.
*
* @param startProp {String} Initial part of the property being completed.
*/
completeProperties(startProp) {
const finalList = [];
if (!startProp) {
return Promise.resolve(finalList);
}
const length = this.propertyNames.length;
let i = 0,
count = 0;
for (; i < length && count < this.maxEntries; i++) {
if (this.propertyNames[i].startsWith(startProp)) {
count++;
const propName = this.propertyNames[i];
finalList.push({
preLabel: startProp,
label: propName,
text: propName + ": ",
});
} else if (this.propertyNames[i] > startProp) {
// We have crossed all possible matches alphabetically.
break;
}
}
return Promise.resolve(finalList);
}
/**
* Returns CSS value suggestions based on the corresponding property.
*
* @param propName {String} The property to which the value being completed
* belongs.
* @param startValue {String} Initial part of the value being completed.
*/
completeValues(propName, startValue) {
const finalList = [];
const list = ["!important;", ...this.cssProperties.getValues(propName)];
// If there is no character being completed, we are showing an initial list
// of possible values. Skipping '!important' in this case.
if (!startValue) {
list.splice(0, 1);
}
const length = list.length;
let i = 0,
count = 0;
for (; i < length && count < this.maxEntries; i++) {
if (list[i].startsWith(startValue)) {
count++;
const value = list[i];
finalList.push({
preLabel: startValue,
label: value,
text: value,
});
} else if (list[i] > startValue) {
// We have crossed all possible matches alphabetically.
break;
}
}
return Promise.resolve(finalList);
}
/**
* A biased binary search in a sorted array where the middle element is
* calculated based on the values at the lower and the upper index in each
* iteration.
*
* This method returns the index of the closest null state from the passed
* `line` argument. Once we have the closest null state, we can start applying
* the state machine logic from that location instead of the absolute starting
* of the CSS source. This speeds up the tokenizing and the state machine a
* lot while using autocompletion at high line numbers in a CSS source.
*/
findNearestNullState(line) {
const arr = this.nullStates;
let high = arr.length - 1;
let low = 0;
let target = 0;
if (high < 0) {
return -1;
}
if (arr[high][0] <= line) {
return high;
}
if (arr[low][0] > line) {
return -1;
}
while (high > low) {
if (arr[low][0] <= line && arr[low[0] + 1] > line) {
return low;
}
if (arr[high][0] > line && arr[high - 1][0] <= line) {
return high - 1;
}
target =
(((line - arr[low][0]) / (arr[high][0] - arr[low][0])) * (high - low)) |
0;
if (arr[target][0] <= line && arr[target + 1][0] > line) {
return target;
} else if (line > arr[target][0]) {
low = target + 1;
high--;
} else {
high = target - 1;
low++;
}
}
return -1;
}
/**
* Invalidates the state cache for and above the line.
*/
invalidateCache(line) {
this.nullStates.length = this.findNearestNullState(line) + 1;
}
/**
* Get the state information about a token surrounding the {line, ch} position
*
* @param {string} source
* The complete source of the CSS file. Unlike resolve state method,
* this method requires the full source.
* @param {object} caret
* The line, ch position of the caret.
*
* @returns {object}
* An object containing the state of token covered by the caret.
* The object has following properties when the the state is
* "selector", "value" or "property", null otherwise:
* - state {string} one of CSS_STATES - "selector", "value" etc.
* - selector {string} The selector at the caret when `state` is
* selector. OR
* - selectors {[string]} Array of selector strings in case when
* `state` is "value" or "property"
* - propertyName {string} The property name at the current caret or
* the property name corresponding to the value at
* the caret.
* - value {string} The css value at the current caret.
* - loc {object} An object containing the starting and the ending
* caret position of the whole selector, value or property.
* - { start: {line, ch}, end: {line, ch}}
*/
getInfoAt(source, caret) {
const { line, ch } = caret;
const sourceArray = source.split("\n");
// Limits the input source till the {line, ch} caret position
const limit = function () {
// `line` is 0-based
if (sourceArray.length <= line) {
return source;
}
const list = sourceArray.slice(0, line + 1);
list[line] = list[line].slice(0, ch);
return list.join("\n");
};
const limitedSource = limit(source);
// Ideally we should be using `cssTokenizer`, which parse incrementaly and returns a generator.
// `cssTokenizerWithLineColumn` parses the whole `limitedSource` content right away
// and returns an array of tokens. This can be a performance bottleneck,
// but `resolveState` would go through all the tokens anyway, as well as `traverseBackward`,
// which starts from the last token.
const limitedSourceTokens = cssTokenizerWithLineColumn(limitedSource);
const state = this.resolveState({
sourceTokens: limitedSourceTokens,
});
const propertyName = this.propertyName;
/**
* Method to traverse forwards from the caret location to figure out the
* ending point of a selector or css value.
*
* @param {function} check
* A method which takes the current state as an input and determines
* whether the state changed or not.
*/
const traverseForward = check => {
let forwardCurrentLine = line;
let forwardCurrentSource = limitedSource;
// loop to determine the end location of the property name/value/selector.
do {
let lineText = sourceArray[forwardCurrentLine];
if (forwardCurrentLine == line) {
lineText = lineText.substring(ch);
}
let prevToken = undefined;
const tokensIterator = cssTokenizer(lineText);
const ech = forwardCurrentLine == line ? ch : 0;
for (let token of tokensIterator) {
forwardCurrentSource += sourceArray[forwardCurrentLine].substring(
ech + token.startOffset,
ech + token.endOffset
);
// WhiteSpace cannot change state.
if (token.tokenType == "WhiteSpace") {
prevToken = token;
continue;
}
const forwState = this.resolveState({
source: forwardCurrentSource,
line: forwardCurrentLine,
column: token.endOffset + ech,
});
if (check(forwState)) {
if (prevToken && prevToken.tokenType == "WhiteSpace") {
token = prevToken;
}
return {
line: forwardCurrentLine,
ch: token.startOffset + ech,
};
}
prevToken = token;
}
forwardCurrentSource += "\n";
} while (++forwardCurrentLine < sourceArray.length);
return null;
};
/**
* Method to traverse backwards from the caret location to figure out the
* starting point of a selector or css value.
*
* @param {function} check
* A method which takes the current state as an input and determines
* whether the state changed or not.
* @param {boolean} isValue
* true if the traversal is being done for a css value state.
*/
const traverseBackwards = (check, isValue) => {
let token;
let previousToken;
const remainingTokens = Array.from(limitedSourceTokens);
// Backward loop to determine the beginning location of the selector.
while (((previousToken = token), (token = remainingTokens.pop()))) {
// WhiteSpace cannot change state.
if (token.tokenType == "WhiteSpace") {
continue;
}
const backState = this.resolveState({
sourceTokens: remainingTokens,
});
if (check(backState)) {
if (previousToken?.tokenType == "WhiteSpace") {
token = previousToken;
}
const loc = isValue ? token.loc.end : token.loc.start;
return {
line: loc.line,
ch: loc.column,
};
}
}
return null;
};
if (state == CSSCompleter.CSS_STATE_SELECTOR) {
// For selector state, the ending and starting point of the selector is
// either when the state changes or the selector becomes empty and a
// single selector can span multiple lines.
// Backward loop to determine the beginning location of the selector.
const start = traverseBackwards(backState => {
return (
backState != CSSCompleter.CSS_STATE_SELECTOR ||
(this.selector == "" && this.selectorBeforeNot == null)
);
});
// Forward loop to determine the ending location of the selector.
const end = traverseForward(forwState => {
return (
forwState != CSSCompleter.CSS_STATE_SELECTOR ||
(this.selector == "" && this.selectorBeforeNot == null)
);
});
// Since we have start and end positions, figure out the whole selector.
let selector = sourceArray.slice(start.line, end.line + 1);
selector[selector.length - 1] = selector[selector.length - 1].substring(
0,
end.ch
);
selector[0] = selector[0].substring(start.ch);
selector = selector.join("\n");
return {
state,
selector,
loc: {
start,
end,
},
};
} else if (state == CSSCompleter.CSS_STATE_PROPERTY) {
// A property can only be a single word and thus very easy to calculate.
const tokensIterator = cssTokenizer(sourceArray[line]);
for (const token of tokensIterator) {
// Note that, because we're tokenizing a single line, the
// token's offset is also the column number.
if (token.startOffset <= ch && token.endOffset >= ch) {
return {
state,
propertyName: token.text,
selectors: this.selectors,
loc: {
start: {
line,
ch: token.startOffset,
},
end: {
line,
ch: token.endOffset,
},
},
};
}
}
} else if (state == CSSCompleter.CSS_STATE_VALUE) {
// CSS value can be multiline too, so we go forward and backwards to
// determine the bounds of the value at caret
const start = traverseBackwards(
backState => backState != CSSCompleter.CSS_STATE_VALUE,
true
);
// Find the end of the value using a simple forward scan.
const remainingSource = source.substring(limitedSource.length);
const parser = new InspectorCSSParser(remainingSource);
let end;
while (true) {
const token = parser.nextToken();
if (
!token ||
token.tokenType === "Semicolon" ||
token.tokenType === "CloseCurlyBracket"
) {
// Done. We're guaranteed to exit the loop once we reach
// the end of the string.
end = {
line: parser.lineNumber + line,
ch: parser.columnNumber,
};
if (end.line === line) {
end.ch = end.ch + ch;
}
break;
}
}
let value = sourceArray.slice(start.line, end.line + 1);
value[value.length - 1] = value[value.length - 1].substring(0, end.ch);
value[0] = value[0].substring(start.ch);
value = value.join("\n");
return {
state,
propertyName,
selectors: this.selectors,
value,
loc: {
start,
end,
},
};
}
return null;
}
}
module.exports = CSSCompleter;