Files
tubestation/devtools/client/framework/source-location.js

138 lines
4.6 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 { Task } = require("resource://gre/modules/Task.jsm");
const { assert } = require("devtools/shared/DevToolsUtils");
/**
* A manager class that wraps a TabTarget and listens to source changes
* from source maps and resolves non-source mapped locations to the source mapped
* versions and back and forth, and creating smart elements with a location that
* auto-update when the source changes (from pretty printing, source maps loading, etc)
*
* @param {TabTarget} target
*/
function SourceLocationController(target) {
this.target = target;
this.locations = new Set();
this._onSourceUpdated = this._onSourceUpdated.bind(this);
this.reset = this.reset.bind(this);
this.destroy = this.destroy.bind(this);
target.on("source-updated", this._onSourceUpdated);
target.on("navigate", this.reset);
target.on("will-navigate", this.reset);
target.on("close", this.destroy);
}
SourceLocationController.prototype.reset = function() {
this.locations.clear();
};
SourceLocationController.prototype.destroy = function() {
this.locations.clear();
this.target.off("source-updated", this._onSourceUpdated);
this.target.off("navigate", this.reset);
this.target.off("will-navigate", this.reset);
this.target.off("close", this.destroy);
this.target = this.locations = null;
};
/**
* Add this `location` to be observed and register a callback
* whenever the underlying source is updated.
*
* @param {Object} location
* An object with a {String} url, {Number} line, and optionally
* a {Number} column.
* @param {Function} callback
*/
SourceLocationController.prototype.bindLocation = function(location, callback) {
assert(location.url, "Location must have a url.");
assert(location.line, "Location must have a line.");
this.locations.add({ location, callback });
};
/**
* Called when a new source occurs (a normal source, source maps) or an updated
* source (pretty print) occurs.
*
* @param {String} eventName
* @param {Object} sourceEvent
*/
SourceLocationController.prototype._onSourceUpdated = function(_, sourceEvent) {
let { type, source } = sourceEvent;
// If we get a new source, and it's not a source map, abort;
// we can ahve no actionable updates as this is just a new normal source.
// Also abort if there's no `url`, which means it's unsourcemappable anyway,
// like an eval script.
if (!source.url || type === "newSource" && !source.isSourceMapped) {
return;
}
for (let locationItem of this.locations) {
if (isSourceRelated(locationItem.location, source)) {
this._updateSource(locationItem);
}
}
};
SourceLocationController.prototype._updateSource = Task.async(function*(locationItem) {
let newLocation = yield resolveLocation(this.target, locationItem.location);
if (newLocation) {
let previousLocation = Object.assign({}, locationItem.location);
Object.assign(locationItem.location, newLocation);
locationItem.callback(previousLocation, newLocation);
}
});
/**
* Take a TabTarget and a location, containing a `url`, `line`, and `column`, resolve
* the location to the latest location (so a source mapped location, or if pretty print
* status has been updated)
*
* @param {TabTarget} target
* @param {Object} location
* @return {Promise<Object>}
*/
function resolveLocation(target, location) {
return Task.spawn(function*() {
let newLocation = yield target.resolveLocation({
url: location.url,
line: location.line,
column: location.column || Infinity
});
// Source or mapping not found, so don't do anything
if (newLocation.error) {
return null;
}
return newLocation;
});
}
/**
* Takes a serialized SourceActor form and returns a boolean indicating
* if this source is related to this location, like if a location is a generated source,
* and the source map is loaded subsequently, the new source mapped SourceActor
* will be considered related to this location. Same with pretty printing new sources.
*
* @param {Object} location
* @param {Object} source
* @return {Boolean}
*/
function isSourceRelated(location, source) {
// Mapping location to subsequently loaded source map
return source.generatedUrl === location.url ||
// Mapping source map loc to source map
source.url === location.url
}
exports.SourceLocationController = SourceLocationController;
exports.resolveLocation = resolveLocation;
exports.isSourceRelated = isSourceRelated;