Initial commit for Chrome.* APIs in Dart

tools/dom/src/chrome/_utils.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file

[blois, 2013/01/23 02:06:12]

2013

[sashab, 2013/01/23 04:45:34]

Done.

+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.

[blois, 2013/01/23 02:06:12]

Normally we don't use leading _ for file names (at least I believe not).

Also- should these types have leading underscores? Right now they are publicly
accessible. Seems a bit misleading from the file name.

Also- 'utils' is one of those names that if you're using it, it's most likely
wrong :)

[sashab, 2013/01/23 04:45:34]

No worries; I can fix this.
Again, I'll remove the _ from the file name.
What should it be called? Should Events and ChromeObject be in their own files?
Or maybe it should all be in chrome.dart?

+
+/**
+ * A set of utilities for use with the Chrome Extension APIs.
+ *
+ * Allows for easy access to required JS objects.
+ */
+part of chrome;
+
+/**
+ * A dart object, that is convertible to JS. Used for creating objects in dart,
+ * then passing them to JS.
+ *
+ * Objects that are passable to JS need to implement this interface.
+ */
+abstract class ChromeObject {
+  /*
+   * Default Constructor
+   *
+   * Called by child objects during their regular construction.
+   */
+  ChromeObject() :
+    _jsObject = null;
+
+  /*
+   * Internal proxy constructor
+   *
+   * Creates a new object using this existing proxy.
+   */
+  ChromeObject._proxy(this._jsObject);
+
+  /*
+   * JS Object Representation
+   */
+  Object _jsObject;
+
+  /*
+   * Return a Map representation of this object's members, non-recursively.
+   */
+  Map _toMap();
+
+  /*
+   * Return a non-recursive serialized representation of this object.
+   *
+   * Returns a Map representation, if this object has not yet been proxied,
+   * or the existing proxy, if it has already been proxied.
+   */
+  Object _serialize() {
+    if (_jsObject == null)
+      return this._toMap();
+    return _jsObject;
+  }
+
+  /*
+   * Returns True if this object has a matching JS object, False otherwise.
+   */
+  bool _hasProxy() {
+    return this._jsObject != null;
+  }
+}
+
+/**
+ * Useful functions for converting arguments.
+ */
+
+/**
+ * Converts the given map-type argument to js-friendly format, recursively.
+ * Returns the new Map object.
+ */
+Object _convertMapArgument(Map argument) {
+  Map m = new Map();
+  for (Object key in argument.keys)
+    m[key] = convertArgument(argument[key]);
+  return convertDartToNative_Dictionary(m);
+}
+
+/*
+Map _convertMapArgument(Map argument) {
+  var object = JS('var', '{}');
+  for (Object key in argument.keys)
+    JS('void', '#[#] = #', object, key, convertArgument(argument[key]));
+  return object;
+}
+ */
+
+/**
+ * Converts the given list-type argument to js-friendly format, recursively.
+ * Returns the new List object.
+ */
+List _convertListArgument(List argument) {
+  List l = new List();
+  for (var i = 0; i < argument.length; i ++)
+    l.add(convertArgument(argument[i]));
+  return l;
+}
+
+/**
+ * Converts the given argument Object to js-friendly format, recursively.
+ *
+ * Flattens out all Chrome objects into their corresponding ._toMap()
+ * definitions, then converts them to JS objects.
+ *
+ * Returns the new argument.
+ *
+ * Cannot be used for functions.
+ */
+Object convertArgument(var argument) {
+  if (argument == null)
+    return argument;
+
+  if (argument is num || argument is String || argument is bool)
+    return argument;
+
+  if (argument is ChromeObject)
+    return convertArgument(argument._serialize());
+
+  if (argument is List)
+    return _convertListArgument(argument);
+
+  if (argument is Map)
+    return _convertMapArgument(argument);
+
+  if (argument is Function)
+    throw new Exception("Cannot serialize Function argument ${argument}.");
+
+  // TODO(sashab): Try and detect whether the argument is already serialized.
+  return argument;
+}
+
+/**
+ * Description of a declarative rule for handling events.
+ */
+class Rule extends ChromeObject {
+  String _id;
+  List _conditions;
+  List _actions;
+  int _priority;
+
+  /*
+   * Public (Dart) constructor
+   */
+  Rule({
+    String id,
+    List conditions,
+    List actions,
+    int priority
+  }) :
+    _id = id,
+    _conditions = conditions,
+    _actions = actions,
+    _priority = priority
+  ;
+
+  /*
+   * Private (JS) constructor
+   */
+  Rule._proxy(_jsObject)
+      : super._proxy(_jsObject);
+
+  /*
+   * Serialisation method
+   */
+  Map _toMap() {
+    Map m = {};
+    if (id != null) m['id'] = id;
+    if (conditions != null) m['conditions'] = conditions;
+    if (actions != null) m['actions'] = actions;
+    if (priority != null) m['priority'] = priority;
+    return m;
+  }
+
+  /*
+   * Public accessors
+   */
+  String get id {
+    if (!this._hasProxy())
+      return this._id;
+    return JS('String', '#.id', this._jsObject);
+  }
+
+  void set id(String id) {
+    if (!this._hasProxy())
+      this._id = id;
+    else
+      JS('void', '#.id = #', this._jsObject, convertArgument(id));
+  }
+
+  List get conditions {
+    if (!this._hasProxy())
+      return this._conditions;
+    return JS('List', '#.conditions', this._jsObject);
+  }
+
+  void set conditions(List conditions) {
+    if (!this._hasProxy())
+      this._conditions = conditions;
+    else
+      JS('void', '#.conditions = #', this._jsObject, convertArgument(conditions));

[blois, 2013/01/23 02:06:12]

line length

[sashab, 2013/01/23 04:45:34]

Done, except for the comments on Events

+  }
+
+  List get actions {
+    if (!this._hasProxy())
+      return this._actions;
+    return JS('List', '#.actions', this._jsObject);
+  }
+
+  void set actions(List actions) {
+    if (!this._hasProxy())
+      this._actions = actions;
+    else
+      JS('void', '#.actions = #', this._jsObject, convertArgument(actions));
+  }
+
+  int get priority {
+    if (!this._hasProxy())
+      return this._priority;
+    return JS('int', '#.priority', this._jsObject);
+  }
+
+  void set priority(int priority) {
+    if (!this._hasProxy())
+      this._priority = priority;
+    else
+      JS('void', '#.priority = #', this._jsObject, convertArgument(priority));
+  }
+
+}
+
+/**
+ * The Event class.
+ *
+ * Chrome Event classes extend this interface.
+ *
+ * e.g.
+ *
+ *  // chrome.app.runtime.onLaunched
+ *  class $Event_ChromeAppRuntimeOnLaunched extends $Event {

[blois, 2013/01/23 02:06:12]

For DOM events, we're moving them over to streams. Not sure how well they'd work
with this API, but would be good to investigate in the future.

[sashab, 2013/01/23 04:45:34]

We could change these to be streams later? Are these events even comparable to
DOM events in their implementation (ie would we ever want them to be
interchangeable/subclasses of the same parent type)?

+ *    // constructor, passing the arity of the callback
+ *    $Event_ChromeAppRuntimeOnLaunched(jsObject) :
+ *     super._(jsObject, 1);
+ *
+ *    // methods, strengthening the Function parameter specificity
+ *    void addListener(void callback(LaunchData launchData))
+ *        => super.addListener(callback);
+ *    void removeListener(void callback(LaunchData launchData))
+ *        => super.removeListener(callback);
+ *    bool hasListener(void callback(LaunchData launchData))
+ *        => super.hasListener(callback);
+ *  }
+ *
+ */
+class $Event {

[blois, 2013/01/23 02:06:12]

Why the leading $?

[sashab, 2013/01/23 04:45:34]

To distinguish it from html:Event. Should I just call it Event?

[Emily Fortuna, 2013/01/23 19:28:04]

I made a comment on this in another version of this file. Yeah, $Event is
unusual for Dart. If someone wants to distinguish between the two, they can
import one library with a prefix: 
"#import foo.dart as foo;"

[sashab, 2013/01/23 22:24:53]

I guess I'm just worried because I'm importing dart:html in this library. Will
Event be overwritten correctly for all files? I don't want to use "import
dart:html as html", as JS() doesn't seem to resolve namespaces correctly (ie it
gets confused when I enter "html.Window" as the type)

+  // JS var
+  Object _jsObject;
+
+  // number of arguments the callback takes
+  int _callbackArity;
+
+  // constructor
+  $Event._(this._jsObject, this._callbackArity);
+
+  // methods
+
+  /**
+   * Registers an event listener <em>callback</em> to an event.
+   */
+  void addListener(Function callback) =>
+      JS('void',
+         '#.addListener(#)',
+         this._jsObject,
+         convertDartClosureToJS(callback, this._callbackArity)
+      );
+
+  /**
+   * Deregisters an event listener <em>callback</em> from an event.
+   */
+  void removeListener(Function callback) =>
+      JS('void',
+          '#.removeListener(#)',
+          this._jsObject,
+          convertDartClosureToJS(callback, this._callbackArity)
+      );
+
+  /**
+   * Returns True if <em>callback</em> is registered to the event.
+   */
+  bool hasListener(Function callback) =>
+      JS('bool',
+          '#.hasListener(#)',
+          this._jsObject,
+          convertDartClosureToJS(callback, this._callbackArity)
+      );
+
+  /**
+   * Returns true if any event listeners are registered to the event.
+   */
+  bool hasListeners() =>
+      JS('bool',
+          '#.hasListeners()',
+          this._jsObject
+      );
+
+  /**
+   * Registers rules to handle events.
+   *
+   * @param eventName Name of the event this function affects.

[blois, 2013/01/23 02:06:12]

Dart doesn't use JS-style param comments.

[sashab, 2013/01/23 04:45:34]

These were taken from events.idl. Should I just rewrite them? This part of the
file will not be automatically generated.

+   * @param rules Rules to be registered. These do not replace previously registered rules.
+   * @param callback Called with registered rules.
+   */
+  void addRules(String eventName, List<Rule> rules, [ void callback(List<Rule> rules) ]) {

[blois, 2013/01/23 02:06:12]

Usually no space between [ and arg-

rules, [void callback...)]) {

[blois, 2013/01/23 02:06:12]

80 char line length (and more below)

[sashab, 2013/01/23 04:45:34]

Done.

[sashab, 2013/01/23 04:45:34]

Done (except for Event comments).

+    // proxy the callback
+    void __proxied_callback(List rules) {};
+
+    if (callback != null)
+      void __proxied_callback(List rules) {
+        List<Rule> __proxy_rules = new List<Rule>();
+
+        for (Object o in rules)
+          __proxy_rules.add(new Rule._proxy(o));
+
+        callback(__proxy_rules);
+      }
+
+    JS('void',
+        '#.addRules(#, #, #)',
+        this._jsObject,
+        convertArgument(eventName),
+        convertArgument(rules),
+        convertDartClosureToJS(callback, 1)
+    );
+  }
+
+  /**
+   * Returns currently registered rules.
+   *
+   * @param eventName Name of the event this function affects.
+   * @param ruleIdentifiers If an array is passed, only rules with identifiers contained in this array are returned.
+   * @param callback Called with registered rules.
+   */
+  void getRules(String eventName, [ List<String> ruleIdentifiers, void callback(List<Rule> rules) ]) {
+    // proxy the callback
+    void __proxied_callback(List rules) {};
+
+    if (callback != null)
+      void __proxied_callback(List rules) {
+        List<Rule> __proxy_rules = new List<Rule>();
+
+        for (Object o in rules)
+          __proxy_rules.add(new Rule._proxy(o));
+
+        callback(__proxy_rules);
+      }
+
+    JS('void',
+        '#.getRules(#, #, #)',
+        this._jsObject,
+        convertArgument(eventName),
+        convertArgument(ruleIdentifiers),
+        convertDartClosureToJS(callback, 1)
+    );
+  }
+
+  /**
+   * Unregisters currently registered rules.
+   *
+   * @param eventName Name of the event this function affects.
+   * @param ruleIdentifiers If an array is passed, only rules with identifiers contained in this array are unregistered.
+   * @param callback Called when rules were unregistered.
+   */
+  void removeRules(String eventName, [ List<String> ruleIdentifiers, void callback() ]) =>
+      JS('void',
+          '#.removeRules(#, #, #)',
+          this._jsObject,
+          convertArgument(eventName),
+          convertArgument(ruleIdentifiers),
+          convertDartClosureToJS(callback, 0)
+      );
+}
+
+
+
+
+
+
+
+
+
+
+
+