<itemvalue="Cancels this subscription. After this call, the subscription no longer receives events. The stream may need to shut down the source of events and clean up after the subscription is canceled. Returns a future that is completed once the stream has finished its cleanup. Typically, cleanup happens when the stream needs to release resources. For example, a stream might need to close an open file (as an asynchronous operation). If the listener wants to delete the file after having canceled the subscription, it must wait for the cleanup future to complete. If the cleanup throws, which it really shouldn't, the returned future completes with that error."/>
<itemvalue="It takes a `data` object, and if it's a `Map`, it calls `getDocumentWithRef` on it, if it's a `List`, it calls `getDocumentValue` on each element of the list, if it's a `DocumentSnapshot`, it calls `getDocumentValue` on the `data` field of the `DocumentSnapshot`, if it's a `QueryDocumentSnapshot`, it calls `getDocumentValue` on the `data` field of the `QueryDocumentSnapshot`, if it's a `DocumentReference`, it calls `getDocumentValue` on the `data` field of the `DocumentReference`, and if it's anything else, it returns the `data` object Args: data (Object): The data to be converted. depth (int): The depth of the document to retrieve. Defaults to 1 Returns: A Future<Object?>"/>
<itemvalue="It calls the native method `callMessage` and passes the parameters to the native method. Args: msgId (String): Message ID chatId (String): chat room id text (String): The content of the message, which is required. richtext (String): The content of the rich text message, which is the same as the text content of the text message. topicId (String): The topicId is the id of the topic, which is the id of the chat room. type (MessageType): MessageType.Text,. Defaults to MessageType image (String): The image path of the image message. selfUserId (String): The user ID of the current user friendUserId (String): The user ID of the other party Returns: A boolean value."/>
<itemvalue="Deletes and signs out the user. Important: this is a security-sensitive operation that requires the user to have recently signed in. If this requirement isn't met, ask the user to authenticate again and then call [User.reauthenticateWithCredential]. A [FirebaseAuthException] maybe thrown with the following error code: - requires-recent-login: - Thrown if the user's last sign-in time does not meet the security threshold. Use [User.reauthenticateWithCredential] to resolve. This does not apply if the user is anonymous."/>
<itemvalue="Waits for multiple futures to complete and collects their results. Returns a future which will complete once all the provided futures have completed, either with their results, or with an error if any of the provided futures fail. The value of the returned future will be a list of all the values that were produced in the order that the futures are provided by iterating [futures]. If any future completes with an error, then the returned future completes with that error. If further futures also complete with errors, those errors are discarded. If `eagerError` is true, the returned future completes with an error immediately on the first error from one of the futures. Otherwise all futures must complete before the returned future is completed (still with the first error; the remaining errors are silently dropped). In the case of an error, [cleanUp] (if provided), is invoked on any non-null result of successful futures. This makes it possible to `cleanUp` resources that would otherwise be lost (since the returned future does not provide access to these values). The [cleanUp] function is unused if there is no error. The call to [cleanUp] should not throw. If it does, the error will be an uncaught asynchronous error. @pragma("vm:recognized", "other")"/>
<itemvalue="Creates an animation controller with no upper or lower bound for its value. [value] is the initial value of the animation. [duration] is the length of time this animation should last. [debugLabel] is a string to help identify this animation during debugging (used by [toString]). `vsync` is the [TickerProvider] for the current context. It can be changed by calling [resync]. It is required and must not be null. See [TickerProvider] for advice on obtaining a ticker provider. This constructor is most useful for animations that will be driven using a physics simulation, especially when the physics simulation has no pre-determined bounds."/>
<itemvalue="Whether the platform is requesting that text be drawn with a bold font weight. See also: [dart:ui.PlatformDispatcher.accessibilityFeatures], where the setting originates."/>
<itemvalue="A constant that is true if the application was compiled to run on the web. This implementation takes advantage of the fact that JavaScript does not support integers. In this environment, Dart's doubles and ints are backed by the same kind of object. Thus a double `0.0` is identical to an integer `0`. This is not true for Dart code running in AOT or on the VM."/>
<itemvalue="The uniform height of all children. All children will be given the BoxConstraints to match this exact height. Must not be null and must be positive."/>
<itemvalue="Convert the given point from the local coordinate system for this box to the global coordinate system in logical pixels. If `ancestor` is non-null, this function converts the given point to the coordinate system of `ancestor` (which must be an ancestor of this render object) instead of to the global coordinate system. This method is implemented in terms of [getTransformTo]. If the transform matrix puts the given `point` on the line at infinity (for instance, when the transform matrix is the zero matrix), this method returns (NaN, NaN)."/>
<itemvalue="Vertical viewport was given unbounded height. Viewports expand in the scrolling direction to fill their container. In this case, a vertical viewport was given an unlimited amount of vertical space in which to expand. This situation typically happens when a scrollable widget is nested inside another scrollable widget. If this widget is always nested in a scrollable widget there is no need to use a viewport because there will always be enough vertical space for the children. In this case, consider using a Column instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size the height of the viewport to the sum of the heights of its children."/>
<itemvalue="The following assertion was thrown during performResize(): Vertical viewport was given unbounded height. Viewports expand in the scrolling direction to fill their container. In this case, a vertical viewport was given an unlimited amount of vertical space in which to expand. This situation typically happens when a scrollable widget is nested inside another scrollable widget."/>
<itemvalue="Convenience method for the value for a single valued header. The value must not have more than one value. Returns null if there is no header with the provided name."/>
