The OffscreenCanvas interface provides a canvas that can be rendered off screen. It is available in both the window and worker contexts.
Page transition events fire when a webpage is being loaded or unloaded.
The PerformanceEntry object encapsulates a single performance metric that is part of the performance timeline. A performance entry can be directly created by making a performance mark or measure (for example by calling the mark() method) at an explicit point in an application. Performance entries are also created in indirect ways such as loading a resource (such as an image).
The PerformanceFrameTiming interface provides frame timing data about the browser's event loop. A frame represents the amount of work a browser does in one event loop such as processing DOM events, resizing, scrolling, rendering, CSS animations, etc. A frame rate of 60fps (frames per second) for a 60Hz refresh rate is the target for a good responsive user experience. This means the browser should process a frame in about 16.7ms.
PerformanceMark is an abstract interface for performance entries with an entry type of "mark". Entries of this type are created by calling performance.mark() to add a named DOMHighResTimeStamp (the mark) to the browser's performance timeline.
PerformanceMeasure is an abstract interface for performance entries with an entry type of "measure". Entries of this type are created by calling performance.measure() to add a named DOMHighResTimeStamp (the measure) between two marks to the browser's performance timeline.
The PerformanceNavigationTiming interface provides methods and properties to store and retrieve high resolution timestamps or metrics regarding the browser's document navigation events. For example, this interface can be used to determine how much time it takes to load or unload a document.
The PerformanceObserver interface is used to observe performance measurement events and be notified of new performance entries as they are recorded in the browser's performance timeline.
The PerformanceObserverEntryList interface is a list of peformance events that were explicitly observed via the observe() method.
The PerformanceResourceTiming interface enables retrieving and analyzing detailed network timing data regarding the loading of an application's resources. An application can use the timing metrics to determine, for example, the length of time it takes to fetch a specific resource, such as an XMLHttpRequest, <SVG>, image, or script.
The PositionOptions interface describes an object containing option properties to pass as a parameter of Geolocation.getCurrentPosition() and Geolocation.watchPosition().
The RadioNodeList interface represents a collection of elements in a <form> or a <fieldset> element.
Calling the Selection.toString() method returns the text contained in the selection, e.g.:
The UIEvent interface represents simple user interface events.
The WebContextEvent interface is part of the WebGL API and is an interface for an event that is generated in response to a status change to the WebGL rendering context.
The WebGLTransformFeedback interface is part of the WebGL 2 API and enables transform feedback, which is the process of capturing primitives generated by vertex processing. It allows to preserve the post-transform rendering state of an object and resubmit this data multiple times.
CSS User Interface is a CSS module that allows to define the rendering and functionality of user interface related features.