interwindow

Interwindow is a term used in graphical user interfaces to describe the mechanisms by which two or more windows can exchange information or coordinate actions. It applies to both windows within the same application and windows across different applications, enabling data transfer, state synchronization, or coordinated control without requiring users to perform manual steps.

Common methods include native window messaging and events, the clipboard, drag-and-drop, and shared data stores. Platform-specific APIs provide richer capabilities: window messages and events in one ecosystem, notifications or distributed objects in another, and various interprocess communication (IPC) primitives in modern desktop environments. In practice, developers may implement interwindow communication through serialized data passed via messages, shared memory, local sockets, or higher-level IPC frameworks such as D-Bus on Linux or platform equivalents on other systems.

Design considerations for interwindow communication include asynchronicity, data serialization format, error handling, and security. Because data may cross process boundaries, there are risks related to data integrity, permissions, and leakage of sensitive information. Performance is another concern, as excessive messaging or large data transfers can degrade responsiveness.

Applications of interwindow communication range from multi-window editors and integrated development environments to web browsers with separate windows or tabs acting as coordinated views. It also enables lightweight inter-application workflows, such as a design tool and a preview pane sharing live data.

See also: Interprocess communication, inter-application communication, clipboard, drag-and-drop.