The proposal in this Git repo explores ideas for a new system keyboard lock API that enables websites to capture and use all available keys and keyboard combinations allowed by the OS, including Escape, Alt+Tab, Cmd/Ctrl+`, Cmd/Ctrl+N.
Here is the problem statement from our explainer document:
Richly interactive web sites, games and remote desktop/application streaming experiences want to provide an immersive, full screen experience. Sites need access to special keys and keyboard shortcuts in full screen, such as Escape, Alt+Tab, Cmd+`, Ctrl+N, for easily or efficiently navigating through windows, tabs, applications, menus and gaming functionality. Today this isn’t possible, as these keys are typically captured by the browser or underlying operating system, making it challenging for developers to embrace the web for these types of applications.
The explainer document contains additional requirements, sample code and an example UX. We hope to further evolve/incubate this API in the WICG.