user-close

Arguments: stream

This function is called when a user of a program makes a closing gesture. Returns true if closing was successful, nil if not (for example if the user canceled the action). stream should be a cg-stream.

An application can add user-close methods that consider whether to grant the user's request to close the window, perhaps by popping up a confirmation dialog. If it is decided that the window should in fact be closed, then the user-close method should call the function close to actually close it.

See also device-close, which is also called when a window is closed, even programmatically.

The default user-close method on basic-pane simply calls close and returns t, unless the close-button property of the window is nil (meaning that there is no "X" close button in the window's title-bar if it has a title-bar), in which case it does nothing and returns nil.

There is also a built-in :around method on basic-pane that checks to see if the window is currently being invoked modally by a call to pop-up-modal-dialog. If so, then this method calls the cancel-button's on-change function if there is a cancel-button on the window, and otherwise calls flag-modal-completion. If the window is not currently being invoked modally, then this method simply calls the next method. This :around method generally should not be overridden.

See also os-exit-request, which can be used to cancel an attempted shutdown of the entire operating system.

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This page was not revised from the 9.0 page.
Created 2015.5.21.