Standard Hooks

Hooks are the observation points the framework runs at defined moments. All four are abnormal hooks: the value is a list of functions, and a buffer-local value, when set, replaces the global list for that buffer. Each row links to the entry that documents the arguments, timing and recovery.

Hook	Runs when	Called with	Errors
ebox-unmount-functions	A mount is being released by ebox-unmount-buffer, before the mount is detached and before the display settings are restored, so the buffer still answers ebox-buffer-mount.	the buffer	An error signals out of ebox-unmount-buffer, aborts the rest of the release and leaves the mount live.
ebox-focus-change-functions	ebox-focus moved the mount's focus; it does not run when the focused node is unchanged, and it runs inside the focus operation, so the mount already reports the new focus.	the previously focused node, or nil, and the newly focused node, or nil	An error propagates from the focus operation that ran the hook.
ebox-after-flush-functions	A flush actually published, after the observer and the background sync; the buffer shows the new output and geometry is settled.	the buffer	An error in one function does not prevent the others from running.
ebox-viewport-change-functions	The viewport size changed, whether by a window resize or ebox-mount-set-viewport, once the relayout for the new size has settled.	the buffer	An error in one function does not stop the others.

Notes

• ebox-unmount-functions is the explicit-release hook. Killing a buffer releases its mount through the buffer's kill hook and does not run it.
• The hooks run in the mount's buffer. Register a function that belongs to one application buffer with a buffer-local entry, (add-hook 'HOOK FUNCTION nil t), and one that belongs to the process with the global list.
• :on-focus-enter is built on ebox-focus-change-functions: ETAF computes the Hosts between the previous and the new node and dispatches the callback on each, nearest first.