on-edit-sequence

Called just before a top-level (i.e., unnested) edit sequence starts.

During an edit sequence, all callbacks methods are invoked normally, but it may be appropriate for these callbacks to delay computation during an edit sequence. The callbacks must manage this delay manually. Thus, when overriding other callback methods, such as on-insert in text%, on-insert in pasteboard%, after-insert in text%, or after-insert in pasteboard%, consider overriding on-edit-sequence and after-edit-sequence as well.

``Top-level edit sequence'' refers to an outermost pair of begin-edit-sequence and end-edit-sequence calls. The embeddeding of an editor within another editor does not affect the timing of calls to on-edit-sequence, even if the embedding editor is in an edit sequence.

• (send an-editor:basic-mixin on-edit-sequence) -> boolean

  Always returns #t. Updates a flag for local-edit-sequence?