Fired BEFORE the canvas menu opens. Mutate Items to replace the default set; Cancel = true suppresses the menu. A Before* handler must not be async — the emitter reads Cancel/Items when emit() returns.
Items
Cancel = true
Before*
Cancel
emit()
Readonly
Fired BEFORE the canvas menu opens. Mutate
Itemsto replace the default set;Cancel = truesuppresses the menu. ABefore*handler must not be async — the emitter readsCancel/Itemswhenemit()returns.