wxBookCtrlEvent(3)

💖 wxBookCtrlEvent 💖

okay bestie, this is an Erlang module definition page for wxBookCtrlEvent — the class that represents all the events your book controls throw at you. think wxNotebook, wxListbook, wxChoicebook, wxTreebook, wxAuiNotebook. yeah. all of them. it's giving group chat with five admins 💅

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✨ DESCRIPTION ✨

PAGE_CHANGING events? they get sent BEFORE the current page actually changes. so the program gets to peek at the current page before anything moves — grab it with getOldSelection/1 — and honestly it can straight up veto the whole page change by calling wxNotifyEvent:veto/1. like, if the values in the controls of the old page are invalid? bye, no page change for you. 🙈

PAGE_CHANGED events are the after-party. they're sent AFTER the page has already changed, and the program cannot veto it any more — it's purely a heads-up that the page changed. no take-backsies, periodt. 💀

so to summarize, fr fr: if the program cares about validating page values before letting the user switch pages, it should process the PAGE_CHANGING event. otherwise PAGE_CHANGED is probably enough. and in any case? it's probably unnecessary to process both events at once. pick a lane bestie 🎀

See:

• wxNotebook
• wxListbook
• wxChoicebook
• wxTreebook
• wxToolbook
• wxAuiNotebook

This class is derived, and can use functions, from:

• wxNotifyEvent
• wxCommandEvent
• wxEvent

wxWidgets docs: wxBookCtrlEvent

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🌸 DATA TYPES 🌸

• wxBookCtrl() :: #wxBookCtrl{}.
• wxBookCtrlEvent() :: wx:wx_object().
• wxBookCtrlEventType() :: command_notebook_page_changed | command_notebook_page_changing | choicebook_page_changed | choicebook_page_changing | treebook_page_changed | treebook_page_changing | toolbook_page_changed | toolbook_page_changing | listbook_page_changed | listbook_page_changing.

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🦋 FUNCTIONS 🦋

getOldSelection(This) -> integer() when This :: wxBookCtrlEvent().

returns the page that was selected before the change. and if none was selected? you get wxNOT_FOUND. iconic behavior honestly 🫶

getSelection(This) -> integer() when This :: wxBookCtrlEvent().

returns the currently selected page, or wxNOT_FOUND if none was selected. same energy as above, just the now version.

Note: under Windows, getSelection/1 will return the same value as getOldSelection/1 when called from the EVT_BOOKCTRL_PAGE_CHANGING handler — and not the page which is going to be selected. so if you're on Windows and you're squinting at this like "why are these the same number", that's why bestie 😭 not a bug, just Windows being Windows 💀

setOldSelection(This, Page) -> ok when This :: wxBookCtrlEvent(), Page :: integer().

sets the id of the page selected before the change. setting that history, lowkey 🎀

setSelection(This, Page) -> ok when This :: wxBookCtrlEvent(), Page :: integer().

sets the selection member variable. that's it, that's the whole vibe ✨

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okay so that's the whole page — every flag, every type, every note, nothing skipped, no cap 🧚 go forth and validate your pages before you let anybody switch tabs, and if you're on Windows, remember the little getSelection/1 gotcha, iykyk 💜

this whole thing came from Ericsson AB, version wx 2.6, and yeah, slay 🌈👑