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Re: Widget events - any other than WhenAction ? [message #52739 is a reply to message #52738]

Sat, 16 November 2019 08:27

xrysf03
Messages: 43
Registered: November 2018
Location: CZ

Member

@Oblivion okay, thanks for your patient explanation. I've learned a new trick Smile

At face value, I can see that there are no ready "When callbacks" for a widget getting or losing focus.

Taking one step back, and using the excellent "API search" function, I have noticed the following methods, defined in Ctrl.cpp:

void Ctrl::GotFocus()                               {}
void Ctrl::LostFocus()                              {}

They're actually documented here. Means to me that this is not... say... a Win32-specific feature, or a Borland VCL feature, but actually there is rudimentary systemic support for this in the U++ GUI layer.

And obviously I'm wondering... to get the desired "callback on an Edit losing focus", I'd need to inherit from say EditDouble and overload its LostFocus() - but next, I'd have to embed that in a layout, so first I'd need to create a visual component, along the lines of MyEditDouble.

I haven't advanced that far yet, maybe I should, but at the same time I'm wondering... how much trouble would it be, instead, to create systemwide WhenGotFocus/WhenLostFocus actions by adding some stuff to Ctrl::GotFocus()/LostFocus() Smile

This is not necessarily a feature request, let me say that I'm just wondering aloud at this stage... Or, would it be against some "design virtues" of U++ to add those? Would it break existing code? Make existing code run slower?

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