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Groups > comp.lang.java.programmer > #32497
| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Newsgroups | comp.lang.c, comp.lang.java.programmer |
| Subject | Re: Self-updating relationship |
| Date | 2015-09-03 12:16 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <ms9rm4$ki2$1@dont-email.me> (permalink) |
| References | (5 earlier) <55E78636.5000908@verizon.net> <ms8g5j$o5k$1@dont-email.me> <ms9llv$pto$1@dont-email.me> <ms9mpb$srk$1@dont-email.me> <ms9p30$8vc$1@dont-email.me> |
Cross-posted to 2 groups.
On 09/03/2015 11:31 AM, Jeff Higgins wrote: > On 09/03/2015 10:53 AM, James Kuyper wrote: >> On 09/03/2015 10:32 AM, Jeff Higgins wrote: >>> On 09/02/2015 11:52 PM, Jeff Higgins wrote: >>>> On 09/02/2015 07:28 PM, James Kuyper wrote: >>> >>>>> Your earlier version had: >>>>>> final javafx.beans.binding.NumberBinding spaces = >>>>>> height.subtract( number ); >>>>> >>>>> which causes spaces.getValue() to behave like the equivalent of a C++ >>>>> member function whose return value is calculated using the specified >>>>> formula freshly each time "spaces" is referred to. Is this a >>>>> characteristic of binding.NumberBinding, or some more general Java >>>>> feature? >>>> >>>> It's a characteristic of the >>>> javafx.beans.binding.Binding<T> interface. >>>> <https://docs.oracle.com/javase/8/javafx/api/javafx/beans/binding/Binding.html> >>>> >>> >>> Sorry, this is incorrect. >>> It's a characteristic of the >>> javafx.beans.property.Property<T> interface. >>> <https://docs.oracle.com/javase/8/javafx/api/javafx/beans/property/Property.html> >> >> According to Stefan Ram, using the following code: >>> final javafx.beans.binding.NumberBinding spaces = >>> height.subtract( number ); >> >> would cause the subtraction to be re-evaluated with the current values >> of height and number, each time spaces.getValue() is called, while > > Correct. > >> >> >>> final javafx.beans.property.IntegerProperty spaces >>> = new javafx.beans.property.SimpleIntegerProperty >>> ( height.getValue() - number.getValue() ); >> >> would cause the subtraction to be performed only once, when spaces is >> created. Are you saying he got those reversed? > > No. OK - I thought I was beginning to understand what was going on, but now I'm thoroughly confused. You're saying that this behavior (Specifically, the behavior of re-calculating the subtraction each time spaces.getValue() is used) is a property of the javafx.beans.property.Property<T> interface, rather than a property of the javafx.beans.binding.Binding<T> interface, despite the fact that it happens when he uses javafx.beans.binding.NumberBinding, and doesn't happen when he uses javafx.beans.property.SimpleIntegerProperty? How does that work? Does javafx.beans.binding.NumberBinding use javafx.beans.property.Property<T> while javafx.beans.property.SimpleIntegerProperty uses javafx.beans.binding.Binding<T>? That's not at all what I would have expected, based solely upon the names. -- James Kuyper
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Re: Self-updating relationship James Kuyper <jameskuyper@verizon.net> - 2015-09-02 17:14 -0400
Re: Self-updating relationship Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-09-02 17:46 -0400
Re: Self-updating relationship Arne Vajhøj <arne@vajhoej.dk> - 2015-09-03 21:06 -0400
Re: Self-updating relationship e.d.programmer@gmail.com - 2015-09-04 04:46 -0700
Re: Self-updating relationship Arne Vajhøj <arne@vajhoej.dk> - 2015-09-04 19:43 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-04 11:49 -0400
Re: Self-updating relationship Arne Vajhøj <arne@vajhoej.dk> - 2015-09-04 19:45 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-04 22:10 -0400
Re: Self-updating relationship Arne Vajhøj <arne@vajhoej.dk> - 2015-09-04 22:31 -0400
Re: Self-updating relationship Arne Vajhøj <arne@vajhoej.dk> - 2015-09-04 22:38 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-04 22:51 -0400
Re: Self-updating relationship James Kuyper <jameskuyper@verizon.net> - 2015-09-02 18:49 -0400
Re: Self-updating relationship James Kuyper <jameskuyper@verizon.net> - 2015-09-02 19:28 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-02 23:52 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 10:32 -0400
Re: Self-updating relationship James Kuyper <jameskuyper@verizon.net> - 2015-09-03 10:53 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 11:31 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 11:35 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 11:49 -0400
Re: Self-updating relationship James Kuyper <jameskuyper@verizon.net> - 2015-09-03 12:16 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 13:03 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 10:55 -0400
Re: Self-updating relationship James Kuyper <jameskuyper@verizon.net> - 2015-09-03 00:06 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-02 23:38 -0400
Re: Self-updating relationship Jeff Higgins <jeff@invalid.invalid> - 2015-09-03 01:22 -0400
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