[REBOL] Re: [View] dirty?
From: SunandaDH:aol at: 10-Oct-2003 11:56
Ingo:
> what's the easiest way to find out, if a layout contains any dirty fields?
> (That is, fields that have been edited).
I don't know the *easiest* but what I do is set a global variable in each
field I'm interested in. Something like:
; function to set global flag if field has changed
global-dirty?: false
set-dirty?: func [face [object!]]
[
if strict-not-equal? face/data face/user-data
[print "face value changed"
face/user-data: copy face/data
global-dirty?: true
]
]
;; sample layout using above function
unview/all
view layout [field [set-dirty? face]
field [set-dirty? face]
button "Exit" [If global-dirty?
[print "need to save here"
global-dirty?: false
]
]
]
This method is precise it that you set global-dirty? only for the fields you
care about. But it's annoying in that you need to add a [set-dirty? face] to
all those fields.
It works for me in the application I use it in because the layout is built
from a template, so I don't have to insert the [set-dirty? face] by hand
everywhere.
You could play with making it more flexible by exploring using styles. This
next example does that. It also defines its own 'last-user-value variable
rather than using 'user-data. And it fixes the "false positive" when you tab out of
a field for the first time:
global-dirty?: false
set-dirty?: func [face [object!]]
[
if strict-not-equal? face/data face/last-user-value
[print "face value changed"
face/last-user-value: copy face/data
global-dirty?: true
]
]
unview/all
view layout [style monitored-field field
with [last-user-value: copy ""]
[set-dirty? face]
monitored-field [set-dirty? face]
monitored-field [set-dirty? face]
button "Exit" [If global-dirty?
[print "need to save here"
global-dirty?: false
]
]
]
Sunanda.
