The combobox measures every row in order to figure out how wide it should be. The datagrid trusts the width information in the columns.
-Alex --- In [email protected], "Matt Chotin" <[EMAIL PROTECTED]> wrote: > Yep, the DG will probably call getItemAt for every visible row > regardless of how many items are actually in the dataProvider. Multiple > calls to length() are simply done as the measurement, layout, and > drawing mechanisms are doing their thing. Same would apply to ComboBox > but obviously there's less to compute and draw there. > > > > Matt > > > > ________________________________ > > From: [email protected] [mailto:[EMAIL PROTECTED] On > Behalf Of rbelknap > Sent: Sunday, June 05, 2005 11:13 AM > To: [email protected] > Subject: [flexcoders] Re: Contract between DataProvider and ComboBox or > DataGrid > > > > I hooked up the dataProvider to a ComboBox and the result was more > what I expected. The ComboBox seems to make 0 to length-1 calls to > getItemAt and then stops. The DataGrid seems to make a fixed number > of calls - perhaps a default grid size? > > > [Debug] cbTest initialized > [Debug] TestDP(undefined) > [Debug] getItemAt(undefined) > [Debug] get length():5 > [Debug] get length():5 > [Debug] get length():5 > [Debug] get length():5 > [Debug] get length():5 > [Debug] get length():5 > [Debug] get length():5 > [Debug] get length():5 > [Debug] getItemAt(0) > [Debug] getItemAt(1) > [Debug] getItemAt(2) > [Debug] getItemAt(3) > [Debug] getItemAt(4) > [Debug] get length():5 > [Debug] get length():5 > [Debug] getItemAt(undefined) > > > --- In [email protected], "Matt Chotin" <[EMAIL PROTECTED]> wrote: > > I'd imagine that if you're seeing numerous calls to length > interspersed > > with getItemAt that we simply didn't do an optimal loop. > > > > > > > > for (var idx = 0; idx < dataProvider.length; ++idx) > > > > { > > > > var item = getItemAt(idx); > > > > } > > > > > > > > get length() is going to be called on every iteration of the loop. > It'd > > obviously be more efficient to store length in a local variable and > just > > use that, but maybe we didn't somewhere. > > > > > > > > Matt > > > > ________________________________ > > > > From: [email protected] > [mailto:[EMAIL PROTECTED] On > > Behalf Of rbelknap > > Sent: Friday, June 03, 2005 3:24 PM > > To: [email protected] > > Subject: [flexcoders] Contract between DataProvider and ComboBox or > > DataGrid > > > > > > > > Hi, > > > > I'm struggling to figure out the implied contract between > > DataProviders and their users like ComboBox or DataGrid. When > either > > a ComboBox or DataGrid first uses a DataProvider they seem to make > > numerous calls to: > > > > public function get length():Number > > > > and > > > > function getItemAt(index : Number) > > > > but it isn't obvious what the logic is behind these calls. > > > > I was expecting to see a call to get the length followed by a > series > > of calls to getItemAt starting at index 0 and running to index > length- > > 1, but that's not what I see. > > > > Has anyone run across any good discussions of DataProviders and > their > > users? > > > > Thanks, > > > > Randy > > > > > > > > > > > > > > ________________________________ > > > > Yahoo! Groups Links > > > > * To visit your group on the web, go to: > > http://groups.yahoo.com/group/flexcoders/ > > > > * To unsubscribe from this group, send an email to: > > [EMAIL PROTECTED] > > <mailto:[EMAIL PROTECTED] subject=Unsubscribe> > > > > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of > > Service <http://docs.yahoo.com/info/terms/> . > > > > > > > ________________________________ > > Yahoo! Groups Links > > * To visit your group on the web, go to: > http://groups.yahoo.com/group/flexcoders/ > > * To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]> > > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of > Service <http://docs.yahoo.com/info/terms/> . Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/flexcoders/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
