On Wed, 04 Oct 2006 12:46:27 +0200
Marc Weustink <[EMAIL PROTECTED]> wrote:
> Mattias Gaertner wrote:
> > On Wed, 04 Oct 2006 11:29:51 +0200
> > Marc Weustink <[EMAIL PROTECTED]> wrote:
> >
> >> Mattias Gaertner wrote:
> >>> On Wed, 4 Oct 2006 09:27:03 +0200
> >>> "Graeme Geldenhuys" <[EMAIL PROTECTED]> wrote:
> >>>
> >>>>>> Changing a property can change various others as well. For
> >>>>>> example changing the Width can change child controls, siblings
> >>>>>> and parent.
> >>>>> Yes, but applying this change to the child form should result in
> >>>>> exactly the same consequences, unless the affected components
> >>>>> were changed already... ?
> >>>>>
> >>>>> Michael.
> >>>> Mattias,
> >>>>
> >>>> This is where my implementation of the Observer using BeginUpdate
> >>>> and EndUpdate plays a roll. See the tiOPF code I sent you.
> >>>> Normally the Subject (FormA) would fire off the Notify method for
> >>>> every small change which could cause lots of screen redraws.
> >>>> BeginUpdate and EndUpdate allows you to make all those small
> >>>> changes and then fire off a single Notify call.
> >>> BeginUpdate can only be called for the IDE tools (OI, AE, ...).
> >>> The component editors will only call the Modified event.
> >>> But there is a solution:
> >>> We could call the update on Idle.
> >> Not really a nice option and hard to work with if some who knows
> >> future designer plugin needs the result of a modification (I'm just
> >> making things up here).
> >
> > Then the plugin can force an update.
> >
> >
> >> But...
> >> component editors call Modified. This Modified method can use
> >> Begin/EndModification. If this is passed to the
> >> "derived form" observer, it knows whan all modifications are done
> >> (and can update itself)
> >
> > Do you mean, all methods, that now call the Modified method should
> > be changed to call Begin/EndModification?
>
> No,
> Modified needs to be modified :)
>
> procedure Modified;
> begin
> SendBeginModificationToAllBeginEndObeservers;
> SendModifiedNotificationToAllModifiedObeservers;
> SendEndModificationToAllBeginEndObeservers;
> end;
But then Begin/End is useless, isn't it? The modification took place
before 'Begin'. For example:
NewToolButton.Parent:=CurToolBar;
Modified;
Mattias
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