Re: [fpc-pascal] How to get a data module to notify of events?
On Thursday 15 September 2011 17:43:22 Frank Church wrote: > > Where is the tmethodlist itself defined? Oh, sorry. http://svn.berlios.de/viewvc/mseide-msegui/trunk/lib/common/kernel/mselist.pas?view=markup Martin ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to get a data module to notify of events?
On 15 September 2011 16:26, Martin Schreiber wrote: > On Thursday 15 September 2011 16:53:35 Frank Church wrote: > > Are there some examples of that somewhere? > > or > > http://svn.berlios.de/viewvc/mseide-msegui/trunk/lib/common/kernel/msegui.pas?view=markup > tmethodlist. > Warning, tmethodlist.remove() must be called before destroying the > registered objects. There is no automatic unliking as in tobjectlinker. > ___ > fpc-pascal maillist - fpc-pascal@lists.freepascal.org > http://lists.freepascal.org/mailman/listinfo/fpc-pascal > Where is the tmethodlist itself defined? -- Frank Church === http://devblog.brahmancreations.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to get a data module to notify of events?
On Thursday 15 September 2011 16:53:35 Frank Church wrote: > Are there some examples of that somewhere? or http://svn.berlios.de/viewvc/mseide-msegui/trunk/lib/common/kernel/msegui.pas?view=markup tmethodlist. Warning, tmethodlist.remove() must be called before destroying the registered objects. There is no automatic unliking as in tobjectlinker. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to get a data module to notify of events?
On Thursday 15 September 2011 16:53:35 Frank Church wrote: > Are there some examples of that somewhere? > http://svn.berlios.de/viewvc/mseide-msegui/trunk/lib/common/kernel/mseclasses.pas?view=markup ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to get a data module to notify of events?
On 15 September 2011 15:48, Martin Schreiber wrote: > On Thursday 15 September 2011 16:28:29 Frank Church wrote: > > I have a form with some threaded objects that notify another form of > events > > by calling one of that forms events. > > > > I want to convert to a data module and any interested object to register > > for those notifications. > > > > My idea is for each thread to have some kind of list of procedure types > and > > each interested object registers its routine eg. > > > > This is the data module. It is a rough sketch and may have some syntax > > errors > > > > Type TOneArg = Procedure (Var X : integer); > > > > > type > > > > > > TMonitorObject = class(TThread) > > > private > > > > > > InterestedObjects: TList > > > procedure DispatchOutput; > > > procedure DisplayRawOutput; > > > > > > protected > > > > > > procedure Execute; override; > > > > > > public > > > > > > constructor Create(CreateSuspended: Boolean); > > > RegisterInterest(interestedProc:TOneArg); > > > > > > end; > > > > > > TMonitorObject.RegisterInterest(TOneArg); > > > begin > > > > > >InterestedObjects.Add(interestedProc); > > > > > > end; > > > > > > procedure TMonitorObject.DispatchOutput; > > > begin > > > > > >foreach InterestedObject do > > > > > > InterestedObject.Procedure.Execute; > > > > > > end; > > > > > > constructor TMonitorObject.Create(CreateSuspended: Boolean); > > > begin > > > > > > inherited Create(CreateSuspended); > > > InterestedObjects := TList.Create > > > FCycleComplete := True; > > > > > > end; > > > > Do the procedures for the objects which require notification need to be > > constructed in some way? > > > MSEgui has such a notification mechanism with automatic unlinking by > destroying the objects, see tobjectlinker in > lib/common/kernel/mseclasses.pas. > Another possibility is to use a tobjectevent descendant and > application.postevent. > > > Am I on the right track here? I am particularly interested in what > happens > > when the objects passing the routines are destroyed without the data > module > > knowing about it. > > The program most likely will crash. :-) > > I want to know if my approach is a workable one and what the right syntax should be, handling the destroyed objects I believe I can deal with by checking for the existence of the object before notifying it. Are there some examples of that somewhere? > Martin > ___ > fpc-pascal maillist - fpc-pascal@lists.freepascal.org > http://lists.freepascal.org/mailman/listinfo/fpc-pascal > -- Frank Church === http://devblog.brahmancreations.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] How to get a data module to notify of events?
On Thursday 15 September 2011 16:28:29 Frank Church wrote: > I have a form with some threaded objects that notify another form of events > by calling one of that forms events. > > I want to convert to a data module and any interested object to register > for those notifications. > > My idea is for each thread to have some kind of list of procedure types and > each interested object registers its routine eg. > > This is the data module. It is a rough sketch and may have some syntax > errors > > Type TOneArg = Procedure (Var X : integer); > > > type > > > > TMonitorObject = class(TThread) > > private > > > > InterestedObjects: TList > > procedure DispatchOutput; > > procedure DisplayRawOutput; > > > > protected > > > > procedure Execute; override; > > > > public > > > > constructor Create(CreateSuspended: Boolean); > > RegisterInterest(interestedProc:TOneArg); > > > > end; > > > > TMonitorObject.RegisterInterest(TOneArg); > > begin > > > >InterestedObjects.Add(interestedProc); > > > > end; > > > > procedure TMonitorObject.DispatchOutput; > > begin > > > >foreach InterestedObject do > > > > InterestedObject.Procedure.Execute; > > > > end; > > > > constructor TMonitorObject.Create(CreateSuspended: Boolean); > > begin > > > > inherited Create(CreateSuspended); > > InterestedObjects := TList.Create > > FCycleComplete := True; > > > > end; > > Do the procedures for the objects which require notification need to be > constructed in some way? > MSEgui has such a notification mechanism with automatic unlinking by destroying the objects, see tobjectlinker in lib/common/kernel/mseclasses.pas. Another possibility is to use a tobjectevent descendant and application.postevent. > Am I on the right track here? I am particularly interested in what happens > when the objects passing the routines are destroyed without the data module > knowing about it. The program most likely will crash. :-) Martin ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
