[Lazarus] Inserting many components on form

[Michael Van Canneyt]

On Mon, 27 Jun 2011, fluisgirardi at gmail.com wrote:

> 
> 
> 2011/6/27 Mattias Gaertner <nc-gaertnma at netcologne.de>
>       On Mon, 27 Jun 2011 16:31:56 -0300
>       "fluisgirardi at gmail.com" <fluisgirardi at gmail.com> wrote:
> 
> > 2011/6/27 Mattias Gaertner <nc-gaertnma at netcologne.de>
> >
> > >
> > > TComponent uses linear searches/notifications for each operation. So
> > > 1000 components is a bad idea.
> > > LCL adds even more searches/notifications, so 300 components is a bad
> > > idea.
> > >
> > >
> > And to make 4000 or 10000 components a good idea, what's must be changed?
> 
> A lot.
> Are you sure you need that many components? For example some components
> uses TCollection and other classes to handle thousands of objects.
> Maybe if you explain what you want to achieve people can give an advice.
> 
> 
> Maybe I started my components with a wrong concept. Each component, represents a memory (or a set of memories) on a remote device (like a PLC) that can be
> read and/or written. These components can be linked with edits, labels, progress bars and others controls created to show/modifies/stores the value of these
> components.
> 
> For now, I did only small projects using these components (using ~150 tags or components). Today, I started my first big project. On the first time, using
> the component wizard, I inserted 255*5+1 components. This action takes some time. After this, I tried using my wizard again, to insert 4000 components, and
> after this the IDE freezes. 
> 
> I thought use the TCollection, but I don't know if I can represent the following configuration (it's a example, it can have how many PLCBlocks, BlockItems,
> TagBit, PLCNumbers or PLCStrings the owner of project wants):
> 
> Owner (TCollection)
>    |
>    |-> PLCBlock (now, each below is a component)
>    |       |
>    |       |-> BlockItem (0..n items)
>    |       |-> BlockItem
>    |       |       |  
>    |       |       |-> TagBit (0..n items)
>    |
>    |-> PLCBlock
>    |       |
>    |       |-> BlockItem (0..n items)  
>    |
>    |-> PLCNumber (0..n items)
>    |       |-> TagBit (0..n items)
>    |
>    |-> PLCString (0..n items)
> 
> Some idea?

In a collection that is written to stream, all items must be of the same type, 
because when reconstructing the collection, 'Add' is called.

There are 2 ways out of this:
- Merge PLCBlock, PLCNumber, PLCString to a single type
- Create different collections, each with a unique type.

If you absolutely need different types, you'll need different collections.

Then, there is nothing to stop you from nesting collections. i.e. PLCBlock can have a collection 
BLockItems which contains items of class BlockItem. They will be streamed correctly.

But the fastest (in terms of streaming and code speed) may be to have something like a 
TTreeNode object, and use DefineProperties to stream it. That's of course more coding for you.

Michael.