🚀 go-pugleaf

Hi JohnC 
 
 JohnC says:
> I have some fairly complicated arrangements of VCL controls on some forms 
> and I have been trying (unsuccessfully) to create an object which I can add 
> to a form to automatically add the items along with the code that I need for 
> their interaction to the form when the form is created.  I would like to 
> hide all the details of their operation and interaction since they would be 
> common for all uses.  I don't especially need to see the objects during 
> design time - I was planning on just putting a panel where the items would 
> go.
> 
> Is this possible?

If I understand You correctly, that shouldn't be a problem, but
please explain what kind of object, what kind of items.

You can create VCL components by using the keyword new, but
if You want them to be visible You have to provide a Parent.


void __fastcall TYourClass::ButtonClick(TObject *Sender)
{
}
//-----------------------------------------------------


TButton *Button = new TButton(NULL); //You must delete
or
TButton *Button = new TButton(Form1); // deleted automaticly
Button->SetBounds(10,10, 150, 23);
Button->Parent = Panel2;
Button->OnClick = ButtonClick;

If You provide the owner the component is deletet by the owner
but if You don't need it anymore You can still delete it You self
like You have to if You dont provide the owner.

P.s. questions like this are better asked in: 
borland.public.cppbuilder.vcl.components.using

Kind regards
Asger

Thanks Asger:
The one I am working on right now has a TStringGrid and several TShape which
I need to allocate into an array.
I thought I was giving them a Parent, but I'll fool around with that a
little more.  Since nothing was showing up, I thought that perhaps there was
something special about the controls that they just needed to be manually
placed on a form.
If you think I should move this over to the other group, just say so and I
will do so.  I don't normally access that group.
Thanks,
   John

----- Original Message ----- 
From: "Asger Joergensen" <junk@Asger-P.dk>
> If I understand You correctly, that shouldn't be a problem, but
> please explain what kind of object, what kind of items.
>
> You can create VCL components by using the keyword new, but
> if You want them to be visible You have to provide a Parent.

OK, Here are the details of what I'm doing:

class TJMCColorTable
{
public:
 TJMCColorTable(TWinControl *   InParent);
...
and more stuff.
//---------------------------------------------------------------------------
TJMCColorTable::TJMCColorTable(TWinControl *   InParent)
{
Parent = InParent;
NmbColorsShown = 6;
InitTable();
Table->Repaint();
}
//---------------------------------------------------------------------------
void TJMCColorTable::InitTable()
{
Table = new TStringGrid(Parent);
Table->Left = 0;
Table->Top = 0;
Table->Width = 443;
Table->Height = 181;
Table->ColCount = 6;
Table->RowCount = NmbColorsShown+1;
Table->DefaultColWidth = 64;
Table->DefaultRowHeight = 24;
Table->ScrollBars = ssBoth;
InitGridTitlesAndWidths();
InitGrid(6);
Table->Visible;
}
//---------------------------------------------------------------------------
void TJMCColorTable::InitGrid(int N)
{
NumberColors = N;
Table->RowCount = N + 1;
for(int i=1;i<=NumberColors;i++)
  Table->Cells[0][i] = IntToStr(i);
}
//---------------------------------------------------------------------------
And here is the call from the main:
//---------------------------------------------------------------------------
void __fastcall TMainForm::FormCreate(TObject *Sender)
{
ColorTable = new TJMCColorTable(MainForm);
}
//---------------------------------------------------------------------------
It runs, but nothing shows up.
I'm probably doing something stupid.
In place of the "MainForm" as a parameter to the constructor, I've also 
tried adding another control to the form and passing it's parent as the 
parameter.  That didn't work either.
   John

OK, I got it.
I added and explicit set of the Parent of the control (not just in the 
constructor) and it worked.
Thanks for your time,
   John

Hi JohnC 
 
 JohnC says:
> Table = new TStringGrid(Parent);
> Table->Left = 0;
> Table->Top = 0;
> Table->Width = 443;
> Table->Height = 181;
Table->SetBounds(0,0,443,181);
is faster.


> And here is the call from the main:
> //---------------------------------------------------------------------------
> void __fastcall TMainForm::FormCreate(TObject *Sender)
> {
> ColorTable = new TJMCColorTable(MainForm);
> }
> //---------------------------------------------------------------------------

You should not use FormCreate when You are working with
BCB, it is a Delphi Event.
Use the constructor instead.
Or if You want the aplication to be fast on screen You 
can use a TTimer set to 50 miliseconds that You enable 
in the OnShowEvent.
Then You create Your colortable in the TimerEvent.

To be able to use the designer You could also build everything 
on a panel at design time and then just make it invisible when 
You don't need it.

Or You can create an extra form, with BorderStyle = bsNone;
Take it of the autocreate list and then when You need it 
You create it with new just like Your TJMCColorTable.
and use Show(); when You want to see it. 

Kind regards
Asger

"Asger Joergensen" <junk@Asger-P.dk> wrote in message 
news:MPG.220c37f435e9dd16989a27@newsgroups.borland.com...
> You should not use FormCreate when You are working with
> BCB, it is a Delphi Event.

This one confuses me.  Why do you say it is a Delphi event?  I've been using 
it for years with C++ code.

> Use the constructor instead.

How would one use the constructor except through a hook?  FormCreate is just 
a hook (into the constructor, I believe).

> To be able to use the designer You could also build everything
> on a panel at design time and then just make it invisible when
> You don't need it.

I've used this trick to avoid crowded forms.  I agree, it can be very 
useful.
The mess I'm trying to avoid is in the code.  What I'm doing is extracting 
things into objects which will allow me to have cleaner code for the main 
form and which will allow me to reuse the composite controls in other 
similar or related applications.

I've got it working now - what I needed was to explicitely set the Parent - 
I had thought that it was enough to include it in the constructor call.

> Kind regards
> Asger
Thanks,
   John 

Hi JohnC 
 
 JohnC says:
> 
> "Asger Joergensen" <junk@Asger-P.dk> wrote in message 
> news:MPG.220c37f435e9dd16989a27@newsgroups.borland.com...
> > You should not use FormCreate when You are working with
> > BCB, it is a Delphi Event.
> 
> This one confuses me.  Why do you say it is a Delphi event?
  
Because it is.

> I've been using it for years with C++ code.

So have a lot of us until we got into trouble once, because of 
the creation order.

> How would one use the constructor except through a hook?

If You look at the top of the form unit file e.g. unit1.cpp
You will see the constructor

__fastcall TForm1::TForm1(TComponent* Owner)
   : TForm(Owner)
{
}
//-------------------------------------------------------
  
> I've used this trick to avoid crowded forms.  I agree, it can be very 
> useful.
> The mess I'm trying to avoid is in the code. 

Oooh I see, then the panel solution is no good. 

> What I'm doing is extracting 
> things into objects which will allow me to have cleaner code for the main 
> form and which will allow me to reuse the composite controls in other 
> similar or related applications.

You could also have a look at "Component Templates"
and maybe "Add To Repository" 

I'm not in any way saying that Your aproach is wrong, I'm just
giving You some options. 

Kind regards
Asger

JohnC wrote:

>This one confuses me.  Why do you say it is a Delphi event?  I've been using 
>it for years with C++ code.

Delphi and C++ construct in different orders.

<HELP>
TCustomForm::OnCreate Event
Note: 
 Use of the OnCreate event is discouraged in C++ code because it can interact badly with
the form's constructor (see OldCreateOrder). It is recommended that you override the form
constructor instead.
</HELP>

>How would one use the constructor except through a hook?  FormCreate is just 
>a hook (into the constructor, I believe).

Form1::Form1()
{	C++ constructor. Startup code goes here.
}
Form1::OnCreate()
{	Delphi constructor. Leave empty.
}

Learn something new every day!
Thanks Gents!
   John 

OK, here's the documentation I found in the BCB6 Help files:

Note: Use of the OnCreate event is discouraged in C++Builder because it can 
interact badly with the form's constructor (see OldCreateOrder). It is 
recommended that you override the form constructor instead.

Now I'm convinced.
John

"JohnC" <jcibulskis@sbcglobal.net> wrote in message 
news:47a2533f$1@newsgroups.borland.com...
> Learn something new every day!
> Thanks Gents!
>   John
>