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Don Taylor · Guest

Creating at runtime multiple instances of a descendant of tGraphicControl
seems very slow.

I've traced this to the point where the Parent property is set. There's a
chunk of complicated-looking code in in tWinControl.SetParent which is
missed out if csReading in ComponentState, but ComponentState is read-only
so I can't set it in my component.

What's the best way of speeding this up? My components do not need to move
or resize or anything complicated, but I need an awful lot which just sit
there and redraw themselves when necessary.

Thanks,

Don Taylor.

Don Taylor · Guest

Sorry, that should be tWinControl.InsertControl, which tests csReading in
aControl.ComponentState.

GrandmasterB · Guest

"Don Taylor" <don (AT) ctrd (DOT) co.uk> wrote

Don Taylor · Guest

Yep, lots of alternatives considered - unfortunately the appearance and
position of many of these controls have to be calculated (before form
creation) depending on user and application options - a single big bitmap
would be extremely complicated.

Lets face it, for the app I'm developing, VCL controls are absolutely
stonkingly ideal and brilliantly simple to use. It's just a shame the
bridge to Windows GDI is clearly processor greedy. This app is being ported
from BPW 7 where I used similar (but less brilliantly simple) visual
components of my own design. This was much, much faster than Delphi 7, but
I can only generate 16-bit apps with it. We now need 32-bit apps to run on
XP, but we'll have trouble convincing users to upgrade if it clearly runs a
lot slower!

Thanks for your comments.

Don.

"GrandmasterB" <Fizzle (AT) shizzle (DOT) com> wrote

Joe Bain · Guest

Don Taylor wrote:

Don Taylor · Guest

"Joe Bain" <j.b.a.i.n@a.d.d.o.n.s.y.s.t.e.m.s..c.o.m> wrote

Joe Bain · Guest

Don Taylor wrote:

Don Taylor · Guest

"Joe Bain" <j.b.a.i.n@a.d.d.o.n.s.y.s.t.e.m.s..c.o.m> wrote

Joe Bain · Guest

I think it is the painting that is taking the time. If you don't set
the parent the control never gets painted the following code takes
250ms to run, but the form takes 3 more seconds to show because of the
painting code.

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls,
Forms,
Dialogs, StdCtrls;

type
TMyButton = class(TButton)

public
Constructor Create(aOwner: tForm; x, y, w, h:integer);overload;
end;

TForm3 = class(TForm)
private
{ Private declarations }
public
constructor Create(AOwner: TComponent); override;
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

{ TMyButton }

constructor TMyButton.Create(aOwner: tForm; x, y, w, h: integer);
begin
inherited Create(aowner);

Left := x;
Top := y;
Width := w;
Height := h;
Parent := aOwner;

end;

{ TForm3 }

constructor TForm1.Create(AOwner: TComponent);
var x,y:integer;
tc:Cardinal;
begin
inherited;
tc := GetTickCount;
for x := 0 to 50 do
for y := 0 to 20 do
TMyButton.Create(self,x*10,y*10,10,10);
showmessage(IntToStr(GetTickCount-tc));
end;

end.

--------------
Joe Bain
www.iegsoftware.com

Don Taylor · Guest

"Joe Bain" <j.b.a.i.n@a.d.d.o.n.s.y.s.t.e.m.s..c.o.m> wrote

Joe Bain · Guest

Then the only thing I could suggest is to do all your drawing to a bmp
and paint it to the form.

--------------
Joe Bain
www.iegsoftware.com

Don Taylor · Guest

I've made a substantial improvement by overriding the parent form's
AlignControls method.

Since my controls don't move, AlignControls is not required.

In the source for tWinControl in Delphi 7 (Controls.pas), InsertControl
calls AlignControl which then calls AlignControls. This reads every
existing control to see if its Align <> alNone. This happens every time you
add a control so the more controls you add, the worse it gets. Adding 400
controls means reading all the Aligns 399+398+397+396...+1 times, even if
they all = alNone. Yuck.

Fortunately, tWinControl.AlignControls is virtual, so it can be overridden
to do nothing. This reduces the time taken to create 400 controls from
1500ms downto 70ms! Well worth doing if no controls use Align.

Don.

"Don Taylor" <don (AT) ctrd (DOT) co.uk> wrote

Peter Below (TeamB) · Guest

In article <428cb881$1 (AT) newsgroups (DOT) borland.com>, Don Taylor wrote:

Don Taylor · Guest

"Peter Below (TeamB)" <100113.1101 (AT) compuXXserve (DOT) com> wrote

Anders Isaksson · Guest

Don Taylor wrote: