Re: [lazarus] TStringGrid to replace TListBox in Messages window

[Bogusław Brandys]

Jesus Reyes wrote:
--- Mattias Gaertner <[EMAIL PROTECTED]> escribió:
On Sun, 21 Jan 2007 17:37:20 +0300
Al Boldi <[EMAIL PROTECTED]> wrote:

Mattias Gaertner wrote:
Al Boldi <[EMAIL PROTECTED]> wrote:
Vincent Snijders wrote:
Jesus Reyes schreef:
--- Al Boldi <[EMAIL PROTECTED]> escribiظÚ&#732;:
TListBox:     10k rows in 73sec
TTreeView:   100k rows in 50sec
TMemo:       100k rows in 30sec
TListView:   100k rows in 1.5sec
TStringGrid: 100k rows in 0.5sec
Are you sure?, this doesn't match with Mattias mail.
Al, did you set the focused row to the last added rows
after
each 10 rows?
Here is the code:
============================
  StringGrid1.RowCount:=100002;
  i:=0;
  repeat
    inc(i);
    StringGrid1.Cells[0,i]:='tst'+inttostr(i);
  until i>100000;
============================
The component is updated several times a second to give the
user
visual feedback during the compilation progress. At the moment
every read line is either added to the TListBox or replacing
the
last line of the TListBox. So changing RowCount would be called
every added line. The message window is using Begin/EndUpdate.
It
calls them about three times a second. So basically there are a
lot
of 'change last item', many adds and several Begin/EndUpdates.
That's why I tried:

  StringGrid1.ColCount:=1;
  StringGrid1.BeginUpdate;
  for i:=1 to 100000 do begin
    StringGrid1.RowCount:=i;
This line basically kills TStringGrid.
Yes, but the IDE does not know the number of lines in advance.

In my opinion, this is not necesary, I don't know nobody that reads
the lines as fast as they are produced, if that was the purpose why
would need to have a dead list anyway.

This only helps to have some visual indication that it's working but 
appart from that it's not that useful.

Of course it would be possible to write a wrapper to add in bigger
chunks.


TStringGrid gains it's speed from preallocating the list.

Preallocating the tree in TTreeView could improve its speed a
lot.

I doubt that. It already works with exponential growth.
I still wonder why your treeview times are so much slower than
mines.
Did you use Begin/EndUpdate?


Mattias


About the unknown number of lines, I think that is a problem of
implementation only. If you enable -va and -vt you are expecting to
have a lot of lines, always. This information could be used to do
optimization. 

At least for StringGrid the preallocation works. With a modification
of al's code and some tweaking it can be obtained decent results.

  StartTimer;
  i:=0;
  repeat
    inc(i);
    if i>stringgrid1.RowCount-1 then begin
      StringGrid1.RowCount := StringGrid1.RowCount + 1000; {1}
    end;
    StringGrid1.Cells[0,i] := 'tst'+inttostr(i);
    if i mod 100 = 0 then begin {2}
      StringGrid1.Row := i;
      Application.processmessages;
    end;
  until i>100000;
  StringGrid1.RowCount:=i;
  StringGrid1.Row:=i-1;
  EndTimer;   

There are two points of tweaking here {1} and {2} changing these
increase or decrease performance.

Please don't misunderstand me. I think the treeview it's ok. I only
wanted to show that well, though StringGrid is not too optimized it
is not also that bad.

Jesus Reyes A.


I see that nobody taken into consideration my idea about using 
persistent storage like sqlite database.Is that so horrible ?



Regards
Boguslaw

_________________________________________________________________
    To unsubscribe: mail [EMAIL PROTECTED] with
               "unsubscribe" as the Subject
  archives at http://www.lazarus.freepascal.org/mailarchives