[Bug] DeleteParas

[Jacek Puczynski]

Hi,
It was a long time now I reported some bugs here.
But I believe I found a bug in TRichView last versions.
After calling DeleteParas(0, 1); at least one time on a full TRichView a text and displaying the component in a visible window:
List index out of bounds


Best regards,
Jacek

[Sergey Tkachenko]

1) Please give step-by-step instructions how to reproduce this problem (or send a sample project to richviewgmailcom)

I tried to reproduce the problem by adding in the ActionTestUni a new toolbar button with the code:

Code: Select all

procedure TForm3.ToolButton71Click(Sender: TObject);
begin
  RichViewEdit1.DeleteParas(0, 1);
end;

I can see no problems.

2) What exactly version of TRichView do you use?

[Jacek Puczynski]

I tested on versions: TRichView v14.5.1 and TRichView 14.0 and they contain this error.

Previously I used TRichView 12 and there was no error of this kind. Also TRichView 13 seems not to have it.

I am implementing a rolling log window with TRichView (not TRichViewEdit as in your code). I have TRichView and a TRVStyle and I simply add paragraphs until the limit is reached:

Code: Select all

richView->Add(someText, C_NORMAL);
richView->FormatTail();
if(richView->ItemCount > TEXT_LIMIT)) {
		richView->DeleteParas(0, 1);
	}

If I set TEXT_LIMIT to 200 for example, the error that will appear will be e.g. List index out of bounds (211).
So the component tries to read an index little larger than the limit.

I hope it explains more.

[Jacek Puczynski]

I forgot about AddNL it might have some impact so it looks more like:

Code: Select all

richView->AddNL(Now().FormatString(timestamp), C_TIME, 0);
richView->Add(someText, C_NORMAL); 
richView->FormatTail(); 
if(richView->ItemCount > TEXT_LIMIT)) { 
      richView->DeleteParas(0, 1); 
   } 

[Sergey Tkachenko]

I tried to reproduce it. Created a new Delphi project, placed RichView1 and RVStyle1, linked RichView1 to RVStyle, added a button with the code:

Code: Select all

procedure TForm1.Button1Click(Sender: TObject);
begin
  richView1.AddNL(DateTimeToStr(Now)+' ', 1, 0);
  richView1.Add('I am implementing a rolling log window with TRichView (not TRichViewEdit as in your code). I have TRichView and a TRVStyle and I simply add paragraphs until the limit is reached', 0);
  richView1.FormatTail;
  if richView1.ItemCount > 20 then
    richView1.DeleteParas(0, 1);
end;

No error.
But I have TRichView version modified since TRichView 14.5.1.
Today I plan to upload the update, so you will be able to test with a new version.
But, for any case, can you post a stack at the moment of exception?
(compile your application with the compiler options: Optimization: Off, Stack frames: On); when the exception occurs, go View | Debug Windows | Call Stack, Ctrl+A to select, Ctrl+C to copy)

[Jacek Puczynski]

Hi Sergey,
Yes I will be able to do it. I will need to also change the version I am using as now. I installed version 3.x to avoid the issue.
Please note that you are using limit 20. I suggested limit 200 because it was more realistic test with the control being scrolled vertically. (My real limit in my application in production is 7000)
I have also set the flag richView->Options << rvoScrollToEnd;

Jacek

[Sergey Tkachenko]

I used 200 initially.
rvoScrollToEnd is included by default.

[Sergey Tkachenko]

New version is uploaded