A few questions about TMemo

I have a few questions to ask regarding the TMemo component
1) Is there a way to open large files (>100kb)?
2) How can I get the position of the cursor (i.e. row and col)?
3) Unlike the TRichEdit component, TMemo component does not have the OnSelectionChange event. I need to display the position of the cursor whenever the cursor is moved. How can I do this?

Thanks in Advance
Ermac
ermacAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

ZifNabCommented:
Which version of Delphi are you using?

A1) ? I don't know.

A2) From lloyd's help file :

Q:  How do I know which line number I am currently on in a TMemo?

A:  The trick is to use the em_LineFromChar message.  Try this:

{Note: First line is zero.}
ShowMessage('Line Number: ' + IntToStr(Memo1.Perform(EM_LineFromChar, $FFFF, 0)));

to get row AND col you might do this:

Row := SendMessage(Memo1.Handle, EM_LineFromChar, Memo1.SelStart, 0);
Col := Memo1.SelStart - SendMessage(Memo1.Handle, EM_LineIndex, Row, 0);


Note:  The answer that this gives indicates where the cursor is in the memo field and not where the cursor is in the display of that memo field.  Remember also that the arrays are zero based.  This means that if the cursor is placed before the first character of the first line, that the row and col values will be zero.

A3) You can use the OnkeyDown or OnKeyUp.
    For mouse movements use the mouse events.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
ermacAuthor Commented:
Thanks!! It works!
But I got another question to ask...

How do I implement Insert/Overwrite operations using TMemo??
(30 points for this answer)
0
ZifNabCommented:
I'll try to find a solution. : this is already one, but I guess there should be better :

At onkeydown or onkeyup, if Insert key is pushed, toggle a boolean variable between false and true (overwrite and insert)

Check if overwrite is selected :
 if so, first delete character your cursor is on then write the character down. You can put this code in Onkeypress
0
Cloud Class® Course: Microsoft Azure 2017

Azure has a changed a lot since it was originally introduce by adding new services and features. Do you know everything you need to about Azure? This course will teach you about the Azure App Service, monitoring and application insights, DevOps, and Team Services.

ermacAuthor Commented:
Have already tried that... However it seems that the Memo flashes a lot when doing this...

Any other solutions??
0
ZifNabCommented:
Still thinking...
0
ermacAuthor Commented:
Or was it because my code was wrong??
Here's my piece of code for doing it...
with Editor do
begin
  if OverwriteText then
    if (GetTextLen > 0) and (Text[SelStart+1] <> '') and               (Text[SelStart+1] <> #13) then
      SelLength := 1;  
end;
0
ZifNabCommented:
No, looks correct. Maybe with selection lot's of repaint.
Thought otherway, just write VK_DELETE and then character, but
I can't get it to work properly


0
ermacAuthor Commented:
Have played with the VK_DELETE too...
Could get it to work but it still flashes a lot :(
0
ZifNabCommented:
Sorry, can't find a better solution, maybe there isn't any :-(
Maybe make a new TMemo component?
0
ermacAuthor Commented:
Anyway thanks for your help! :)
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Delphi

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.