Solved

Loading large file in a TRichEdit

Posted on 2014-04-08
9
377 Views
Last Modified: 2014-04-09
Hi all this question is related this one: http://www.experts-exchange.com/Programming/Languages/Pascal/Delphi/Q_28407456.html#a39986818

I thought the problem was the StringList but the bottleneck is TRichEdit. The file is very fastly loaded in the StringList but it takes a long time to be loaded in TRichEdit and when it is loaded it freezes the program. I use TRichEdit because I have a piece of code which allows me to use a different font color for certain words.
In my case, I highlight all non existent paths to allow the user to edit them accordingly to his system.

How can solve this problem?
Thanks in advance
Marco
0
Comment
Question by:Marco Gasi
  • 5
  • 4
9 Comments
 
LVL 45

Accepted Solution

by:
aikimark earned 500 total points
ID: 39987055
I can offer this work-around.  Use a listbox control and use custom drawing to do your highlighting.  When the user clicks on a listbox item, you move that selected item into an edit control.  Update the listbox item after the user has finished editing.

a code example is in this article:
http://delphi.about.com/cs/adptips2002/a/bltip0602_4.htm
0
 
LVL 31

Author Comment

by:Marco Gasi
ID: 39987167
Okay, aikimark, Listbox is very fast! But I still have an issue with the OwnerDraw event. Here's my code:

procedure TfrmIncorrectPaths.lbxRegFileDrawItem(Control: TWinControl;
  Index: Integer; Rect: TRect; State: TOwnerDrawState);
var
  myColor: TColor;
  myBrush: TBrush;
  rx: TPerlRegEx;
  I: Integer;
begin
  myBrush := TBrush.Create;
  try
    rx := TPerlRegEx.Create;
    try
      with (Control as TListBox).Canvas do
      begin
          rx.Options := [preCaseLess,preExtended];
          rx.RegEx := '\b[a-z]:\\                    # Drive'#10 +
                      '(?:[^\\/:*?"<>|\r\n]+\\)*     # Folder'#10 +
                      '[^\\/:*?"<>|\r\n]*            # File';
          rx.Subject := lbxRegFile.Items[Index];
          if rx.Match then
          begin
            if (not DirectoryExists(ExtractFilePath(rx.MatchedText))) then
              myColor := clYellow
            else
              myColor := clWhite;
          end;
        myBrush.Style := bsSolid;
        myBrush.Color := myColor;
        Winapi.Windows.FillRect(handle, Rect, myBrush.Handle) ;
        Brush.Style := bsClear;
        TextOut(Rect.Left, Rect.Top,
                 (Control as TListBox).Items[Index]) ;
      end;
    finally
      rx.Free;
    end;
  finally
    MyBrush.Free;
  end;
end;

Open in new window


It correctly draws a yellow background for non existent directories (it highlights the whole item instead of the directory string only but I can accept it), but all the rest is black! It's sure because I don't understand brush tecniques: can you help me?
0
 
LVL 45

Expert Comment

by:aikimark
ID: 39987339
The only difference I notice between your code and the article's code is
Winapi.Windows.FillRect()
vs.
Windows.FillRect()

What version of Delphi are you using?
0
Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

 
LVL 31

Author Comment

by:Marco Gasi
ID: 39987846
XE3. If I only use Windows.FillRect I get 'Undeclared identifier: Windows' error when I try to compile.
0
 
LVL 31

Author Comment

by:Marco Gasi
ID: 39987918
Solved. The working code is the following:

procedure TfrmIncorrectPaths.lbxRegFileDrawItem(Control: TWinControl;
  Index: Integer; Rect: TRect; State: TOwnerDrawState);
var
  myColor: TColor;
  myBrush: TBrush;
  rx: TPerlRegEx;
  I: Integer;
begin
  myBrush := TBrush.Create;
  try
    rx := TPerlRegEx.Create;
    try
      rx.Options := [preCaseLess,preExtended];
      rx.RegEx := '\b[a-z]:\\                    # Drive'#10 +
                  '(?:[^\\/:*?"<>|\r\n]+\\)*     # Folder'#10 +
                  '[^\\/:*?"<>|\r\n]*            # File';
      rx.Subject := lbxRegFile.Items[Index];
      if rx.Match then
      begin
        if (not DirectoryExists(ExtractFilePath(rx.MatchedText))) then
          myColor := clYellow
        else
          myColor := clWhite;
      end
      else
        myColor := clWhite;
      with (Control as TListBox).Canvas do
      begin
        myBrush.Style := bsSolid;
        myBrush.Color := myColor;
        Winapi.Windows.FillRect(handle, Rect, myBrush.Handle) ;
        Brush.Style := bsClear;
        TextOut(Rect.Left, Rect.Top,
                 (Control as TListBox).Items[Index]) ;
      end;
    finally
      rx.Free;
    end;
  finally
    MyBrush.Free;
  end;
end;

Open in new window


Thanks
0
 
LVL 31

Author Closing Comment

by:Marco Gasi
ID: 39987919
Thank you so mutch!
0
 
LVL 45

Expert Comment

by:aikimark
ID: 39988447
You're welcome.

Ah.  I see the problem now as well.  Thanks for posting the fixed/correct code. I missed the default white color being lost.  Maybe it is only a style difference, but you might try the following structure to see if it is faster than the else clause.
      myColor := clWhite;
      if rx.Match then
        if (not DirectoryExists(ExtractFilePath(rx.MatchedText))) then
          myColor := clYellow;

Open in new window

0
 
LVL 45

Expert Comment

by:aikimark
ID: 39988471
Note: I edited my comment, tweaking the code for simplicity.
0
 
LVL 31

Author Comment

by:Marco Gasi
ID: 39988581
Okay, I'll try it. Yhank you for this further help. Please, if you can take a look at the other quesiton: http://www.experts-exchange.com/Programming/Languages/Pascal/Delphi/Q_28408505.html
Cheers
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
Introduction The parallel port is a very commonly known port, it was widely used to connect a printer to the PC, if you look at the back of your computer, for those who don't have newer computers, there will be a port with 25 pins and a small print…
Microsoft Active Directory, the widely used IT infrastructure, is known for its high risk of credential theft. The best way to test your Active Directory’s vulnerabilities to pass-the-ticket, pass-the-hash, privilege escalation, and malware attacks …
Established in 1997, Technology Architects has become one of the most reputable technology solutions companies in the country. TA have been providing businesses with cost effective state-of-the-art solutions and unparalleled service that is designed…

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question