Solved

Loading large file in a TRichEdit

Posted on 2014-04-08
9
375 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
Complete VMware vSphere® ESX(i) & Hyper-V Backup

Capture your entire system, including the host, with patented disk imaging integrated with VMware VADP / Microsoft VSS and RCT. RTOs is as low as 15 seconds with Acronis Active Restore™. You can enjoy unlimited P2V/V2V migrations from any source (even from a different hypervisor)

 
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

Netscaler Common Configuration How To guides

If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.

Question has a verified solution.

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

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
This Micro Tutorial will teach you how to censor certain areas of your screen. The example in this video will show a little boy's face being blurred. This will be demonstrated using Adobe Premiere Pro CS6.
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…

803 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