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QplaintextEdit Paste problem of memory

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  • A Offline
    A Offline
    Aouache
    wrote on last edited by
    #1

    Hello,

    Is it normal that QPlaintextEdit moreover optimized as TextEdit is very slow when you copy a text such as a code of 1,000,000 lines or sometimes right clic application it takes 2 minutes to copy everything and after modifying this text is slow, and animation windows and also very slow and takes a lot of processor memory. someone an explanation for that? or solution?

    Thank you.

    1 Reply Last reply
    0
    • mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #2

      Hi
      Well it's not as fast as a native text edit it seems.
      it get slow around 100.000 here
      on win 7. so 1 million lines would make it hang for long time.
      (on my machine at least)

      void MainWindow::on_pushButton_released()
      {
          ui->plainTextEdit->setUpdatesEnabled(false);
          for (long int var = 0; var < 100000; ++var) {
          ui->plainTextEdit->insertPlainText(QString::number(var)+"\n");
          }
          ui->plainTextEdit->setUpdatesEnabled(true);
      }
      
      A 1 Reply Last reply
      0
      • mrjjM mrjj

        Hi
        Well it's not as fast as a native text edit it seems.
        it get slow around 100.000 here
        on win 7. so 1 million lines would make it hang for long time.
        (on my machine at least)

        void MainWindow::on_pushButton_released()
        {
            ui->plainTextEdit->setUpdatesEnabled(false);
            for (long int var = 0; var < 100000; ++var) {
            ui->plainTextEdit->insertPlainText(QString::number(var)+"\n");
            }
            ui->plainTextEdit->setUpdatesEnabled(true);
        }
        
        A Offline
        A Offline
        Aouache
        wrote on last edited by
        #3

        @mrjj yes ca takes a long time to load and notepad ++ is really fast and ca not take much memory. what's the function do ?

        mrjjM 1 Reply Last reply
        0
        • A Aouache

          @mrjj yes ca takes a long time to load and notepad ++ is really fast and ca not take much memory. what's the function do ?

          mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by
          #4

          @Aouache
          the function just add 100 000 lines to a plaintext
          to speed it up slightly it disables redraw while it adds.
          setUpdatesEnabled turns of/on redraws.

          A 1 Reply Last reply
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          • mrjjM mrjj

            @Aouache
            the function just add 100 000 lines to a plaintext
            to speed it up slightly it disables redraw while it adds.
            setUpdatesEnabled turns of/on redraws.

            A Offline
            A Offline
            Aouache
            wrote on last edited by
            #5

            @mrjj thanks you but thert is a nother problem, it takes a lot of memory, you think that there are two different methods, one that handles data and another for rendering.

            mrjjM 1 Reply Last reply
            0
            • A Aouache

              @mrjj thanks you but thert is a nother problem, it takes a lot of memory, you think that there are two different methods, one that handles data and another for rendering.

              mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by
              #6

              @Aouache
              yeah it has. It has support for paragraphs with more so maybe it is the creation of those that takes all that memory.
              It won't handle 1 million lines very well.
              Can I ask what you are trying to program?
              A source code editor?

              A 1 Reply Last reply
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              • mrjjM mrjj

                @Aouache
                yeah it has. It has support for paragraphs with more so maybe it is the creation of those that takes all that memory.
                It won't handle 1 million lines very well.
                Can I ask what you are trying to program?
                A source code editor?

                A Offline
                A Offline
                Aouache
                wrote on last edited by
                #7

                @mrjj No it's a program billing for to a shop they need à software

                mrjjM 1 Reply Last reply
                0
                • A Aouache

                  @mrjj No it's a program billing for to a shop they need à software

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by
                  #8

                  @Aouache
                  Ok. so why do you have 1 million lines textedit?
                  Will they have that many bills or ?

                  A 1 Reply Last reply
                  0
                  • mrjjM mrjj

                    @Aouache
                    Ok. so why do you have 1 million lines textedit?
                    Will they have that many bills or ?

                    A Offline
                    A Offline
                    Aouache
                    wrote on last edited by
                    #9

                    @mrjj there have bills into pages that may contain 800,000 to lines and wanted to know if it is possible to display only one time in a qplaintextedit with formatting without separating and without the programe takes a lot of memory.

                    mrjjM 1 Reply Last reply
                    0
                    • A Aouache

                      @mrjj there have bills into pages that may contain 800,000 to lines and wanted to know if it is possible to display only one time in a qplaintextedit with formatting without separating and without the programe takes a lot of memory.

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #10

                      @Aouache
                      I think it will take a lot of memory for 800.000 lines.
                      If you save it as file with notepad++, what is file size then?

                      Do they need to edit it? a QListWIdget will handle it better, scrolling etc
                      but still memory though.

                      A 1 Reply Last reply
                      0
                      • mrjjM mrjj

                        @Aouache
                        I think it will take a lot of memory for 800.000 lines.
                        If you save it as file with notepad++, what is file size then?

                        Do they need to edit it? a QListWIdget will handle it better, scrolling etc
                        but still memory though.

                        A Offline
                        A Offline
                        Aouache
                        wrote on last edited by
                        #11

                        @mrjj QListWIdget ok I'll try and I would keep you informed if it's work thanks

                        mrjjM 1 Reply Last reply
                        0
                        • A Aouache

                          @mrjj QListWIdget ok I'll try and I would keep you informed if it's work thanks

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by
                          #12

                          @Aouache
                          how long is each line ?
                          very long or just a few letters?
                          When loaded, what to they want to do with it?

                          A 1 Reply Last reply
                          0
                          • mrjjM mrjj

                            @Aouache
                            how long is each line ?
                            very long or just a few letters?
                            When loaded, what to they want to do with it?

                            A Offline
                            A Offline
                            Aouache
                            wrote on last edited by
                            #13

                            @mrjj a line contains approximately 150 characters. There are two modes is read only opening a file and the other editable (copy, paste, edit the text). I found a solution for Qplainttextedit. is to fix each qplaintexteedit 50,000 lines after them within a QScrollArea and amending stylsheet I can bring them closer and make him look like a single qplaintextedit. that's what I wanted to create a QThread that handles data copied from a program and insert it in a QTextDocument before displaying it in ca Qplaintextedit is the role of my thread but I have two problems:

                            the first is when I copy a text and I stick it in my application displays this message with me debug thread:

                            "thread lancer.....
                            
                            QObject::connect: Cannot queue arguments of type 'QTextBlock'
                            
                            (Make sure 'QTextBlock' is registered using qRegisterMetaType().)
                            
                            QObject::connect: Cannot queue arguments of type 'QTextCursor'
                            
                            (Make sure 'QTextCursor' is registered using qRegisterMetaType().)
                            
                            thread terminer.....  "
                            

                            even it works when I have the text displayed in my application and the second concern is when I try to paste another text or the same text before. the appilcation plant by displaying this message:

                            "ASSERT failure in QCoreApplication::sendEvent: "Cannot send events to objects owned by a different thread. Current thread aa869744c0. Receiver '' (of type 'QTextDocument') was created in thread aa846a1400", file kernel\qcoreapplication.cpp, line 553".
                            

                            any idea ?

                            1 Reply Last reply
                            0
                            • mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by
                              #14

                              @Aouache said:
                              Hi thank you for the info.

                              Cannot send events to objects owned by a different thread

                              Well you are not allowed to use Gui things from other threads.
                              You must use the worker approach described here
                              http://doc.qt.io/qt-5.5/qthread.html#details

                              If you google it, its a common issue.

                              Would it be possible for the other program to save it to file?

                              A 1 Reply Last reply
                              0
                              • mrjjM mrjj

                                @Aouache said:
                                Hi thank you for the info.

                                Cannot send events to objects owned by a different thread

                                Well you are not allowed to use Gui things from other threads.
                                You must use the worker approach described here
                                http://doc.qt.io/qt-5.5/qthread.html#details

                                If you google it, its a common issue.

                                Would it be possible for the other program to save it to file?

                                A Offline
                                A Offline
                                Aouache
                                wrote on last edited by
                                #15

                                @mrjj its not working what you showed me the example of QThread he always shows me the same bug:

                                "thread lancer.....
                                
                                QObject::connect: Cannot queue arguments of type 'QTextBlock'
                                
                                (Make sure 'QTextBlock' is registered using qRegisterMetaType().)
                                
                                QObject::connect: Cannot queue arguments of type 'QTextCursor'
                                
                                (Make sure 'QTextCursor' is registered using qRegisterMetaType().)
                                
                                thread terminer.....  "
                                

                                after it crashes.

                                this is my code of my thread pastethread.cpp :

                                #include "pastethread.h"
                                #include <QDebug>
                                
                                PasteThread::PasteThread(QObject* parent):
                                    QThread(parent)
                                {
                                    mydata = new QMimeData();
                                }
                                
                                PasteThread::~PasteThread()
                                {
                                //    exit();
                                //    wait();
                                
                                //    mydata = NULL;
                                //    myedit = NULL;
                                
                                //    delete mydata;
                                //    delete myedit;
                                }
                                
                                void PasteThread::run()
                                {
                                
                                    qDebug()<<"thread lancer.....";
                                
                                    QByteArray data = mydata->data(mydata->formats().first());
                                
                                    QTextDocument *dd = new QTextDocument();
                                
                                    dd = myedit->document();
                                
                                    QTextStream *stream = new QTextStream(&data);
                                
                                    dd->setPlainText(stream->readAll());
                                
                                    emit Send_data(dd);
                                
                                }
                                
                                

                                this my code of document dockshow.cpp

                                #include "dockshow.h"
                                #include <QDebug>
                                #include <QApplication>
                                
                                Dockshow::Dockshow(QWidget *parent) :
                                    QPlainTextEdit(parent)
                                {
                                
                                }
                                
                                void Dockshow::startWorkInAThread()
                                {
                                
                                    mythread = new PasteThread(this);
                                
                                    mythread->mydata = tt;
                                    mythread->myedit = this;
                                
                                    connect(mythread, &PasteThread::Send_data, this, &Dockshow::Get_data);
                                    connect(mythread, &PasteThread::finished, mythread, &QObject::deleteLater);
                                
                                    mythread->start();
                                }
                                
                                void Dockshow::insertFromMimeData(const QMimeData *data)
                                {
                                    tt = new QMimeData();
                                    tt = const_cast<QMimeData*>(data);
                                
                                    load = new Loading(this);
                                    load->show();
                                
                                    startWorkInAThread();
                                
                                }
                                
                                void Dockshow::Get_data(QTextDocument *doc)
                                {
                                    this->setDocument(doc);
                                    load->hide();
                                }
                                
                                
                                
                                1 Reply Last reply
                                1
                                • mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by mrjj
                                  #16

                                  hi
                                  It is still created in the context of the main thread.
                                  As far as I know all GUI 'widgets must be in main thread.

                                  Please see this example
                                  https://fabienpn.wordpress.com/2013/05/01/qt-thread-simple-and-stable-with-sources/

                                  and notice the:
                                  worker->moveToThread(thread);

                                  This makes it 100% detached from main thread.

                                  So the worker can get data from clipboard into qstringlist/QTextDocument and then send it to
                                  qplaintexteedit via signal.

                                  You are almost there but it seems your code is just a thread and not using a worker object but
                                  directly runs the code via PasteThread::run()

                                  A 1 Reply Last reply
                                  0
                                  • mrjjM mrjj

                                    hi
                                    It is still created in the context of the main thread.
                                    As far as I know all GUI 'widgets must be in main thread.

                                    Please see this example
                                    https://fabienpn.wordpress.com/2013/05/01/qt-thread-simple-and-stable-with-sources/

                                    and notice the:
                                    worker->moveToThread(thread);

                                    This makes it 100% detached from main thread.

                                    So the worker can get data from clipboard into qstringlist/QTextDocument and then send it to
                                    qplaintexteedit via signal.

                                    You are almost there but it seems your code is just a thread and not using a worker object but
                                    directly runs the code via PasteThread::run()

                                    A Offline
                                    A Offline
                                    Aouache
                                    wrote on last edited by
                                    #17

                                    @mrjj Hello,

                                    the thread works fine but now I have another bug that's when I copy texts sometimes the bug software and it shows me this message

                                    "ASSERT:" isEmpty () "in file C: \ Qt \ QT5. 5.0 \ 5.5 \ msvc2013_64 \ include \ QtCore / qlist.h, line 316 "
                                    

                                    and when I google I didn't find someone who has this bug. I also see the line 316 qlist.h file and from what I understand it is a problem of iterator loop which one I do not know ?????

                                    mrjjM 1 Reply Last reply
                                    0
                                    • A Aouache

                                      @mrjj Hello,

                                      the thread works fine but now I have another bug that's when I copy texts sometimes the bug software and it shows me this message

                                      "ASSERT:" isEmpty () "in file C: \ Qt \ QT5. 5.0 \ 5.5 \ msvc2013_64 \ include \ QtCore / qlist.h, line 316 "
                                      

                                      and when I google I didn't find someone who has this bug. I also see the line 316 qlist.h file and from what I understand it is a problem of iterator loop which one I do not know ?????

                                      mrjjM Offline
                                      mrjjM Offline
                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on last edited by mrjj
                                      #18

                                      @Aouache said:
                                      Hi Good work!
                                      seems to be this line
                                      inline T& first() { Q_ASSERT(!isEmpty()); return *begin(); }
                                      so It something internal maybe from QDocument or plainedit.

                                      Try to insert some check from data you read that it is not NULL or empty.
                                      Else try to look at data when it happens.
                                      Sadly its a Q_ASSERT so it most likely just kills the program.

                                      Also I have been meaning to ask you. Since you put it in Edit widget. Is
                                      it important to edit the data or is viewing simply enough ?

                                      A 1 Reply Last reply
                                      0
                                      • mrjjM mrjj

                                        @Aouache said:
                                        Hi Good work!
                                        seems to be this line
                                        inline T& first() { Q_ASSERT(!isEmpty()); return *begin(); }
                                        so It something internal maybe from QDocument or plainedit.

                                        Try to insert some check from data you read that it is not NULL or empty.
                                        Else try to look at data when it happens.
                                        Sadly its a Q_ASSERT so it most likely just kills the program.

                                        Also I have been meaning to ask you. Since you put it in Edit widget. Is
                                        it important to edit the data or is viewing simply enough ?

                                        A Offline
                                        A Offline
                                        Aouache
                                        wrote on last edited by
                                        #19

                                        @mrjj yes edit the data and the users can change the mode read only for example. i try to find the bug in the data .

                                        mrjjM 1 Reply Last reply
                                        0
                                        • A Aouache

                                          @mrjj yes edit the data and the users can change the mode read only for example. i try to find the bug in the data .

                                          mrjjM Offline
                                          mrjjM Offline
                                          mrjj
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #20

                                          @Aouache
                                          Ok. so you do need to edit also.
                                          Well the error suggest its something unusual so
                                          try to see if any hints with the data when it happens.

                                          1 Reply Last reply
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