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How to create in QT main chat windows like this?

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  • Q Offline
    Q Offline
    qwe3
    wrote on last edited by qwe3
    #5

    @mrjj I wrote "I can add QLabel to QTableView". This is wrong. Now my code is very strange - I try do something good.

    My class delegate:

    delegate::delegate()
    {
    
    }
    
    QWidget *delegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const
    {
            QLabel *label = new QLabel( parent);
            label->setStyleSheet("QLabel {background-color:red}");
            return label;
    }
    
    void delegate::setEditorData(QWidget *editor, const QModelIndex &index) const
    {
            QLabel *label = static_cast<QLabel *>(editor);
            label->setText(index.data().toString());
    }
    
    void delegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
    {
        QLabel *label = static_cast<QLabel *>(editor);
        label->setText("abcde");
        model->setData(index, index.data());
    }
    
    void delegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const
    {
        editor->setGeometry(option.rect);
    }
    
    void delegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
    {
    
    }
    
    

    I find in youtube movie about Qt Delegate and rewrite the code and try change it to my needs.

    My mainApp:

        table = new QTableView(this);
        deleg = new delegate;
        table->setGeometry(0,0,500,500);
        model = new QStandardItemModel(10,2, this);
        item = new QStandardItem("somethingABC");
        model->setItem(0,0,item);
    
        table->setModel(model);
        for(int i=0;i<100;i++)
            model->appendRow(QList<QStandardItem *>());
    
        table->setItemDelegate(deleg);
        table->setShowGrid(false);
        table->verticalHeader()->hide();
        table->horizontalHeader()->hide();
        table->setColumnWidth(0,250);
        table->setColumnWidth(1,250);
    

    When I double click on first cel ( 0,0 ) I get red rectangle with text "somethingABC". I would like to have this text when I execute the app ( no when I double click in QTableView ).

    EDIT:

    I would like something like:
    After 5 sec ( I can use QTimer and timeout()) I would like to add to my QTableView new QLabel in color red with text ( for example "Hello!" ) and this QLabel I would like to be rounded ( I know I can use setStyleSheet ).

    I would like to create GUI like in first post.

    1 Reply Last reply
    0
    • mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #6

      Hi
      2 things that caught my eye.

      1:

      void delegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
      {
          QLabel *label = static_cast<QLabel *>(editor);
          label->setText("abcde");
          model->setData(index, index.data());
      }
      This function writes back the data to the model. You write back the same data
      so not sure what you do with label :) 
      

      2:
      You are not painting anything. (no code)

      void delegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
      {
      call base class paint here or simply delete it if you have no need for extra paitning
      }
      
      

      Hi
      Did you read about Delegates ?
      The Editor is only active when editing, rest of the time its not shown.
      Then its paint job to show the data.

      1 Reply Last reply
      1
      • Q Offline
        Q Offline
        qwe3
        wrote on last edited by
        #7

        @mrjj Yes, I read about editor. But my problem is: I don't know what can I write in paint. I have 3 args: painter, option and index. I don't access to QLabel which I create in createEditor() function.

        mrjjM 1 Reply Last reply
        0
        • Q qwe3

          @mrjj Yes, I read about editor. But my problem is: I don't know what can I write in paint. I have 3 args: painter, option and index. I don't access to QLabel which I create in createEditor() function.

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

          @qwe3
          Ok. its important to read the docs as the Delegate follow a system so
          one has to understand how it acts.

          In paint you have access to the model which has the data.
          So you can use QPainter and drawText to draw it. Also make it red if needed etc.
          The QLabel you use is for Editing and not display.

          1 Reply Last reply
          1
          • Q Offline
            Q Offline
            qwe3
            wrote on last edited by
            #9

            @mrjj Okay. But Can I create text in red background which is in rounded background by QPainter. I never do something like that :)

            mrjjM 1 Reply Last reply
            0
            • Q qwe3

              @mrjj Okay. But Can I create text in red background which is in rounded background by QPainter. I never do something like that :)

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

              @qwe3
              Yes all StyleSheet and Widgets use QPainter internally.
              So you can make look like anything you like.

              https://stackoverflow.com/questions/29196610/qt-drawing-a-filled-rounded-rectangle-with-border

              QPainter p(this);
              p.setRenderHint(QPainter::Antialiasing);
              QPainterPath path;
              path.addRoundedRect(QRectF(10, 10, 100, 50), 10, 10);  
              QPen pen(Qt::black, 10);
              p.setPen(pen);
              p.fillPath(path, Qt::red);
              p.drawPath(path);
              

              Do note the cell area is in option.rect
              so you have to use its values to draw the right place. else you draw somewhere else on the view :)

              1 Reply Last reply
              1
              • Q Offline
                Q Offline
                qwe3
                wrote on last edited by
                #11

                @mrjj Now I add to paint() function:

                    QPen pen(Qt::black, 1);
                    painter->setPen(pen);
                    painter->drawText(0,0,100,100,0,index.data().toString());
                

                and it works!

                But I see next 2 problems:

                1. I have to write 100,100 in drawText() function. Is there any way to get size which my index.data().toString() needs?

                2. When I add this lines to my paint() function I only see this text in first cell (0,0).

                I have:

                    item = new QStandardItem("somethingABC");
                    item2 = new QStandardItem("somethingABC");
                    item3 = new QStandardItem("somethingABC");
                    model->setItem(0,0,item);
                    model->setItem(1,0,item2);
                    model->setItem(2,0,item3);
                

                So I think I have to get 3 texts "somethingABC" in my QTableView. Right?

                mrjjM 1 Reply Last reply
                0
                • Q qwe3

                  @mrjj Now I add to paint() function:

                      QPen pen(Qt::black, 1);
                      painter->setPen(pen);
                      painter->drawText(0,0,100,100,0,index.data().toString());
                  

                  and it works!

                  But I see next 2 problems:

                  1. I have to write 100,100 in drawText() function. Is there any way to get size which my index.data().toString() needs?

                  2. When I add this lines to my paint() function I only see this text in first cell (0,0).

                  I have:

                      item = new QStandardItem("somethingABC");
                      item2 = new QStandardItem("somethingABC");
                      item3 = new QStandardItem("somethingABC");
                      model->setItem(0,0,item);
                      model->setItem(1,0,item2);
                      model->setItem(2,0,item3);
                  

                  So I think I have to get 3 texts "somethingABC" in my QTableView. Right?

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

                  @qwe3 said in How to create in QT main chat windows like this?:

                  1
                  The cell area is in option.rect. (one of the parameters to paint)
                  2:
                  i think its related to 1 as all cells then paint its text in 100,100 :)

                  painter->drawText(option.rect, index.data().toString());

                  1 Reply Last reply
                  1
                  • Q Offline
                    Q Offline
                    qwe3
                    wrote on last edited by
                    #13

                    @mrjj One line and 2 problems aren't now problems :D Perfect!

                    mrjjM 1 Reply Last reply
                    1
                    • Q qwe3

                      @mrjj One line and 2 problems aren't now problems :D Perfect!

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #14

                      @qwe3
                      Super.
                      Delegates are a bit complicated to begin with but later you love them as you can do anything you like.
                      and then have good performance too \o/

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                      0
                      • Q Offline
                        Q Offline
                        qwe3
                        wrote on last edited by
                        #15

                        @mrjj I create rounded rectangle and it works :)

                        But I don't know how can I do the last thing:

                        The message text can be longer than one line. I think I have to change row's height. This is not a problem: table->setRowHeight(1,240);

                        But when I have to do that? In delegate functions()?

                        mrjjM 1 Reply Last reply
                        0
                        • Q qwe3

                          @mrjj I create rounded rectangle and it works :)

                          But I don't know how can I do the last thing:

                          The message text can be longer than one line. I think I have to change row's height. This is not a problem: table->setRowHeight(1,240);

                          But when I have to do that? In delegate functions()?

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by
                          #16

                          @qwe3
                          Hi
                          Nope, its not the delegates job
                          if its for all rows then

                          QHeaderView *verticalHeader = myTableView->verticalHeader();
                          verticalHeader->setSectionResizeMode(QHeaderView::Fixed);
                          verticalHeader->setDefaultSectionSize(24);
                          
                          1 Reply Last reply
                          1
                          • Q Offline
                            Q Offline
                            qwe3
                            wrote on last edited by
                            #17

                            @mrjj Thank you! I have to change your code to:

                            verticalHeader->setSectionResizeMode(QHeaderView::ResizeToContents);
                            

                            But you helped me next time! :)

                            Thank you

                            mrjjM 1 Reply Last reply
                            0
                            • Q qwe3

                              @mrjj Thank you! I have to change your code to:

                              verticalHeader->setSectionResizeMode(QHeaderView::ResizeToContents);
                              

                              But you helped me next time! :)

                              Thank you

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

                              @qwe3
                              Hi
                              Super.
                              Congratulation on your first Delegate.

                              1 Reply Last reply
                              0
                              • Q Offline
                                Q Offline
                                qwe3
                                wrote on last edited by qwe3
                                #19

                                @mrjj Only in 50%.

                                I need one more:

                                QWidget *delegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const
                                {
                                    return nullptr;
                                }
                                
                                void delegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const
                                {
                                    editor->setGeometry(option.rect);
                                }
                                
                                void delegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
                                {
                                    if(index.row()%2==0 && index.column()!=1)
                                    {
                                        QPen pen2(Qt::yellow, 1);
                                        painter->setPen(pen2);
                                    
                                        QPainterPath path;
                                        path.addRoundedRect(QRectF(option.rect), 10, 10);
                                        painter->fillPath(path, Qt::yellow);
                                        painter->drawPath(path);
                                        QPen pen(Qt::black, 1);
                                        painter->setPen(pen);
                                        painter->drawText(option.rect,Qt::AlignCenter, index.data().toString());
                                    }
                                }
                                

                                I would like to select text message, click on it right mouse button, get the list, where is "copy" and other possibilities. How can I do this?

                                Now I can't select text and click right mouse button

                                1 Reply Last reply
                                0
                                • mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #20

                                  Hi
                                  For right click menu you can use a context menu

                                  https://forum.qt.io/topic/31233/how-to-create-a-custom-context-menu-for-qtableview/8

                                  1 Reply Last reply
                                  1
                                  • Q Offline
                                    Q Offline
                                    qwe3
                                    wrote on last edited by
                                    #21

                                    @mrjj Next small problem :)

                                    I have now ( in the picture is small error - the third row have smaller rectangle ( whre is text "somethingABC ") - I change it in paint application; this rectangle have width like the others )

                                    example4.png

                                    My delegate:

                                    path.addRoundedRect(QRectF(option.rect), 10, 10);
                                    

                                    When I change it to:

                                    path.addRoundedRect(QRectF(option.rect.x(), option.rect.y(),option.rect.width()/2,option.rect.height()), 10, 10);
                                    

                                    I get:
                                    example5.png

                                    There are 3 columns in QTableView:
                                    the first one for my messages
                                    the second one - seperator
                                    the third for other person's messages

                                    I would like to align to right the third column - yellow rectangles. Like this:
                                    example6.png

                                    With the text there is not a problem:

                                    painter->drawText(QRect(option.rect),Qt::AlignVCenter, index.data().toString());
                                    

                                    But function

                                    painter->drawPath(path);
                                    

                                    doesn't have a parameter with alignments

                                    mrjjM 1 Reply Last reply
                                    0
                                    • Q qwe3

                                      @mrjj Next small problem :)

                                      I have now ( in the picture is small error - the third row have smaller rectangle ( whre is text "somethingABC ") - I change it in paint application; this rectangle have width like the others )

                                      example4.png

                                      My delegate:

                                      path.addRoundedRect(QRectF(option.rect), 10, 10);
                                      

                                      When I change it to:

                                      path.addRoundedRect(QRectF(option.rect.x(), option.rect.y(),option.rect.width()/2,option.rect.height()), 10, 10);
                                      

                                      I get:
                                      example5.png

                                      There are 3 columns in QTableView:
                                      the first one for my messages
                                      the second one - seperator
                                      the third for other person's messages

                                      I would like to align to right the third column - yellow rectangles. Like this:
                                      example6.png

                                      With the text there is not a problem:

                                      painter->drawText(QRect(option.rect),Qt::AlignVCenter, index.data().toString());
                                      

                                      But function

                                      painter->drawPath(path);
                                      

                                      doesn't have a parameter with alignments

                                      mrjjM Offline
                                      mrjjM Offline
                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #22

                                      @qwe3
                                      Hi
                                      Only drawText uses align. Not other paint functions as far as i know :0

                                      Since option.rect IS the cell, i think you just need to set
                                      ui->table->horizontalHeader()->setStretchLastSection(true);

                                      so the last col is actually to the far right

                                      1 Reply Last reply
                                      0
                                      • Q Offline
                                        Q Offline
                                        qwe3
                                        wrote on last edited by qwe3
                                        #23

                                        @mrjj Thank you, I think I can use something like:

                                        path.addRoundedRect(QRectF(option.rect.x()+100, option.rect.y(),option.rect.width()/2,option.rect.height()), 10, 10);
                                        

                                        for the last column.

                                        But there is next problem :D

                                        When I use:

                                        table->verticalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);
                                        

                                        I get the perfect height for cell (0,0). Perfect. But cell (0,1) must has the same height like cell (0,0), so it can be too big for cell (0,1).

                                        mrjjM 1 Reply Last reply
                                        0
                                        • Q qwe3

                                          @mrjj Thank you, I think I can use something like:

                                          path.addRoundedRect(QRectF(option.rect.x()+100, option.rect.y(),option.rect.width()/2,option.rect.height()), 10, 10);
                                          

                                          for the last column.

                                          But there is next problem :D

                                          When I use:

                                          table->verticalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);
                                          

                                          I get the perfect height for cell (0,0). Perfect. But cell (0,1) must has the same height like cell (0,0), so it can be too big for cell (0,1).

                                          mrjjM Offline
                                          mrjjM Offline
                                          mrjj
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #24

                                          @qwe3
                                          Hi

                                          • I get the perfect height for cell (0,0). Perfect. But cell (0,1) must has the same height like cell (0,0), so it can be too big for cell (0,1).

                                          Im not really sure what you say here :)

                                          1 Reply Last reply
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