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Forum Update on Monday, May 27th 2025

Create a matrix from a .csv file

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  • A Offline
    A Offline
    AliM93
    wrote on 31 May 2020, 02:08 last edited by
    #119

    done! but i only see the grid, not the content

    M 1 Reply Last reply 31 May 2020, 02:09
    0
    • A AliM93
      31 May 2020, 02:08

      done! but i only see the grid, not the content

      M Offline
      M Offline
      mrjj
      Lifetime Qt Champion
      wrote on 31 May 2020, 02:09 last edited by
      #120

      @AliM93
      \o/
      Good work.
      I hope you learn a few Creator tricks.

      we didnt paint the values yet :)
      just all other stuff :=)

      But its 4 in the morning so rest must be tomorrow as its bed time for me :)

      A 1 Reply Last reply 31 May 2020, 02:10
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      • M mrjj
        31 May 2020, 02:09

        @AliM93
        \o/
        Good work.
        I hope you learn a few Creator tricks.

        we didnt paint the values yet :)
        just all other stuff :=)

        But its 4 in the morning so rest must be tomorrow as its bed time for me :)

        A Offline
        A Offline
        AliM93
        wrote on 31 May 2020, 02:10 last edited by
        #121

        @mrjj yes! but i don't even see the number

        M 1 Reply Last reply 31 May 2020, 02:11
        0
        • A Offline
          A Offline
          AliM93
          wrote on 31 May 2020, 02:10 last edited by
          #122

          anyway, ok for tomorrow, you have been too much patient with me, thanks. and for the first time, i can say thay i better undestand how qt works! i start to appreciate it

          1 Reply Last reply
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          • A AliM93
            31 May 2020, 02:10

            @mrjj yes! but i don't even see the number

            M Offline
            M Offline
            mrjj
            Lifetime Qt Champion
            wrote on 31 May 2020, 02:11 last edited by
            #123

            @AliM93
            well do you have that version of paint ?

            
            void MatrixWidget::paintEvent(QPaintEvent *event)
            {
            
                QPainter p(this);
                // draw frame.
                p.drawRect(0, 0, width() - 1, height() - 1);
            
                // size of area we have. w = width , h = height , we take 2 pixles for border
                int w = width() - 2;
                int h = height() - 2;
            
                // now we find out how big each box should be which area we have  divided with how many on x and y
                bw = w / max_x;
                bh = h / max_y;
            
                // now we loop and drw the boxes
                for (int xi = 0; xi < max_x; ++xi) {
                    for (int yi = 0; yi < max_x; ++yi) {
                        p.drawRect( QRect( xi * bw, yi * bh, bw, bh  ) )  ;
                        p.drawText(QRect( xi * bw, yi * bh, bw, bh  ),
                                   QString::number(xi + 1) + "," + QString::number(yi+1) ); // the +1 aswe dont want to use first at 0,0
                    }
                }
            
            }
            
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            • A Offline
              A Offline
              AliM93
              wrote on 31 May 2020, 02:11 last edited by
              #124

              yes i have

              M 1 Reply Last reply 31 May 2020, 02:12
              0
              • A AliM93
                31 May 2020, 02:11

                yes i have

                M Offline
                M Offline
                mrjj
                Lifetime Qt Champion
                wrote on 31 May 2020, 02:12 last edited by
                #125

                @AliM93
                But it dont draw numbers ?
                That seems very odd.

                But you do see grid ?

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                • A Offline
                  A Offline
                  AliM93
                  wrote on 31 May 2020, 02:13 last edited by
                  #126

                  sorry! now i have, i lost a part of that version of matrix, sorry!

                  M 1 Reply Last reply 31 May 2020, 02:14
                  0
                  • A AliM93
                    31 May 2020, 02:13

                    sorry! now i have, i lost a part of that version of matrix, sorry!

                    M Offline
                    M Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on 31 May 2020, 02:14 last edited by
                    #127

                    @AliM93
                    Ok that good news as it would be very impossible that numbers went missing :)

                    what is remaining is the click logic and to actual draw the 1.

                    how shall we draw 0 ones ?
                    just no value in cell and cant be selected or what is the goal?

                    1 Reply Last reply
                    0
                    • A Offline
                      A Offline
                      AliM93
                      wrote on 31 May 2020, 02:16 last edited by
                      #128

                      my idea was to color all the 1s in green and the 0s in gray. so the user know that can select only the green cells, is it possible?

                      1 Reply Last reply
                      0
                      • A Offline
                        A Offline
                        AliM93
                        wrote on 31 May 2020, 02:17 last edited by
                        #129

                        i don't want to disturb you anymore tonight, if you want and if you have time we can continue tomorrow

                        1 Reply Last reply
                        0
                        • M Offline
                          M Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on 31 May 2020, 02:21 last edited by
                          #130

                          Yes its possible. we can paint it any way we like. teasers included.

                          Well im getting very tired as 4.20 in the morning is late for me even i do love programming at night.

                          Tomorrow we add the last part. It's not that much. Promise.
                          You did good. First custom widget is always a bit tuff.

                          alt text

                          alt text

                          1 Reply Last reply
                          0
                          • A Offline
                            A Offline
                            AliM93
                            wrote on 31 May 2020, 02:23 last edited by
                            #131

                            thank you so much! you help me a lot also in understand the ideas. thanks. night!

                            1 Reply Last reply
                            0
                            • M Offline
                              M Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on 31 May 2020, 11:20 last edited by mrjj
                              #132

                              Hi
                              The last remaining steps are to
                              +Add box width/height as members to use when clicking and a variable to keep track of the number of selected

                              class MatrixWidget : public QWidget
                              {....    
                                  int bw =0;
                                  int bh =0;
                                  int selCount=0; // to make sure we can only select 3
                              ,...
                              

                              +call loadData from construtor.

                              +Set some colors in void MatrixWidget::LoadData()
                              for 0 cells and 1 cells (see code)

                              +Add selection logic to mousePress

                              void MatrixWidget::mousePressEvent(QMouseEvent *event)
                              {
                                  QPoint p = event->pos(); // where we clicked
                              
                                  int xindex =  p.x() / bw;
                                  int yindex =  p.y() / bh;
                              
                                  qDebug() << xindex << " " << yindex;
                                  // get the data point ( we should check index is not outside array...)
                                  DataPoint &dp = Data[xindex + 1 ][yindex + 1]; 
                              
                                  // value zero cannot be selected
                                  if ( dp.value == 0 ) return;
                              
                                  // selection logic. If not already selected, select it and set color. Else deselect and reset color
                                  if ( dp.isSelected == false) {
                              
                                      // no more than 3 selected ( 0,1,2 )
                                      if ( selCount > 2 ) return;
                              
                                      dp.DrawColor = Qt::blue;
                                      dp.isSelected = true;
                                      selCount++; // extra selected
                                  } else {
                                      dp.DrawColor =  Qt::green;
                                      dp.isSelected = false;
                                      selCount--; // less selected
                                  }
                                  update(); // tell it to redraw grid
                              
                              }
                              
                              

                              +Adjust draw to skip 0,0 as we don't use it but the array must start at zero.

                              void MatrixWidget::paintEvent(QPaintEvent *event)
                              {
                              
                                  QPainter p(this);
                                  // draw frame.
                                  p.drawRect(0, 0, width() - 1, height() - 1);
                              
                                  // size of area we have. w = width , h = height , we take 2 pixles for border
                                  int w = width() - 2;
                                  int h = height() - 2;
                              
                                  // now we find out how big each box should be which area we have  divided with how many on x and y
                                  bw = w / max_x;
                                  bh = h / max_y;
                              
                                  // now we loop and draw the boxes. we dont use the boxes from 0,0 as data starts with 1,1
                                  for (int xi = 0; xi < max_x - 1; ++xi) {
                                      for (int yi = 0; yi < max_x - 1; ++yi) {
                                          p.setBrush(QBrush( Data[xi + 1][yi + 1].DrawColor )); // +1 as we dont want to use from 0,0
                                          QRect cellRect( xi * bw, yi * bh, bw, bh  );
                                          p.drawRect( cellRect );
                                          // show x,y . just for debug
                                          p.drawText( cellRect ,
                                                     QString::number(xi + 1) + "," +
                                                     QString::number(yi +1) );
                              
                                      }
                                  }
                              }
                              
                              
                              

                              Then we have a working version.

                              alt text

                              project
                              https://www.dropbox.com/s/z4nllgag1tjy4j3/GridWidgetApp.zip?dl=0

                              Things to improve/add
                              The limit of how many points user can select,
                              should be a parameter to the class so it can be set to anything and not a fixed value.

                              The colors could also be parameters ( for not selectable, selectable and selected)

                              Add a function to return the selected data pointsby looping the Data list and check isSelected.

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                              • A Offline
                                A Offline
                                AliM93
                                wrote on 31 May 2020, 11:59 last edited by AliM93
                                #133

                                thanks! i'll do it step by step, i quite understand it, but when i run i got a black grid, and the error floating point exeption (core dumped) No more error, (i also see the coordinates in the debug), but black grid.

                                M 1 Reply Last reply 31 May 2020, 12:06
                                0
                                • A AliM93
                                  31 May 2020, 11:59

                                  thanks! i'll do it step by step, i quite understand it, but when i run i got a black grid, and the error floating point exeption (core dumped) No more error, (i also see the coordinates in the debug), but black grid.

                                  M Offline
                                  M Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on 31 May 2020, 12:06 last edited by
                                  #134

                                  @AliM93 said in Create a matrix from a .csv file:

                                  it, but when i run i got a black grid, and the error floating point exeption (core dumped)

                                  In my project or yours ?

                                  A 1 Reply Last reply 31 May 2020, 12:06
                                  0
                                  • M mrjj
                                    31 May 2020, 12:06

                                    @AliM93 said in Create a matrix from a .csv file:

                                    it, but when i run i got a black grid, and the error floating point exeption (core dumped)

                                    In my project or yours ?

                                    A Offline
                                    A Offline
                                    AliM93
                                    wrote on 31 May 2020, 12:06 last edited by
                                    #135

                                    @mrjj in mine

                                    M 1 Reply Last reply 31 May 2020, 12:08
                                    0
                                    • A AliM93
                                      31 May 2020, 12:06

                                      @mrjj in mine

                                      M Offline
                                      M Offline
                                      mrjj
                                      Lifetime Qt Champion
                                      wrote on 31 May 2020, 12:08 last edited by
                                      #136

                                      @AliM93

                                      Ok, i would guess that you forgot something from the maxtric class to put in yours.
                                      But if the grid is drawn ( you see it) and then when you click error comes ?

                                      1 Reply Last reply
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                                      • A Offline
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                                        AliM93
                                        wrote on 31 May 2020, 12:11 last edited by
                                        #137
                                        This post is deleted!
                                        M 1 Reply Last reply 31 May 2020, 12:13
                                        0
                                        • A AliM93
                                          31 May 2020, 12:11

                                          This post is deleted!

                                          M Offline
                                          M Offline
                                          mrjj
                                          Lifetime Qt Champion
                                          wrote on 31 May 2020, 12:13 last edited by mrjj
                                          #138

                                          @AliM93
                                          If it compiles then all includes are fine.

                                          Do you load data ?

                                          Did you change LoadData function to set colors ?
                                          (or use mine, just change the path to the data file)

                                          I think all is just black :)
                                          (default zero)

                                          A 1 Reply Last reply 31 May 2020, 12:18
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