Create a matrix from a .csv file

mrjj

Hi
Super
Now we add a new function to our new class.
lets call it LoadData.

add these to the .cpp 
#include <QFile>
#include <QTextStream>
#include <QDebug>

// this is changed version of your reader code
void MatrixWidget::LoadData()
{
    QFile file("/home/alice/catkin_ws/src/agree_gui/resources/Punti_tappetino.csv");
    if (!file.open(QFile::ReadOnly | QFile::Text)) {
        qDebug() << "FIle not exist";

    } else {
        QTextStream in(&file);
        while (!in.atEnd()) {
            QString line = in.readLine();
            QStringList list = line.split(";");
            int x = list.at(0).toInt();
            int y = list.at(1).toInt();
            bool value = list.at(2).toInt();
            if ( x < max_x && y < max_y) // to make sure we dont crash
                Data[x][y].value = value; // here we store value
            else
                qDebug() << "x or y bigger than matrix!";
        }

    }
    file.close();
}

Do you follow so far ?
I have not tried this before so not sure how easy its to follow :)

AliM93

@mrjj yes i understand all the flow! super clear, so far.

mrjj

@AliM93
Super!
Could you open Punti_tappetino.csv in textEditor and copy it to say
https://paste.ofcode.org/
and give me url ?
Then i also have some real data to read it to check loaddata works :)

AliM93

@mrjj Done! are you seing it?

mrjj

@AliM93
where is the url ?

you have to press paste it and then copy the adress from the top of browser
like
https://paste.ofcode.org/vYJiPZBPqzaDNArjpqPYE7
(just test)

AliM93

@mrjj https://paste.ofcode.org/XLhSxBmaWcaKj2L9CapQ3s

sorry my bad

i have also to declare the function iLoadData in the .h file, right? in the private, protected or in the public slot?

mrjj

@AliM93
ah better :)
yes also add to public section.
we might call it from outside so its public.

AliM93

@mrjj ok! but i get some trouble with the struct. invalid use of non-static data member.

mrjj

@AliM93
can you show line where it says that ´
Mine compiles fine.

AliM93

This post is deleted!

mrjj

@AliM93
nope its not cmake

it seems you forgot the ending of the DataPoint class ?
the }; part ?

struct DataPoint {
    int x;
    int y;
    bool value;
    QColor DrawColor; // we change this from selected / not selected.
    bool isSelected; // we set this when we click on it.
};

AliM93

sorry.
solved. and now in public slot :
i add : void::Matrixwidget LoadData?

mrjj

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

void::Matrixwidget LoadData?

yes but mind the use of ::
its only use outside class so in .h its just

void LoadData();

AliM93

done! thanks, now we have to modify the paintevent in order to show the grid, right?

mrjj

@AliM93

Ok, small fix.
You data has max x,y as
x: 14 y: 21
so our array is one to small as we start in 0 (zero)
so change

const int max_x = 14;
const int max_y = 21;

to

const int max_x = 15;
const int max_y = 22;

as else we drop some :)

AliM93

@mrjj ok thanks

mrjj

Ok next step is to add some paint code.

So in .cpp

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
    int bw = w / max_x;
    int 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  ) )  ;
        }
    }

}

and then next we will add to some UI so we can see what it start working :)
Teaser.
alt text

AliM93

@mrjj thanks also for comments, so i can better follow the flow. but sorry i have to include QPainter somewhere? yes solved!

mrjj

@AliM93
Yep, need includes.

I hope comments are enough to understand it.
its just calculating how big each box should when we have max_x and max_y and some area ( the widgets area)

Shall we try to add it and UI and see something?
I want to show you a Creator feature called Promotion that makes it easy to use such custom control.

(note i bumped your upvotes so you should be able to post faster now)

AliM93

@mrjj sure! the only thing is, as you can image from my images, i'm working into a bigger file, and when i run the app i have also a main_window.ui. so i have to link all the things to that. is it possilbe, isn'it it?