How to include .txt on Qt



  • Hello,
    I'm on a project and i want to include a Database on Qt.
    I choose a .txt, but i don't know how to code it on my Qt project.
    I need to include 10 or 15 variables with 3 parameter per
    variable, do you have any advices ? Thanks.


  • Lifetime Qt Champion

    Hi and welcome to devnet,

    Do you want a file with these values ? e.g. an XML or JSON structure ? Or are real database like SQLite ?



  • My project is :

    I have a pixeled picture (with i think 50 square who contained 1 color by square) my program already detect the color(in RGB), and for every color i have a picture and a price.

    So i thought of create a kind of database who contained a picture and a price for "every color" (i know that there is an infinite of color so i will choose only the most used color for a picture) and what i want is that for a red color for example (255,0,0 in rgb) it will replace by a picture (that i will choose) and a price

    so at the end it will count all price and return me like 255 dollars (for example)



  • Hi,
    I am taking this opportunity to ask you how to enter Subject line in new post edited since I see no Subject line input box under Firefox for Windows XP.
    All I see top is blue and no room to enter subject of my post.

    thank you


  • Lifetime Qt Champion

    What kind of picture do you have in mind ? What size ?

    @darius Please don't highjack other's people thread with unrelated questions.

    When you create a new topic you have line edit which contains "Enter your topic title here..."
    If you want to edit late use the three doted menu on the far right and you'll have your topic title editable at the same place.



  • it depends, but at the end i will have only 40 - 50 squares with just one color in them.

    So what i want is that Qt replace a color by a picture, ( so i will have 40 - 50 pictures ) and a total price (like 100 dollars)



  • @KzR69100
    My 2 cents :)

    I would go with custom class / structure and serialization. That way there is no need for any kind of database / parsing (per say).
    Also id squares not by color, because after fill You will loose that color, but by some sort of id and keep it's rectangle.



  • @KzR69100 ... @LuGRU gives good advice. But, if you use an ID then your database idea would work as you could make the ID the table entry ID.

    The only recommendation I have is to look at what you are trying to solve. What is the future of what you are trying to solve. Then, pick the appropriate solution. I have seen too many times solutions that don't fit the problem to solve because of a "cool tool" or package someone just had to use.



  • I have a function who return me a color (QColor function)

    QColor Color(...){
    
    return color;
    }
    

    like that, and i thought that after the "return color" i will have a "if color == red, add 6 dollars, and replace it by a picture"

    the problem is that i will have to do this with many colors so it will take a lot of place in my code, thats why i thought use a database that i will include in my Qt who contained a sort of "x = add 6 dollars, and replace it by a picture"

    so i will just have to do :

    if color == red, red = x ;

    is this possible ?



  • @SGaist said in How to include .txt on QT:

    When you create a new topic you have line edit which contains "Enter your topic title here..."

    When I was trying to create a new topic for the last 3 days, forum.qt.io opened in Firefox (latest version) for Windows with oversized font header and blue header frame was made of two lines.
    Topic input frame was lost due to the bug in html code.

    In the meantime I have notified Qt about the bug and today Input box for topic title is back.
    There is another bug in html code visible in Firefox, since there is no send/post button
    I assume, an arrow in upper right corner should replace this button (not easy or user-friendly solution)


  • Lifetime Qt Champion

    @darius Can't reproduce that on Firefox on macOS, the Submit combo is sitting there on the far right.



  • @SGaist thank you. I use upper right arrow on blue background to send this reply.
    Thank you for your time.



  • And for my problem ? :p


  • Qt Champions 2016

    @KzR69100

    So what u want is

    RGB value, ImageName, Cost

    So for a given RGB value, u want to look up ImageName, and Cost?

    How many of those looks up will you need?
    If only 10 or 15 , then a DB might be a bit overkill.

    Do you need it to be dynamic or could it be 100% predefined?



  • """"So for a given RGB value, u want to look up ImageName, and Cost?"""

    Yes exactly,

    i got 10 pictures who got 1 colors and 5 - 6 pictures who got 2 colors (if 2 squares beside equal got the same color as the picture who got 2 colors, so i will do 2 square = 1 picture)

    but the principal is the 10 picture who got 1 color.

    It will be all predefined no dynamic


  • Lifetime Qt Champion

    Which size should these picture be ?


  • Qt Champions 2016

    @KzR69100
    Hi
    You can make such small number very compact in code.
    Add the images to a qres file and store name as :/imagename and
    you can get a pixmap directly from it. ( as in Pixmap p(":/img");
    Sample code. very basic but could be enough for your case.

    struct CostInfo {
      QString ImageName;
      int Cost;
    };
    
    QMap<QRgb, CostInfo > Costs = {
      { QColor(255, 0, 120).rgb(), { ":/imageinres", 10 }},
      { QColor(110, 255, 110).rgb(), { "xxxx", 20 }},
      { QColor(120, 255, 20).rgb(), { "xxxx", 30 }},
      { QColor(130, 255, 90).rgb(), { "xxxx", 40 }},
      { QColor(140, 255, 10).rgb(), { "xxxx", 50 }},
      { QColor(100, 100, 100).rgb(), { "MEEEE", 60 }},
      { QColor(110, 255, 40).rgb(), { "xxxx", 70 }},
      { QColor(210, 255, 50).rgb(), { "xxxx", 80 }},
      { QColor(30, 255, 60).rgb(), { "xxxx", 3310 }},
      { QColor(20, 255, 70).rgb(), { "xxxx", 4410 }},
      { QColor(40, 255, 80).rgb(), { "xxx", 150 }},
      { QColor(50, 255, 90).rgb(), { "xxx", 160 }}
    };
    
    
    void Test() {
      QColor col = QColor(100, 100, 100); // getColor()..
      if (Costs.contains( col.rgb() )) {
        CostInfo& ci = Costs[col.rgb()];
        qDebug() << "found:" << "cost:" << ci.Cost << "img:" << ci.ImageName;
      }
    }
    
    

    Running test() gives
    found: cost: 60 img: "MEEEE"



  • @SGaist i don't know it depends as i said, but in all case i think it will contain like 50 squares.

    @mrjj Thanks for your help.
    I don't understand the " QMap<QRgb, CostInfo > Costs "

    and my problem i think, it's if i got a QColor(105,4,85) there will be a problem because it will not found a QColor who corresponds.

    So i thought use a "for" to take a value range, and have all possible color, that's correct ?


  • Qt Champions 2016

    • I don't understand the " QMap<QRgb, CostInfo > Costs "
      Its a associative list. Using QRgb ( the color ) as key and it returns a Costs struct that is the
      data associated with that key.
      Read about it here
      http://doc.qt.io/qt-5/qmap.html
      Its a lookup list so to speak.

    • and my problem i think, it's if i got a QColor(105,4,85) there will be a problem because it will not found a QColor who corresponds.

    Well if not in list, { QColor(105,4,85).rgb(), { "xxxx", 50 }},
    then nothing happens as you test with
    if (Costs.contains( col.rgb() )) { << test if found
    xxxonly do if foundxxx



  • @mrjj
    So if nothing happens that's bad :p

    What do you think about use a "for" ?

    Like i don't care if it's a dark red, or a simple red etc..

    My question is :

    If nothing if found, how function can i use to find the "closer" color to the define color in my struct ?

    thanks


  • Qt Champions 2016

    • If nothing if found, how function can i use to find the "closer" color to the define color in my struct ?

    Hi
    use the QMapIterator instead of "for"

    QMapIterator<QString, int> i(map);
    while (i.hasNext()) {
    i.next();
    cout << i.key() << ": " << i.value() << endl;
    }
    http://doc.qt.io/qt-5/qmap.html#details

    That allows you to go over all and get the keys. (i.key())
    QColor TheColor(i.key())
    Then you can calculate if the RGB values for TheColor is
    close enough for you to accept it.
    For inspiration see here
    http://stackoverflow.com/questions/9018016/how-to-compare-two-colors

    int diffRed   = Math.abs(c1.getRed()   - c2.getRed());
    int diffGreen = Math.abs(c1.getGreen() - c2.getGreen());
    int diffBlue  = Math.abs(c1.getBlue()  - c2.getBlue());
    Those values you can just divide by the amount of difference saturations (255), and you will get the difference between the two.
    
    float pctDiffRed   = (float)diffRed   / 255;
    float pctDiffGreen = (float)diffGreen / 255;
    float pctDiffBlue   = (float)diffBlue  / 255;
    After which you can just find the average color difference in percentage.
    
    (pctDiffRed + pctDiffGreen + pctDiffBlue) / 3 * 100
    


  • That is very complicated.

    QMap is a kind of database, a dictionary that is right ?

    I will try with you'r first code :

    I don't understand the function void Test.

    I got a function who return me a color in QRGB, it named "color" can i say just :

    If (color == (the color in the Qmap (i dont know how to call it))){
    cost = 50;
    image = (red image)
    }
    ?

    The problem is that i understand QMap, but i don't know how to use it and i'm new to programmation


  • Qt Champions 2016

    @KzR69100 said in How to include .txt on Qt:

    • That is very complicated.
      Ok, its plain c++ and maps are often used. I didnt mean to make it
      complicated. Using say a DataBase would be 10 times the code.

    QMap is a kind of database, a dictionary that is right ?
    Yes. You tell it ( whatkey, whatvalue)
    and then u can ask for it to return the value for a key.
    In this sample we used a color as key.

    I don't understand the function void Test.

    void Test() {
      // this is the color to look for
      QColor col = QColor(100, 100, 100); // getColor()..
     // check the map if it has the color ( suing contains)
      if (Costs.contains( col.rgb() )) {
        CostInfo& ci = Costs[col.rgb()]; // take the struct from list
        qDebug() << "found:" << "cost:" << ci.Cost << "img:" << ci.ImageName;
      }
    }
    
    > 
    > I got a function who return me a color in QRGB, it named "color" can i say just :
    > If (color == (the color in the Qmap (i dont know how to call it))){
    You cannot use == you must use Contains function.
    if (Costs.contains( color.rgb() )   ) {
        CostInfo& ci = Costs[color.rgb()]; // take the struct from list
       QColor TheColor(i.key()); // this is the base color
       int Cost=ci.Cost; // use the values.
      }
    


  • void Test() {
      // this is the color to look for
      QColor col = QColor(100, 100, 100); // getColor()..
     // check the map if it has the color ( suing contains)
      if (Costs.contains( col.rgb() )) {
        CostInfo& ci = Costs[col.rgb()]; // take the struct from list
        qDebug() << "found:" << "cost:" << ci.Cost << "img:" << ci.ImageName;
      }
    }
    

    So the QColor col is my returned color that is right ?

    i don't understand the "CostInfo& ci"

    And do the size of the picture in the Qmap have to be resized?

    PS :
    my function is :

    for(int x = topLeft.x(); x < maxX; ++x) {
    		for(int y = topLeft.y(); y < maxY; ++y) {
    			image.setPixelColor(x, y, colour);
                                                  if (Costs.contains( colour.rgb() )) {          // it will be that ?
                                                       CostInfo& ci = Costs[colour.rgb()];
    		}
    	}
    }
    

    to have all RGB in my struct can i use a "for" (sorry to always say "can i use a for") but the problem is that i want all RGB value with my 15 - 20 pictures


  • Qt Champions 2016

    @KzR69100

    • So the QColor col is my returned color that is right ?
      Yes, the Color to look for.

    • i don't understand the "CostInfo& ci"

    It means a reference to a CostInfo.
    We ask the map to return the CostInfo for the key and instead of
    having it as a copy we actually point to the one in the list.
    so if you do

    ci.Cost = 100; you would update the one in the list.

    if we did
    CostInfo ci = Costs[col.rgb()];
    It would make a copy and ci would be a copy and not point to one in the list.

    So if it was integers and a normal list.
    int a= List[1]; // copy
    int &a = List[1]; // a points to the int in index [1]

    • And do the size of the picture in the Qmap have to be resized?

    The qmap only store the file names of the images
    I assume you are adding the images to a QRes file
    http://www.bogotobogo.com/Qt/Qt5_Resource_Files.php
    So all images are build into the program
    and then load them with ":/" syntax.
    That would be easy and fast.
    http://doc.qt.io/qt-5/resources.html

    
    for(int x = topLeft.x(); x < maxX; ++x) {
    		for(int y = topLeft.y(); y < maxY; ++y) {
    			image.setPixelColor(x, y, colour);
                                                  if (Costs.contains( colour.rgb() )) {          // it will be that ?  YES
                                                       CostInfo& ci = Costs[colour.rgb()];
                                                         int Cost = ci.Cost;
                                                          Pixmap pix( ci.ImageName ); 
    		}  
    	}
    }
    

    to have all RGB in my struct can i use a "for" (sorry to always say "can i use a for") but the problem is that i want all RGB value with my 15 - 20 pictures

    Not sure what you are asking here :)
    Are you asking how to use a FOR with the QMAP `?
    u can do

    
    QMapIterator<QRgb, CostInfo >i(Costs);
    while (i.hasNext()) {
        i.next();
        cout << i.key() << ": " << i.value().Cost << endl;
    }
    

    Pleases read
    http://doc.qt.io/qt-5/qmap.html



  • thanks,

    i already read the doc for Qmap,

    my question was the same as before (sorry) i asked that if i got a square who have a color like ( 255 , 2 , 2 - It's near red ) how can i display a red file because on my Qmap i have only

    QColor(250,0,0).rgb(), { "C:\Users\David\Desktop\Red\strawberry", 10) (i will use :/ after created my QRes file)

    the i.hasNext is the answer to my question right ? he will found a value next to his value ?

    My other question was that i have to browse all my picture with a double for (because i got 50 square in my picture)

    so i have to put the

    if (Costs.contains( colour.rgb() )) {          
                                                      CostInfo& ci = Costs[colour.rgb()];
                                                        int Cost = ci.Cost;
                                                         Pixmap pix( ci.ImageName );
    

    and then the while (i.hasNext()) ?


  • Qt Champions 2016

    @KzR69100

    • my question was the same as before (sorry) i asked that if i got a square who have a color like ( 255 , 2 , 2 - It's near red )

    For that you need to a function that can compare the RGB values.
    And if Base Color and the color you come with ( from image) is
    within some threshold you also accept it.
    http://stackoverflow.com/questions/9018016/how-to-compare-two-colors
    like
    bool IsCloseColor( QColor c1, QColor c2 ) {
    // this you must fill in . read link.
    }
    If you want a clever mathcing , this is also interresting
    http://stackoverflow.com/questions/2103368/color-logic-algorithm

    • the i.hasNext is the answer to my question right ? he will found a value next to his value ?
      Yes the code shown will go over map. Just like a "For"
      Something like:
      QMapIterator<QRgb, CostInfo >i(Costs);
      while (i.hasNext()) {
        i.next();
        QColor BaseColor( i.key() );
        if (Costs.contains( colour.rgb() ) || IsCloseColor(BaseColor, colour)   )  {
          CostInfo& ci = Costs[colour.rgb()];
          int Cost = ci.Cost;
          QPixmap pix( ci.ImageName );
        }
      }// while
    


  • i got :

    bool IsCloseColor( QColor c1, QColor c2 ) {
    	int diffRed   = Math.abs(c1.red() - c2.red());
    	int diffGreen = Math.abs(c1.green() - c2.green());
    	int diffBlue  = Math.abs(c1.blue()  - c2.blue());
    
    	if (diffBlue+diffRed+diffGreen< z){	// i block for the z how can i say "the smallest" ?
    		return c1;
    
    
    	}
    }
    

    i got a lot of errors, i tried to google it but no answer :

    like : request for meme "key in 'i'", which is of non-class type 'int'

    template argument 2 is invalid (QMap<QRgb, CostInfo ">" Costs =)

    scalar object 'Costs' requires one element in initializer


  • Qt Champions 2016

    @KzR69100

    z you must decide for.
    Best is to test with different colors and see how close its still ok.

    With the exact code and the exact line it's impossible to say what error comes from.

    You can try my test project. It compiles and you can test the color matching.
    https://www.dropbox.com/s/6mc3e4qe375qzih/mylookup.zip?dl=0



  • My code is : (cpp)

    #include "mainwindow.h"
    #include "ui_mainwindow.h"
    #include <QPixmap>
    #include <QImage>
    #include <QFileDialog>
    #include <QColor>
    #include <QPoint>
    #include <QSize>
    #include <iostream>
    using namespace std;
    
    
    QColor Couleurdominante(const QImage& image, const QPoint& topLeft, const QSize& rectSize);
    void Remplissage(QImage& image, const QPoint& topLeft, const QSize& rectSize, const QColor& colour);
    
    
    MainWindow::MainWindow(QWidget *parent) :
    	QMainWindow(parent),
    	ui(new Ui::MainWindow)
    {
    		ui->setupUi(this);
    
    }
    
    
    MainWindow::~MainWindow()
    {
    	delete ui;
    }
    
    
    
    
    void MainWindow::on_push_clicked()
    {
    	QString fileName = QFileDialog::getOpenFileName(this,
    	tr("Open Image"), "/", tr("Image Files (*.png *.jpg *.bmp)"));
    	QPixmap pix(fileName);
    	ui->label->setPixmap(pix);
    	const QSize s = pix.size();
    	pixi = QImage(pix.toImage());
    
    	ui->label_2->setText( "Size: " + QString::number(s.width()) +" "+ QString::number(s.height()) );
    
    }
    
    void MainWindow::on_push2_clicked()
    {
    
    
    	for (int i=0;i<pixi.width();i+=a){
    						 for (int j=0;j<pixi.height();j+=b){
    	Remplissage(pixi,QPoint(i,j),QSize(a,b),Couleurdominante(pixi,QPoint(i,j),QSize(a,b)));
    	}}
    
    	pixa=QPixmap::fromImage(pixi);
    	ui->label_3->setPixmap(pixa);
    
    }
    
    
    
    
    void Remplissage(QImage& image, const QPoint& topLeft, const QSize& rectangle, const QColor& colour) {
    
    	int maxX = topLeft.x() + rectangle.width();
    	int maxY = topLeft.y() + rectangle.height();
    
    	for(int x = topLeft.x(); x < maxX; ++x) {
    		for(int y = topLeft.y(); y < maxY; ++y) {
    			image.setPixelColor(x, y, colour);
    			QMapIterator<QRgb, CostInfo >i;
    			while (i.hasNext()) {
    				i.next();
    				QColor BaseColor( i.key() );
    				if (Costs.contains( colour.rgb() ) || IsCloseColor(BaseColor, colour) )  {
    					CostInfo& ci = Costs[colour.rgb()];
    					int Cost = ci.Cost;
    					QPixmap pix( ci.ImageName );
    				}
    			}
    		}
    	}
    }
    
    
    QColor Couleurdominante(const QImage & image,const QPoint & topLeft, const QSize & rectangle)
    {
    		int rouge = 0, vert = 0, bleue = 0;
    
    		int  X = topLeft.x() + rectangle.width();
    		int  Y = topLeft.y() + rectangle.height();
    
    		for (int y = topLeft.y(); y < Y; y++)  {
    				for (int x = topLeft.x(); x < X; x++)   {
    						QRgb pixel = image.pixel(x, y);
    
    						rouge += qRed(pixel);
    						vert += qGreen(pixel);
    						bleue += qBlue(pixel);
    				}
    		}
    
    		int n = rectangle.width() * rectangle.height();
    
    		Q_ASSERT(n);
    		if (n <= 0)
    				return Qt::black;
    
    		return QColor(rouge / n, vert / n, bleue / n);
    }
    
    
    
    QMap<QRgb, CostInfo > Costs = {
    	{ QColor(255 , 0 , 0 ).rgb(), { "://fraise.png", 10 }},
    	{ QColor(0 , 255 , 0 ).rgb(), { "://balleverte.png", 20 }},
    	{ QColor(0 , 0 , 255 ).rgb(), { "://ballebleue.png", 20 }},
    	{ QColor(255 , 255 , 255 ).rgb(), { "://balleblanche.png", 20 }},
    	{ QColor(255 , 128 , 0 ).rgb(), { "://ballepeche.png", 20 }},
    	{ QColor(0 , 0 , 0 ).rgb(), { "://noir.png", 20 }},
    	{ QColor(102 , 51 , 0 ).rgb(), { "://marron.png", 20 }},
    	{ QColor(255 , 102 , 78 ).rgb(), { "://rose.png", 20 }},
    	{ QColor(0 , 204 , 204 ).rgb(), { "://turquoise.png", 20 }},
    	{ QColor(255 , 178 , 102 ).rgb(), { "://beige.png", 20 }},
    	{ QColor(76 , 0 , 153 ).rgb(), { "://violet.png", 20 }},
    	{ QColor(100 , 100 , 100 ).rgb(), { "://gris.png", 20 }},
    };
    
    bool IsCloseColor( QColor c1, QColor c2 ) {
    	int diffRed   = Math.abs(c1.red() - c2.red());
    	int diffGreen = Math.abs(c1.green() - c2.green());
    	int diffBlue  = Math.abs(c1.blue()  - c2.blue());
    
    	if (diffBlue+diffRed+diffGreen< 100){	/
    		return c1;
    
    
    	}
    }
    
    
    

    i took z = 100. For the moment

    .h :

    #ifndef MAINWINDOW_H
    #define MAINWINDOW_H
    
    #include <QMainWindow>
    #include <QPixmap>
    #include <QPoint>
    #include <QSize>
    #include <iostream>
    
    namespace Ui {
    	class MainWindow;
    }
    
    class MainWindow : public QMainWindow
    {
    	Q_OBJECT
    
    public:
    	explicit MainWindow(QWidget *parent = 0);
    
    
    	~MainWindow();
    
    
    
    
    
    private slots:
    	void on_push_clicked();
    	struct CostInfo {
    		QString ImageName;
    		int Cost;
    	};
    
    	void on_push2_clicked();
    
    	void on_verticalSlider_sliderMoved(int position);
    
    private:
    	Ui::MainWindow *ui;
    	QImage pixi;
    	QPixmap pixa;
    	int a;
    	int b;
    };
    
    #endif // MAINWINDOW_H
    

  • Qt Champions 2016

    Hi
    In your
    bool IsCloseColor( QColor c1, QColor c2 ) {
    int diffRed = Math.abs(c1.red() - c2.red());
    int diffGreen = Math.abs(c1.green() - c2.green());
    int diffBlue = Math.abs(c1.blue() - c2.blue());

    if (diffBlue+diffRed+diffGreen< 100){	/
    	return c1; <<<<<< you should return true
        else //////////////////you need this part also
           return false;  /////////


  • Thank you i corrected.

    And for my other error ?

    in : if (Costs.contains( colour.rgb() ) || IsCloseColor(BaseColor, colour) )

    for the function IsCloseColor, its not better to return a color ? like QColor IsCloseColor();, i don't understand what we can do if we return "false" or "true"



  • i up ! need help ^^



  • for the function IsCloseColor, its not better to return a color ? like QColor IsCloseColor();, i don't understand what we can do if we return "false" or "true"


  • Qt Champions 2016

    @Payx

    It just checks if the color is "close " to base color
    No reason to return color ?
    we say
    if (Costs.contains( colour.rgb() ) || IsCloseColor(BaseColor, colour) )

    So if we have direct match OR
    the colour is close to BaseColor then we think its ok.



  • Okay thank you,

    i have

    diffBlue+diffRed+diffGreen< 100
    

    but if many colors correspond ?
    it can return many colors no ?


  • Qt Champions 2016

    @Payx
    No it cant..
    IsCloseColor tells if 2 colors are close. It return true/false.
    it dont return any color. it tells you if they color u have "in the hand" matches the
    base color given.
    You already have the color (colour var) so no reason to return it.



  • So it cant be possible to have 2 colors who is <100 ?


  • Qt Champions 2016

    @Payx
    ofc, just compare 2 times or more times. Once pr color.
    IsCloseColor(BaseColor, col1)
    IsCloseColor(BaseColor, col2)
    IsCloseColor(BaseColor, col3)
    ....



  • So if i have like 27 colors, i have to do 27 function ?


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