Qt / C++ - qDebug << class - c++

Question

How do I make qDebug print whether my class exists or not, or information about that class?? Can't believe there's nothing about this on the internet. I need to make sure that my ink = new InkSpot(this;) is actually returning something valid.
ink = new InkSpot(this);
qDebug << ink;
X:\Development\InkPuppet\inkpuppet.cpp:70: error: C3867: 'QMessageLogger::debug': function call missing argument list; use '&QMessageLogger::debug' to create a pointer to member
I've tried using QMessageLogger but just get various errors.
My program is crashing because I do something to ink.widget, so I'll post the code for ink
The code calling it is this:
header:
InkSpot *ink;
void InkPuppet::testButton()
{
ink = new InkSpot(this);
qDebug() << ink->widget;
ui->testButton->setText("working");
}
inkspot.h
#ifndef INKSPOT_H
#define INKSPOT_H
#include <QObject>
#include <QWidget>
#include <QPainter>
#include <QPaintEvent>
#include <QLabel>
namespace Ui {
class InkSpot;
}
class InkSpot : public QWidget
{
Q_OBJECT
public:
explicit InkSpot(QWidget *parent = 0);
void draw(QPainter *painter);
QWidget *widget;
QLabel *label;
signals:
public slots:
protected:
void paintEvent(QPaintEvent *event);
private:
Ui::InkSpot *ui;
};
#endif // INKSPOT_H
inkspot.cpp
#include "inkspot.h"
#include "inkpuppet.h"
#include "ui_inkpuppet.h"
#include <QtCore>
#include <QtGui>
#include <QWidget>
#include <QPainter>
#include <QPaintEvent>
InkSpot::InkSpot(QWidget *parent) :
QWidget(parent)
{
}
void InkSpot::paintEvent(QPaintEvent *event)
{
QFile *brushInput; //takes raw 8 bit grayscale image, 8 bit values only
char *brushProto;
uchar *brushData;
brushInput = new QFile("x:\\Development\\InkPuppet\\brush.raw"); //open the raw file
brushInput->open(QIODevice::ReadOnly);
QDataStream in;
in.setDevice(brushInput);
int size = brushInput->size(); //set size to length of raw file
brushProto = new char[size];
in.readRawData(brushProto, size); //read file into prototype
brushData = new uchar[size];
for(int i = 0; i < size; ++i)
{
brushData[i] = (uchar)brushProto[i]; //copy char to uchar array
}
QImage test(brushData, 128, 128, QImage::Format_Indexed8);
QImage test2(128, 128, QImage::Format_ARGB32);
QVector<QRgb> vectorColors(256); //create color table
for(int c = 0; c < 256; c++)
{
vectorColors[c] = qRgb(c, c, c);
}
test.setColorTable(vectorColors);
for(int iX = 0; iX < 100; ++iX)
{
for(int iY = 0; iY < 100; ++iY)
{
test2.setPixel(iX, iY, qRgba(255 - (qrand() % 100), 0 + (qrand() % 100), 0 + (qrand() % 100), qAbs((int)test.pixel(iX, iY)-255)));
}
}
//final conversion for stencil and color brush
QPixmap testPixmap = QPixmap::fromImage(test2);
QPixmap testPixmap2 = QPixmap::fromImage(test);
QPainter painter(this);
painter.drawPixmap(150, 50, 100, 100, testPixmap);
painter.drawPixmap(50, 50, 100, 100, testPixmap2);
delete[] brushProto;
delete[] brushData;
delete brushInput;
}

Answer 1

Not trivial what you want to do. That qDebug() displays something useful you have to implement the 'operator<<'. The following is a rough example, how this could look like:
QDebug inline operator<<(QDebug d, const InkSpot &f){
QDebug nsp = d.nospace();
nsp << f.label->text();
nsp << "\n";
return d;
}
This prints your InkSpot's label text. Add whatever else information your need. Put above code in your InkSpot.h file, but outside the class definition. If your need to access InkSpots private data, you must make QDebug operator<< a friend of InkSpot.