Custom Widget in QListWidget doesn't show correct in list

[astodolski]

I created a custom widget in Qt designer, (with source for changing properties) consisting of a label, progress bar and a checkbox. I have that as an object in a mainwindow to display in a list when triggered. The first trigger displays the widget. Each successive trigger displays the widget in a subsequent row down the list but there only exists one widget with empty rows above.

Widget Code:
Controls.h

#ifndef CONTROLS_H
#define CONTROLS_H
 
#include <QWidget>
 
namespace Ui {
class Controls;
}
 
class Controls : public QWidget
{
    Q_OBJECT
 
public:
    explicit Controls(QWidget *parent = 0);
    ~Controls();
 
public:
    Ui::Controls* ui;
 
public slots:
    void WriteInfoNumber(int);
 
private:
//    Ui::Controls *ui;
};
 
#endif // CONTROLS_H

#ifndef CONTROLS_H
#define CONTROLS_H

#include <QWidget>

namespace Ui {
class Controls;
}

class Controls : public QWidget
{
    Q_OBJECT

public:
    explicit Controls(QWidget *parent = 0);
    ~Controls();

public:
    Ui::Controls* ui;

public slots:
    void WriteInfoNumber(int);

private:
//    Ui::Controls *ui;
};

#endif // CONTROLS_H

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Controls.cpp

#include "controls.h"
#include "ui_controls.h"
 
#include <QDebug>
 
Controls::Controls(QWidget *parent) : QWidget(parent), ui(new Ui::Controls)
{
    ui->setupUi(this);
}
 
Controls::~Controls()
{
    delete ui;
}
 
void Controls::WriteInfoNumber(int value)
{
    qDebug() << "ID Value = " << value;
    ui->label->setText(QString::number(value));
}

#include "controls.h"
#include "ui_controls.h"

#include <QDebug>

Controls::Controls(QWidget *parent) : QWidget(parent), ui(new Ui::Controls)
{
    ui->setupUi(this);
}

Controls::~Controls()
{
    delete ui;
}

void Controls::WriteInfoNumber(int value)
{
    qDebug() << "ID Value = " << value;
    ui->label->setText(QString::number(value));
}

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MainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include "controls.h"
 
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
  Q_OBJECT
 
public:
  explicit MainWindow(QWidget *parent = 0);
  ~MainWindow();
 
signals:
    void    UpdateInfo(int);
 
private slots:
  void on_actionFile_triggered();
 
  void on_actionE_xit_triggered();
 
private:
  Ui::MainWindow*   ui;
  Controls*         ctls;
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "controls.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
  Q_OBJECT

public:
  explicit MainWindow(QWidget *parent = 0);
  ~MainWindow();

signals:
    void    UpdateInfo(int);

private slots:
  void on_actionFile_triggered();

  void on_actionE_xit_triggered();

private:
  Ui::MainWindow*   ui;
  Controls*         ctls;
};

#endif // MAINWINDOW_H

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MainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "ui_Controls.h"
#include <QTime>
 
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow)
{
  ui->setupUi(this);
  ctls = new Controls();
  connect(this, SIGNAL(UpdateInfo(int)), ctls, SLOT(WriteInfoNumber(int)));
}
 
MainWindow::~MainWindow()
{
  delete ui;
}
 
void MainWindow::on_actionE_xit_triggered()
{
  QApplication::quit();
}
 
void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
    ui->listWidget->insertItem(ui->listWidget->size().height(),item);
    ui->listWidget->setItemWidget(item, ctls);
    emit UpdateInfo(t.msec());
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "ui_Controls.h"
#include <QTime>

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow)
{
  ui->setupUi(this);
  ctls = new Controls();
  connect(this, SIGNAL(UpdateInfo(int)), ctls, SLOT(WriteInfoNumber(int)));
}

MainWindow::~MainWindow()
{
  delete ui;
}

void MainWindow::on_actionE_xit_triggered()
{
  QApplication::quit();
}

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
    ui->listWidget->insertItem(ui->listWidget->size().height(),item);
    ui->listWidget->setItemWidget(item, ctls);
    emit UpdateInfo(t.msec());
}

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It seems so straightforward. Don't know what I'm missing.

[anda_skoa]

You only have one object of type Controls, obviously it can only be displayed in one place.

Cheers,
_

P.S.:you don't need to insert the QListWidgetItem, passing the list widget to the constructor takes care of that already.

[astodolski]

You only have one object of type Controls, obviously it can only be displayed in one place.

Cheers,
_

P.S.:you don't need to insert the QListWidgetItem, passing the list widget to the constructor takes care of that already.

Yes that's correct. I only want one type of object displayed in the list. I want to add it to the list for every trigger so as to get a list of rows of the object displayed.

Hope that's clearer than what I originally wrote.

[ChrisW67]

What anda_skoa said was, "You only have one object of type Controls", not "You only have one type of object." It stands to reason that a single Controls widget can be displayed in only the one place. If you want to simultaneously display multiple widgets of type Controls then you need to create multiple objects of that type.

[astodolski]

What anda_skoa said was, "You only have one object of type Controls", not "You only have one type of object." It stands to reason that a single Controls widget can be displayed in only the one place. If you want to simultaneously display multiple widgets of type Controls then you need to create multiple objects of that type.

.

Right!

So call new Controls() in line 29 rather than ctls does the trick for handling multiple entries but breaks the emitted signal for updating the label part of the custom widget. What broke? Perhaps I need a different sender in the signal/slot line in the ctor?

[anda_skoa]

.
So call new Controls() in line 29 rather than ctls does the trick for handling multiple entries but breaks the emitted signal for updating the label part of the custom widget. What broke? Perhaps I need a different sender in the signal/slot line in the ctor?

How do you connect now?

Cheers,
_

[astodolski]

How do you connect now?

Cheers,
_

Line 10 MainWindow.cpp. I connect the emitted signal to the method WriteInfoNumber in Control.cpp

[anda_skoa]

That was from before, when you had only one instance.

If you want all instances of your widget to receive the signal, you need to connect to each one after its respective creation.

Cheers,
_

[astodolski]

That was from before, when you had only one instance.

If you want all instances of your widget to receive the signal, you need to connect to each one after its respective creation.

Cheers,
_

So my trigger method is now as follows:

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
    ui->listWidget->insertItem(ui->listWidget->size().height(),item);
    ui->listWidget->setItemWidget(item, new Controls);
    emit UpdateInfo(t.msec());
}

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
    ui->listWidget->insertItem(ui->listWidget->size().height(),item);
    ui->listWidget->setItemWidget(item, new Controls);
    emit UpdateInfo(t.msec());
}

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The slot connected to UpdateInfo does not change the label. If as you suggest, I connect to each successive instance, I still don't get a change in the label from the slot associated. What I do see however is a call to the slot for each entry in the list: i.e 1 call for the first, 2 calls for the second entry, 3 calls for the third in the list etc.

Should there be a different connect?

What I was able to do as perhaps an interitm step is to call the following which fortunately sets the text for the label:

item->setText(QString::number(t.msec()));

item->setText(QString::number(t.msec()));

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Since I have two other controls, that being a progress bar and the other a checkbox, I still am not sure how to set those other items in the custom widget

[anda_skoa]

So my trigger method is now as follows:

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
    ui->listWidget->insertItem(ui->listWidget->size().height(),item);
    ui->listWidget->setItemWidget(item, new Controls);
    emit UpdateInfo(t.msec());
}

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
    ui->listWidget->insertItem(ui->listWidget->size().height(),item);
    ui->listWidget->setItemWidget(item, new Controls);
    emit UpdateInfo(t.msec());
}

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That is still missing the connect

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
 
    // create instance of Controls
    Controls *ctls = new Controls;
 
    // connect signal to Controls instance
    connect(this, SIGNAL(UpdateInfo(int)), ctls, SLOT(WriteInfoNumber(int)));
 
    ui->listWidget->setItemWidget(item, ctls);
    emit UpdateInfo(t.msec());
}

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));

    // create instance of Controls
    Controls *ctls = new Controls;

    // connect signal to Controls instance
    connect(this, SIGNAL(UpdateInfo(int)), ctls, SLOT(WriteInfoNumber(int)));

    ui->listWidget->setItemWidget(item, ctls);
    emit UpdateInfo(t.msec());
}

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Cheers,
_

[astodolski]

That is still missing the connect

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));
 
    // create instance of Controls
    Controls *ctls = new Controls;
 
    // connect signal to Controls instance
    connect(this, SIGNAL(UpdateInfo(int)), ctls, SLOT(WriteInfoNumber(int)));
 
    ui->listWidget->setItemWidget(item, ctls);
    emit UpdateInfo(t.msec());
}

void MainWindow::on_actionFile_triggered()
{
    QTime t = QTime::currentTime();
    QListWidgetItem* item = new QListWidgetItem(ui->listWidget);
    item->setSizeHint(QSize(300, 35));

    // create instance of Controls
    Controls *ctls = new Controls;

    // connect signal to Controls instance
    connect(this, SIGNAL(UpdateInfo(int)), ctls, SLOT(WriteInfoNumber(int)));

    ui->listWidget->setItemWidget(item, ctls);
    emit UpdateInfo(t.msec());
}

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Cheers,
_

I may be misunderstanding. The Controls instance is the object named ctls. The signal UpdateInfo is connected to the WriteInfoNumber slot belonging to the Controls class.