Accessing widgets from my class

[MuldeR]

[quote author="Flurite" date="1335222560"]
Anyhow, the errors were as mentioned in a previous post this:

invalid use of incomplete struct type ‘struct Ui::Clock_Application’ --- at line 40
forward declaration of ‘struct Ui::Clock_Application’ --- at line 11
invalid use of incomplete struct type ‘struct Ui::Clock_Application’ --- at line 73
forward declaration of ‘struct Ui::Clock_Application’ --- at line 11,

Lines 40 and 73 are lines in my changeValue() method that try and access the widget.. not surprising lol..[/quote]

There are different methods to use the .ui files generated with Qt Designer:
http://doc-snapshot.qt-project.org/4.8/designer-using-a-ui-file.html

It seems that you have decided for the "Using a Pointer Member Variable" method:
http://doc-snapshot.qt-project.org/4.8/designer-using-a-ui-file.html#using-a-pointer-member-variable

However it seems like you are missing to include the header file (.h) generated by the UIC.
You have the forward declaration (probably in your header file), but are missing the actual definition!
Make sure you include the header file generated by UIC in your source file...

[Flurite]

[quote author="MuldeR" date="1335223272"]
[quote author="Flurite" date="1335222560"]
Anyhow, the errors were as mentioned in a previous post this:

invalid use of incomplete struct type ‘struct Ui::Clock_Application’ --- at line 40
forward declaration of ‘struct Ui::Clock_Application’ --- at line 11
invalid use of incomplete struct type ‘struct Ui::Clock_Application’ --- at line 73
forward declaration of ‘struct Ui::Clock_Application’ --- at line 11,

Lines 40 and 73 are lines in my changeValue() method that try and access the widget.. not surprising lol..[/quote]

There are different methods to use the .ui files generated with Qt Designer:
http://doc-snapshot.qt-project.org/4.8/designer-using-a-ui-file.html

It seems that you have decided for the "Using a Pointer Member Variable" method:
http://doc-snapshot.qt-project.org/4.8/designer-using-a-ui-file.html#using-a-pointer-member-variable

However it seems like you are missing to include the header file (.h) generated by the UIC.
You have the forward declaration (probably in your header file), but are missing the actual definition!
Make sure you include the header file generated by UIC in your source file...[/quote]

No wait, you're saying that I did not include the header file in my clock_application.cpp file? I think I did include that. These are the files I have included in my clock_application.cpp file:

#include "clock_application.h"
#include "ui_clock_application.h"
#include "QString"
#include "QRegExp"
#include "vector"
#include "QThread"

[MuldeR]

“ui_clock_application.h” is what the UIC created from your .UI file, right?

Did you inspect that file? In you case it should contain:

@/********************************************************************************
** Form generated from reading UI file 'Clock_Application.ui'
**
** Created: Sun 22. Apr 02:04:07 2012
** by: Qt User Interface Compiler version 4.8.1
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

...

QT_BEGIN_NAMESPACE

class Ui_Clock_Application
{
public:

....

}

namespace Ui {
class Clock_Application: public Ui_Clock_Application {};
}@

If that header file does not define Ui::Clock_Application, then that explains why you get the error.

[Flurite]

I do not know. It's included in the .cpp file, but I cannot find it in the project's folder.

[MuldeR]

Actually your compiler would throw an error, if you include a file that does not exist.

So it has to exist - somewhere.

If you create GUI's with the Qt Designer, you first get a .UI file. But C++ doesn't know anything about .UI files.

The UIC program needs to be used to create a C++ header file (.h) from your UI file.

Then the header file created by UIC can be included. It contains the required definitions, of Ui::MyDialgClass.

In your case, it should contain the definition of Ui::Clock_Application. Otherwise you have a problem...

[Flurite]

Hmm.. I'm positive that I used Qt Designer.. but I'm somehow doubting that's the problem because my program will run if I reset it to what it originally was.

clock_application.h contains my definition of Clock_Application

[MuldeR]

Defining your own class is not sufficient.

Somehow the code generated by UIC (based on your .UI file from the Qt Designer) needs to be incorporated.

And Qt offers different ways to do that. You apparently chose the "Using a Pointer Member Variable" way.

Please carefully read:
http://doc-snapshot.qt-project.org/4.8/designer-using-a-ui-file.html

[Flurite]

Sorry I'm probably being really dumb right now.

Anyway, I read it, but I am not understanding how this will help me. The header file that contains the code you said previously is called clock_application.h

[MuldeR]

Well, did you manage to locate the header file generated by UIC?

If so, did you inspect that file to make sure it contains a definition of Ui::Clock_Application ???

In your code you use the Ui::Clock_Application class (note hat that is one is different from the Clock_Application class without the "Ui::"). This requires that this class is defined somewhere. Your error message indicates that you have a forward-declaration of that class, but no definition of it! A forward-declaration is sufficient to declare the pointer member variable in your own class, but as soon as you want to dereference the pointer, a full definition is required. That definition usually is given in the header file generated by UIC (from your .UI file).

[Flurite]

Aha, I found it! I just recalled there are two folders for a project! Let me copy and paste the code for you. It's a long piece.

@
/********************************************************************************
** Form generated from reading UI file 'clock_application.ui'
**
** Created: Sat Mar 17 18:50:58 2012
** by: Qt User Interface Compiler version 4.7.4
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef UI_CLOCK_APPLICATION_H
#define UI_CLOCK_APPLICATION_H

#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#include <QtGui/QLineEdit>
#include <QtGui/QMainWindow>
#include <QtGui/QPushButton>
#include <QtGui/QStatusBar>
#include <QtGui/QTabWidget>
#include <QtGui/QToolBar>
#include <QtGui/QWidget>

QT_BEGIN_NAMESPACE

class Ui_Clock_Application
{
public:
QWidget *centralWidget;
QTabWidget *ClockSet;
QWidget *Stopwatch;
QLineEdit *Output;
QPushButton *Start;
QPushButton *Pause;
QPushButton *Reset;
QWidget *Alarm;
QToolBar *mainToolBar;
QStatusBar *statusBar;

void setupUi(QMainWindow *Clock_Application)
{
    if (Clock_Application->objectName().isEmpty())
        Clock_Application->setObjectName(QString::fromUtf8("Clock_Application"));
    Clock_Application->resize(400, 300);
    centralWidget = new QWidget(Clock_Application);
    centralWidget->setObjectName(QString::fromUtf8("centralWidget"));
    ClockSet = new QTabWidget(centralWidget);
    ClockSet->setObjectName(QString::fromUtf8("ClockSet"));
    ClockSet->setGeometry(QRect(10, 0, 371, 241));
    ClockSet->setTabPosition(QTabWidget::North);
    ClockSet->setTabShape(QTabWidget::Rounded);
    Stopwatch = new QWidget();
    Stopwatch->setObjectName(QString::fromUtf8("Stopwatch"));
    Output = new QLineEdit(Stopwatch);
    Output->setObjectName(QString::fromUtf8("Output"));
    Output->setGeometry(QRect(120, 50, 131, 31));
    Output->setAlignment(Qt::AlignCenter);
    Start = new QPushButton(Stopwatch);
    Start->setObjectName(QString::fromUtf8("Start"));
    Start->setGeometry(QRect(40, 110, 81, 31));
    Pause = new QPushButton(Stopwatch);
    Pause->setObjectName(QString::fromUtf8("Pause"));
    Pause->setGeometry(QRect(150, 110, 81, 31));
    Reset = new QPushButton(Stopwatch);
    Reset->setObjectName(QString::fromUtf8("Reset"));
    Reset->setGeometry(QRect(250, 110, 81, 31));
    ClockSet->addTab(Stopwatch, QString());
    Alarm = new QWidget();
    Alarm->setObjectName(QString::fromUtf8("Alarm"));
    ClockSet->addTab(Alarm, QString());
    Clock_Application->setCentralWidget(centralWidget);
    mainToolBar = new QToolBar(Clock_Application);
    mainToolBar->setObjectName(QString::fromUtf8("mainToolBar"));
    Clock_Application->addToolBar(Qt::TopToolBarArea, mainToolBar);
    statusBar = new QStatusBar(Clock_Application);
    statusBar->setObjectName(QString::fromUtf8("statusBar"));
    Clock_Application->setStatusBar(statusBar);

    retranslateUi(Clock_Application);
    QObject::connect(Start, SIGNAL(clicked()), Clock_Application, SLOT(timer_Start()));

    ClockSet->setCurrentIndex(0);


    QMetaObject::connectSlotsByName(Clock_Application);
} // setupUi

void retranslateUi(QMainWindow *Clock_Application)
{
    Clock_Application->setWindowTitle(QApplication::translate("Clock_Application", "Clock_Application", 0, QApplication::UnicodeUTF8));
    Output->setText(QApplication::translate("Clock_Application", "00:00:00", 0, QApplication::UnicodeUTF8));
    Start->setText(QApplication::translate("Clock_Application", "Start", 0, QApplication::UnicodeUTF8));
    Pause->setText(QApplication::translate("Clock_Application", "Pause", 0, QApplication::UnicodeUTF8));
    Reset->setText(QApplication::translate("Clock_Application", "Reset", 0, QApplication::UnicodeUTF8));
    ClockSet->setTabText(ClockSet->indexOf(Stopwatch), QApplication::translate("Clock_Application", "Stopwatch", 0, QApplication::UnicodeUTF8));
    ClockSet->setTabText(ClockSet->indexOf(Alarm), QApplication::translate("Clock_Application", "Alarm", 0, QApplication::UnicodeUTF8));
} // retranslateUi

};

namespace Ui {
class Clock_Application: public Ui_Clock_Application {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_CLOCK_APPLICATION_H
@

[MuldeR]

So Ui::Clock_Application is defined (lines 103 to 105).

But then I don't understand why the compiler throws the following error:
@invalid use of incomplete struct type ‘struct Ui::Clock_Application’ @

Are you 100% sure the source code file that throws this error includes the exactly same header file you quoted?

[Flurite]

I've had a problem like that before with mutual friendship classes. I fixed it by simply defining the functions after both classes were defined. Obviously, this is not the problem in this case..

[MuldeR]

Time to post your complete clock_application.h and clock_application.cpp, I think.

[Flurite]

clock_application.h:

@

#ifndef CLOCK_APPLICATION_H
#define CLOCK_APPLICATION_H

#include <QMainWindow>
#include <QTimer>
#include <QLineEdit>

namespace Ui {
class Clock_Application;
}

class Clock_Application : public QMainWindow
{
Q_OBJECT

public:
explicit Clock_Application(QWidget *parent = 0);
~Clock_Application();
public slots:
void timer_Start();
void changeTime();
private:
Ui::Clock_Application ui;
QTimer timer;
};

void Clock_Application::timer_Start()
{
timer = new QTimer();
connect(timer, SIGNAL(timeout()), this, SLOT(changeTime()));
timer->start(1000);
}

void Clock_Application::changeTime()
{
std::vector<int> times;
QRegExp findTimeSequences("(\d+)");
QString currentTime(ui->Output->text());

int posOffset(0);
while ((posOffset = findTimeSequences.indexIn(currentTime, posOffset)) != -1)
{
    times.push_back(findTimeSequences.cap(1).toInt());
    posOffset += findTimeSequences.matchedLength();
}

times[2] += 1;

QString outputTime;
for (int i = (int) times.size() - 1; i >= 0; i--)
{
    if (times[i] == 60 && i > 0)
    {
        times[i-1] += 1;
        times[i] = 0;
    }

    QString currentNum; currentNum.setNum(times[i]);
    if (times[i] <= 9 && i >= 0)
    {
        currentNum.insert(0, QString("0"));
    }
    if (i < 2)
    {
        currentNum.append(":");
    }

    outputTime.insert(0, currentNum);
}

ui->Output->setText(outputTime);

}

#endif // CLOCK_APPLICATION_H
@

clock_application.cpp:

@

#include "clock_application.h"
#include "ui_clock_application.h"
#include "QString"
#include "QRegExp"
#include "vector"
#include "QThread"

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

Clock_Application::~Clock_Application()
{
delete ui;
}
@

[MuldeR]

In your header file you are trying to dereference ui, although you only have a forward-declartion of Ui::Clock_Application there! This can't work, obviously. The definition of the Ui::Clock_Application class in "ui_clock_application.h" is included in your .cpp file only! Simply move Clock_Application::changeTime() and Clock_Application::timer_Start() into the .cpp file. These don't belong into the header file anyway...

Solution:

clock_application.h:
@#ifndef CLOCK_APPLICATION_H
#define CLOCK_APPLICATION_H

#include <QMainWindow>
#include <QTimer>
#include <QLineEdit>

namespace Ui {
class Clock_Application; //Only forward-declartion here !!!
}

class Clock_Application : public QMainWindow
{
Q_OBJECT

public:
explicit Clock_Application(QWidget *parent = 0);
~Clock_Application();
public slots:
void timer_Start();
void changeTime();
private:
Ui::Clock_Application ui; //forward-declartion sufficient here
QTimer timer;
};

#endif // CLOCK_APPLICATION_H@

clock_application.cpp:
@#include "clock_application.h"
#include "ui_clock_application.h" //Contains the full class definition
#include "QString"
#include "QRegExp"
#include "vector"
#include "QThread"

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

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

void Clock_Application::timer_Start()
{
timer = new QTimer();
connect(timer, SIGNAL(timeout()), this, SLOT(changeTime()));
timer->start(1000);
}

void Clock_Application::changeTime()
{
std::vector<int> times;
QRegExp findTimeSequences("(\d+)");
QString currentTime(ui->Output->text()); //Requires full class definition !!!

int posOffset(0);
while ((posOffset = findTimeSequences.indexIn(currentTime, posOffset)) != -1)
{
    times.push_back(findTimeSequences.cap(1).toInt());
    posOffset += findTimeSequences.matchedLength();
}

times[2] += 1;

QString outputTime;
for (int i = (int) times.size() - 1; i >= 0; i--)
{
    if (times[i] == 60 && i > 0)
    {
        times[i-1] += 1;
        times[i] = 0;
    }

    QString currentNum; currentNum.setNum(times[i]);
    if (times[i] <= 9 && i >= 0)
    {
        currentNum.insert(0, QString("0"));
    }
    if (i < 2)
    {
        currentNum.append(":");
    }

    outputTime.insert(0, currentNum);
}

ui->Output->setText(outputTime); //Requires full class definition !!!

}@

[Flurite]

Works like a charm. Thanks for all the help!