I am implementing a card game. I want the window ui to be an object of class Rule, so that Rule can modify the GUI directly.
So Rule has an object Window * ui initialized in the constructor.
But during compilation, the compiler tells me that in rule.h, "Window has not been declared", "Window is not a type". I included <window.h>, everything has the same type, everything is initialized, so I run out of ideas of why it does not work.
EDIT: I edited the code following alexisdm's notes. In addition, in rule.h, I had to change the definition of ui from Window * ui to Ui::Window *ui, because in window.h, ui is defined as Ui::Window * ui, and this is the object I want Rule::rule to control.
But now, in rule.cpp, ui->do_stuff() does not compile, because Ui::Window does not have the do_stuff() function, but Window does...
Arg! What to do?!! ui->do_stuff() works fine in window.cpp. Inheritance problem?
window.cpp:
Window::Window(QWidget *parent) :
QDialog(parent),
ui(new Ui::Window)
{
ui->setupUi(this);
player = new Game_state(); /* Game state */
rule = new Rule(player, ui); /* Implement the action of cards*/
}
void Window::do_stuff(){
//Do stuff
}
window.h
#include <QDialog>
#include "game_state.h"
#include "rule.h"
class Rule;
namespace Ui {
class Window;
}
class Window : public QDialog
{
Q_OBJECT
public:
explicit Window(QWidget *parent = 0);
~Window();
Game_state * player;
Rule * rule;
void do_stuff();
private:
Ui::Window *ui;
};
rule.h
#ifndef RULE_H
#define RULE_H
#include "window.h"
#include <game_state.h>
class Window;
class Rule{
public:
Rule(Game_state *, Ui::Window *);
void action(Card *);
private:
Game_state * player;
Ui::Window * ui;
};
#endif // RULE_H
rule.cpp
#include <rule.h>
Rule::Rule(Game_state * game, Ui::Window * window){
player = game;
ui = window;
}
void Rule::stuff(){
ui->do_stuff();
}
There is a circular dependency in your headers: window.h and rule.h are referencing each other.
You should replace both #include by forward declarations to avoid it.
class Window; // instead of #include "window.h"
class Rule; // instead of #include "rule.h"
You'll still need to add #include "window.h" in rule.cpp, and #include "rule.h" in window.cpp.
My guess is the name of your class, Window, is too generic and #include <window.h> probably includes the system one instead of yours.
Try change the clase and header name to something more specific to your app like CardWindow, or use #include "window.h"
Related
I have a compositor based on the IVI compositor example in which I can manipulate visibility of surfaces via the "visible" property of the respective surface.
However, when a client tries to hide a QWidget via the hide() method, the compositor will destroy the surface instead of just setting the visible property to false.
Is this the intended behavior, and if so, is there a way to change that?
Steps to reproduce:
Build and run the compositor example
Create a new Qt Widgets Project in QtCreator, leave all settings at default
Change mainwindow.h and mainwindow.cpp to look like this:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QTimer>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
private:
Ui::MainWindow *ui;
QTimer *pTimer;
private slots:
void hideWindow();
};
#endif // MAINWINDOW_H
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QProcess>
#include <QDebug>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
pTimer = new QTimer();
pTimer->setInterval(1000);
connect(pTimer, SIGNAL(timeout()), this, SLOT(hideWindow()));
pTimer->start();
}
void MainWindow::hideWindow()
{
if (isVisible())
{
qDebug() << "hide!";
hide();
}
else
{
qDebug() << "show!";
show();
}
}
MainWindow::~MainWindow()
{
delete ui;
}
When you build and run this program, it will periodically hide and show its mainwindow, but the way it does this is not by telling the compositor to set the "visible" property of the widget, and instead destroying and re-creating the surface.
Also note that you need to set some environment variables before starting the app:
To start a Qt application using the ivi-application protocol with the right id, you need to set QT_WAYLAND_SHELL_INTEGRATION to ivi-shell and QT_IVI_SURFACE_ID to 1337
I am trying to make a helper with QTextBrowser. As I understood, home(), backward() and forward() are already implemented in QTextBrowser and required only connections to the buttons. Below there is .h and .cpp files
#ifndef HELPWINDOW_H
#define HELPWINDOW_H
#include <QDialog>
namespace Ui {
class HelpWindow;
}
class HelpWindow : public QDialog
{
Q_OBJECT
public:
explicit HelpWindow(QWidget *parent = 0);
~HelpWindow();
private slots:
private:
Ui::HelpWindow *ui;
};
#endif // HELPWINDOW_H
and
#include "helpwindow.h"
#include "ui_helpwindow.h"
HelpWindow::HelpWindow(QWidget *parent) :
QDialog(parent),
ui(new Ui::HelpWindow)
{
ui->setupUi(this);
// connection
connect(ui->pushButton_home,SIGNAL(clicked()),ui->textBrowser,SLOT(home()));
connect(ui->pushButton_forward,SIGNAL(clicked()),ui->textBrowser,SLOT(forward()));
connect(ui->pushButton_backward,SIGNAL(clicked()),ui->textBrowser,SLOT(backward()));
}
HelpWindow::~HelpWindow()
{
delete ui;
}
There is no any error message. It is possible to read and click the links inside QTextBrowser. Only there are no any actions with buttons. What do I miss here?
You need to call either one or both of the following properties
ui->textBrowser.setOpenLinks(true);
ui->textBrowser.setOpenExternalLinks(true);
and if you want filter or re-route the links at runtime
connect(ui->textBrowser, SIGNAL(sourceChanged(QUrl)), pointerToYourCode, SLOT(slotSourceChanged(QUrl)));
and implement
void YourCode::slotSourceChanged(const QUrl& url) {...}
I found why it did not work. The initial source should be specify:
ui->textBrowser->setSource(QUrl::fromLocalFile("help/index.html"));
Thank you, Jens for spending time.
For example here is my code
QScopedPointer<QTimer> timer2(new QTimer);
But I want to define
QScopedPointer<QTimer> timer2;
in mainwindow.h and create an instance
timer2(new QTimer);
in the mainwindow.cpp
How?
Try the following:
// mainwindow.h
class MainWindow : public QMainWindow
{
private:
QScopedPointer<QTimer> timer2;
};
If you want to create the instance in the constructor, use the following:
// mainwindow.cpp
MainWindow::MainWindow()
:timer2(new QTimer)
{
}
Alternately, if you want to create the instance in some arbitrary member function of MainWindow, use this:
// mainwindow.cpp
void MainWindow::someFunction()
{
timer2.reset(new QTimer);
}
It's also worth reviewing initialization lists in C++ and the documentation for QScopedPointer.
Use method reset of QScopedPointer
timer2.reset(new QTimer());
What you're doing amounts to a premature pessimization. You're creating members of a MainWindow class separately and individually on the heap, when you should be simply putting them into the class as members:
// interface
#include <QMainWindow>
#include <QTimer>
class MainWindow : public QMainWindow {
Q_OBJECT
QTimer m_timer;
public:
MainWindow(QWidget * parent = 0, Qt::WindowFlags flags = 0);
};
// implementation
MainWindow::MainWindow(QWidget * parent, Qt::WindowFlags flags) :
QMainWindow(parent, flags),
m_timer()
{
...
}
Of course, you would ordinarily not want to expose all the details of the MainWindow's implementation in the interface (header) file. Thus you would leverage the PIMPL idiom:
// interface
#include <QMainWindow>
class MainWindowPrivate;
class MainWindow : public QMainWindow {
Q_OBJECT
Q_DECLARE_PRIVATE(MainWindow)
QScopedPointer<MainWindowPrivate> const d_ptr;
public:
MainWindow(QWidget * parent = 0, Qt::WindowFlags flags = 0);
}
// implementation
#include "MainWindow.h"
#include <QTimer>
class MainWindowPrivate {
public:
QTimer timer;
}
MainWindow::MainWindow(QWidget * parent, Qt::WindowFlags flags) :
QMainWindow(parent, flags),
d_ptr(new(MainWindowPrivate())
{
Q_D(MainWindow);
d->timer.start( ... );
...
}
I tried to do a bunch of research on how to solve this problem, and everything is slightly different than my situation, or didn't work to fix my problem. I will start off by explaining my main goal. I have a main window with 7 buttons on it(amongst other things), when you hit each button, it closes out the current window and opens up a new window. All the windows will have the same 7 buttons, so you can go between each window. With all windows having the exact same 7 buttons, I wanted to set up a function that each class can call to set up each button and connect to a slot() in my mainwindow.cpp(called setupSubsystemButtons in example below). The actual buttons are being placed there, but they only work when pressed from my mainwindow.cpp....when I press them from a different class nothing happens.
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QtWidgets>
#include <QDialog>
namespace Ui {
class MainWindow;
}
class MainWindow : public QDialog
{
Q_OBJECT
public:
MainWindow(QWidget *parent = 0);
QWidget *window;
void setupSubsystemButtons(QGridLayout *layout);
~MainWindow();
private:
Ui::MainWindow *ui;
QLineEdit *tempValueBox;
QLineEdit *humidityValueBox;
QLineEdit *c02ValueBox;
...
public slots:
void ECSgeneralScreen();
void homeScreen();
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "ecsgeneralcommand.h"
#include <QtWidgets>
#include <QtCore>
MainWindow::MainWindow(QWidget *parent) : QDialog(parent)
{
QGridLayout *layout = new QGridLayout;
...
setLayout(layout);
}
void MainWindow::ECSgeneralScreen()
{
ECSgeneralCommand *ECSgeneral = new ECSgeneralCommand;
this->close();
ECSgeneral->show();
//opens up the ECS screen
}
void MainWindow::homeScreen()
{
MainWindow *home = new MainWindow;
this->close();
home->show();
//opens up the home screen
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::setupSubsystemButtons(QGridLayout *layout)
{
//Push Button Layout
homeScreenButton = new QPushButton("Home");
layout->addWidget(homeScreenButton, 3, 11);
connect(homeScreenButton, SIGNAL(clicked()), this, SLOT(homeScreen()));
ECSgeneralScreenButton = new QPushButton("General");
layout->addWidget(ECSgeneralScreenButton,5,11);
connect(ECSgeneralScreenButton, SIGNAL(clicked()), this, SLOT(ECSgeneralScreen()));
}
ecsgeneralcommand.h
#ifndef ECSGENERALCOMMAND_H
#define ECSGENERALCOMMAND_H
#include <QDialog>
#include <QMainWindow>
#include <QtWidgets>
#include <QObject>
#include "mainwindow.h"
class ECSgeneralCommand : public QDialog
{
Q_OBJECT
public:
explicit ECSgeneralCommand(MainWindow *parent = 0);
private:
...
public slots:
};
#endif // ECSGENERALCOMMAND_H
ecsgeneralcommand.cpp
#include "ecsgeneralcommand.h"
#include "mainwindow.h"
#include <QtWidgets>
#include <QtCore>
ECSgeneralCommand::ECSgeneralCommand(MainWindow *parent) : QDialog(parent)
{
QGridLayout *layout = new QGridLayout;
QWidget::setFixedHeight(600);
QWidget::setFixedWidth(550);
...
MainWindow setupButtons;
//Setup Subsystem Buttons
setupButtons.setupSubsystemButtons(layout);
setLayout(layout);
};
MainWindow setupButtons;
//Setup Subsystem Buttons
setupButtons.setupSubsystemButtons(layout);
This will create the buttons and connect their signals to slots of setupButtons, which will get deleted as soon as it's out of scope (the end of the ECSgeneralCommand constructor). So your buttons will be left connected to nothing.
You need to connect the button signals to an object that will exist at the time the button is pressed, such as the ECSgeneralCommand itself. Then it could close itself and spawn the correct window.
Or, possibly a much better solution, if applicable for your application: Use a single main window, with a QStackedWidget that switches widgets when a button is pressed. That's what's typically done.
I have built an app in Qt that contains two buttons: an exit button and an import button. When the import button is pushed, a list of buttons is shown in a scrollarea on the screen (the file loggers.csv contains the data 1;2;3;4;5;).
It all works fine, but when I push the exit button (which of course should close everything), the app is not stopped properly (the stop button of Qt is still active, and the play button isn't). When I run the debugger and push the exit button it gives an error: Invalid address specified to RtlFreeHeap( 0ADF0000, 0028FE40 ). Can anybody help me?
main
#include <QtGui/QApplication>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.showFullScreen();
return a.exec();
}
Mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QtGui>
#include "logger.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
QPushButton exit_btn;
QPushButton import_btn;
private slots:
void createMenus();
void exit();
void import();
private:
int window_width;
int window_height;
int numLoggers;
int numSelected;
QVector<Logger*> loggers;
QScrollArea * scroll_area;
QVBoxLayout scrollLayout;
QWidget viewport;
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
Mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "QtGui"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
window_width = QApplication::desktop()->width();
window_height = QApplication::desktop()->height();
createMenus();
connect(&exit_btn,SIGNAL(clicked()),this,SLOT(exit()));
connect(&import_btn,SIGNAL(clicked()),this,SLOT(import()));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::createMenus()
{
import_btn.setParent(ui->centralWidget);
import_btn.setGeometry(400,300,100,100);
import_btn.setText("IMPORT");
exit_btn.setText("EXIT");
exit_btn.setParent(ui->centralWidget);
exit_btn.setGeometry(window_width-50,12,32,32);
viewport.setLayout(&scrollLayout);
viewport.resize(0,0);
scroll_area = new QScrollArea(ui->centralWidget);
scroll_area->setGeometry(0,66,317,window_height-116);
scroll_area->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
scroll_area->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
scroll_area->setWidget(&viewport);
scroll_area->setGeometry(0,97,317,window_height-228);
scrollLayout.setMargin(0);
scrollLayout.setSpacing(0);
}
void MainWindow::exit()
{
close();
qApp->quit();
}
void MainWindow::import()
{
numSelected=0;
QFile f("Loggers3.csv");
if (f.open(QIODevice::ReadOnly))
{
numLoggers=0;
QString data;
data = f.readAll();
QStringList vals = data.split(';');
while(vals.size()>=1)
{
Logger * logger = new Logger;
logger->setNumber(vals[0].toInt());
vals.removeAt(0);
loggers<<logger;
numLoggers++;
}
f.close();
for(int i=0; i<numLoggers;i++)
{
loggers[i]->createButtons();
scrollLayout.addWidget(loggers[i]->button);
}
viewport.resize(367,numLoggers*60);
}
}
logger.h
#ifndef LOGGER_H
#define LOGGER_H
#include <QtGui>
class Logger : public QWidget
{
Q_OBJECT
public:
explicit Logger(QWidget *parent = 0);
~Logger();
int number;
QLabel num;
QToolButton * button;
bool checked;
signals:
public slots:
void setNumber(int number);
void createButtons();
};
#endif // LOGGER_H
logger.cpp
#include "logger.h"
#include <QtGui>
Logger::Logger(QWidget *parent) :
QWidget(parent)
{
button = new QToolButton;
button->setCheckable(true);
button->setMinimumSize(317,60);
button->setStyleSheet("QToolButton{background-image: url(images/btn_bg); border:none}");
}
Logger::~Logger()
{
}
void Logger::setNumber(int logNumber)
{
number=logNumber;
}
void Logger::createButtons()
{
QLayout * layout = new QHBoxLayout;
QSpacerItem *spacer = new QSpacerItem(120, 31, QSizePolicy::Maximum, SizePolicy::Maximum);
num.setStyleSheet("color: white; font: bold 16px");
num.setText(QString::number(number));
layout->addWidget(&num);
layout->addItem(spacer);
button->setLayout(layout);
}
I'm not entirely certain about what you are trying to achieve... but your problem lies with these two lines:
viewport.setLayout(&scrollLayout);
viewport.resize(0,0);
In the documentation for the QWidget class it states that:
If there already is a layout manager installed on this widget, QWidget
won't let you install another. You must first delete the existing layout manager (returned by layout()) before you can call setLayout() with the new layout.
This is where your problem lies. Don't believe me, add this check before those two lines of code.
if(layout()){
qDebug() << "Another layout exists";
}
Source: QVBoxLayout Class Reference
The QVBoxLayout class lines up widgets vertically.
This class is used to construct vertical box layout objects. See QBoxLayout for details.
The simplest use of the class is like this:
QWidget *window = new QWidget;
QPushButton *button1 = new QPushButton("One");
QPushButton *button2 = new QPushButton("Two");
QPushButton *button3 = new QPushButton("Three");
QPushButton *button4 = new QPushButton("Four");
QPushButton *button5 = new QPushButton("Five");
QVBoxLayout *layout = new QVBoxLayout;
layout->addWidget(button1);
layout->addWidget(button2);
layout->addWidget(button3);
layout->addWidget(button4);
layout->addWidget(button5);
window->setLayout(layout);
window->show();
First, we create the widgets we want in the layout. Then, we create the QVBoxLayout object and add the widgets into the layout. Finally, we call QWidget::setLayout() to install the QVBoxLayout object onto the widget. At that point, the widgets in the layout are reparented to have window as their parent.
Critical source of error in your project:
Widgets should be constructed on the heap because they will be deleted automatically when their parents are deleted. You have a custom widget class that you instantiate on the heap. The members should also go on the heap. Also, you should consider using the parent /child hierarchy in your GUI code to ensure proper memory management and proper deletion.
In my experience, if your program stops in RtlFreeHeap it is a good sign of memory corruption.
When calling
import_btn.setParent(ui->centralWidget);
centralWidget takes ownership of import_btn. That means, when centralWidget is deleted (which happens as part of delete ui;in your MainWindow's destructor), it will call delete on your member variable!
This leads to the reported memory corruption.
You need to allocate your QPushButton's dynamically, not as a plain member variable. So make them QPushButton*.
Here's how I did it from mainwindow.cpp, thanks to and this question: How to create a correct exit button in qt
QPushButton * quit_btn = new QPushButton(this);
quit_btn->setGeometry(540,440,93,27);
quit_btn->setText("Exit");
QObject::connect(quit_btn,SIGNAL(clicked()),qApp,SLOT(quit()));
Works flawlessly :D