Qt-interest Archive, December 2006
Dialogs, parents, and memory with Model View Controller Architecture
Message 1 in thread
First I would like to apologize if this is only tangentially Qt related.
I am implementing a model-view-controller framework for my Qt image analysis application, where a QGraphicsView is the view, and I am implementing my own model and controller.
I am trying to pass a pointer to the main window down through the viewer class to the model class, so that it can open a QFileDialog as a child of the main window. This works fine in "release" mode, but when I run the application in "debug" mode, gdb crashes with this complaint:
BFD: C:\WINDOWS\system32\wmvcore.dll (.reloc): Section flag IMAGE_SCN_MEM_NOT_PAGED (0x8000000) ignored
Perhaps this is a gdb bug, but allow me to post a small snippet that can reproduce the error. When compiled in debug mode (on my Windows XP system, with mingw, gcc 3.4.2 and gdb 5.2.1), I get the above error when I start typing in the "File name" text box (after clicking the "Open Image" button that signals the openFiles() slot.). The application continues until I click "Open" to close the file dialog, then gdb bails and the application bails. (Note the error does not occur if I simple double click a file rather than typing in the File name text box).
Am I doing something stupid here, such as screwing up the parent-child relationships between the windows?
Thanks,
-Eric
---------8<----------dialogimpl.h-------------
#ifndef DIALOGIMPL_H
#define DIALOGIMPL_H
#include "ui_dialog.h"
#include "QFileDialog"
class Model : public QObject
{
Q_OBJECT
public:
Model(QWidget*);
void openFiles();
private:
QWidget *parent;
};
class View : public QObject
{
Q_OBJECT
public:
View(QWidget*);
void openModelFiles();
private:
Model *model;
};
class DialogImpl : public QMainWindow, public Ui::Dialog
{
Q_OBJECT
public:
DialogImpl( QWidget * parent = 0, Qt::WFlags f = 0 );
public slots:
void openFiles();
private slots:
private:
Ui::Dialog ui;
View *view;
};
#endif
---------8<----------dialogimpl.cpp-------------
#include "dialogimpl.h"
DialogImpl::DialogImpl( QWidget * parent, Qt::WFlags f)
: QMainWindow(parent, f)
{
ui.setupUi(this);
QObject::connect(ui.OpenFiles, SIGNAL(clicked()), this, SLOT(openFiles()));
view = new View(this);
}
void DialogImpl::openFiles() {
view->openModelFiles();
}
View::View(QWidget* parent) : QObject(parent)
{
model = new Model(parent);
}
void View::openModelFiles() {
model->openFiles();
}
Model::Model(QWidget* app) : QObject(app)
{
parent = app;
}
void Model::openFiles() {
QList <QImage*> image;
QStringList files = QFileDialog::getOpenFileNames(parent,
tr("Open File"),
"/",
tr("Images (*.tif; *.TIF; .jpg; .JPG)"));
return;
}
#include <QApplication>
#include "dialogimpl.h"
---------8<----------main.cpp-------------
int main(int argc, char ** argv)
{
QApplication app( argc, argv );
DialogImpl win;
win.show();
app.connect( &app, SIGNAL( lastWindowClosed() ), &app, SLOT( quit() ) );
return app.exec();
}
---------8<----------dialog.ui-------------
<ui version="4.0" >
<class>Dialog</class>
<widget class="QMainWindow" name="Dialog" >
<property name="geometry" >
<rect>
<x>0</x>
<y>0</y>
<width>598</width>
<height>388</height>
</rect>
</property>
<property name="windowTitle" >
<string>MainWindow</string>
</property>
<widget class="QWidget" name="centralwidget" >
<widget class="QPushButton" name="OpenFiles" >
<property name="geometry" >
<rect>
<x>60</x>
<y>60</y>
<width>75</width>
<height>24</height>
</rect>
</property>
<property name="text" >
<string>Open Files</string>
</property>
</widget>
</widget>
<widget class="QMenuBar" name="menubar" >
<property name="geometry" >
<rect>
<x>0</x>
<y>0</y>
<width>598</width>
<height>19</height>
</rect>
</property>
</widget>
<widget class="QStatusBar" name="statusbar" />
</widget>
<resources/>
<connections/>
</ui>
---------8<----------test.pro-------------
TEMPLATE = app
QT += gui \
core
CONFIG += qt \
warn_on \
console \
debug_and_release
FORMS = dialog.ui
HEADERS = dialogimpl.h
SOURCES = dialogimpl.cpp \
main.cpp
--
[ signature omitted ]
