Open file via double-click

JonB

If I launch it via cmd it crashes instead.

So what happens if you launch it from Creator debugger, like I asked?

Put in some qDebug() statements to see if it gets as far as your main, and then where.

UnitScan

I did as you asked, and this is the result:

#include "mainwindow.h"
#include <QApplication>
#include <QTimer>
#include <stdio.h>
#include <iostream>

int main(int argc, char *argv[])
{
    for (int i = 0; i < argc; ++i) {
        std::cout << "The " << i << "th argument is " << argv[i] << std::endl;
    }
    QApplication a(argc, argv);
    MainWindow w;
    QTimer::singleShot(0, & w, SLOT(initialize()));
    w.show();

    return a.exec();
}

Application output in Debug mode:

ASSERT failure in QList<T>::at: "index out of range", file C:/Qt/Qt5.14.0/5.14.0/mingw73_32/include/QtCore/qlist.h, line 571

JonB

@UnitScan
You must run it in the debugger, from Creator, not just compile for debug. Then when the ASSERT is hit and the debugger traps it you will find there is a stack trace window. That will show the qlist.h line, and then trace back through all the levels to some line in your code, which is what was being executed when the ASSERT happened.

And please use qDebug() for debug output statements, not std::cout.

Separately, since you persist in using SLOT(), all bets are off as to how that might behave at runtime.

And finally, I hope you know what you're doing with seemingly initializing on a timer, seems hokey to me. You sure you understand exactly when initialize() will be executed, compared to other initializations (like in constructors) you are doing?

ODБOï

@UnitScan hi

@UnitScan said in Open file via double-click:

argv[i]

this is the kind of code that can cause "index out of range" error.
you can use
https://doc.qt.io/qt-5/qcoreapplication.html#arguments
or
https://doc.qt.io/qt-5/qcommandlineparser.html
to retrive the arguments

JonB

@LeLev
In this case he is using main(argc, argv) correctly. The point (to me) is:

ASSERT failure in QList<T>::at: "index out of range", file C:/Qt/Qt5.14.0/5.14.0/mingw73_32/include/QtCore/qlist.h, line 571

I don't see how that can arise from his argc/argv/std::cout loop. Has to be a QList involved!

UnitScan

@JonB well, I found the origin of the assert failure

void MainWindow::performStyles()
{
    QString theme = settings->value("app/theme").toString();
    settings->beginGroup("themes");
    QStringList colors = settings->value(theme).toString().split(",");
    settings->endGroup();
    QString stylesheet = (
                "QSlider::groove:horizontal {"
                "border: 1px solid #999999;"
                "height: 5px;"
                "background: qlineargradient(x1:0, y1:0, x2:0, y2:1, stop:0 #B1B1B1, stop:1 #c4c4c4);"
                "border-radius: 3px;"
                "}"
                "QSlider::handle:horizontal {"
                "background: qlineargradient(x1:0, y1:0, x2:1, y2:1, stop:0 #b4b4b4, stop:1 %3);"
                "border: 1px solid #5c5c5c;"
                "width: 16px;"
                "margin: -2px 0;"
                "border-radius: 3px;"
                "}"
                "QSlider::handle:horizontal:hover {"
                "background: qlineargradient(x1:0, y1:0, x2:1, y2:1, stop:0 #FFFFFF, stop:1 %3);"
                "border: 1px solid #808080;"
                "width: 16px;"
                "margin: -2px 0;"
                "border-radius: 3px;"
                "}"
                "QSlider::add-page:horizontal {"
                "background: #c0c0c0;"
                "border-radius: 3px;"
                "margin: 0 -1px;"
                "}"
                "QSlider::sub-page:horizontal {"
                "background: qlineargradient(x1:0, y1:0, x2:1, y2:1, stop:0 #b4b4b4, stop:1 %3);"
                "border-radius: 3px;"
                "}"
                "QFrame#data {"
                "border: 1px solid gray;"
                "border-radius: 5px;"
                "background-color: %1;"
                "}"
                "QLabel#display {"
                "font-size: 20px;"
                "color: %2;"
                "padding-bottom: 1px;"
                "background-color: %1;"
                "}"
                "QLabel#kbps, QLabel#hz, QLabel#channels  {"
                "font-size: 10px;"
                "text-align: center;"
                "color: %2;"
                "}"
                "ScrollText {"
                "font-size: 14px;"
                "text-align: center;"
                "color: %2;"
                "}"
                "QTableView {"
                "border: 1px solid gray;"
                "border-radius: 5px;"
                "background-color: %1;"
                "color: %2;"
                "}"
                "QTableView::item:selected {"
                "border-radius: 3px;"
                "background-color: %2;"
                "color: %1;"
                "}"
                "QScrollBar#vscrollbar:vertical {"
                "border: 1px solid grey;"
                "border-radius: 3px;"
                "background: %1;"
                "width: 15px;"
                "margin: 0px 0 0px 0;"
                "}"
                "QScrollBar#vscrollbar::handle:vertical {"
                "background: qlineargradient(x1:0, y1:0, x2:1, y2:1, stop:0 #b4b4b4, stop:1 %1);"
                "border: 1px solid #5c5c5c;"
                "width: 16px;"
                "min-height: 16px;"
                "border-radius: 3px;"
                "}"
                "QScrollBar#vscrollbar::add-line:vertical {"
                "border: 0px solid grey;"
                "background: #32CC99;"
                "height: 0px;"
                "subcontrol-position: bottom;"
                "subcontrol-origin: margin;"
                "}"
                "QScrollBar#vscrollbar::sub-line:vertical {"
                "border: 0px solid grey;"
                "background: #32CC99;"
                "height: 0px;"
                "subcontrol-position: top;"
                "subcontrol-origin: margin;"
                "}"
                "QScrollBar#vscrollbar::add-page:vertical, QScrollBar::sub-page:vertical {"
                "background: none;"
                "}"
                "QListWidget::item:selected {"
                "background-color: none;"
                "border: 3px solid grey;"
                "}"
                "QListWidget::item:selected { background: transparent; }"
                "QListWidget::item:selected { border: 1px solid red; }"
                );
    this->setStyleSheet(stylesheet.arg(colors.at(0),colors.at(1),colors.at(2)));
}

This seems to be the line causing the error

this->setStyleSheet(stylesheet.arg(colors.at(0),colors.at(1),colors.at(2)));

My ini settings file is written like this

[themes]
Red="#C21212,#ffffff,#C21212"

I must have misused the QString arg method

ODБOï

@JonB yes you are right, my bad.
i thought about argv[i] as a QList for some reason

JonB

@UnitScan
Your colors.at() expressions are fine so long as

QStringList colors = settings->value(theme).toString().split(",");

really does returns 3 colors. My guess is that, depending on how you run the program --- e.g do you read from "the current working directory"? or, what is qDebug() << theme, or qDebug() << settings->value(theme).toString()? --- you're not picking up the right thing? Code like yours which relies on 3 elements from the split() should have a Q_ASSERT(colors.count() == 3);. Anyway, somehow that differs when you run your code in different ways.

I hope now that you have found using the debugger helps find such errors!

UnitScan

I suppose the problem is bigger: when I run the program via cmd it doesn't even load the icons: https://i.imgur.com/yqvpYnl.png

sierdzio

as @JonB pointed out, this is probably related to working directory. Make sure you load your settings from the right path! This might come in handy: https://doc.qt.io/qt-5/qcoreapplication.html#applicationDirPath

UnitScan

@sierdzio said in Open file via double-click:

as @JonB pointed out, this is probably related to working directory. Make sure you load your settings from the right path! This might come in handy: https://doc.qt.io/qt-5/qcoreapplication.html#applicationDirPath

Thank you very much!