General and Desktop

I also run now in this issue using Qt 5.15. I tried to send a command to a thermostate and expected an response from it. After using the workaround menthioned above everything works. Is there a plan to fix this or is it maybe already fixed in Qt > 6 ?

I solved my problem via event filter of scene. ui->graphicsView->scene()->installEventFilter(this); bool MainWindow::eventFilter(QObject* obj, QEvent* event){ if(event->type() == QEvent::GraphicsSceneMousePress){ if(ui->addServerBtn->isChecked()){ QGraphicsSceneMouseEvent* mouseSceneEvent; mouseSceneEvent = static_cast<QGraphicsSceneMouseEvent *>(event); Server *serv = new Server(mouseSceneEvent->scenePos().toPoint()); scene->addItem((QGraphicsPixmapItem*)serv); } } return false; }

@fi11222 Hello and welcome. If you have a question it is usual to write a few words of your own rather that only referencing some other thread. You can see there that you were asked to provide more details. Which right now you are doing. You need to produce the crash in the debugger and then post the stack trace (not something else), which you can find in its own window.

@mpergand , @Chris-Kawa Thanks peeps. I know you are waiting to find out how I got on this Boxing day.... I used menuAboutToShow() signal and actionGeometry() there. This did indeed give me a correct height, and setting my widget's fixed height to that achieves what I wanted. There was one little wrinkle. My QWidgetAction is actually the (only) item on a QMenu sub-menu, i.e. an item which has the ... > to display a "slide-out" sub-menu. It is that whose height I want my QWidgetAction's widget to match. But QMenu::actionGeometry() requires a QAction to measure, there is no QMenu::subMenuGeometry() method. I made an educated guess to use QMenu::menuAction() and went for: const QRect &geom(ui->parentMenu->actionGeometry(ui->subMenu->menuAction())); which delivered what I needed. So I guess a for a QMenu sub-menu there is a "hidden" QAction which can be accessed via QMenu::menuAction().

@mpergand said in Question about plugin environment: You can't do that in C++: I found an interesting discussion at SO, which points out, that my code is valid but incomplete. There are (theoretically) 2 options: add using A:riseError; - but that leads to qtcreator crash override both functions in class B meanwhile my project has reached a size where qtcreator crashes quite often. I stil have troubles getting the new project structure built. Following the plugandpaint example my project does not build. Everything gets compiled, but the libraries and plugins are not linked - so lots of unresolved externals. I have to confess, that I don't understand the qmake-hacks in plugandpaint example. I did not find any words in docs. I add the pro-file of one plugin: TEMPLATE = lib CONFIG += plugin static QT += widgets INCLUDEPATH += ../../app HEADERS = basictoolsplugin.h SOURCES = basictoolsplugin.cpp TARGET = $$qtLibraryTarget(pnp_basictools) DESTDIR = ../../plugins qtLibraryTarget is used, but no word about where it is defined. So how could I solve it?

Do this for the widgets inside the ToolBox: widget->setBackgroundRole(QPalette::Base);

@HowardHarkness Hi there was a similar topic / question few years ago. @SGaist explained why there is one additional space after every mask -> to allow text selection by keyboard. Of course Ctrl + A kinda "hacks" it (to select all, at least) and if you dont need it, you could implement a workaround, but unfortunately there is no "Qt-way" to switch it off. https://forum.qt.io/topic/60633/qlineedit-using-input-mask-with-blank-space-replacement-cursor-select-replacement-char

It's the QToolButton class that provides this out of the box.

@Alexey-Serebryakov .. I am actively using those codes. With only one difference. QTableWidget instead of QTableView. else if(yapi->slAlan[i] == "ISLEM") { auto * checkWidget = new QWidget(this); auto * check = new QCheckBox(this); auto * checkLayout = new QHBoxLayout(checkWidget); checkLayout->addWidget(check); checkLayout->setAlignment(Qt::AlignCenter); checkLayout->setContentsMargins(0,0,0,0); check->setMaximumWidth(yapi->slColumnWidth[i].toInt()); check->setChecked(q.value(yapi->slAlan[i]).toString() == "2"); check->setCheckable(!bPasif); if(!renk.isEmpty()) { checkWidget->setStyleSheet(tr("background-color: %1").arg(renk)); } tablo->setCellWidget(iSatir, i, checkWidget); checkWidget->setContextMenuPolicy(Qt::CustomContextMenu); connect(checkWidget, &QMenu::customContextMenuRequested, this, &kucukbas::doganPopupMenu); connect(check, &QCheckBox::stateChanged, this, [=]() { doganKaydet("ISLEM", check->isChecked() ? "2" : "0", idDogan()); }); }

There is no built-in widget or component for this. Can be implemented, though.

@Alexey-Serebryakov Well what about starting from @VRonin's https://forum.qt.io/topic/94049/how-to-center-a-column-with-a-checkbox-in-qtableview/8 ?

Hi, Sounds rather something for a QStyledItemDelegate so you can control the appearance of the cells the way you want it.

Hi and welcome to devnet, You should add the link to the relevant documentation you are mentioning as well as the code you are using to show what the issue might be.

@mrdebug changing to QMysql worked. Thank you for that. Happy Holidays.

I tried to redefine the parent for these buttons of scroller (for the QToolButton's), in this case, there is no overlap on hover, but the width of the buttons do not always turn out to be the same (despite the fact that in css tables they are defined as buttons of the same width).

Use a debugger, run your program in there, see where it crashes, take a look into the backtrace and fix your program.

you do understand that floating point numbers are approximations, right? Never expect floating point math to represent an exact value. Always compare within a properly scaled tolerance range. isEqual = abs(a-b) < tolerance;

@JKSH said in showing custom widget inside the mainWindow: @Swati777999 said in showing custom widget inside the mainWindow: @JKSH said in showing custom widget inside the mainWindow: I believe you have missed @Pl45m4's point. He is asking you to explain: What do you expect this line to do?: QMainWindow *main = new QMainWindow(); Actually, I was trying to write some codes after that [like setting a layout or so]so as to I can add WindowWidget to it, something like that. You should add your WindowWidget to your ScrollAreaApp (which is this in your ScrollAreaApp's constructor). You should not be adding it to some extra QMainWindow. Yes, my other application has code for it and I should be writing this code there while trying but I chose to create another project file for experimenting. Unfortunately, the way that you're carrying out these experiments is making it harder for you to understand the important basics of widget parent-child relationships and layout management. In summary: It is completely wrong to create a new QMainWindow() in your custom widget's constructor. Don't do it, ever... not even for experimenting. This is because the ScrollAreaApp's constructor should only contain things that are placed inside the ScrollAreaApp. (Does this make sense? If not, please ask) I completely understand what you want to convey. So, basically it is preferred to experiment in the same location of the complete application rather than writing a part of code in different project file.