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Questions tagged [qt]

Qt is a cross-platform application development framework widely used for the development of application software that can be run on various software and hardware platforms with little or no change in the underlying codebase, while having the power and speed of native applications. Qt is available with both commercial and open source licenses.

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QT Application freezes

We have developed a system which integrates with camera and micro controller. GUI shows the image from the camera and serial count from micro controller, we used a serial thread to poll the data from ...
0
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0answers
12 views

SVG layers into Bitmap [QT]

How do I save each layer as a separate PNG? ...............................................................................................................................................................
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1answer
17 views

How can I connect to oracle 12c via ODBC driver in qt?

I have qt open source 5.12 and ubuntu 18.04. How do I connect to oracle 12c via ODBC? I tried: db = new QSqlDatabase(QSqlDatabase::addDatabase("QODBC")); db->setPort(1234); db->setDatabaseName("...
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1answer
20 views

How to reproduce draggable windows

So i am working on an editor for a game engine. Everything works just fine with a single problem. The UI is not customizable. How can this be reproduced?
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1answer
14 views

Qt Cmake error compilation “GuiSupportQt not found”

I'm new to Qt and i already have a problem so i start to create a simple UI for my VTK project, first of all, i tested a sample project UI designed by Qt in Qt 5.5.0 and compiled in Cmake 3.10 and ...
0
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0answers
13 views

GTK WebAssembly support in the near future?

Do you have any information about GTK WebAssembly support in the near future? QT has announced this week the WebAssembly support, and provided a few impressive online demo. I would like to stick with ...
0
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2answers
26 views

How to create second QT .ui form?

Well, what I want is make 2 windows application ( 1 window has a button that open second window in the previous window) So far I've got this: login.h login.cpp login.ui mainwindow.h ( no errors ...
0
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0answers
17 views

load glyph failed err=23 face=0x0, glyph=25 Error in Qt

Can any body help to understand & sort out the below give Qt application error: load glyph failed err=23 face=0x0, glyph=25 I am getting this qt error inside the one function where am inserting ...
0
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1answer
15 views

QUdpSocket bind failed

I'm having an issue with QT Udp sockets. Assuming all headers are correctly included, I'm writing: QUdpSocket* s = new QUdpSocket(); bool ok = s->bind(QHostAddress::Any, 8081); if(!ok) { std::...
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0answers
21 views

How do I test the component given to the highlight property of a ListView?

I'm writing the tests of a component which looks something more or less like this: FocusScope { property ... id: root width: parent.width Component { id: focusMarker Item { z:...
0
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1answer
45 views

calculate the area of circle ,ellipse (dynamic method)

I draw a circle in real time and I want to calculate the area of this( circle ellipse )by calculating the pixel number each time the shape is changed by the cursor . label.h QPainter painter; ...
0
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0answers
38 views

Sends two bytes when data is over 7bit?

I have a strange behaviour of QSerialPort in QT Creator when I write down bytes, which are bigger than the ASCII number 127. Somehow It always sends the number 194 first, then comes the number I ...
1
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0answers
33 views

Qtreewidgetitem with checkbox

A checkbox is added correctly when I set the check state of a qtreewidgetitem, but I´m not able to check/uncheck it in my qtreewidget. What am I doing wrong? QTreeWidgetItem* item = new ...
0
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1answer
23 views

Programmatically Cycle through Tab-Order in QT5

I have a QT5 application in which I have to simulate a tab keypress on an external event i.e. I need to cycle through the taborder list and setFocus on the next element. I cannot find any method to ...
0
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1answer
23 views

How to get signal in Qt from a printer when it finishes printing?

I am trying to get notifications in Qt for a printer but unfortunately couldn't find any solution. I've already tried to check the state but it never changes, it is always 'PrinterState::Idle'. void ...
0
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0answers
25 views

How to link a particular function in SLOT

This is my Wavefrontrenderer class. Class WavefrontRenderer : public QMainWindow , private Ui::WavefrontRendererClass { Q_OBJECT //Q_PROPERTY( QColor m_color READ m_color NOTIFY colorChanged) ...
1
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1answer
26 views

Q_REVISION meaning in Qt Class

what is Q_REVISION in Qt function body? I saw this so many times in qt source codes. I have looked into Qt documentation and i saw this documentations says : Apply this macro to declarations of ...
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0answers
11 views

How to link selenium webbrowser to Qt application

My application is a Qt c++ application and I only need to verify that an information was added to Menu1 or Menu2 or Menu3 so I have to double click each one. And for this I need to read the resulting ...
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0answers
18 views

how to open the new widget on current page by click the label in qt

I'm developing the flight control configuration system, in that i have develop the FC frame design in qt qml. i have used the drawer for side bar and list the contain in listview and also used ...
0
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1answer
22 views

Mouse hover events not working in the header of the TableView

Similar question is asked here How to get Clicked or Pressed event on QML TableView header? I want to highlight the header when hovered over. But the behavior in headerDelegate is weird. ...
0
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1answer
10 views

QTime to String with AM/PM and installed translator

This little application make some problems: int main(int argc, char *argv[]) { QTranslator* translator = new QTranslator(); QString langCode = "en_GB"; translator->load(QString("Core_%1.qm")....
0
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0answers
19 views

Android c++ application and OpenMP [on hold]

In write a little QML application with c++ back-end which use several libs (OpenCV, Tesseract). Libs was configured as static via CMake and cross built with Android NDK 16 toolchain. App works fine, ...
0
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1answer
23 views

Problem with static building QT C++ project

I am using community QT latest version. When I successfuly build my project I end up with .exe file and few .dll's . My question is, how set up the type of building (static or dynamic), because I want ...
1
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1answer
36 views

How to change the title of a chart axis in Qt?

I'm trying to develop a chart that shows the number of sales of each day of the month, it works but I can not change the caption of each position of the x axis. This is the way I'm trying to change: ...
0
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1answer
19 views

How to take user input In Q-t with image background Widget view?

I want the user to enter a password to starts the Q-t application. To take the input from the user I am using the QInputDialog widget. the problem is I doesn't know how to add this widget on the ...
0
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1answer
12 views

enums and enum classes in Qt Queued Slots

Following advice from Qt documentation and this question's answers, I have code structured like so: emulator.h: class Emulator : public QObject { Q_OBJECT public: enum HaltCause ...
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0answers
24 views

How to Pass data between 2 Dialogs in QT?

I need to pass an Array from one Dialog to another in Qt. I have 6 Lineedits from wich i collect numbers to store in my Array. I want to transfer USERZAHLEN[] from SecDialog to ThirdDialog. I've ...
0
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1answer
36 views

How can I convert from JSON to CSV in Qt

I'm developing an embedded application. In my application everytime a chef starts cooking, I store the cooking data (e.g set point temperature, cooking type, name of recipe and so on). Now I'm ...
0
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0answers
38 views

Smart pointers Object pool test application fails at finish/exit

I have written a multi-threaded app in Qt/C++11 , Windows. The idea was to have and recycle some strings from a pool, using smart pointers. Here is stringpool.cpp: #include "stringpool.h" QMutex ...
0
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1answer
18 views

Qt - How to syncronously request data from QObject

Part of my code are two C++ classes 'ClassA' and 'ClassB' which are both inherited from QObject. And in some of its methods ClassB needs to syncronously request data stored in ClassA. ClassA <...
0
votes
1answer
21 views

SpinBoxDelegate displayed as a DoubleSpinBoxDelegate

I've created a SpinBoxDelegate for a tableView. When i edit a integer value(QVariant) in the Table the editorWidget behaves like a QDoubleSpinbox even though it is a QSpinBox. I'm using QT 5.5.1 not ...
0
votes
1answer
25 views

Qt Creator fails to start debugging on Mac

Recently (I suspect some system/homebrew update) the Qt's debugger stopped working. It hangs forever on Setting up inferior... The internal log: dStart parameters: 'QGIS' mode: 1 dABI: x86-darwin-...
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2answers
21 views

my program seems good on Windows,while on Ubuntu it is crashed

I'm programing a plane game on Windows by QT which seems good,while on Ubuntu it is crashed.It has a QLinkedList<Bullet *> Bullet_list.and it is crashed after Bullet_list.removeOne(*ite) I've ...
1
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1answer
22 views

How to avoid SIGPIPE (due to a timeout?) when debugging an X11 program?

Sometimes, when I'm debugging my Qt program on X11, I need to have a breakpoint at a point when the program has created a window (QWidget), but no window has yet been shown. In this case, when I ...
0
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1answer
34 views

QQmlProperty::write is not working as expected

I am new to Qt. I am trying to enable and disable the image from main window with 2 seconds delay but it is always taking the last property which i am setting. Please find my sample code below. I ...
0
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1answer
43 views

TableView - How to get hovered row without loosing styleData.selected

I need to highlight the hovered row in a TableView. By default there is no hovering effect. I can use a MouseArea inside rowDelegate to achieve this. But this will disable selection mechanism in ...
0
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2answers
27 views

QML Keys.onReleased fire on pressing key

Env: Qt 5.13 + Mingw32 + Windows 10 64bit or Qt 5.11 + Mingw32 + Windows 10 64bit Demo code: import QtQuick 2.12 import QtQuick.Window 2.12 Window { visible: true width: 640 height: ...
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0answers
38 views

How to make your app starts when Microsoft word starts? [on hold]

I have an application and I want to start it when the user starts MS Word. I know that I can create an application that runs on background and watch the running processes and open my app when Ms word ...
0
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0answers
17 views

Using GStreamer for IOS in Qt

I try to develop an ios app with Qt. One of frameworks I need to integrate is GStreamer 1.16.0. I downloaded prebuilt GStreamer binaries for ios from GStreamer's webpage. Website has examples working ...
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1answer
38 views

Where is Qt QOpenGLWidget?

I'm trying to write a C++ application that uses QOpenGLWidget, but qtcreator gives "'QOpenGLWidget' file not found" error on this line: #include <QOpenGLWidget> Documentation says ...
1
vote
1answer
33 views

eventFilter(QObject *obj, QEvent *e) does not detect right object

I expect my program to print "mouse on label name" when my mouse is located on the labelname (a QLabel), and to print"mouse not on label name" when my mouse is not located on the labelname. Even ...
0
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0answers
9 views

compile qt 5.12.4 with open ssl static fail

I am trying to compile qt with open ssl statically I could compile openssl using vs2017 after install perl and configuring it i used nmake and it worked with -no-shared smoothly. Then i open the ...
1
vote
1answer
30 views

How to get the ID from a newly inserted row with QSqlQuery and SQLite?

I have a table T that has an field id, which is an INTEGER PRIMARY KEY AUTOINCREMENT, and a INTEGER field f. With Qt5 I insert a row with the following code: QSqlQuery insert; insert.exec("INSERT ...
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votes
0answers
19 views

Syntax error when using Qt Creator to debug code

I just updated my Qt from 5.11.3 (with Qt Creator 4.7.2) to 5.12.4 (with Qt Creator 4.9.1) on my Mac. When opened a previous project and test it. The popup terminal said that: source /var/folders/l9/...
0
votes
1answer
17 views

Issue with QDockwidget. Gets squeezed to minimum with only buttons visible

I create a QDockWidget and I do a setwidget with my own QMenu instance. My QMenu has n number of QActions displayed sequentially one after another and there is a blank space at the end of all action ...
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0answers
23 views

Unable to build Android app on Windows using QtCreator

After not being able to compile a Python app for Android using pyqtdeploy on my Linux machine I now have tried to build a sample app on Windows using QtCreator. I got the same error as on Linux: ...
0
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2answers
46 views

QML ListView default behavior when model is updated

I have the following ListView that always show the beginning of the list when the QStringListModel is updated by using setStringList on the C++ side. For example, the user can scroll up and down in ...
1
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1answer
19 views

QML: What does the “x” property exactly do and what's the difference with anchors.leftMargin/rightMargin in a ListView?

I tried to add a margin to a ListView element using anchors.leftMargin expecting it would create a margin between the screen border and the beginning of the list, but it didn't work at all. Using x ...
0
votes
1answer
12 views

QFrame is not adjusting its size as per the size adjustment of parent widget

I created a widget class. This class will be maintaining child_1 of type QFrame(which is of type QWidget) and also a child_2 of type QGridLayout . child_2 will be adding child_1 to itself. The child_1 ...
0
votes
1answer
32 views

Problem: 2d Vector (nested Vector) with datatype of new class

I made 2 classes, one of them is "Cells" and another one is "Calculation". cells is a 2d vector with a datatype of class "Cells" and i want to put the object of "Cells" - content of the Cell - in a ...