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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How to execute a functor or a lambda in a given thread in Qt, GCD-style?
In ObjC with GCD, there is a way of executing a lambda in any of the threads that spin an event loop. For example:
dispatch_sync(dispatch_get_main_queue(), ^{ /* do sth */ });
or:
dispatch_async(...
- 67.3k
128
votes
8
answers
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Adding external library into Qt Creator project
How can I add external library into a project built by Qt Creator RC1 (version 0.9.2)? For example, the win32 function EnumProcesses() requires Psapi.lib to be added in the project to build.
- 12.9k
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votes
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Passing an argument to a slot
I want to override mouseReleaseEvent with a bunch of QActions and QMenus...
connect(action1, SIGNAL(triggered()), this, SLOT(onStepIncreased()));
connect(action5, SIGNAL(triggered()), this, SLOT(...
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In a templated derived class, why do I need to qualify base class member names with "this->" inside a member function?
While I investigate source code of Qt I saw that trolltech guys explicitly use this keyword to access a field on destructor.
inline ~QScopedPointer()
{
T *oldD = this->d;
Cleanup::cleanup(...
- 1,716
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votes
2
answers
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QLabel does not display in QWidget
I have the following hierarchy in my Qt Application:
QMainWindow > QWidget (centralWidget) > QWidget (subclassed) > QLabel
Initialization code in my QMainWindow code:
centralWidget = new QWidget();
...
- 3,909
81
votes
7
answers
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Qt static linking and deployment
I am trying to deploy(release to public) a simple qt application I made recently, but got stuck at static linking qt libs.
I followed the guide on qt docs to re-build qt and my app statically. But ...
15
votes
1
answer
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In PyQt, what is the best way to share data between the main window and a thread
I'm in the process of writing my very first GUI application with PyQt4 and I've come upon a question that seems very basic, yet I don't seem to find a good answer:
I'm using a thread to continuously ...
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votes
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answers
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Connecting overloaded signals and slots in Qt 5
I'm having trouble getting to grips with the new signal/slot syntax (using pointer to member function) in Qt 5, as described in New Signal Slot Syntax. I tried changing this:
QObject::connect(spinBox,...
- 1,815
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votes
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answers
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Sending a sequence of commands and wait for response
I have to update firmware and settings on a device connected to a serial port.
Since this is done by a sequence of commands, I send a command and wait until I recive an answer. Inside the answere (...
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votes
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Qt Linker Error: "undefined reference to vtable" [duplicate]
This is my header:
#ifndef BARELYSOCKET_H
#define BARELYSOCKET_H
#include <QObject>
//! The First Draw of the BarelySocket!
class BarelySocket: public QObject
{
Q_OBJECT
public:
...
- 1,565
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votes
1
answer
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How to create a generic object model for use in QML?
I would like to know if there is any macro or way how to register Qt model as property of QObject.
For example, I have AnimalModel (http://doc.qt.io/qt-5/qtquick-modelviewsdata-cppmodels.html#...
- 1,690
145
votes
6
answers
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Detect if stdin is a terminal or pipe?
When I execute "python" from the terminal with no arguments it brings up the Python interactive shell.
When I execute "cat | python" from the terminal it doesn't launch the interactive mode. Somehow, ...
- 9,754
66
votes
1
answer
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How to use the Qt's PIMPL idiom?
PIMPL stands for Pointer to IMPLementation. The implementation stands for "implementation detail": something that the users of the class need not to be concerned with.
Qt's own class implementations ...
69
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6
answers
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How to make item view render rich (html) text in Qt
Suppose my model has items with the following string for Qt::DisplayRole
<span>blah-blah <b>some text</b> other blah</span>
I want QTreeView (actually, any item view) to ...
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votes
3
answers
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My signal / slot connection does not work
I repeatedly see people having problems with slots not being called. I would like to collect some of the most common reasons. So maybe I can help people and avoid a lot of redundant questions.
What ...
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