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Search found 1902 results on 77 pages for 'qt contextmenu'.

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  • How to return a const QString reference in case of failure?

    - by moala
    Hi, consider the following code: const QString& MyClass::getID(int index) const { if (i < myArraySize && myArray[i]) { return myArray[i]->id; // id is a QString } else { return my_global_empty_qstring; // is a global empty QString } } How can I avoid to have an empty QString without changing the return type of the method? (It seems that returning an empty QString allocated on the stack is a bad idea) Thanks.

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  • Is there a way to implement OnReady() callback in Qt4?

    - by lilo
    I want to do something which will access network when a QMainWindow is ready. I suppose I should not do it in the constructor, so I try to find a signal the widget will get and try to implement something like a OnReady() call back in other UI library. But I still can not find a way to do this. Thanks a lot in advance.

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  • C++ and virtual methods overriding

    - by silent
    Sorry for this stupid question, but I can't find an answer by myself, I'm too new in C++ :( class DBObject : public QObject { ... protected: virtual QString tableName() { return ""; }; }; class DBUserObject : public DBObject { ... protected: virtual QString tableName() { return "profiles"; }; }; And I have this code in parent: bool DBObject::load(quint32 id) { QString query = QString("select %1 from %2 where id = :id") .arg(fieldList().join(",")) .arg(tableName()); <--- here is trouble ... } So I'm trying to execute: DBUserObject user; user.load(3); But in result I have a query with empty table name cause tableName() method returns empty string. Why not "profiles"?

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  • Trouble getting QMainWindow to scroll

    - by random
    A minimal example: class MainWindow(QtGui.QMainWindow): def __init__(self, parent = None): QtGui.QMainWindow.__init__(self, parent) winWidth = 683 winHeight = 784 screen = QtGui.QDesktopWidget().availableGeometry() screenCenterX = (screen.width() - winWidth) / 2 screenCenterY = (screen.height() - winHeight) / 2 self.setGeometry(screenCenterX, screenCenterY, winWidth, winHeight) layout = QtGui.QVBoxLayout() layout.addWidget(FormA()) mainWidget = QtGui.QWidget() mainWidget.setLayout(layout) self.setCentralWidget(mainWidget) FormA is a QFrame with a VBoxLayout that can expand to an arbitrary number of entries. In the code posted above, if the entries in the forms can't fit in the window then the window itself grows. I'd prefer for the window to become scrollable. I've also tried the following... replacing mainWidget = QtGui.QWidget() mainWidget.setLayout(layout) self.setCentralWidget(mainWidget) with mainWidget = QtGui.QScrollArea() mainWidget.setLayout(layout) self.setCentralWidget(mainWidget) results in the forms and entries shrinking if they can't fit in the window. Replacing it with mainWidget = QtGui.QWidget() mainWidget.setLayout(layout) scrollWidget = QtGui.QScrollArea() scrollWidget.setWidget(mainWidget) self.setCentralWidget(scrollWidget) results in the mainwidget (composed of the forms) being scrunched in the top left corner of the window, leaving large blank areas on the right and bottom of it, and still isn't scrollable. I can't set a limit on the size of the window because I wish for it to be resizable. How can I make this window scrollable?

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  • QT4: How to restart application? Reset settings?

    - by Revollt
    Hi. 1.) I would like to restart my QT4 application. Just a normal shutdown and start of the same application. 2.) Why? Well i need an Option to "reset" everything. To restart the application seems to be the easiest way to do this. The problem is, that there are a LOT of classes and everything. I dont have the time to put every setting of them back to standard, every textBox, Widget to clear... I Know application restart is not the best way, what do you think is there another way? Thank You

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  • How to make the tittle bold?

    - by Solitaire
    Hi all, In Qmessagebox how can I make the tittle text bold? Here is the sample code, which I am using to disply a messagebox int ret = QMessageBox::warning(this, tr("My Application"), tr("document has been modified.\n" "Do you want to save your changes?"), QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel, QMessageBox::Save); I just want “tr("My Application")” to be bold, and rest to be in normal font. How can I do that? By default I am getting the normal font for both title and descriptive text. Thanks.

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  • When should we use * and & and . and -> ?

    - by uzay95
    Why we are using * character when we are creating button but we aren't adding it to app instance? #include <QApplication> #include <QPushButton> int main(int argc,char *argv[]) { QApplication app(argc,argv); QPushButton *button = new QPushButton("Button Text"); QObject::connect(button,SIGNAL(clicked()),&app,SLOT(quit())); button->show(); return app.exec(); } When should we use * and & and . and - ?

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  • Repositioning a label with mouseevents to anywhere on the screen

    - by user2947295
    I've created a label and used setPixmap to attach a .png image to the label. I've also setWindowFlags to disable the title bar and create a frameless window. Because I've disabled those, it also disables the ability to drag anything around, so I want to create mouseevents (unless there's a better method) to position my label anywhere on the screen exactly like dragging the frame of a window. How would I do that? An example and brief explanation would be greatly appreciated.

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  • returning null or throwing an exception?

    - by MoKi
    I have the following types: typedef QPair < QTime , QTime > CalculatedTimeSlotRange; typedef QList < CalculatedTimeSlotRange > CalculatedTimeSlotRangeList; typedef QHash < quint8 , CalculatedTimeSlotRangeList > TimeSlotsTable; I have a function like the following: const CalculatedTimeSlotRangeList* TimeSlots::getCalculatedTimeSlotRangeList(const quint8 id) const { QHashIterator<quint8,CalculatedTimeSlotRangeList> it(mTimeSlotsTable); while (it.hasNext()) { it.next(); if(it.key() == id) { return &it.value(); } } return NULL; } as you can see my function returns a null if it fails to find a key that matches id. Is this correct? or should I just throw an exception if the key does not exist? how should i throw an exception for this situation?

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  • reading root element in xml not the child

    - by Umesha MS
    Hi I am working on an application which reads XML file. Here I am trying to read the node under the not under the node . When I tried to read the I get both. Please help me to solve the problem. Bellow is the sample. "a" "x"..."/X" "b" "name" 123 "/name" "/b" "name" main "/name" "c".."/c" "/a" QDomDocument mDocument; QDomElement mDocumentElement; if (!mDocument.setContent(file.readAll())) { return ; } mDocumentElement = mDocument.documentElement(); QDomNodeList list = mDocumentElement.elementsByTagName("a").at(0).toElement().elementsByTagName("name"); int count = list.count(); for (int i = 0; i < count; i++) { QString str = list.at(i).nodeValue(); QMessageBox::information(this, "text", str, QMessageBox::Yes, 0); }

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  • A pointer member variable having different values

    - by Rohan Prabhu
    Ok, to begin with, this is my code: HyperSprite::HyperSprite() { _view = 0; } void HyperSprite::publish(QGraphicsView* view) { _view = view; } void HyperSprite::getKFrame() { if(_view != 0) { qDebug()<<(void*)_view; } } Now, if I call HyperSprite::getKFrame() from within main(), I get the output: 0xbf8ffb84 I have a TCP server, which requires this QGraphicsView* variable. So whenever a new connection is made, HyperSprite::getKFrame() is called. However, whenever I make a connection to my server, this is the output: 0x1e425ff I honestly don't understand this. Shouldn't the value of a member remain same throughout? Why is the pointer value changing? As is obvious, whenever I try to use the _view pointer to access any of its members, a Segmentation Fault occurs. I tried using QSharedPointer, but it also results in the same problem. The data of the QSharedPointer automatically changes. Why is this happening?

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  • QFileDialog used as widget

    - by lvp
    Hi! My goal is: user can choose file (only *mp3) and after clicking twice on it it should play (so the QString to file should be send to play() funtion) Firstly I started to work with QTreeView, but it has signal when the file is selected. So I decided to create QFileDialog and used it as widget built-in into MainWindow. The only problem that I have, that after double-click it dissapers. It is possible to avoid it? Should I work with some QDialog::finished() signal or, QDialog::done()?

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  • Translate sequence in macro parameters to separate macros

    - by Alex Tiger
    How to acces each element in macro if the definition is like MACRO(name, seq) and the code is like: MACRO("TheName", (Elem1) (Elem2) (Elem3) ) I want to generate the next code: MACRO("TheName", ELEMMACRO(Elem1) ELEMMACRO(Elem2) ELEMMACRO(Elem3) ) Or something like that. In other words, I want to process every parameter separately (I don't care of definition, even if it will be something like MACRO("TheName", Elem1, Elem2, Elem3 ) There could be more elements, there could be less. I have tried V_ARGS (I need it only for gcc), but I can only copy all the elements by that, not to process them separately. What can I do? P.S. Because of some reasons, I can't use Boost.

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  • QMake et au-delà : le futur de l'outil de compilation de Qt, un article de Marius traduit par Louis

    Bonjour, QMake est un outil qui simplifie grandement le processus de compilation pour de différentes plateformes. Son prédécesseur était un script Perl nommé TMake, qui, dépassé, avait vite été remplacé par le QMake que nous connaissons. Aujourd'hui, ce dernier semble à son tour ne plus apporter une réponse au besoin initial, étant devenu difficile à maintenir. Ainsi, devant la diversité et le nombre des avis internes, Marius a décidé de rédiger un article dans les Qt Labs Blogs afin de demander aux développeurs aguerris leur avis sur la question. Qu'allons-nous faire de QMake ? C'est la question, posée par Marius en début...

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  • As a Qt GUI programmer, how to improve (career & skill)?

    - by linjunhalida
    hello, I'm a python & Qt programmer, and my daily job is create small PC GUI programs ship with hardware devices. the problem is, My job is simple, read/write data to device by using serial port(pyserial), display and edit data(PyQt + PyQwt), that's all. although I'm a linux user, my program is running under windows XP, but thanks to PyQt, I can still develop under linux. And I'm always afraid of being replaced by the people cheaper and younger than me in the future. (I'm 26 now.. not too much time for playing..) So I need improve myself, and make me more competitive in the global market, and I like programming, and want coding till the end of my life. any roadmap suggestion?

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  • Sortie de Qt Mobility 1.0.0, 10 nouvelles API pour les plateformes mobiles : envoi de SMS au rendez-

    Après un peu d'attente, voilà enfin la première sortie officielle de Qt Mobility. Cette release contient 10 API dont 9 sont considérées comme finales et 1 comme beta. Les 9 API finales sont les suivantes : Service Framework Bearer Management Messaging Contacts Versit Publish and Subscribe Location System Information Sensors L'API multimédia quant à elle est à un très bon état de développement, mais l'équipe de développement se réserve la possibilité de modifier cette version. Dans ce cas, cette version beta ne sera pas maintenue, il est donc à vos risques et périls de l'utiliser dès à présent. Où les trouver ? Elles sont disponibles sur ...

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  • c++ program debugged well with Cygwin4 (under Netbeans 7.2) but not with MinGW (under QT 4.8.1)

    - by GoldenAxe
    I have a c++ program which take a map text file and output it to a graph data structure I have made, I am using QT as I needed cross-platform program and GUI as well as visual representation of the map. I have several maps in different sizes (8x8 to 4096x4096). I am using unordered_map with a vector as key and vertex as value, I'm sending hash(1) and equal functions which I wrote to the unordered_map in creation. Under QT I am debugging my program with QT 4.8.1 for desktop MinGW (QT SDK), the program works and debug well until I try the largest map of 4096x4096, then the program stuck with the following error: "the inferior stopped because it received a signal from operating system", when debugging, the program halt at the hash function which used inside the unordered_map and not as part of the insertion state, but at a getter(2). Under Netbeans IDE 7.2 and Cygwin4 all works fine (debug and run). some code info: typedef std::vector<double> coordinate; typedef std::unordered_map<coordinate const*, Vertex<Element>*, container_hash, container_equal> vertexsContainer; vertexsContainer *m_vertexes (1) hash function: struct container_hash { size_t operator()(coordinate const *cord) const { size_t sum = 0; std::ostringstream ss; for ( auto it = cord->begin() ; it != cord->end() ; ++it ) { ss << *it; } sum = std::hash<std::string>()(ss.str()); return sum; } }; (2) the getter: template <class Element> Vertex<Element> *Graph<Element>::getVertex(const coordinate &cord) { try { Vertex<Element> *v = m_vertexes->at(&cord); return v; } catch (std::exception& e) { return NULL; } } I was thinking maybe it was some memory issue at the beginning, so before I was thinking of trying Netbeans I checked it with QT on my friend pc with a 16GB RAM and got the same error. Thanks.

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