USB barcode reader in Qt4
Hi. I was wondering how could I integrate a USB barcode scanner into a Qt application, as well as a barcode printer. I looked for tutorials but didn't find anything interesting out there. Any ideas? Thanks in advance. ...
qt4
Qt4 QSettings save enumeration value (for example Qt::CheckState)
i wanna save state of QCheckBok in QSetting, i can cast its value to int but maybe exists more simple and proper method to do it? here is my code: QSetting setting; Qt::CheckState checkState; //... checkState = (Qt::CheckState)setting.value("checkState", Qt::Unchecked).toUInt(); //... setting.setValue("checkState", (uint)checkState); s...
QObject (QPlainTextEdit) & Multithreading issues
Im currently trying to learn Networking with Python asyncore and pyqt4. I coded a small server, which basically listens on some port, and resends all messages it recieves to the sender. Since both qts QApplication.exec_() and asyncore.loop() are functions which never return i could not start them both in one thread, so i stared asyncor...
resize qwidget in a layout manually on runtime
I have a QVBoxLayout with a few widgets in it (QTableViews). Now these QTableViews all have the same size. What can I do, that the user can change the size of one QTableView on runtime (so that 1 QTableView is bigger than the other one)? Maybe with a "seperator" which you can change with the mouse? ...
WCF service with Qt?
I would like my Qt app to expose a service to another app written in .Net using WCF. Is there any support in Qt for implementing WCF services? ...
Qt Multimedia API and video decode
Hi, I'm looking to Qt Multimedia API becouse I want to show the same video on 2 different widget. After hacking a little bit the boundled "videographicsitem" example it works using 2 GraphicsView. But this example use QMovie to decode gif, I want to decode avi, mp4, etc. What can I use to replace QMovie? Is the multimedia API supported o...
Seeking advice on using QGLWidget in Qt4
Hi all, I'm new here, and have a question about opengl in Qt4, which I've been learning over the last few months. Particularly, I'm seeking advice on the best way to compose a scene in a good object-oriented fashion using the QGLWidget. I'd ideally like every item in my scene to be sub-classes of a super 'Entity' class. Then in my main...
QT slot get Signaled twice
In QT4.5, I use a QTableWidget, and I have connected the signal QTableWidget::itemClicked() to a custom slot like this: connect(_table, SIGNAL(itemClicked(QTableWidgetItem*)), item, SLOT(sloItemClicked(QTableWidgetItem*))); I create such a connection for each row I add to the table. The problem is that the slot sloItemClicked get ca...
Qt4: QAbstractTableModel Drag and Drop w/o MIME
I have a class which inherits QAbstractTableModel, and holds some complex structs in a QMap. The QVariant data(QModelIndex index, ...) method just returns an enum which describes how a custom item delegate should draw the contents of a cell. I would like to implement drag and drop functionality in this model so that users can reorder th...
Qt4: QTableView mouse button events not caught
I have a QTableView in which I am displaying a custom model. I would like to catch right mouse clicks so that I can open a contextual drop down menu on the underlying table data: MainWindow::MainWindow() { QTableView * itsView = new QTableView; itsView->installEventFilter(this); ... //Add other widgets and display them all } ...
Performance issue with QGraphicsScene::createItemGroup
I'm using the Qt graphics API to display layers in some GIS software. Each layer is a group, containing graphic primitives. I have a performance issue when loading fairly large data sets, for example this is what happens when making a group composed of ~96k circular paths (points from a shapefile): The complete callgrind dump is here...
Run linux command line commands from Qt4
...and of course obtaining the output in some way I can use it. I'd use it for an ls | grep, but it's good to know for any future issues. Thanks in advance. ...
Qt4: Read Default mimeData from QAbstractTableModel
By default, the QAbstractTableModel class has a mimeData() function that returns a QMimeData object which has it's data set as an encoded QModelIndexList (see here). I would like to unpack this data in an overloaded dropMimeData() function, but can't figure out how to convert this QMimeData back into a QModelIndexList. I tried the obviou...
PyQt and Bespin (KDE style)
What tab widget decorate by Bespin Tabs? I tried QTabWidget, QTabBar, KTabWidget, KTabBar, bau no effect. What Im doing wrong? All KDE apps and SMPlayer decorate by Bespin, but acetoneiso and PyQt apps have regular tabs=( I mean this Bespin: http://kde-look.org/content/show.php/Bespin?content=63928 ...
Qt - Drawing a Rect/Frame out of a bigger Pixmap image.
Hi there, I've been banging my head about this seemingly easy task and I could really use some help. I have a wide Image loaded in the gui (using the designer..) and I want to be able to draw only a portion of it, a rectangle. I need to be able to change this rectangle position over the large image, in order to draw a different part of ...
No such signal QTableWidget::cellChanged(int, int)
The title describes my problem quite well. The offending line of code: connect(table, SIGNAL(cellChanged(row, 5)), this, SLOT(updateSP())); I can think of no reason why that signal is not valid. I googled around, and found a couple people with the same problem, but the solutions posed there don't work. I'm using Qt 4.5.2 on Ubuntu ...
Is it possible to use Win32 Hooks in Qt applications.
I like to know if its possible to use win32 keyboard hook function (SetWindowsHookEx , SetWindowsHookEx ) in a Qt application. If possible pls provide a sample code on using SetWindowsHookEx , SetWindowsHookEx functions in Qt. //Update as of 18 Feb 2010 // I havent figured out how to do that in QT yet. But as a workaround I have cre...
QtEmbedded (for Kindle!): How are the device plugins supposed to get feedback from the app?
I'm not having an easy time making a workable mouse pointer interface on the Kindle with Qt (unofficial, of course). The fiveway joystick can't track more than one direction at a time (no diagonal moves), and the screen is too slow to update for good feedback. I've got limited acceleration, but with the screen delay it's very frustrati...
How to end line with QTextEdit
Hi, I'm trying to create QTextEdit with some text, and in this text I have end of line signs (\n), but it is not accepted in QTextEdit object (whole text is displayed without any breaks). Any reason why? Could anyone help me with this? Thank you. ...
QTableWidget: How can I get tighter lines with less vertical spacing padding?
The QTableWdiget is fabulous for simple grid displays. Changing colors, fonts, etc is straightforward. However, I did not manage to give the grid a 'tighter' look with less vertical whitespace. I see that the Qt documentation talks (eg here) about margin border padding around widgets, but when I set these I only get changes aroun...