General and Desktop

What I want to know is, what function does model call on treeView that tells it to redraw None. Model doesn't know anything about the existance of a view (or views). The relationship is the inverse - it's the view that connects to model's signals when you call setModel() on it. As for what signals are emmited by the model - see the documentation of QAbstractItemModel. There are pairs of before/after signals for different operations, e.g. rowsAboutToBoInserted()/rowsInserted(). There's also the mentioned dataChanged() for when a range of items changes one of its roles values. Say my treeViews is linked to a widget displaying data of the selected item, if selection change, then every treeView should notify their own data widgets to update as well. Selection is not a function of the model. This is handled by a selection model that is set on the view, so each view has its own. You can connect to its selectionChanged() signal. Another example could be that if I rename a item, I would want that rename to trigger other events too for each treeViews. This you can handle by connecting to the dataChanged() signal of the model as mentioned above Wait thats dataChanged on model one, what about treeView one? I need tree to react to data/specific data change not model. The data changes in the model so you connect to the model's signals not the view. The views provided by Qt already connect to all the signals of the model. If you want to do extra things in the view you can subclass and connect again to the signals of your choice. You can make the connections in the override of setModel() of your subclass.

The idea is that you have your container widget getting resized and in its resize event, you change the size of the inner widgets with the ratio you want.

Hi layout ->setContentsMargins(0,0,0,0); is the cure. The default margins cuts the checkbox.

That solved indeed my problem! Thanks!

@bluesparrow Hi and welcome to devnet What is the reason for handling in different threads? In case your assumption is that you do not want to miss incoming data, there is no reason to worry. The in-coming data is buffered until you are retrieving it. Typically one may wait for a readyRead signal and read the data, but you may also wait and check bytesAvailable

Hi @wimschuiteman, Peak does not distinguish between 32 and 64 bit, the library is called pcanbasic.dll in both cases. So you need to use the correct one, 32 or 64 bit, depending on your Qt architecture.

@kuzulis I've had a look at socat, and that looks to work! I now have a small example where I can write/read from a serial port. On the other end I am using screen, and my program picks up data as expected! Thanks for the pointer to socat! Didn't know about it..

When I originally did this it was in Windows 7. The feature has been supported since Windows Vista. I would think if you wanted to support windows 7 you would need the Windows 7 sdk. At the very least you will probably need to be using MSVC. When I built my solution I was working solely in Visual Studio using a game engine. I believe you can develop windows specific features in Qt, but I have not done this yet. I don't know if using the Windows 10 SDK will allow development for Windows 7. I would use the Windows 7 SDK if targeting Windows 7.

@Patrick-Wright Qt has the container class of QQueue for situations just as yours ;-)

Many thanks - this has solved the problem

@Pepas an easy way to prevent accidental connectSlotsByName connects would be the use of proper CamelCase notation like every self-respecting c++ programmer should :P

Hi @kripashree QDdesktopServices::openUrl() should do that.

@Christian-Ehrlicher thank you, that worked, I tried /n before :). I paid more attention now.

@mrjj Thanks. It worked. Was a very simple and quick solution. pixmap = QtGui.QPixmap(self.ui.tab_2.size()) self.ui.tab_2.render(pixmap) pixmap.save('abc.jpg','jpg')

Sorrry ... I see these olt post only now .... because try to work my app on my hystorical pc with intel I5 4th gen, ubuntu 16.04 update every mouth .... normally for camera pourpuse I use an other pc with ubuntu 16.04 and work well .... these historical pc actually not work with camera.cpp example provided for QT5.10 .... In these pc there are v4l gstreamer mesa opencv etc etc all updated to recent version .... in the past I used modified by me libv4l.so version (or similar one) and my opencv app work on these pc. But I suppose that modified version is updated and rewrite now from software center updater. Any how ... there are another problem similar to your ... and the problem generally become from firmware of camera not from SO. In the past i modified v4l lib because the firmware of camera was not "standard". regards Giorgio

Thank you very much , it worked !

@victor-wang said in How to judge there is content in QTextEdit?: However, it didn't show anything unless I use "Settext" at the first time then "append". That's strange. Which version of Qt? This code works for me on Qt 5.12.0 (MinGW 7.3.0, 64-bit): QTextEdit e; e.append("Hello"); e.show();

@dheerendra I used QProgressDialog for this case. But it keeps wait UI when function process is long. I mean when process is long, 'not responding' shown over the top of QProgressDialog. Should i call function with QFuture and Qt::Concurrent.run() ? @mrjj