When running my qt application, that is updated from qt 5.9 to qt 5.15, I get the following application output:
Using QByteRef with an index pointing outside the valid range of a QByteArray
The application is quite big and has plenty qbytearrays and qbyterefs. The project is a few thousand files big so I do not want to search for it manually. Is there an easy way to find the location of the application output. e.g. show the line/file that generates the output.
The line is generated by qt and not a custom qdebug or anything.
I would suggest you to check Stop when qWarning() is called under the Debugger section of the Qt Creator's Options:
By default, this option is off, as shown in the screenshot.
Related
I installed the last Qt 5.12.2 . Then I open the cmake project via Qt Creator.
First I see a huge count on the intellisence issues: from "udeclared identifies of nullptr" to errors with each type "unknown type name".
The build proceeded successfully and I receive correct binary.
But any breakpoint marked as "Unclaimed breakpoint" and I cant debug any .qml (the .cpp could be debug)
So why it happens and how to debug the QML? (this future is still supported?)
UPDATE: The "QQmlDebuggingEnabler enabler;" and "doc.qt.io/qt-5/qtquick-debugging.html" doesnt helps :(
UPDATE2: #Amfasis -
I created a CMake-based Qt Quick project, and it shown that it supports QML/JS debugging. I checked the CMakeLists.txt, and found one relevant line:
target_compile_definitions(${PROJECT_NAME} PRIVATE $<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:QT_QML_DEBUG>)
So I think if you'd like to debug your CMake-based Qt Quick project, you should also add this line to your CMakeLists.txt.
And don't forget to check on enable QML in the project setting within the sector of debugging setting.
I have a reMarkable tablet , which I mostly love except for the lack of linux support (surprising given it is a linux-based OS). However, I've managed to find a version of a linux application that is now unofficial. This github is actually a Qt docker app, but if you look in the code for the 'Dockerfile' you can find where to download the app, which is apparently still on the server even though there's not a link from the main web page. Anyway, I downloaded it and got it mostly working, figuring out a few dependencies based on same Dockerfile code. But, I can't seem to get file dialogs to work, which is the main reason for using the app.
The error I get is:
ERROR: No native FileDialog implementation available.
Qt Labs Platform requires Qt Widgets on this setup.
Add 'QT += widgets' to .pro and create QApplication in main().
I'm not a Qt developer, so I'm lost. I'd love to get this to work. Thanks.
In the .pro file of you project you should add this line QT += widgets
or just add widgets to the line with QT += ...
Qt can use native file dialogs on some platforms, and will fall back to its own implementation if none is available. But that requires that the application is built including the QtWidgets module, and using a QApplication.
If you don't have the source code of the app and a possiblity to rebuild it, there's no chance to fix this from a binary
The problem now is that I don't know how I can use qml live preview?
I saw a video:
https://vimeo.com/145921618
I saw this post about erase this function for Qt Creator.
How i can implementlive coding into my app?
Perhaps you mean Terrarium?
Terrarium is a cross platform QML Playground: the view renders lively
as you type in the editor, makes prototyping and experimenting with
QtQuick a lot more fun!
It monitors changes in its TextEdit, and triggers the view to reload
source from the local http server. If you're looking for a file system
watcher implementation, please refer to QML LiveReload.
Or LiveReload?
As is evident from the video, this is as simple as auto reloading a QML file each time a chance to the file has been saved.
You can easily do that yourself, set up a QFileSystemWatcher and every time the file is modified, load the file in a QML view. And there you have it.
Of course, this is only good for previewing standalone components which can work on their own. You could go further, set the file system watcher to monitor the entire QML project and reload the main QML file every time something changes. It is a two step process, you need to monitor the directory, which only reflects adding or removing of files, and you subsequently add or remove those files from watching for changes.
Just for the sake of it, I want to share another tool that I found online.
It is a web based QML editor that gives immediate preview while writing the code. It has its limits, but still it's pretty useful for live QML coding
https://qmlweb.github.io/
If someone is still interested, in my Qt 5.10 installation, there is a qmlscene.exe in bin folder (same location as qmake or assistant). Running on command line is fine, however it is not in Qt creator.
PS: I found this:
http://doc.qt.io/qt-5/qtquick-qmlscene.html
How can I import these code examples into QT Creator 3.4.0 ? I tried the available import options but they don't work.
I tried to create an empty QML project and add the rectangle.qml file to it. When I tried to run it, nothing showed up.
The book examples contain files .qmlproject - which seems to be a project descriptor. I wonder if it is somehow possible to import these .qmlproject files into QT Creator, click and run the examples.
I think this link might help in finding the solution : https://forum.qt.io/topic/27525/what-is-qmlproject-file/3 .
Usually I'd say that you should go to File > Open File or Project... and select the .qmlproject and you're done, but support for this type of project file was disabled by default. If you try to do this now (I believe the change is in Creator 3.4), you'll just get an error message about Creator not supporting the mime type of the file, or something. Unfortunately, this is not a very useful error message for a beginner, and it won't tell you how to fix the problem.
If you want to use .qmlproject files in newer versions of Creator, you have to navigate to Help > About Plugins... and enable the QmlProjectManager plugin (it's under the Qt Quick section) by checking the box.
So this is how you should normally open project files in Qt Creator. As for the window not showing up, that's also commonly encountered and can be fixed by making the root item in your scene a Window:
Unlike QQuickView, QQmlApplicationEngine does not automatically create a root window. If you are using visual items from Qt Quick, you will need to place them inside of a Window.
Qt Creator's new project wizard handles this for you when you create a new Qt Quick project, as you saw when you got the "Hello World" window to open in your video. It was when you loaded concepts/rectangle.qml which had a Rectangle as its root item, that it stopped showing up. That QML file was likely used in a project where a QQuickView was displaying it.
I am trying to develop a user interface using QtCreator on a Windows 7 64-bit machine. This user interface will be deployed on a 32-bit Windows 7 machine, and will control a projector and a camera for a structured-light application. For reasons beyond my control (compatibility with camera and projector's APIs), I will use the MS VS 2010 32bit compiler for this. After a couple of weeks trying to have everything I need working together (Qt 4.8.4, QtCreator and Point Cloud Library), I am now facing a slight problem.
Is there a way that I can embed the PCL Point Cloud Viewer inside my main Qt GUI window? The problem is that when I use the PCL viewer, it brings up a separate window. I want this window to be embedded inside my main window, and I want to still be able to interact with it (rotate, pan, zoom, etc.).
As you may be able to tell from my post, I am a newbie on Qt/PCL/etc., so any example with minimal code to do this would be greatly appreciated. I have done weeks of research on this and I have not been able to find a solution, although I get the impression that a Qt Widget might be the way to go.
You can simply use PCL's PCLVisualizer, which is extensively described here, via the QVTKWidget. This is the setup I'm currently running. So you would end up doing something along the lines of the following (pseudo-)code:
In your header:
class PointCloudWidget : public QVTKWidget
{
//Whatever comes before (constructor, methods, etc.)
private:
pcl::visualization::PCLVisualizer m_visualizer;
};
And in your cpp:
PointCloudWidget::PointCloudWidget(QWidget *parent) : QVTKWidget(parent)
{
this->SetRenderWindow(m_visualizer.getRenderWindow());
}
You can then use the visualizer to achieve the same functionality as the PCL viewer has.
Look at the kind of minimal code I put here (PCL Viewer with Qt GUI minimal code).
There are some redundancies, but the code I believe is pretty straightforward.
The main idea is to put the files in the one folder and start project from CMakeLists.txt (Qt cmake wizard).
I use build directory inside project dir. (this is important, because in pclwindow.cpp I hardcoded the path to the generated file #include "build/ui_pclwindow.h"
If app builds, but crashes you'll probably need to add some dependencies (e.g. dll files on Win platform)
I hope it will give you fast and simple start!