QML and Qt Quick

@streetcoder said in qml - How to show a window?: Im following the beginner tutorial and it says to replace the Window object with a Rectangle object to set state, yet when I do that, no graphic is fired when the app is ran. Any idea how I can set the state on a window object or get the rectangle object to show up? I'm not sure which tutorial you mean. Can you please post your code? (Also, in the future please open a new thread for new questions)

https://doc.qt.io/qt-5/qtqml-cppintegration-exposecppattributes.html https://doc.qt.io/qt-5/qtqml-cppintegration-overview.html#:~:text=Overview - QML and C%2B%2B Integration QML is,C%2B%2B functionality to be invoked directly from QML. create a class extends QObject use Q_PROPERTY, Q_INVOKE ... to expose attribute to qml create a instance of this type rootObject setContentProperties() in main.cpp then you can use this instance, in rootObject qml

@jeremy_k "I never got into Stack Overflow point collecting. Thanks for the offer." I like you even more now. Marked as solved. I forgot to do this yesterday.

If the model needs to be updated (even if not), I would advise to use https://github.com/benlau/qsyncable and its JsonListModel. It's a QAbstractListModel under the hood that calculates the diff between the new and old model and only emit the necessary signals (dataChanged, rowInserted/Removed), no complete model reset and delegate deletion/recreation.

@Holiday I also made once this: https://github.com/DeiVadder/RuntimeQmlReload to reload QML files during runtime. But it's not made to do it from inside a dll, but from inside the main program. But it may help?

this error is solved by using multithreads Signal & slots . For example : connect(workerA, SIGNAL(printMessage(QString)), this, SLOT(printMessage(QString)), Qt::QueuedConnection);

@sierdzio Thanks for answering, overriding worked. Also for your information, i am a beginner so may be wrong but without ScrollView, it still can be scrolled.

Anyway thank for Help <3

@jsulm OK I know, thanks.

Similar problem here. Reading https://doc.qt.io/qt-5/qml-qtlocation-mapcircle.html#backend-prop, it looks like certain-- perhaps even all-- QtLocation items were drawn with software, not GPU acceleration. Trying out with and without acceleration, I can definitely tell a difference in panning. However, it's still not "good" with ~2.7k points. Even setting the environment variable QTLOCATION_OPENGL_ITEMS to 1, in case there are other elements subtly serving as bottlenecks, I don't see what I would consider to be good, smooth performance. It's hard to know if this limitation isn't also possibly due to the fact that calculating a polygon-- in this case a MapCircle-- is intensive no matter what. Also, my GPU is an integrated Intel UHD Graphics 617, so nothing stellar. However, presumably my PC GPU is better than the standard phone GPU, so it's a reasonable performance data point. However, since I can pan and zoom on maps with aplomb, it seems like there's still low-hanging fruit available. Here's hoping to see future speed bumps.

Hi! I tried the Blur effects types. I experimented with Gaussian Blur. The result I got was slightly different. When I apply it on the map, there is an iteration. As in the image, the effect repeats 6 times. I added it as a link because the image size is large. https://www.hizliresim.com/mn1jrfb Here is the code block. import QtQuick 2.15 import QtQuick.Window 2.15 import QtGraphicalEffects 1.15 import QtLocation 5.15 import QtPositioning 5.15 Map { id: _map gesture.acceptedGestures: MapGestureArea.PinchGesture | MapGestureArea.PanGesture | MapGestureArea.FlickGesture gesture.flickDeceleration: 3000 plugin: Plugin { name: "QGroundControl" } opacity: 0.99 Item { id: test width:1280 height: 800 Rectangle { id: rect anchors.centerIn: parent color:"grey" opacity: 0.6 width: test.width*1/2 height: test.height*1/2 } } ShaderEffectSource { id: shader anchors.fill: test sourceItem: test sourceRect: Qt.rect(x,y,width,height) } GaussianBlur { radius: 80 anchors.fill: test source: _map samples: 1 + radius * 2 } readonly property real maxZoomLevel: 20

I'm running on Linux (actually WSL)...that might be part of the problem, though you said it wasn't working for you, either. So, do I infer correctly that there's a process for manually adding fonts to Qt?

Hi, Yes it is. See the QML CPP integration chapter in Qt's documentation.