I have a python file and a qml file.
There is a button in the qml file to load a FileDialog. When I directly use qmlscene test.qml, the FileDialog is ok. But when I use python3 main.py, the FileDialog is strange, and I can't select a file by it. Please tell me how to fix it.
This is the normal file-dialog:
And this is the strange file-dialog:
The code is the following:
test.qml
import QtQuick 2.4
import QtQuick.Dialogs 1.2
import QtQuick.Controls 1.3
import QtQuick.Controls.Styles 1.3
import QtQuick.Layouts 1.1
Rectangle {
width: 400
height:30
Button {
id: save
text: "save"
onClicked: {
fileDialogLoader.item.open()
}
}
Loader {
id: fileDialogLoader
sourceComponent: fileDialog_com
}
Component{
id: fileDialog_com
FileDialog {
id: fileDialog
title: "select a file"
nameFilters: ["pdf files(*.pdf)"]
selectExisting: false
onAccepted: {
console.log(" you choose: "+ fileDialog.fileUrls)
}
}
}
}
main.py
#!/usr/bin/env python
# encoding: utf-8
from PyQt5.QtCore import QUrl, QObject, pyqtSlot
from PyQt5.QtGui import QGuiApplication
from PyQt5.QtQuick import QQuickView
class MyMain(QObject):
pass
if __name__ == '__main__':
path = 'test.qml'
app = QGuiApplication([])
view = QQuickView()
con = MyMain()
context = view.rootContext()
context.setContextProperty("con",con)
view.engine().quit.connect(app.quit)
view.setSource(QUrl(path))
view.show()
app.exec()
The "strange" file-dialog is a default implementation that has been written entirely in QML. Qt will use this as a fallback when it cannot create either the platform's native dialog or the built-in QFileDialog.
The reason why your example uses the qml fallback, is because you are using QGuiApplication, which is not widget-based. If you switch to QApplication, your example will work as expected:
# from PyQt5.QtGui import QGuiApplication
from PyQt5.QtWidgets import QApplication
...
# app = QGuiApplication([])
app = QApplication([])
Related
I am trying to create a circular guage using Qml in Python as a QQuickWidget.
I am unable to do so as I receive the Error CircularGauge.qml:18:9: NumberAnimation is not a type
I am working on windows, where I have added C:\Qt\Tools\QtCreator\bin\qml to my path.
I have copied CircularGauge.qml exactly as is from example found on the Qt site doc.qt.io
to solve this issue I tried adding import QtQuick 2.0 to the CircularGauge.qml file, but then I receive the error CircularGauge is instantiated recursively
My python code is as follows:
import sys
from PySide6.QtWidgets import QApplication, QWidget, QVBoxLayout
from PySide6.QtQuick import QQuickView, QQuickWindow, QSGRendererInterface
from PySide6.QtQuickWidgets import QQuickWidget
if __name__ == '__main__':
app = QApplication()
QQuickWindow.setGraphicsApi(QSGRendererInterface.OpenGL)
widget = QQuickWidget()
widget.setSource('CircularGauge.qml')
layout = QVBoxLayout(widget)
widget.show()
sys.exit(app.exec())
I have confirmed this works with other qml exampls,
for example if I replace widget.setSource('CircularGauge.qml') with widget.setSource('view.qml')
where view.qml is:
import QtQuick
Rectangle {
id: main
width: 200
height: 200
color: "green"
Text {
text: "Hello World"
anchors.centerIn: main
}
}
I get the desired result of a qml file loaded into a QQuickWidget
How can I load the CircularGauge in the same way?
I want show charts in my app with Python back-end and qml front-end but I got an error.
Import:
import QtCharts 2.3
Error:
module "QtCharts" is not installed
I installed qtcharts with maintaince.exe
How to solve this?
In PyQt6 the chart module comes in a separate package and you must run:
python -m pip install PyQt6-Charts PyQt6
On the other hand maintaince.exe only works for C++ so installing QtCharts does not affect PyQt6.
In the next part there is a demo:
import os
from pathlib import Path
import sys
from PyQt6.QtCore import QCoreApplication, Qt, QUrl
from PyQt6.QtWidgets import QApplication
from PyQt6.QtQml import QQmlApplicationEngine
CURRENT_DIRECTORY = Path(__file__).resolve().parent
def main():
app = QApplication(sys.argv)
engine = QQmlApplicationEngine()
filename = os.fspath(CURRENT_DIRECTORY / "main.qml")
url = QUrl.fromLocalFile(filename)
def handle_object_created(obj, obj_url):
if obj is None and url == obj_url:
QCoreApplication.exit(-1)
engine.objectCreated.connect(
handle_object_created, Qt.ConnectionType.QueuedConnection
)
engine.load(url)
sys.exit(app.exec())
if __name__ == "__main__":
main()
import QtQuick
import QtQuick.Controls
import QtCharts
ApplicationWindow {
id: root
width: 640
height: 480
visible: true
title: qsTr("Login Page")
ChartView {
id: chartView
anchors.fill: parent
LineSeries {
XYPoint {
x: 0
y: 0
}
XYPoint {
x: 1.1
y: 2.1
}
}
}
}
Note: In Qt6 the versions of the QML modules should not be indicated.
I have added a simple QML component ("qml/MyButton") to my "resource.qrc" file:
<RCC>
<qresource prefix="/">
<file>qml/MyButton.qml</file>
</qresource>
</RCC>
I then compiled the QRC to a python module with:
pyside2-rcc -o resource.py resource.qrc
Then I imported resource.py in main.py:
import sys
import os
from PySide2.QtGui import QGuiApplication
from PySide2.QtQml import QQmlApplicationEngine
import resource
if __name__ == "__main__":
app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()
engine.load(os.path.join(os.path.dirname(__file__), "main.qml"))
if not engine.rootObjects():
sys.exit(-1)
sys.exit(app.exec_())
And called MyButton component in main.qml:
import QtQuick 2.13
import QtQuick.Window 2.13
Window {
width: 640
height: 480
visible: true
title: qsTr("Hello World")
MyButton {
}
}
This is "qml/MyButton.qml":
import QtQuick 2.0
import QtQuick.Controls 2.13
Button {
text: 'Click Me'
}
When I run the program I get the error that "MyButton is not a type". I want to use the QML component by using the python generated resource file. I don't know what I am doing wrong.
Automatic import if the .qml is next to the main file but in your case MyButton.qml is not next to the main.qml so the package has to be imported:
import QtQuick 2.13
import QtQuick.Window 2.13
import "qrc:/qml"
Window {
width: 640
height: 480
visible: true
title: qsTr("Hello World")
MyButton {
}
}
I have a problem with Toolbar when I use the qml file with PyQt5. The result is not the seem : no background image when mouse is over, image no resize automatically.
I want to know if it's normal.
How can I do for have the same result with PyQt5
The result with qmlscene:
The result with Python:
Thanks you for your help.
File : _test.py
from PyQt5.QtCore import (
pyqtProperty,
pyqtSignal,
pyqtSlot,
QAbstractListModel,
QModelIndex,
QObject,
Qt,
QTimer,
)
from PyQt5.QtGui import QGuiApplication
from PyQt5.QtQml import QQmlApplicationEngine
from PyQt5.QtQuick import QQuickView
class MainWindow(QObject):
def __init__(self, parent=None):
super().__init__(parent)
if __name__ == "__main__":
import sys
app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()
engine.quit.connect(app.quit)
main_window = MainWindow()
engine.load("_test.qml")
if not engine.rootObjects():
sys.exit(app.exec_())
sys.exit(app.exec())
File : _test.qml
import QtQuick 2.4
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.3
import QtQuick.Controls.Styles 1.3
ApplicationWindow {
width: 500
height: 200
visible: true
ToolBar {
Layout.fillWidth: true
RowLayout {
anchors.fill: parent
ToolButton {
//width: parent.height
anchors.margins: 4
iconSource: "ico/abacus.png"
}
ToolButton {
width: parent.height
Image {
source: "ico/quitter.png"
anchors.fill: parent
anchors.margins: 4
}
}
ToolButton {
width: parent.height
iconSource: "ico/start.png"
anchors.margins: 4
}
ToolButton {
width: parent.height
Image {
source: "ico/stop.png"
anchors.fill: parent
anchors.margins: 4
}
}
}
}
}
Analyzing the source code of qmlscene and testing with the --apptype option I get the following:
qmlscene _test.qml --apptype gui
qmlscene _test.qml --apptype widgets
So analyzing the fundamental difference is that QApplicacion is being used and not QGuiApplication, so internally it should activate some flag that scales the icons.
Considering the above, the solution is:
from PyQt5.QtCore import QUrl
from PyQt5.QtWidgets import QApplication
from PyQt5.QtQml import QQmlApplicationEngine
if __name__ == "__main__":
import os
import sys
app = QApplication(sys.argv)
engine = QQmlApplicationEngine()
current_dir = os.path.dirname(os.path.realpath(__file__))
file = os.path.join(current_dir, "_test.qml")
engine.load(QUrl.fromLocalFile(file))
if not engine.rootObjects():
sys.exit(-1)
sys.exit(app.exec_())
According to the docs of Qt Quick Controls 1:
Note: We are using QApplication and not QGuiApplication in this
example. Though you can use QGuiApplication instead, doing this will
eliminate platform-dependent styling. This is because it is relying on
the widget module to provide the native look and feel.
So it seems that the scaling of the icons is part of the style of the platform.
Each type of project requires a QXApplication:
Console application: You can use any of the 3 types of QXApplication, but using QCoreApplication is the most optimal since the other QXApplication require that they have a window system that in that case is an unnecessary requirement.
QML Application: It requires at least one QGuiApplication, but for certain ones such as the need to use the styles of each platform it is necessary to use QApplication.
Qt Widgets Application: A QApplication is necessary because QWidgets use the styles of each platform.
The fact that sizes change, is this a problem of QtQuick.Controls 1?
Yes, one of the main differences between QQC1 and QQC2 is that the first one is developed to support desktop platforms so you use the styles, unlike the second one that is designed for embedded systems where the main objective is performance. For more information read Differences with Qt Quick Controls 1
Conclusions:
If you want your GUI made with QML to respect the styles of your desktop platform then you must use QQC1 with QApplication.
If your goal is that the style of your application does not respect the style of the desktop in addition to wanting more performance you should use QQC2 with QGuiApplication.
I am fairly new to Qt/PyQt and currently struggling with some basic functionality. What I'm trying to do is, to dynamically load QML-Views (*.qml) files from python and replace specific content on the fly. For example a checkbox gets checked and part of my current view is replaced with another qml file. First I wanted to provide this logic via PyQt, but it seems a StackView is a better idea (multiple qml files in pyqt).
However, in this case I am not able to inject properties into my QML files. I am only able to inject a property into the rootContext. That however limits the usage of my QML-Views since I can only use one view (of the same type) at once. I would like to inject properties dynamically into QML-Views and make them only visible to this particular view. In this case I can use the same view more than once with more than one object in the back-end to catch the signals.
Here is my SimpleMainWindow.qml file (the main view:
import QtQuick 2.9
import QtQuick.Window 2.2
import QtQuick.Controls 2.3
import QtQuick.Controls 1.4
ApplicationWindow {
id: window
visible: true
width: 640
height: 480
title: qsTr("Hello World")
objectName : "WINDOW"
property ApplicationWindow appWindow : window
}
And here the file I try to load (TestViewButton.qml):
import QtQuick 2.9
import QtQuick.Controls 1.4
Button {
id: test
text: "test"
objectName : "Button"
onClicked: {
configurator.sum(1, 2)
configurator.info("TestOutput")
}
}
Python file loading QML-View (Component)
from PyQt5.QtCore import QObject, QUrl
from PyQt5.QtGui import QGuiApplication
from PyQt5.QtQml import QQmlApplicationEngine, QQmlComponent
if __name__ == "__main__":
app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()
engine.load("qml/SimpleMainWindow.qml")
engine.quit.connect(app.quit)
rootWindow = engine.rootObjects()[0].children()[0].parent()
# create component
component = QQmlComponent(engine)
component.loadUrl(QUrl("qml/TestViewButton.qml"))
configurator = SignalHandler()
component.setProperty("configurator", configurator)
itm = component.create()
itm.setParentItem(rootWindow.children()[0])
itm.setProperty("configurator", configurator)
app.exec_()
And the python object that I use to handle the signals from the view (SignalHandler.py):
from PyQt5.QtCore import QObject, pyqtSlot
class SignalHandler(QObject):
#pyqtSlot(int, int)
def sum(self, arg1, arg2):
print("Adding two numbers")
#pyqtSlot(str)
def info(self, arg1):
print("STR " + arg1)
The button loads fine (by the way, is there a better way to identify the parent I want to add my button to, wasn't having any look with findChild). What is not working is the component.setProperty.... part. If I set the property in the rootContext of the engine it works fine (the SignalHandler methods are called). Already checked similar topics (like Load a qml component from another qml file dynamically and access that component's qml type properties ...)
Is this possible, or am I getting something wrong here?
thanks
From what I understand, you want to load the configuration object only in TestViewButton.qml and it is not visible in SimpleMainWindow.qml.
To do this TestViewButton.qml must have its own QQmlContext when it is loaded and is not the rootContext().
To test my response and observe that behavior we will create a similar button that tries to use the configurator, if this is pressed it should throw an error noting that the property does not exist but if the button loaded is pressed by the QQmlComponent should do its job normally.
qml/SimpleMainWindow.qml
import QtQuick 2.9
import QtQuick.Window 2.2
import QtQuick.Controls 2.3
import QtQuick.Controls 1.4
ApplicationWindow {
id: window
visible: true
width: 640
color: "red"
height: 480
title: qsTr("Hello World")
Button {
x: 100
y: 100
text: "ApplicationWindow"
onClicked: {
console.log("ApplicationWindow")
configurator.sum(1, 2)
configurator.info("TestOutput")
}
}
}
As I commented previously I added the component with a new context:
if __name__ == "__main__":
app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()
configurator = SignalHandler()
engine.load("qml/SimpleMainWindow.qml")
engine.quit.connect(app.quit)
rootWindow = engine.rootObjects()[0]
content_item = rootWindow.property("contentItem")
context = QQmlContext(engine)
component = QQmlComponent(engine)
component.loadUrl(QUrl("qml/TestViewButton.qml"))
itm = component.create(context)
context.setContextProperty("configurator", configurator)
itm.setProperty("parent", content_item)
sys.exit(app.exec_())
At the end we get the following output:
qml: Component
Adding two numbers
STR TestOutput
qml: ApplicationWindow
file:///xxx/qml/SimpleMainWindow.qml:20: ReferenceError: configurator is not defined
qml: Component
Adding two numbers
STR TestOutput
qml: ApplicationWindow
file:///xxx/qml/SimpleMainWindow.qml:20: ReferenceError: configurator is not defined
Where we observe the desired behavior. The complete example can be found in the following link.