[PyQt] QQmlApplicationEngine and QGuiApplication

Daniel Krause madakr at web.de
Sat Feb 27 17:20:53 GMT 2016


Hi,

I replaced the  ApplicationWindow{...} with Rectangle{...} that did the
trick, also for nested structures
The QML-code:

import QtQuick 2.5
import QtQuick.Controls 1.4

Rectangle {
    id: mainForm1
    color: "#383535"
    anchors.fill: parent

    SplitView {
        id: splitView1
        width: 100
        anchors.left: parent.left
        anchors.leftMargin: 36
        anchors.bottom: parent.bottom
        anchors.bottomMargin: 8
        anchors.top: parent.top
        anchors.topMargin: 8
        orientation: Qt.Vertical

        Button {
            id: btn_welcome
            x: 49
            y: 21
            text: qsTr("Welcome")
        }

        Button {
            id: btn_bye
            x: 49
            y: 50
            text: qsTr("Bye")
        }

        MouseArea {
            id: mouseArea1
            x: 0
            y: 191
            width: 100
            height: 100
        }
    }
}


The Python code:

import sys
from PyQt5.QtCore import QUrl, QRect
from PyQt5.QtWidgets import QApplication
from PyQt5.QtQuick import QQuickView

class MyQmlApplication(QApplication):
    _application_name = "UNDEFINED"
    _qquickview = None
    _engine = None
    _settings = None

    def __init__(self, title, args):
        QApplication.__init__(self, args)
        self._qquickview = QQuickView()
        self._qquickview.setTitle(title)
        self._qquickview.setResizeMode(QQuickView.SizeRootObjectToView)
        self._qquickview.setGeometry(QRect(200,200,200,100))
        self._engine = self._qquickview.engine()

    def showAndExec(self, qml_url):
        self._qquickview.setSource(qml_url)
        self._qquickview.show()
        return self.exec_()

if __name__ == '__main__':
    app = MyQmlApplication('Test',sys.argv)
    app.showAndExec(QUrl("main.qml"))

[image: Inline-Bild 1]

Thanks for the hints!
Daniel

2016-02-25 23:56 GMT+01:00 Jérôme Godbout <jerome at bodycad.com>:

> Sound like you are missing the plugin and module path maybe. You can add
> this function to your new MyQmlApplication class:
>
> def loadPluginPath(self):
>         for i in os.environ['QT_PLUGIN_PATH'].split(';'):
>             self._engine.addPluginPath(i)
>
>
> You can also add the following before creating the application object:
>
> os.environ['QML2_IMPORT_PATH'] = ';'.join(['.', r"qml"])
> os.environ['QT_PLUGIN_PATH'] = ';'.join(['.', r"plugins"])
>
> Add any required path to both depending on your use case. Call the
> app.loadPluginPath() before the app.showAndExec()
>
> This way the QQmlEngine will known where the module and plugin can be
> found.  Make sure you have the Qt modules and plugin available inside those
> path list.
>
> Also on another note, Try to remove the ApplicationWindow from the script
> and try a simple script that only display a simple Item like this, you may
> have some Qml errors preventing the application from launching:
>
> TestMain.qml:
> import QtQuick 2.5
> Rectangle
> {
>    color: 'red'
>    width: 500
>    height: 500
> }
>
> On Thu, Feb 25, 2016 at 4:25 PM, Daniel Krause <madakr at web.de> wrote:
>
>> Thank you for your suggestions.
>>
>> @Jerome
>> I used you code "as is", but for the last lines: I changed them to
>>
>> if __name__ == '__main__':
>>     app = MyQmlApplication("MyAppTitle", sys.argv)
>>     app.showAndExec(QUrl("main.qml"))
>>
>> The code executes, but the Window is empty.
>>
>> [image: Inline-Bild 1]
>>
>> @Miguel:
>> I changed additionally the name "MainForm" to "Rectangle" as you
>> suggested. But still, the window is empty...
>>
>> I have the feeling, that the qml-file is not found / loaded. If I change
>> the file name to "Main.qml" (which does not exist), the window looks the
>> same...
>> Could it be an OS-problem, as I am working on windows?
>>
>> Any ideas would be welcome.
>>
>> Daniel
>>
>> 2016-02-25 18:37 GMT+01:00 Jérôme Godbout <jerome at bodycad.com>:
>>
>>> No sure what is wrong with yours, but I'm using a QQuickView inside a
>>> QApplication and it work well.
>>>
>>> import sys
>>>
>>> from PyQt5.QtCore import QSettings, QUrl, QRect, pyqtSignal, pyqtSlot
>>> from PyQt5.QtWidgets import QApplication
>>> from PyQt5.QtQuick import QQuickView, QQuickWindow
>>>
>>> class MyQmlApplication(QApplication):
>>>     _application_name = "UNDEFINED"
>>>     _qquickview = None
>>>     _engine = None
>>>     _settings = None
>>>
>>>     def __init__(self, title, args):
>>>         QApplication.__init__(self, args)
>>>         self._qquickview = QQuickView()
>>>         self._qquickview.setTitle(title)
>>>         self._qquickview.setResizeMode(QQuickView.SizeRootObjectToView)
>>>         self._qquickview.setGeometry(QRect(100,100,600,800))
>>>         self._engine = self._qquickview.engine()
>>>
>>>     def showAndExec(self, qml_url):
>>>         self._qquickview.setSource(qml_url)
>>>         self._qquickview.show()
>>>         return self.exec_()
>>>
>>> app = BodycadQmlApplication("MyAppTitle", sys.argv)
>>> app.showAndExec(QUrl("Main.qml"))
>>>
>>>
>>> On Thu, Feb 25, 2016 at 10:43 AM, Daniel Krause <madakr at web.de> wrote:
>>>
>>>> Hello,
>>>>
>>>> I am new to PyQt and having trouble to include QML-Code into an python
>>>> application.
>>>>
>>>> The QML-File (main.qml) I can build in a project in QtCreator (a Qt
>>>> Quick Application was used to create the project).
>>>>
>>>> import QtQuick 2.5
>>>> import QtQuick.Controls 1.4
>>>> import QtQuick.Dialogs 1.2
>>>> import QtQml.Models 2.1
>>>>
>>>> ApplicationWindow {
>>>>     visible: true
>>>>     width: 640
>>>>     height: 480
>>>>     title: qsTr("Hello World")
>>>>
>>>>     menuBar: MenuBar {
>>>>         Menu {
>>>>             title: qsTr("File")
>>>>             MenuItem {
>>>>                 text: qsTr("&Open")
>>>>                 onTriggered: console.log("Open action triggered");
>>>>             }
>>>>             MenuItem {
>>>>                 text: qsTr("Exit")
>>>>                 onTriggered: Qt.quit();
>>>>             }
>>>>         }
>>>>     }
>>>>
>>>>     MainForm {
>>>>         id: mainForm1
>>>>         anchors.fill: parent
>>>>
>>>>         SplitView {
>>>>             id: splitView1
>>>>             width: 100
>>>>             anchors.left: parent.left
>>>>             anchors.leftMargin: 36
>>>>             anchors.bottom: parent.bottom
>>>>             anchors.bottomMargin: 8
>>>>             anchors.top: parent.top
>>>>             anchors.topMargin: 8
>>>>             orientation: Qt.Vertical
>>>>
>>>>
>>>>             Button {
>>>>                 id: btn_welcome
>>>>                 x: 49
>>>>                 y: 21
>>>>                 text: qsTr("Welcome")
>>>>             }
>>>>
>>>>             Button {
>>>>                 id: btn_database
>>>>                 x: 49
>>>>                 y: 50
>>>>                 text: qsTr("Database")
>>>>             }
>>>>
>>>>             MouseArea {
>>>>                 id: mouseArea1
>>>>                 x: 0
>>>>                 y: 191
>>>>                 width: 100
>>>>                 height: 100
>>>>             }
>>>>         }
>>>>     }
>>>> }
>>>>
>>>> It results in the following window:
>>>>
>>>>
>>>> To create the application in Python I tried to use QGuiApplication
>>>> and  QQmlApplicationEngine.
>>>> main.py and main.qml are located in the same directory:
>>>>
>>>> import sys
>>>> from PyQt5.QtQml import QQmlApplicationEngine
>>>> from PyQt5.QtGui import QGuiApplication
>>>>
>>>> if __name__ == '__main__':
>>>>     app = QGuiApplication(sys.argv)
>>>>     engine = QQmlApplicationEngine("main.qml")
>>>>     print(engine)
>>>>     sys.exit(app.exec_())
>>>>
>>>> The print()-statement is never executed, no window is appearing.
>>>>
>>>> What did I miss?
>>>>
>>>> Thanks in advance
>>>>
>>>> Daniel
>>>>
>>>> _______________________________________________
>>>> PyQt mailing list    PyQt at riverbankcomputing.com
>>>> https://www.riverbankcomputing.com/mailman/listinfo/pyqt
>>>>
>>>
>>>
>>
>> _______________________________________________
>> PyQt mailing list    PyQt at riverbankcomputing.com
>> https://www.riverbankcomputing.com/mailman/listinfo/pyqt
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.riverbankcomputing.com/pipermail/pyqt/attachments/20160227/1c8906eb/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 3019 bytes
Desc: not available
URL: <https://www.riverbankcomputing.com/pipermail/pyqt/attachments/20160227/1c8906eb/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 7969 bytes
Desc: not available
URL: <https://www.riverbankcomputing.com/pipermail/pyqt/attachments/20160227/1c8906eb/attachment-0003.png>


More information about the PyQt mailing list