Open and close additional window (QML) - qt

Question

Currently I have a window openning in the following way:
property variant win
Button {
id: testButton
MouseArea {
onClicked: {
var component = Qt.createComponent("test.qml");
win = component.createObject(testButton);
win.show();
}
}
}
Is it ok to create a window like this or there is a better way to do it (from QML, not from C++)?
When I close this additional window (just by clicking "x" button), I want to connect it to another event (for example, changing color of the button). How to do it?
Thanks.

Answer 1

It is usually nicer to have it more declarative. If you want your button to only open one window, the usage of a Loader might be right for you.
I think this is what you want, as you store it in one variable, and if you click the button multiple times, you would lose access to your instance. If you need a larger amount of Windows created by the same Button, you might use a ListModel and a Instantiator to create the instances.
With the Loader this might look like this:
Button {
id: ldbutton
onClicked: winld.active = true
Rectangle {
id: ldindic
anchors {
left: parent.left
top: parent.top
bottom: parent.bottom
}
width: height
color: winld.active ? 'green' : 'red'
}
Loader {
id: winld
active: false
sourceComponent: Window {
width: 100
height: 100
color: 'green'
visible: true
onClosing: winld.active = false
}
}
}
In this code is also already the answer to your second question: The signal you are looking for is called closing - connect to it to do what ever is necessary.
In the case of the Loader it is necessary to unload the window, so it can be loaded again later, maybe. If you have the window created by a Instantiator, you need to remove the corresponding index from the Instantiator's ListModel.
This might look like this:
Button {
id: rpbutton
onClicked: rpmodel.append({})
text: 'Open Windows ' + rpmodel.count
ListModel {
id: rpmodel
}
Instantiator { // from QtQml 2.0
model: rpmodel
delegate: Window {
width: 100
height: 100
color: 'blue'
visible: true
onClosing: rpmodel.remove(index)
}
}
}
In your code you could connect to it, either by using a Connection-object, that connects to your property win, or by changing the JS onClicked like so:
onClicked: {
var component = Qt.createComponent("test.qml");
win = component.createObject(testButton);
win.closing.connect(function() { console.log('do something') })
win.show();
}