QML precreate items to show in a StackView - qt

Question

I want to instantiate items and then display them using a StackView, via
MyItem0
{
id: item0
}
MyItem1
{
id: item1
}
myStackView.push(item0)
...
myStackView.pop()
myStackView.push(item1)
The problem is that when I create items item0 and item1, they are all shown, which is obviously not what I want.
I guess it somehow relates to this post.
Any idea?

Answer 1

You can implement the items as properties rather than children, which will result in them not showing until they are pushed on the stack view:
property Item item0: MyItem0 { }
property Item item1: MyItem1 { }
However, if you pop, the item will remain visible, as its parent will no longer be null.
pop() is said to return the popped item, so pop().parent = null should do the trick, but for me for some reason it returns a null.
So instead you can simply set the parent explicitly to null:
pop()
item0.parent = null
Naturally, you can just as well set the visible or opacity properties. Which may be preferable, as even more funky and illogical behavior surfaces. if you try to push the same item again after it has been pushed and popped once, it doesn't work, and there is an nothing to push error message in the debug console.
Edit: OK, regarding the last paragraph, it seems that whatever method used, once an object has been pushed and popped, the same object cannot be pushed again, even if the parent is not set to null. This looks like a bug.

Answer 2

Create them with no parent:
import QtQuick 2.5
import QtQuick.Controls 2.0
import QtQuick.Window 2.0
ApplicationWindow {
id: window
visible: true
width: 600
height: 600
StackView {
anchors.fill: parent
id: sv
initialItem: Button {
id: b
onClicked: sv.push(b1)
text: "0"
}
}
Button {
id: b1
parent: null
onClicked: sv.push(b2)
text: "1"
x: 100
onParentChanged: console.log('parent', parent, 1)
onVisibleChanged: console.log('visible', visible, 1)
}
Button {
id: b2
parent: null
onClicked: sv.push(b3)
text: "2"
x: 200
onParentChanged: console.log('parent', parent, 2)
onVisibleChanged: console.log('visible', visible, 2)
}
Button {
id: b3
parent: null
onClicked: sv.pop()
text: "3"
x: 300
onParentChanged: console.log('parent', parent, 3)
onVisibleChanged: console.log('visible', visible, 3)
}
Button {
id: back
onClicked: sv.pop()
text: 'pop'
Binding {
target: back.background
property: 'color'
value: 'orange'
}
}
Button {
id: clear
x: 150
onClicked: sv.clear()
text: 'clear'
Binding {
target: clear.background
property: 'color'
value: 'orange'
}
}
}
In QtQuick.Controls 2.x the will be reparented to null when you pop() them, effectively hiding them.
In QtQuick.Controls 1.x they will be reparented to some ContentItem but their visible property will be set to false, hiding them aswell.
To test it, just change line 2 to import QtQuick.Controls 1.4
Remember: pop() will leave the item with index 0 on the stack. To remove that, call clear()