QML DoubleValidator changing decimal to int on focus change - qt

Question

I'm using QML and I need textfields that only accept doubles. I used DoubleValidator for this. However, when I enter, for example a 0.2 in the textfield and hit tab, it will change the value to 2. The same holds for any number formatted as "0.00...0x". When I write any other number after the x, though, it will work correctly. I have no idea why this is and why anyone would want this. What am I doing wrong?

Answer 1

I try this Example and it works well for me :
import QtQuick 2.15
import QtQuick.Window 2.15
Window {
id: window
width: 640
height: 480
visible: true
title: qsTr("Example")
Rectangle{
id:rect1
y: 140
height: 40
border.width: 2
anchors.rightMargin: 250
anchors.leftMargin: 131
antialiasing: true
anchors.left: parent.left
anchors.right: parent.right
TextInput {
id: textInput
anchors.fill: rect1
font.pixelSize: 18
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
activeFocusOnTab: true
focus: true
validator: DoubleValidator{}
}
}
Rectangle{
id:rect2
y: 200
height: 40
border.width: 2
anchors.rightMargin: 250
anchors.leftMargin: 131
antialiasing: true
anchors.left: parent.left
anchors.right: parent.right
TextInput {
id: textInput2
anchors.fill: rect2
font.pixelSize: 18
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
activeFocusOnTab: true
focus: true
validator: DoubleValidator{}
}
}
Text {
id: text1
x: 51
y: 147
width: 74
height: 27
text: qsTr("Text Input 1")
font.pixelSize: 12
}
Text {
id: text2
x: 45
y: 215
width: 74
height: 25
text: qsTr("Text Input 2")
font.pixelSize: 12
}
}
output:

Answer 2

Paraphrasing my answer from forum.qt.io:
The DoubleValidator's behavior depends on the locale being used.
In some country like France for example, the period (.) is not a decimal marker but just a separator for thousands, millons, etc. The actual decimal marker is the comma (,).
If you want to force your DoubleValidator to use the english locale you can do so for each instance: DoubleValidator { locale: "en"; /* ... */ } or do it for the whole application once by calling QLocale::setDefault before instantiating your QGuiApplication.