QML - How do I make the TabButtons in TabBar visible? - qml

Question

I'm using qtcreator 4.4.1 with qt 5.9.2-1 on linux
I'm trying to create a tabbar with a stackview so that I can switch between the different tabs. But the tabbuttons in the tabbar never show up, and they aren't functional either if I click the area where they should have been.
I've tried adding all sorts of colored rectangles to see if I could somehow bring it to the surface, but it never shows... And I also added visible: true on most of the components. Also I tried to make sure everything has a width and height. But nonetheless, I still am unable to see it.
This is what it looks like
import QtQuick 2.7
import QtQuick.Controls 2.2
import QtQuick.Extras 1.4
import QtQuick.Layouts 1.3
import QtQuick.Templates 2.2
ApplicationWindow {
id: root
flags: Qt.FramelessWindowHint
visible: true
width: 382
height: 748
Column {
id: column1
width: parent.width
height: parent.height
visible: true
TabBar {
id: bar
width: parent.width
height: 50
visible: true
TabButton {
visible: true
text: qsTr("Fruit")
width: parent.width
height: parent.height
Rectangle {
anchors.fill: parent
color: "#ff0000"
visible: true
}
}
TabButton {
visible: true
text: qsTr("Vegetables")
width: parent.width
height: parent.height
Rectangle {
anchors.fill: parent
color: "#00ff00"
visible: true
}
}
TabButton {
text: qsTr("Demons")
width: parent.width
height: parent.height
Rectangle {
anchors.fill: parent
color: "#0000ff"
visible: true
}
}
}
StackLayout {
width: parent.width
height: parent.height
visible: true
currentIndex: bar.currentIndex
Item {
id: fruitTab
Rectangle {
anchors.fill: parent
color: "#ff0000"
visible: true
}
}
Item {
id: vegetableTab
Rectangle {
anchors.fill: parent
color: "#00ff00"
visible: true
}
}
Item {
id: demonTab
Rectangle {
anchors.fill: parent
color: "#0000ff"
visible: true
}
}
}
}
}
I also tried the simple example given by the qt docs: https://doc.qt.io/qt-5/qml-qtquick-controls2-tabbar.html#details but that didn't work either.
It looks like this

Answer 1

In addition to what #derM said (I would just leave out the width and height assignments altogether), the last import is a problem:
import QtQuick.Templates 2.2
Since the templates and controls have a one-to-one mapping of type names, this will cause the controls types to be shadowed by the ones from templates (since the templates import comes last).
You should always import the templates into their own namespace if you're also importing the controls:
import QtQuick.Templates 2.2 as T
http://doc.qt.io/qt-5/qtqml-syntax-imports.html#import-types explains this in detail:
This import allows multiple modules which provide conflicting type names to be imported at the same time, however since each usage of a type provided by a module which was imported into a qualified namespace must be preceded by the qualifier, the conflict is able to be resolved unambiguously by the QML engine.
In your example it looks like you're not using the templates at all, so you can just remove the import.

Answer 2

Try to remove the width in your TabButtons.
The problem seems to be, the dynamic sizing of the buttons.
You set them to be of the same width as the tab bar. So each button would fill the whole bar on its own.
When it tries to layout this, it obviously fails.
The same goes, if you set all of them, e.g. to width = parent.width / 2 as the parent's width is determined by the width of the children.
You need to either set the width of the buttons in relation to the TabBars width, by using myTabBarsId.width or you can just leave it out and let it be sized dynamically.
TabBar {
id: bar
width: parent.width
height: 50
visible: true
TabButton {
width: bar.width / 2 // Define width based on the `TabBar` width
text: qsTr("Fruit")
height: parent.height
}
TabButton {
text: qsTr("Vegetables")
height: parent.height
}
TabButton {
text: qsTr("Demons")
height: parent.height
}
}