How I can dropdown options when I check on checkbox? - qt

Question

I have one Checkbox with onCheckedChanged handler and what I want is, when the Checkbox is checked, dropdown a menu with several texts and text fields. I have the following code:
CheckBox {
id: box
onCheckedChanged: {
// TODO here to dropdown a menu with settings
}
}
I have texts and text fields like the following:
Component {
id: label
Text {
color: "red"
antialiasing: true
smooth: true
}
}
I'm a newbie in QML so please be patient.

Answer 1

You didn't really say where this menu is located, if it's floating or if it is to just appear maybe displacing other elements on the view. Anyway, to anwser your question, you can achieve what you're asking by setting the height of your 'menu' to zero then, when the CheckBox is checked, setting it to however tall you want it to be. To make the menu grow smoothing you can use a NumberAnimation.
You can change your onCheckedChanged() slot to look like this:
onCheckedChanged: {
menu.height = checked ? 100 : 0
}
and add the following, as a child of your menu element:
Behavior on height { NumberAnimation {...} }
to make the menu's height grow from 0 to 100 over a period of time to make it grow smoothly.
Another approach, which I'd prefer, is to use States with a Transition (instead of a Behavior).
Here is an example of a 'menu' which, when the CheckBox is checked, will slide out from beneath the CheckBox:
import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Window 2.2
ApplicationWindow {
title: qsTr("Hello World")
width: 640
height: 480
visible: true
Rectangle {
id: checkboxContainer
anchors.top: parent.top
anchors.left: parent.left
anchors.right: parent.right
height: 100
color: "pink"
CheckBox {
id: menuCheckBox
anchors.centerIn: parent
text: qsTr("Click Me")
}
}
Rectangle {
id: menu
anchors.top: checkboxContainer.bottom
anchors.left: parent.left
anchors.right: parent.right
height: 0 //This is the default value when the 'default' state is active. That is whenever we're not in the "openState"
clip: true // this hurts rendering performance a bit but is required to make sure child elements don't exceed the bounderies of this object (so when height is zero you don't see the text)
color: "lightblue"
states: [
State {
name: "openState"
when: menuCheckBox.checked // This state is only active when the check box is checked. When you uncheck the check box we move to the 'default' state (which sets the menu's hight back to zero)
PropertyChanges {
target: menu
height: 100
}
}
]
transitions: Transition {
NumberAnimation {
property: "height"
duration: 350 //This means when the height property is changed it will take 350ms to move from what its at to what your changing it to (i.e. 0 to 100 or 100 to 0).
easing.type: Easing.InOutQuad
}
}
Text {
anchors.centerIn: parent
color: "red"
antialiasing: true
smooth: true
text: qsTr("HELLO")
}
}
}
I hope this answers your question.