QML Listview selected item highlight on click - qt

Question

Hi I want to put this code :
highlight: Rectangle {
color: "black"
radius: 5
opacity: 0.7
focus: true
}
into mouseArea in onclick handler:
MouseArea {
id: mouse_area1
z: 1
hoverEnabled: false
anchors.fill: parent
onClicked: {
}
This is all listView:
ListView {
id: listview1
x: 0
y: 82
// width: 574
// height: 967
width: window.width
height: window.height
visible: true
keyNavigationWraps: false
boundsBehavior: Flickable.DragAndOvershootBounds
opacity: 1
maximumFlickVelocity: 2500
anchors.leftMargin: 0
highlightMoveSpeed: 489
contentWidth: 0
preferredHighlightEnd: 2
spacing: 5
highlightRangeMode: ListView.NoHighlightRange
snapMode: ListView.SnapToItem
anchors.bottomMargin: 0
anchors.rightMargin: 0
anchors.topMargin: 82
anchors.fill: parent
model: myModel
delegate:Component {
//id: contactDelegate
Item {
property variant myData: model
width: 574; height: 90
Column {
x: 12
y: 0
width: 562
height: 90
anchors.rightMargin: 0
anchors.bottomMargin: 0
anchors.leftMargin: 12
anchors.topMargin: 0
anchors.fill: parent
spacing: 2
Text { text: '<b>ID: </b> ' + id_user ; verticalAlignment: Text.AlignTop; wrapMode: Text.NoWrap; horizontalAlignment: Text.AlignHCenter; color:"steelblue"; font.family: "Helvetica"; font.pointSize: 10 }
Text { text: '<b>Name: </b> ' + user_name; horizontalAlignment: Text.AlignHCenter; color:"steelblue"; font.family: "Helvetica"; font.pointSize: 10 }
Text { text: '<b>Lastname: </b> ' + user_lastname; horizontalAlignment: Text.AlignHCenter; color:"steelblue"; font.family: "Helvetica"; font.pointSize: 10 }
Text { height: 16; text: '<b>Tel number: </b> ' + user_number; verticalAlignment: Text.AlignVCenter; horizontalAlignment: Text.AlignHCenter; color:"steelblue"; font.family: "Helvetica"; font.pointSize: 10 }
Text { text: '<b>Address: </b> ' + user address; horizontalAlignment: Text.AlignHCenter; color:"steelblue"; font.family: "Helvetica"; font.pointSize: 10 }
MouseArea {
id: mouse_area1
z: 1
hoverEnabled: false
anchors.fill: parent
onClicked:
Item
{
}
}
}
}
}
//delegate: contactDelegate
highlight: Rectangle
{
color:"black"
radius: 5
opacity: 0.7
focus: true
}
}
For now highlight is working only when using arrows, bbut this will be app for android so I need on touch that same effect, and SECOND question is how to read certain data from selected item in listview?
Inside I have like id,name,lastname,number and adress.
I want to put those values into text_input boxes.
Thank you

Answer 1

It appears you need two solutions to your question:
You want to be able to set the current item of the ListView when it's clicked
You want to be able to know when the current selection changes
The Qt5 documentation says this about ListView mouse and touch handling:
The views handle dragging and flicking of their content, however they do not handle touch interaction with the individual delegates. In order for the delegates to react to touch input, e.g. to set the currentIndex, a MouseArea with the appropriate touch handling logic must be provided by the delegate.
Key input will work out-of-the-box but you'll need to explicitly catch the mouse/touch event on the delegate, and change the ListView.currentIndex value based on the index value of the selected delegate item.
Here's a full example:
import QtQuick 2.4
import QtQuick.Window 2.2
Window {
width: 640
height: 480
visible: true
ListModel {
id: model
ListElement {
name:'abc'
number:'123'
}
ListElement {
name:'efg'
number:'456'
}
ListElement {
name:'xyz'
number:'789'
}
}
ListView {
id: list
anchors.fill: parent
model: model
delegate: Component {
Item {
width: parent.width
height: 40
Column {
Text { text: 'Name:' + name }
Text { text: 'Number:' + number }
}
MouseArea {
anchors.fill: parent
onClicked: list.currentIndex = index
}
}
}
highlight: Rectangle {
color: 'grey'
Text {
anchors.centerIn: parent
text: 'Hello ' + model.get(list.currentIndex).name
color: 'white'
}
}
focus: true
onCurrentItemChanged: console.log(model.get(list.currentIndex).name + ' selected')
}
}
It does the following things:
creates a simple list and model
uses a MouseArea item within the item delegate to update set the list.currentIndex = index which is a local var and unique to the selected item
listens for the onCurrentItemChanged event of the ListView to show how to access the current model item values
binds the text value of the currently selected item to the highlight item to show using the currently selected values elsewhere

Answer 2

Answer provided by denoth: You need to add this line:
listview1.currentIndex = index

Answer 3

ListView provides so called "attached properties", i.e. properties available in the delegate for the list. Among them Listview.view is a reference to the list itself. It can be used to access currentIndex property and update it. Hence, to solve your issue just:
Uncomment //id: contactDelegate.
Set contactDelegate.ListView.view.currentIndex = index in the
OnClick even handler.

Answer 4

For those who use highlighting on a ListView with a specific height (being: not 100% height filled):
Be sure to enable the clip property of the ListView, as else the highlight will still be visible outside the ListView's borders while scrolling.
ListView
{
clip: true
}
As discussed here:
Hide the highlight of a ListView while scrolling

Answer 5

Simplest than ever, you can use: onCurrentItemChanged
ListView{
id: listViewMainMenu
signal Myselect(int playmode)
onCurrentItemChanged: {
Myselect(listViewMainMenu.currentIndex)
console.log("index changed see this " + currentIndex)
}
// ...
}
// do not forget to connect to this signal
otheritem.connect(thisitem.Myselect) //used in drag and works also with pathview

Answer 6

The answer is indeed listView.currentIndex = index.
Whilst playing around with this answer, I found that the ListView may not have keyboard focus, so, I found it may be necessary to call listView.forceActiveFocus() so that up and down arrow key presses are handled.
I found the delegate, particularly the usage of Text in the ListView delegate to be verbose and cumbersome. To clean that up, I refactored an AppInfo component for rendering the contact in a nice manner.
To polish the answer, I provided some sample data for the contacts ListModel and cleaned up the highlight mechanism:
import QtQuick
import QtQuick.Controls
import QtQuick.Layouts
Page {
ListView {
id: listView
anchors.fill: parent
model: contacts
clip: true
focus: true
delegate: Item {
width: frame.width
height: frame.height
Frame {
id: frame
background: Item { }
ColumnLayout {
id: columnLayout
AppInfo { label: "ID"; value: id_user }
AppInfo { label: "Name"; value: user_name }
AppInfo { label: "Last Name"; value: user_lastname }
AppInfo { label: "Tel number"; value: user_number }
AppInfo { label: "Address"; value: user_address }
}
}
MouseArea {
anchors.fill: parent
onClicked: {
listView.currentIndex = index;
listView.forceActiveFocus();
}
}
}
highlight: Rectangle {
border.color: "black"
radius: 5
opacity: 0.7
focus: true
}
}
ListModel {
id: contacts
ListElement {
id_user: "bgates"
user_name: "Bill"
user_lastname: "Gates"
user_number: "555-Microsoft"
user_address: "1 Microsoft Way"
}
ListElement {
id_user: "sjobs"
user_name: "Steve"
user_lastname: "Jobs"
user_number: "555-Apple"
user_address: "1 Apple St"
}
ListElement {
id_user: "jbezos"
user_name: "Jeff"
user_lastname: "Bezos"
user_number: "555-Amazon"
user_address: "1 Amazon Ave"
}
}
}
//AppInfo.qml
import QtQuick
import QtQuick.Controls
import QtQuick.Layouts
RowLayout {
property string label: "ID"
property string value: "id"
Text {
Layout.preferredWidth: 100
text: label
verticalAlignment: Text.AlignTop
wrapMode: Text.NoWrap
horizontalAlignment: Text.AlignRight
color: "steelblue"
font.family: "Helvetica"
font.pointSize: 10
font.bold: true
}
Text {
Layout.preferredWidth: 100
text: value
verticalAlignment: Text.AlignTop
wrapMode: Text.NoWrap
horizontalAlignment: Text.AlignLeft
font.family: "Helvetica"
font.pointSize: 10
}
}
You can Try it Online!

Answer 7

There's ItemDelegate since Qt 5.7. It reacts to mouse clicks by default.
import QtQuick
import QtQuick.Controls
ListView {
model: ListModel {
ListElement {
name: "Item 1"
}
ListElement {
name: "Item 2"
}
ListElement {
name: "Item 3"
}
}
delegate: ItemDelegate {
text: name
}
}