How to switch back between two windows in QML - qt

I Create qml file like this :
main.qml
Item {
width: 200; height: 200
Loader { id: pageLoader }
MouseArea {
anchors.fill: parent
onClicked: pageLoader.source = "Page1.qml"
}
}
I want to back to main page from Page1.qml.
How I can do this Work?

just set the source of pageLoader in Page1 to nothing:
Main Page :
import QtQuick 1.0
Rectangle {
width: 360
height: 360
Text {
anchors.centerIn: parent
text: "Main Page"
}
MouseArea {
anchors.fill: parent
onClicked: {
ld.source="Test.qml"
}
}
Loader{
id:ld;
anchors.fill: parent;
}
}
Test.qml
Rectangle {
width: 100
height: 62
color: "navy";
Text {
anchors.centerIn: parent
text: "Page 1"
}
MouseArea{
anchors.fill: parent;
onClicked: ld.source="";
}
}

Don't you have to instanciate the loader once again in Test.qml to access it via var

Related

How to update or read TextFiled inside GridLayout which is in TabView

I have below stack of components and I want to read and set value of the TextFiled:
-Rectangle
-----TabView
---------Tab
-----------Rectangle
--------------GridLayout
------------------Rectangle
--------------------TextField <--- I want to access this TextField
I have also a case where I need to access Repeater inside the Tab:
-Rectangle
-----TabView
---------Tab
-----------Rectangle
--------------GridLayout
------------------Repeater
--------------------TextField <--- I want to access this TextField also
I have tried to access it using:
var tab0 = myTabView.getTab(0);
tab0.children[0].text = "Some Text"; // I get Undefined Error
I have tried to access the component using a function inside the Tab:
import QtQuick 2.0
import QtQuick.Controls 2.14 as QQC2
import QtQuick.Layouts 1.14
import QtQuick.Controls 1.4 as QQC1
QQC2.Item {
QQC1.TabView {
QQC1.Tab {
title: "tab1"
function printValue () {
console.log("myTextFld.txt: "+myTextFld.txt); // <-- Getting Error myTextFld undefined.
}
Rectangle {
id: tabHolderRext
color: "blue"
GridLayout {
id: myGrid
model: 7
Repeater {
id: herderRepeater
model: header
delegate: Rectangle {
TextField {
// I want to Access This TextField also
}
}
}
Rectangle {
id: row0Rect
Layout.row: 0
Layout.column: index
TextFiled {
id: myTextFld
text: modelData
}
}
// Rest of the rows
}
}
}
}
}
Item id can be used to access the values from TextField if you have all items in same qml file. If you have different qml files then make use of alias types link to access the values.
Repeater case: The Textfield has to update the underlying modelview --> model first then we can make use of the model's data.
Here is a sample code. I have stacked all item's in the same qml file so that access by id works here.
import QtQuick 2.9
import QtQuick.Window 2.2
import QtQuick.Controls 1.4
Window {
visible: true
width: 640
height: 480
Item {
anchors.fill: parent
anchors.margins: 10
TabView {
anchors.fill: parent
Tab {
title: "TextField"
Item {
anchors.fill: parent
Grid {
spacing: 20
anchors.fill: parent
anchors.margins: 10
Rectangle {
height: 40
width: 150
TextField {
id: inputId
anchors.fill: parent
placeholderText: "enter text"
}
}
Button {
height: 40
width: 150
text: "show txt"
onClicked: labelId.text = inputId.text
}
Rectangle {
height: 40
width: 150
Label {
id: labelId
anchors.fill: parent
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
}
}
}
}
}
Tab {
title: "Repeater"
Item {
anchors.fill: parent
Grid {
spacing: 20
anchors.fill: parent
anchors.margins: 10
columns: 3
ListModel {
id: fruitModel
ListElement { name: "Apple" }
ListElement { name: "Orange" }
ListElement { name: "Banana" }
}
Repeater {
width: parent.width
height: parent.height / 2
model: fruitModel
delegate: Rectangle {
height: 40
width: 150
TextField {
anchors.fill: parent
text: name
onTextChanged: fruitModel.setProperty(index, "name", text) // update model data
}
}
}
Repeater {
width: parent.width
height: parent.height / 2
model: fruitModel
delegate: Rectangle {
height: 40
width: 150
Label {
text: name
anchors.fill: parent
horizontalAlignment: Text.AlignHCenter
verticalAlignment: Text.AlignVCenter
}
}
}
}
}
}
}
}
}

Choreography in qml

Is there possible to use choreography animations in qml (in a REUSABLE manner)?
for example in StackView transitions from page1 to page2.
I tried following code, but ParentChange does not work as expected. This code just changes red rectangle's position.
import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3
ApplicationWindow {
visible: true
width: 640
height: 480
title: qsTr("Hello World")
StackView {
id: stack
anchors.fill: parent
initialItem: Page {
id: page1
Label {
text: qsTr("First page")
anchors.centerIn: parent
}
Rectangle {
id: rect
width: 50
height: 50
x: 600
y: 100
color: "red"
states: [
State {
when: stack.depth > 1
ParentChange { target: rect; parent: stack.currentItem; x: 100; y: 100; }
}
]
transitions: Transition {
ParentAnimation {
NumberAnimation { properties: "x,y"; duration: 1000 }
}
}
}
MouseArea {
anchors.fill: parent
onClicked: stack.push(page2)
}
}
Component {
id: page2
Page {
background: Rectangle { color: "yellow"; anchors.fill: parent }
Label {
text: qsTr("Second page")
anchors.centerIn: parent
}
}
}
}
Rectangle {
id: back
color: "blue"
width: 50
height: 50
radius: 25
MouseArea {
anchors.fill: parent
onClicked: stack.pop()
}
}
}
but the usage is not limited to StackView. It can be used in many other situations. (just like above link)

How can I expand a list in a Toolbar in QML when the user tap the title of the it?

I want to perform the expansion action in the ToolBar when the user taps on the title of it, as in the pictures that I attach.
When the user touches the title of the toolbar then you should see a list of the filters that you can apply.
You have any ideas on how to implement this action in QML?
Pretty easy. Copy the following in the awesome QML web editor:
import QtQuick 2.0
Column {
width: 500
Rectangle {
id: toolbar
width: parent.width
height: 50
Text {
text: "Elenco"
anchors.centerIn: parent
font.pointSize: 24; font.bold: true
}
MouseArea {
anchors.fill: parent
onClicked: listBox.visible = !listBox.visible
}
}
Rectangle {
id: listBox
color: "gray"
width: parent.width
visible: false
height: 200
Column {
width: parent.width
Repeater {
model: 4
delegate:
Rectangle {
width: parent.width
color: index % 2 ? "#C9D6DE" : "#E7F6FF"
height: 50
Text { anchors.centerIn: parent; text: "Persona " + (index + 1) }
}
}
}
}
}

How to propertly connect signal in Loader's item?

I want connect one signal from QObject to various pages, loaded by the "Loader" qml element. My problem similar Dead QML elements receiving signals? but loaded items destroyed before calling the "onDestruction" method.
For example below, if switch from page1 to page2 in console writed:
"QML: Loading status: 1 Item: QDeclarativeRectangle(0x8dcd408, "page2")
QML Item: Loaded QDeclarativeRectangle(0x8dcd408, "page2") 1
qrc:/page1.qml:12: TypeError: Result of expression 'parent' [null] is not an object.
qrc:/page1.qml:15: ReferenceError: Can't find variable: page1text"
every second. So there can't disconnect from signal because parent object is destroyed.
How to handle signals from QObject (root) in loaded items? or How to disconnect signal from unloaded page?
main.qml
import QtQuick 1.1
Rectangle {
id: root
objectName: "root"
width: 360
height: 360
state: "page1"
color: "white"
Item {
width: parent.width
height: parent.height/2
anchors.top: parent.top
Loader {
id: pageLoader
objectName: "pageLoader"
anchors.fill: parent
anchors.centerIn: parent
signal textMsg(variant params)
onStatusChanged: console.log("QML: Loading status: ", status, " Item: ", item)
onLoaded: { console.log("QML Item: Loaded",item,status); }
}
}
states: [
State {
name: "page1"
PropertyChanges { target: pageLoader; source: "qrc:/page1.qml"}
}
,State {
name: "page2"
PropertyChanges { target: pageLoader; source: "qrc:/page2.qml"}
}
]
Timer {
// simulate signals from QObject
interval: 1000; running: true; repeat: true
onTriggered: pageLoader.textMsg({"msg2page1":"test","msg2page2":"test"})
}
Rectangle {
anchors.left: parent.left
anchors.bottom: parent.bottom
width: parent.width/2
height: parent.height/2
border {
color: "black"
width: 1
}
color: "yellow"
Text{
anchors.fill: parent
anchors.centerIn: parent
text: "Set Page 1"
}
MouseArea {
anchors.fill: parent
onClicked: {
root.state = "page1";
}
}
}
Rectangle {
anchors.right: parent.right
anchors.bottom: parent.bottom
width: parent.width/2
height: parent.height/2
border {
color: "black"
width: 1
}
color: "red"
Text{
anchors.fill: parent
anchors.centerIn: parent
text: "Set Page 2"
}
MouseArea {
anchors.fill: parent
onClicked: {
root.state = "page2";
}
}
}
}
page1.qml
import QtQuick 1.1
Rectangle {
id: page1
objectName: "page1"
color: "yellow"
Component.onCompleted: {
parent.textMsg.connect(msgHandler);
}
Component.onDestruction: {
parent.textMsg.disconnect(msgHandler);
}
function msgHandler(params) {
page1text.text += " "+params.msg2page1;
}
Text {
id: page1text
anchors.fill: parent
wrapMode: Text.WordWrap
text: "page1"
}
}
page2.qml
import QtQuick 1.1
Rectangle {
id: page2
objectName: "page2"
color: "red"
}
That's nicely described in Loader documenation. It reads:
Any signals emitted from the loaded item can be received using the Connections element.
There is also an example, I copy it below for the sake of clarity:
// Application.qml
import QtQuick 1.0
Item {
width: 100; height: 100
Loader {
id: myLoader
source: "MyItem.qml"
}
Connections {
target: myLoader.item
onMessage: console.log(msg)
}
}
// MyItem.qml
import QtQuick 1.0
Rectangle {
id: myItem
signal message(string msg)
width: 100; height: 100
MouseArea {
anchors.fill: parent
onClicked: myItem.message("clicked!")
}
}
Clearly, if item is destroyed, any signal handlers are ignored until the target is recreated again.
My answer is: Don't use the "Loader", create child object by JS and destroy it as no needed, for example:
main.qml
import QtQuick 1.1
import "qrc:/pageloader.js" as Pageloader
Rectangle {
id: root
objectName: "root"
width: 360
height: 360
state: "page1"
color: "white"
signal textMsg (variant params)
states: [
State {
name: "page1"
StateChangeScript{ script: Pageloader.createPageObject("qrc:/page1.qml");}
}
,State {
name: "page2"
StateChangeScript{ script: Pageloader.createPageObject("qrc:/page2.qml");}
}
]
Timer {
// simulate signals from QObject
interval: 1000; running: true; repeat: true
onTriggered: textMsg({"msg2page1":"test","msg2page2":"test"})
}
Rectangle {
anchors.left: parent.left
anchors.bottom: parent.bottom
width: parent.width/2
height: parent.height/2
border {
color: "black"
width: 1
}
color: "yellow"
Text{
anchors.fill: parent
anchors.centerIn: parent
text: "Set Page 1"
}
MouseArea {
anchors.fill: parent
onClicked: {
root.state = "page1";
}
}
}
Rectangle {
anchors.right: parent.right
anchors.bottom: parent.bottom
width: parent.width/2
height: parent.height/2
border {
color: "black"
width: 1
}
color: "red"
Text{
anchors.fill: parent
anchors.centerIn: parent
text: "Set Page 2"
}
MouseArea {
anchors.fill: parent
onClicked: {
root.state = "page2";
}
}
}
}
pageloader.js
var component;
var sprite;
function createPageObject(path) {
if(sprite){
console.log("sprite.destroy() ",typeof sprite);
sprite.destroy();
console.log("component.destroy() ",typeof component);
component.destroy();
}
component = Qt.createComponent(path);
if (component.status === Component.Ready)
finishCreation();
else
component.statusChanged.connect(finishCreation);
}
function finishCreation() {
if (component.status == Component.Ready) {
sprite = component.createObject(root);
if (sprite == null) {
// Error Handling
console.log("Error creating object");
}
} else{
if (component.status === Component.Error) {
// Error Handling
console.log("Error loading component:", component.errorString());
}else{
console.log("Component status changed:", component.status);
}
}
}
page1.qml and page2.qml not changed.
I got it. My setup:
qml file to display ListViews
Several qml files defining Listviews, each takes a different column of different SQL tables. The model comes from C++
So here is the shortened code:
Dialog {
id: dialog
width: 1000; height: 400
property Component listViewItem
signal newDatabaseEntry( string text ) [1]
contentItem: Rectangle {
[...]
TextInputWithButton { [3]
id: newRecords
onInputAccepted: { newDatabaseEntry( text ) } [1]
}
}
[...]
Loader {
id: listViewPlaceholder
anchors.fill: parent
sourceComponent: dialog.listViewItem
onLoaded: {
if( typeof listViewPlaceholder.item.insertRecord === "function" )
// newRecords.inputAccepted.connect( listViewPlaceholder.item.insertRecord ) [1]
dialog.newDatabaseEntry.connect( listViewPlaceholder.item.insertRecord ) [2]
}
The above code is the general view of ListViews. The signal roundtrip [1] is necessary, otherwise no data is passed. How to chain signals is described here:
http://doc.qt.io/qt-5/qtqml-syntax-signals.html#connecting-signals-to-methods-and-signals
The input button [3] delivers the confirmed data to be inserted into the db.
A ListView passed to the above function looks like this:
DialogSqlSingleColumnEdit {
listViewItem: ListView {
function insertRecord( text ) {
console.log( "done:" + text )
sqlModel.insertRecord( text )
}
[...]
The insertRecord is called forwards the text to the sql-C++ model.

Adding Items to a layout of a custom component

I have a custom Footer Component which I would like to reuse in different place in my QML App:
Rectangle {
color: "gold"
height: 50
anchors {
bottom: parent.bottom
left: parent.left
right: parent.right
}
RowLayout {
anchors.fill: parent
anchors.margins: 10
Button {
text: "quit"
}
}
}
The use of this is easy:
Window {
visible: true
Footer {
}
}
But now I would like to add a "ButtonA" to the RowLayout of my Footer in one view and a "ButtonB" in another view.
How can I achieve that?
See this answer.
You have to declare a default property in Footer.qml:
import QtQuick 2.0
import QtQuick.Controls 1.2
import QtQuick.Layouts 1.1
Rectangle {
color: "gold"
height: 50
default property alias content: rowLayout.children
anchors {
bottom: parent.bottom
left: parent.left
right: parent.right
}
RowLayout {
id: rowLayout
anchors.fill: parent
anchors.margins: 10
Button {
text: "quit"
}
}
}
This ensures that any items declared as children of Footer instances will be added to its RowLayout.
main.qml:
import QtQuick 2.4
import QtQuick.Controls 1.3
ApplicationWindow {
width: 640
height: 480
visible: true
StackView {
id: stackView
anchors.fill: parent
initialItem: viewAComponent
}
Component {
id: viewAComponent
Rectangle {
id: viewA
color: "salmon"
Footer {
id: footerA
Button {
text: "Go to next view"
onClicked: stackView.push(viewBComponent)
}
}
}
}
Component {
id: viewBComponent
Rectangle {
id: viewB
color: "lightblue"
Footer {
id: footerB
Button {
text: "Go to previous view"
onClicked: stackView.pop()
}
}
}
}
}
I used StackView as a convenient way of navigating between the views.

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