BlackBerry10 cascades :cannot access control objects from QML in c++ - blackberry-10

Question

In my project, I have two qml files viz. main.qml and DetailsPage.qml.
I am trying to change the text of a label of DetailsPage.qml from c++ using findChild() method.
This is the code in c++ file and DetailsPage.qml
Myfile.cpp code:
using namespace bb::cascades;
AbstractPane *root;
AbstractPane *root1;
Navigater::Navigater
(bb::cascades::Application *app):QObject(app)
{
QmlDocument *qml = QmlDocument::create("asset:///main.qml").parent(this);
QmlDocument *qml1 = QmlDocument::create("asset:///DetailsPage.qml").parent(this);
qml->setContextProperty("_app", this);
qml1->setContextProperty("_app", this);
root = qml->createRootObject<AbstractPane>();
root1 = qml1->createRootObject<AbstractPane>();
app->setScene(root);
}
void Navigater::tr1()
{
Label *tryLabel1 = root1->findChild<Label*>("labelObj");
if(tryLabel1)
{
qDebug()<<"tttt "<<tryLabel1->text(); //initial text
tryLabel1->setText("Hello!!!!!!!") ;
qDebug()<<"yyyy "<<tryLabel1->text(); //changedText gets reflected on DeviceLog but not on UI
}
else
{
qDebug()<<"Not Found";}
}
DetailsPage.qml code:
// Navigation pane project template
import
bb.cascades 1.0
Page
{
// page with a picture detail
id: pgDetail
actions: [
ActionItem {
title: qsTr("Break")
onTriggered: {
_app.tr1();
imgView.imageSource = "asset: //images/picture1br.png"
}
}
]
paneProperties: NavigationPaneProperties {
backButton: ActionItem {
onTriggered: {
navigationPane.pop()
}
}
}
onCreationCompleted: {
_app.tr1();
}
Container {
background: Color.Black
Label {
objectName: "labelObj" // control to be found
text: "Page 2"
horizontalAlignment: HorizontalAlignment.Center
textStyle {
base: SystemDefaults.TextStyles.TitleText
color: Color.Yellow
}
}
ImageView {
id: imgView
imageSource: "asset:///images/picture1.png"
horizontalAlignment: HorizontalAlignment.Center
}
Label {
text: qsTr("Picture description")
horizontalAlignment: HorizontalAlignment.Center
}
}
}
Change I have made is not getting reflected in simulator...but visible on device log.
Is there any way to access control objects from multiple pages i.e pages other than main.qml?
Could you please look into it.

Answer 1

You can use a navigation pane, add main.qml as page contents and details page as attachedObjects in the navigation pane like
attachedObjects: [
ComponentDefinition {
id: secondPageDefinition
source: "DetailsPage.qml"
}
in main page action add
onClicked: {
// show detail page when the button is clicked
var page = secondPageDefinition.createObject();
navigationPane.push(page);
}
i think this will solve your issue and in the main.cpp page change the content as follows
QmlDocument *qml = QmlDocument::create("asset:///main.qml").parent(this);
qml->setContextProperty("_app", this);
root = qml->createRootObject<AbstractPane>();
app->setScene(root);
and
void Navigater::tr1()
{
Label *tryLabel1 = root ->findChild<Label*>("labelObj");
if(tryLabel1)
{
qDebug()<<"tttt "<<tryLabel1->text(); /////////////intial text
tryLabel1->setText("Hello!!!!!!!") ;
qDebug()<<"yyyy "<<tryLabel1->text(); ////////////changedText gets reflected on DeviceLog but not on UI
}
else
{
qDebug()<<"Not Found";}
}

Answer 2

you can navigate in qml easily without using c++
1.page1.qml
Page {
id: rootPage
Container {
background: Color.LightGray
layout: DockLayout {
}
Label {
text: "First page"
horizontalAlignment: HorizontalAlignment.Center
verticalAlignment: VerticalAlignment.Center
}
}
actions: [
ActionItem {
title: "Next page"
ActionBar.placement: ActionBarPlacement.OnBar
onTriggered: {
var page = pageDefinition.createObject();
navigationPane.push(page);
}
attachedObjects: ComponentDefinition {
id: pageDefinition
source: "PageTwo.qml"
}
}
]
}
onPopTransitionEnded: {
page.destroy();
}