Show, change data and keep QQmlListProperty in qml - c++

Question

in the past i resolved a problem with QQmlListProperty for expose c++ qlist to qml, and the problem was resolved, now i try use their solution again, but i can't.
the first time the list exposed to qml every time are different, this time no, i have a Qlist in a main class, and many data from her are loaded from db, and others changed in runtime.
When the application start, the load of data and exposed to Qml is ok, i need change of page(gui) and keep the data stored in program and probably used many of their data in other guis (as text), and every time i change of page (with loader element) the program crashes, i believe a directions of pointers are changed in qml when the data from c++ class is copied to gui in qml.
My Code from QmlListproperty class and method of Load data in qml, and copy from the main qml to page.
definition of class ListBombsUi.h"
#include "StructBombUi.h"
class ListBombsUi: public QObject{
Q_OBJECT
Q_PROPERTY(QQmlListProperty<CStructBombUi> bombsUi READ bombsUiList NOTIFY bombsUiChanged);
Q_CLASSINFO("DefaultProperty", "bombsUi");
public:
ListBombsUi(QObject *parent=0);
QQmlListProperty<CStructBombUi> bombsUiList();
static void appendBombUi(QQmlListProperty<CStructBombUi> *list, CStructBombUi *pdt);
static void clear(QQmlListProperty<CStructBombUi> *property);
static int listSize(QQmlListProperty<CStructBombUi> *property);
static CStructBombUi *bombUiAt(QQmlListProperty<CStructBombUi> *property, int index);
void addBomb(CStructBombUi *bombUi);
Q_INVOKABLE int size();
void Q_INVOKABLE getMemory();
Q_INVOKABLE void clearList();
CStructBombUi* getValue(int index) const;
QList<CStructBombUi *> copyList();
signals:
void bombsUiChanged();
public:
int lastAdded;
private:
CStructBombUi *item;
QList<CStructBombUi*> m_BombsUi;
i register how qmltype
qmlRegisterType<ListBombsUi>("BombsListUiModel", 1, 0, "ListBombsUi");
definition of main methods of ListBombsUi
ListBombsUi::ListBombsUi(QObject *parent):QObject(parent)
{}
QQmlListProperty<CStructBombUi> ListBombsUi::bombsUiList()
{
return QQmlListProperty<CStructBombUi>(this, &m_BombsUi, &ListBombsUi::appendBombUi,
&ListBombsUi::listSize,
&ListBombsUi::bombUiAt,
&ListBombsUi::clear);
emit bombsUiChanged();
}
void ListBombsUi::appendBombUi(QQmlListProperty<CStructBombUi> *list, CStructBombUi *pdt)
{
ListBombsUi *bombsList= qobject_cast<ListBombsUi *>(list->object);
if(bombsList) {
pdt->setParent(bombsList);
bombsList->m_BombsUi.append(pdt);
bombsList->bombsUiChanged();
}
}
void ListBombsUi::clearList()
{
m_BombsUi.clear();
emit bombsUiChanged();
}
void ListBombsUi::addBomb(CStructBombUi *bombUi)
{
m_BombsUi.append(bombUi);
emit bombsUiChanged();
}
definition in main class for two data, i use the first as aux, but is possible use the second directly(their are my idea originallly)
QList<CStructBombUi * > listBombs;
ListBombsUi *listBufferBombs;
i assign a listBufferBombs to element in qml
listBufferBombs = mainObject->findChild<ListBombsUi*>("listGralBombs");
method for expose data to qml
void EgasWindowWork::setDataOfBombsInModels()//, const QList <CEstrucBombUi> *const dataArrayBombs)
{
if( (mainObject) ) {
CStructBombUi e,k,j;
e.initializing(QStringList()<<"text1"<<"text2"<<"text3");
e.update(QString("15"), QString("1"), QString("1"), QString("1"),QString("1"));
k.initializing(QStringList()<<"text1"<<"text2");
k.update(QString("2"), QString("2"), QString("2"), QString("2"),QString("2"));
listBombs.append(&e);
listBombs.append(&k);
for(qint16 i=0; i<listBombs.size() ; i++)
{ listBufferBombs->addBomb( listBombs.value(i) ); }
QMetaObject::invokeMethod(mainObject, "setDataOfModelBombs"); //this method copy the list located in main qml for page
}
the metod in main.qml file
function setDataOfModelBombs()
{
if(itemOfPageLoaded) {
itemOfPageLoaded.listBombs=listed
itemOfPageLoaded.setDataOfBombs() //this function put every data inside the every field of qml gui element
}
}
declaration of loader element in main.qml file
Loader{
id: pageLoader
focus: true
//anchors.horizontalCenter: parent.horizontalCenter
width: parent.width
height: parent.height-50
anchors.top: headerIcons.bottom
objectName: "switchPages"
z: 2
source: "BombsUi.qml"
property bool valid: item !== null
Binding {
target: pageLoader.item
property: "numberBombs"
value: numberOfBombs
when: pageLoader.status == Loader.Ready
}
}
method in qml file loaded as page
function setDataOfBombs()
{
var size=newList.size()
arrayBombs.model=size //i use a repater container, and model is the number of elements loaded
if(size>0) {
for(var i=0; i<size; i++) {
//exactly in the next line the error happens
arrayBombs.itemAt(i).priceText=newList.bombsUi[i].ultimateProductPrice
arrayBombs.itemAt(i).volumeText = newList.bombsUi[i].ultimateProductVolume
//exist mor date, but with this are sufficient
}
}
}
and here is declaration of element repeater-grid
Item{
width: parent.width; height: parent.height
Item{
id: bombsArea
height: parent.height; width: parent.width*0.7
anchors.leftMargin: 10
y: 3
x: 2
Grid{
id: gridOfBombsModel
width: parent.width; height: parent.height
spacing: 7
rows: 6; columns: Math.round((parent.width/165))
Repeater{
id: arrayBombs
BombModel{
numberBomb: (index + 1)
MouseArea{
anchors.fill: parent
onClicked:{
parent.borderProperties.color="red"
parent.borderProperties.width=1.5
}
}
}
}
}
}
the program load the page 1 ok, but i change a page "n" and return to page 1, crashes. i accept alternatives to, Thanks for your help.

Answer 1

Well, i detected two things, fail in constructor of CStructBombsUi and i descart use of auxiliar list, and the use of CStructBombsUi* exclusively, and change the function in qml file, i show the changes.
Changes in main.qml
function setDataOfModelBombs()
{
if(itemOfPageLoaded) {
itemOfPageLoaded.numberBombs=listBombs.size()
itemOfPageLoaded.setDataOfBombs(listBombs.bombsUi)
}
}
changes in detailsbombs.qml (file loaded as page), and here i don't instance a ListBombs
function setDataOfBombs(bombsUi)
{
if(numberBombs>0) {
for(var i=0; i<numberBombs; i++)
{
arrayBombs.itemAt(i).priceText=bombsUi[i].ultimateProductPrice
arrayBombs.itemAt(i).volumeText = bombsUi[i].ultimateProductVolume
arrayBombs.itemAt(i).amountText= bombsUi[i].getUltimateProductMount()
arrayBombs.itemAt(i).fuelText= bombsUi[i].getUltimateProductName()
if(bombsUi[i].getFuels())
{arrayBombs.itemAt(i).setListOfFuelsInBomb( bombsUi[i].getFuels() ) }
}
}
}
The next line don't exist more
QList<CStructBombUi* > listBombs;
And every is a pointer
CStructBombUi *e=new CStructBombUi();
i don't use a list of values, with this adjusts the program don't crashes