I have two model classes. The first class is Vector, the second is SequenceUnit. SequenceUnit stores different types of objects, to identify them there is a type property:
Vector.h
#ifndef VECTOR_H
#define VECTOR_H
#include <QObject>
#include <QPointF>
#include <QVariantList>
class Vector : public QObject {
Q_OBJECT
Q_PROPERTY(int index READ index WRITE setIndex NOTIFY changedIndex)
Q_PROPERTY(QPointF point READ point WRITE setPoint NOTIFY changedPoint)
public:
explicit Vector(QObject *parent = 0) {}
int index() {
return m_index;
}
void setIndex(int index) {
if (m_index == index) {
return;
}
m_index = index;
emit changedIndex();
}
QPointF point() {
return m_point;
}
void setPoint(const QPointF& point) {
if (m_point == point) {
return;
}
m_point = point;
emit changedPoint();
}
signals:
void changedIndex();
void changedPoint();
private:
int m_index = -1;
QPointF m_point = QPointF(0, 0);
};
#endif // VECTOR_H
SequenceUnit:
#ifndef UNITSEQUENCE_H
#define UNITSEQUENCE_H
#include "Vector.h"
#include <QObject>
class SequenceUnit : public QObject {
Q_OBJECT
Q_PROPERTY(QString type READ type WRITE setType NOTIFY typeChanged)
Q_PROPERTY(QObject* unit READ unit WRITE setUnit NOTIFY unitChanged)
public:
QString type() {
return m_type;
}
void setType(QString type) {
if (m_type == type) {
return;
}
emit typeChanged();
m_type = type;
}
QObject* unit() {
return m_unit;
}
void setUnit(QObject* unit) {
if (m_unit == unit) {
return;
}
emit unitChanged();
m_unit = unit;
}
signals:
void typeChanged();
void unitChanged();
private:
QString m_type;
QObject* m_unit;
};
#endif // UNITSEQUENCE_H
The VectorController and LinkSequence controllers are responsible for creating objects in qml. VectorController for creating vectors. LinkSequence for creating unit objects:
VectorController:
#ifndef VECTORCONTROLLER_H
#define VECTORCONTROLLER_H
#include "Vector.h"
#include <QObject>
class VectorController : public QObject {
Q_OBJECT
public:
explicit VectorController(QObject *parent = 0) { };
Q_INVOKABLE Vector* createVector() {
return new Vector();
}
};
#endif // VECTORCONTROLLER_H
LinkSequence:
#ifndef LINKSEQUENCE_H
#define LINKSEQUENCE_H
#include "SequenceUnit.h"
class LinkSequence : public QObject {
Q_OBJECT
public:
explicit LinkSequence(QObject *parent = 0) { };
Q_INVOKABLE SequenceUnit* createUnit() {
return new SequenceUnit();
}
};
#endif // LINKSEQUENCE_H
I register all these controllers and methods through main cpp:
qmlRegisterType<Vector>("Model", 1, 0, "Vector");
qmlRegisterType<SequenceUnit>("Model", 1, 0, "Unit");
qmlRegisterType<VectorController>("Controller", 1, 0, "VectorController");
qmlRegisterType<LinkSequence>("Controller", 1, 0, "LinkSequence");
There are errors in main qml. The program crashes after 100 clicks:
import QtQuick 2.15
import QtQuick.Window 2.15
import Model 1.0
import Controller 1.0
Window {
id: window
width: 640
height: 480
visible: true
title: qsTr("Hello World")
Item {
id: root
width: window.width; height: window.height
property var points: {
[Qt.point(75.0, 0.0),
Qt.point(150.0, 100.0),
Qt.point(100.0, 200.0),
Qt.point(50.0, 200.0),
Qt.point(0.0, 100.0),
Qt.point(75.0, 0.0)
]
}
property var handledPoints: {
let newPoints = points.map((point) => Qt.point(point.x, point.y))
const sequence = list
for (let i = 0; i < sequence.length; ++i) {
if (sequence[i] !== null) {
console.log(i, 'not null')
const vector = list[i].unit
for (let a = 0; a < newPoints.length; ++a) {
if (vector.index === (a % (newPoints.length - 1))) {
const point = vector.point
newPoints[a].x += point.x
newPoints[a].y += point.y
}
}
} else {
console.log(i, 'null')
}
}
return newPoints
//link model:
property list<Unit> list
VectorController {
id: cntr
}
LinkSequence {
id: link
}
Repeater {
anchors.fill: parent
model: root.handledPoints.length - 1
Rectangle {
id: circle
x: root.handledPoints[index].x - height / 2; y: root.handledPoints[index].y - width/ 2
width: 20; height: 20;
radius: 20
color: 'violet'
MouseArea {
anchors.fill: circle
cursorShape: Qt.PointingHandCursor
property point pressedPoint; property point positionPoint
property var vector; property var unit
onPressed: {
pressedPoint = circle.mapToItem(root, mouseX, mouseY)
vector = cntr.createVector()
vector.index = index
const unit = link.createUnit()
unit.type = 'vector'
unit.unit = vector
root.list.push(unit)
}
onPositionChanged: {
positionPoint = circle.mapToItem(root, mouseX, mouseY)
vector.point = Qt.point(positionPoint.x - pressedPoint.x,positionPoint.y - pressedPoint.y)
}
}
}
}
}
}
an error appears in the console - "TypeError: Cannot read property 'index' of null" and after one more click the program crashes.
I don't understand why it doesn't work. My task is to combine multiple models into one and then use it on another qml item. That is, get a model that will link to other models:
The model I want to get linkmodel
How do I combine multiple models into one model that will link other models in qml? And what could be the problem with the code?
source code: https://github.com/svirid132/qml-list-problem
