Newbie and the QTreeWidget... Not getting what I think should be ?

grpace

This is likely something simple that I'm overlooking. I'm not having success getting a child QTreeWidgetItem to display as a child item.

I have two functions: one for adding a parent item and one for adding a child item:

void window_Main::treeAddParent(QString name) {
    QTreeWidgetItem *treeitemParent = new QTreeWidgetItem(ui->treeWidget);

    treeitemParent->setText(0, name);
    ui->treeWidget->addTopLevelItem(treeitemParent);
}

void window_Main::treeAddChild(QTreeWidgetItem treeitemParent, QString name) {
    QTreeWidgetItem *treeitemChild = new QTreeWidgetItem(treeitemParent);

    treeitemChild->setText(0, name);
    treeitemParent.addChild(treeitemChild);
}

I'm calling these functions in this generic manner (strTemp is a QString containing their names):

strTemp = "parent";
treeitemParent.setText(0, strTemp);
treeAddParent(strTemp);

strTemp="child";
treeitemChild.setText(0, strTemp);
treeAddChild(treeitemParent, strTemp);

The Parent item displays... The Child item does not.
I'm not getting errors, just no child element displaying.

Could someone explain what I'm missing ?
Thanks !

VRonin

2 mistakes:

treeitemParent.setText(0, strTemp); is not the same as QTreeWidgetItem *treeitemParent = new QTreeWidgetItem(ui->treeWidget); so the first treeitemParent is actually an item with no relation to your widget
You are passing the parent by value, that will create a copy.

grpace

Yes, I understand your first point... They are completely separate, only with the same name to try to avoid confusing myself. The

QTreeWidgetItem *treeitemParent = new QTreeWidgetItem(ui->treeWidget)

is local within the AddParent function only.

I have tried prototyping the AddChild function and using it like this:

void treeAddChild(QTreeWidgetItem *parent, QString name);

But so far I haven't found a way to get a pointer to the parent QTreeWidgetItem without errors. Again, I'm brand new to Qt.

VRonin

QTreeWidgetItem* window_Main::treeAddParent(QString name) {
    QTreeWidgetItem *treeitemParent = new QTreeWidgetItem(ui->treeWidget);

    treeitemParent->setText(0, name);
    ui->treeWidget->addTopLevelItem(treeitemParent);
return treeitemParent;
}

void window_Main::treeAddChild(QTreeWidgetItem* treeitemParent, QString name) {
    QTreeWidgetItem *treeitemChild = new QTreeWidgetItem(treeitemParent);

    treeitemChild->setText(0, name);
    treeitemParent->addChild(treeitemChild);
}

strTemp = "parent";
QTreeWidgetItem * treeitemParent = treeAddParent(strTemp);
strTemp="child";
treeAddChild(treeitemParent, strTemp);

grpace

Thank You !

It occurred to me to try returning the created object from the AddParent function, and was hacking at it. I'll try your suggestion. Will let you know.

grpace

@VRonin ...
Worked like a charm !!

Many of the video tutorials on YouTube show guys adding the child nodes inside the function that added the parent nodes (example here, at around 9:06 in the video).

I knew that wouldn't work for my needs. My opinion is that example is not good design. For at least the last 3 evenings, I've looked for a better approach, but didn't find one. Qt docs really don't explain it, either.

Thank you so much for your help !
You are the man !!
:)