How to make a subchild to a child in QTreeWidget? - c++

Question

I want to make it so that I can expand a third level (subchild) to a child under the top level item (root). All I've been able to do is make multiple children to a single root.
this is in my .cpp
QStringList string1, string2;
string1 << "xxxxxxxx" << "xxxxxxxxxxx";
string2 << "yyyyyy" << "yy";
m_treeWidget->insertTopLevelItem(0, new QTreeWidgetItem(string1));
m_treeWidget->insertTopLevelItem(1, new QTreeWidgetItem(string2));
//here I add a child
AddChild(m_treeWidget->topLevelItem(0),"hello","world", m_treeWidget);
//here I make two attempts to make a sub child
AddChild(m_treeWidget->itemBelow(m_treeWidget->topLevelItem(0)),"hello_sub1","world_sub1", m_treeWidget);
AddChild(m_treeWidget->itemAt(0,0),"hello_sub2","world_sub2", m_treeWidget);
The following is my Add Child Method also in the same .cpp file:
void Dialog::AddChild (QTreeWidgetItem *parent, QString name, QString Description, QTreeWidget* treeWidget)
{
QTreeWidgetItem *item = new QTreeWidgetItem(treeWidget);
item->setText(0,name);
item->setText(1, Description);
parent->addChild(item);
}

Answer 1

In order to make a tree hierarchy you can use the QTreeWidgetItem's API, especially its constructors. Constructors can accept either QTreeWidget or QTreeWidgetItem as a parent object. In the first case, the top level item will be added to the tree widget and in the second case - child item of another item. This API is easier to use because you don't need to explicitly append items to the tree widget. Here is the sample code that implements the idea:
QStringList string1, string2;
string1 << "xxxxxxxx" << "xxxxxxxxxxx";
string2 << "yyyyyy" << "yy";
QTreeWidget tv;
// The top level items
QTreeWidgetItem *top1 = new QTreeWidgetItem(&tv, string1);
QTreeWidgetItem *top2 = new QTreeWidgetItem(&tv, string2);
// A child item.
QTreeWidgetItem *child1 =
new QTreeWidgetItem(top1, QStringList() << "Hello" << "World");
// The grandchildren.
new QTreeWidgetItem(child1, QStringList() << "Hello_sub1" << "World_sub1");
new QTreeWidgetItem(child1, QStringList() << "Hello_sub2" << "World_sub2");

Answer 2

Actually I was able to solve it another way...
in the .cpp:
//Initialize the QTreeWidget with 2 columns
QTreeWidget m_treeWidget = new QTreeWidget();
m_treeWidget->setColumnCount(2);
//these are the method calls:
AddRoot("Root1_Column1", "Root2_Column2", m_treeWidget);
AddRoot("Root2_Column1", "Root2_Column2", m_treeWidget);
//topLevelItem(0) makes it a child of the first root... topLevelItem(1) makes it a child of the second root
AddChild(m_treeWidget->topLevelItem(0),"Child1_Column1","Child1_Column2");
AddChild(m_treeWidget->topLevelItem(1),"Child2_Column1","Child2_Column2");
AddSubChild(m_treeWidget->itemBelow(m_treeWidget->topLevelItem(0)),"SubChild_Column1", "SubChild_Column2");
With these being the methods I used within the same .cpp file:
void Dialog::AddRoot (QString name, QString Description, QTreeWidget* treeWidget)
{
QTreeWidgetItem *item = new QTreeWidgetItem(treeWidget);
item->setText(0,name);
item->setText(1,Description);
item->setExpanded(true); //expand automatically
treeWidget->addTopLevelItem(item);
}
void Dialog::AddChild (QTreeWidgetItem *parent, QString name, QString Description)
{
QTreeWidgetItem *item = new QTreeWidgetItem();
item->setText(0,name);
item->setText(1, Description);
parent->addChild(item);
}
void Dialog::AddSubChild (QTreeWidgetItem *parent, QString name, QString Description)
{
QTreeWidgetItem *item = new QTreeWidgetItem();
item->setText(0,name);
item->setText(1, Description);
parent->addChild(item);
}