How to update a QTreeWidget by Clicking on QPushbutton - c++

Question

I'm developing a Qt app in C++
I have create a layout with button bar, TreeView...
The Treeview is defined in my MainWindow.cpp
MainWindow::MainWindow()
{
setWindowTitle(QString::fromUtf8("PULS"));
resize(800,600);
setUnifiedTitleAndToolBarOnMac(true);
createDeviceStatusBar();
createSectionBar();
createTreeView();
QWidget *MainWindowWidget = new QWidget();
QVBoxLayout *MainWindowLayout = new QVBoxLayout(MainWindowWidget);
BrowserSection = new QGroupBox();
QWidget *BrowserWidget = new QWidget();
QHBoxLayout *BrowserLayout = new QHBoxLayout(BrowserWidget);
BrowserLayout->addWidget(SectionBar);
BrowserLayout->addWidget(TreeSection);
BrowserSection->setLayout(BrowserLayout);
MainWindowLayout->addWidget(DeviceSection);
MainWindowLayout->addWidget(BrowserSection);
setCentralWidget(MainWindowWidget);
show();
}
The createSectionBar() is a layout defined as below:
void MainWindow::createSectionBar()
{
SectionBar = new QGroupBox();
QVBoxLayout *SectionBarlayout = new QVBoxLayout;
SectionBarlayout->setContentsMargins(QMargins(0,0,0,0));
MusicButton = new QPushButton();
MusicButton->setFixedSize(110,150);
MusicButton->setIcon(QIcon(":/images/music.png"));
MusicButton->setIconSize(QSize(90,144));
MusicButton->setFlat(true);
MusicButton->setAutoFillBackground(true);
connect(MusicButton, SIGNAL(clicked()), this, SLOT(MusicTreeFile()));
SectionBarlayout->addWidget(MusicButton);
SectionBar->setLayout(SectionBarlayout);
}
The createTreeView() is defined as below to enable TreeView and Items.
void MainWindow::createTreeView()
{
TreeSection = new QGroupBox();
QVBoxLayout *TreeLayout = new QVBoxLayout;
MyTree = new TreeWidget();
MyTree->setSortingEnabled(true);
MyTree->setColumnWidth(0, 400);
QTreeWidgetItem* headerItem = new QTreeWidgetItem();
headerItem->setText(0,QString("File Name"));
headerItem->setText(1,QString("Size (Bytes)"));
headerItem->setText(2,QString("Date"));
MyTree->setHeaderItem(headerItem);
MyTree->setAutoFillBackground(true);
TreeLayout->addWidget(MyTree);
TreeSection->setLayout(TreeLayout);
}
What I need is to find a way to file the MyTree with
while (file != NULL && file->parent_id == folder_parent) {
QTreeWidgetItem* item = new QTreeWidgetItem();
int i;
LIBMTP_file_t *oldfile;
item->setText(0,file->filename);
Tree->addTopLevelItem(item);
....
}
here is the header file:
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow();
protected:
private slots:
void MusicTreeFile();
private:
void createSectionBar();
void createTreeView();
void createDeviceStatusBar();
QGroupBox *SectionBar;
QGroupBox *TreeSection;
QGroupBox *DeviceSection;
QGroupBox *BrowserSection;
QPushButton *MusicButton;
TreeWidget *MyTree;
};
but it needs to be done only when clicking on MusicPushButton, I have already connected the MusicTreeFile() to the PushButton() action. but how to access to MyTree as it's also defined in another class..

Answer 1

You do not connect a signal to a class. You connect it to an instance of a class. And both of your instances are defined in MainWindow. So after both widgets are created you can call
QObject::connect(this->MusicButton, SIGNAL(clicked()), this->MyTree, SLOT(slot_name()));
With slot_name being your function
TreeWidget::slot_name{
while (file != NULL && file->parent_id == folder_parent) {
....
}
}