Alignment in groupbox without modifying size policy

[VRonin]

Imagine I have a QVoxLayout with a QGroupBox and a QTreeView. now inside of the QGroupBox I have another QVBoxLayout with 2 buttons that I want aligned to the top but I still want the QTreeView to take any extra space when resizing. Any suggestions? if I use addStrech or addSpacerItem on the inside layout it will compete with the view for extra space

[J.Hilk]

@VRonin mmh, in your Top VBoxLayout, set the SizePoilzy of the GroupBox to 'preferred' give it a stretch factor of 0 and your Treeview of 1. void QBoxLayout::setStretch(int index, int stretch)

Your QGroupBox should resize to the min-height of your Buttons

[VRonin]

I realised I did not provide enough informations in the question so here is a minimal code that shows the problem:

#include <QWidget>
#include <QVBoxLayout>
#include <QTreeView>
#include <QGridLayout>
#include <QGroupBox>
#include <QLabel>
#include <QPushButton>
class TestWidget : public QWidget{
    Q_OBJECT
    Q_DISABLE_COPY(TestWidget)
public:
    explicit TestWidget(QWidget* parent = Q_NULLPTR)
        : QWidget(parent)
    {
        QGridLayout* mainLay = new QGridLayout(this);
        QTreeView* treeView=new QTreeView(this);
        QGroupBox* groupBox1=new QGroupBox(this);
        QVBoxLayout* group1Lay = new QVBoxLayout(groupBox1);
        QPushButton* button1 = new QPushButton("button1",this);
        QPushButton* button2 = new QPushButton("button1",this);
        QGroupBox* groupBox2=new QGroupBox(this);
        QVBoxLayout* group2Lay = new QVBoxLayout(groupBox2);
        group2Lay->addWidget(new QLabel("SpaceTaker",this));
        group2Lay->addWidget(new QLabel("SpaceTaker",this));
        group2Lay->addWidget(new QLabel("SpaceTaker",this));
        group2Lay->addWidget(new QLabel("SpaceTaker",this));
        group2Lay->addWidget(new QLabel("SpaceTaker",this));
        group1Lay->addWidget(button1);
        group1Lay->addWidget(button2);
        group1Lay->addStretch(); // problem
        mainLay->addWidget(groupBox1,0,0);
        mainLay->addWidget(groupBox2,0,1);
        mainLay->addWidget(treeView,1,0,1,2);
    }
};

@J-Hilk
I'll try your solution