Which Step do I missed? About Frameless QWidget

[Manifolds]

• framelesswindows.hh

#ifndef FRAMELESSWINDOW_HH
#define FRAMELESSWINDOW_HH

#include <QWidget>

struct FramelessWindowPrivate;
class FramelessWindow : public QWidget
{
public:
    explicit FramelessWindow(QWidget *contentWidget, QWidget *parent = 0);
    ~FramelessWindow();
private:
    FramelessWindowPrivate *d;
};

#endif // FRAMELESSWINDOW_HH

• framelesswindow.cc

#include "framelesswindow.hh"

#include <QMouseEvent>
#include <QVBoxLayout>
#include <QGraphicsDropShadowEffect>



struct FramelessWindowPrivate {
    FramelessWindowPrivate(QWidget *contentWidget) : contentWidget(contentWidget) {}
    QWidget *contentWidget;
};

FramelessWindow::FramelessWindow(QWidget *contentWidget, QWidget *parent)
    : QWidget(parent)
{
    this->setWindowFlags(Qt::FramelessWindowHint | Qt::WindowSystemMenuHint | Qt::WindowMinMaxButtonsHint);
    this->setAttribute(Qt::WA_TranslucentBackground);

    d = new FramelessWindowPrivate(contentWidget);
    QVBoxLayout *lo = new QVBoxLayout(this);
    lo->addWidget(contentWidget);
}
FramelessWindow::~FramelessWindow() {
    delete d;
}

• Widget.hh

#ifndef WIDGET_HH
#define WIDGET_HH

#include <QWidget>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private:
    Ui::Widget *ui;
};

#endif // WIDGET_HH

• Widget.cc

#include "widget.hh"
#include "ui_widget.h"

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
}

Widget::~Widget()
{
    delete ui;
}

• Widget.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Widget</class>
 <widget class="QWidget" name="Widget">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="focusPolicy">
   <enum>Qt::ClickFocus</enum>
  </property>
  <property name="windowTitle">
   <string>Widget</string>
  </property>
  <property name="autoFillBackground">
   <bool>false</bool>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout_3">
   <item>
    <layout class="QVBoxLayout" name="verticalLayout_2">
     <item>
      <widget class="QPushButton" name="pushButton">
       <property name="text">
        <string>PushButton</string>
       </property>
      </widget>
     </item>
     <item>
      <widget class="QLabel" name="label">
       <property name="text">
        <string>TextLabel</string>
       </property>
      </widget>
     </item>
     <item>
      <spacer name="verticalSpacer">
       <property name="orientation">
        <enum>Qt::Vertical</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
         <height>40</height>
        </size>
       </property>
      </spacer>
     </item>
     <item>
      <widget class="QLabel" name="label_2">
       <property name="text">
        <string>TextLabel</string>
       </property>
      </widget>
     </item>
    </layout>
   </item>
  </layout>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>

The button, labels are seems not in the same Widget, and I can't click the QSpacerItem region. If open the autoFillBackground option, the widget will not have transparency.

I want to know which step I have missed.

[Manifolds]

@Manifolds

SOLVED

[mpergand]

Maybe you need to draw a border yourself ...
Something like that:

void FramelessWindow::paintEvent(QPaintEvent *)
{
QPainter painter(this);
QPainterPath path;
path.addRoundedRect(contentsRect(), 5,5);
QColor backgroundColor=palette.color(QPalette::Window);
painter.fillPath(path,backgroundColor);
}

[Manifolds]

@mpergand

Yes, It does work.

But If I have QWidget that is not the top-level, then the background remains when I close the widget.

[Manifolds]

@Manifolds

SOLVED