Faire une fenêtre sans bordure avec pour Qt

Il y a un exemple d'application dans votre répertoire de Qt: exemples/widgets/windowsflags.

OriginalL'auteur Fernando Lopez Jr.

J'ai créé un petit exemple de comment créer VS2013 comme sans cadre fenêtre en Qt5:

Vous pouvez obtenir les sources complètes ici: https://github.com/Jorgen-VikingGod/Qt-Frameless-Window-DarkStyle

Sinon ici une présentation générale du code de la façon d'intégrer le "principal" mainwindow dans le "cadre" de la fenêtre. Vous pouvez également voir comment ajouter de la barre de titre, les boutons et faire de maximiser, de les redimensionner et de déplacer des charges importantes dans la fenêtre.

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtWidgets>

/*
place your QMainWindow code here
*/
namespace Ui {
  class MainWindow;
}

class MainWindow : public QMainWindow
{
  Q_OBJECT
public:
  explicit MainWindow(QWidget *parent = 0);
  ~MainWindow();
private:
  Ui::MainWindow *ui;
};

/*
this class is to add frameless window supoort and do all the stuff with titlebar and buttons
*/
class BorderlessMainWindow: public QMainWindow
{
  Q_OBJECT
public:
  explicit BorderlessMainWindow(QWidget *parent = 0);
  ~BorderlessMainWindow() {}
protected:
  void mouseMoveEvent(QMouseEvent* event);
  void mousePressEvent(QMouseEvent* event);
  void mouseReleaseEvent(QMouseEvent* event);
  void mouseDoubleClickEvent(QMouseEvent *event);
private slots:
  void slot_minimized();
  void slot_restored();
  void slot_maximized();
  void slot_closed();
private:
  MainWindow *mMainWindow;
  QWidget *mTitlebarWidget;
  QLabel *mWindowTitle;
  QPushButton *mMinimizeButton;
  QPushButton *mRestoreButton;
  QPushButton *mMaximizeButton;
  QPushButton *mCloseButton;
  QPoint mLastMousePosition;
  bool mMoving;
  bool mMaximized;
};

#endif //MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
/*
frameless window class: it adds the MainWindow class inside the centralWidget
*/
BorderlessMainWindow::BorderlessMainWindow(QWidget *parent) : QMainWindow(parent, Qt::CustomizeWindowHint ) {
setObjectName("borderlessMainWindow");
setWindowFlags(Qt::FramelessWindowHint| Qt::WindowSystemMenuHint);
mMainWindow = new MainWindow(this);
setWindowTitle(mMainWindow->windowTitle());
QVBoxLayout *verticalLayout = new QVBoxLayout();
verticalLayout->setSpacing(0);
verticalLayout->setMargin(1);
QHBoxLayout *horizontalLayout = new QHBoxLayout();
horizontalLayout->setSpacing(0);
horizontalLayout->setMargin(0);
mTitlebarWidget = new QWidget(this);
mTitlebarWidget->setObjectName("titlebarWidget");
mTitlebarWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
mTitlebarWidget->setLayout(horizontalLayout);
mMinimizeButton = new QPushButton(mTitlebarWidget);
mMinimizeButton->setObjectName("minimizeButton");
connect(mMinimizeButton, SIGNAL(clicked()), this, SLOT(slot_minimized()));
mRestoreButton = new QPushButton(mTitlebarWidget);
mRestoreButton->setObjectName("restoreButton");
mRestoreButton->setVisible(false);
connect(mRestoreButton, SIGNAL(clicked()), this, SLOT(slot_restored()));
mMaximizeButton = new QPushButton(mTitlebarWidget);
mMaximizeButton->setObjectName("maximizeButton");
connect(mMaximizeButton, SIGNAL(clicked()), this, SLOT(slot_maximized()));
mCloseButton = new QPushButton(mTitlebarWidget);
mCloseButton->setObjectName("closeButton");
connect(mCloseButton, SIGNAL(clicked()), this, SLOT(slot_closed()));
mWindowTitle = new QLabel(mTitlebarWidget);
mWindowTitle->setObjectName("windowTitle");
mWindowTitle->setText(windowTitle());
horizontalLayout->addWidget(mWindowTitle);
horizontalLayout->addStretch(1);
horizontalLayout->addWidget(mMinimizeButton);
horizontalLayout->addWidget(mRestoreButton);
horizontalLayout->addWidget(mMaximizeButton);
horizontalLayout->addWidget(mCloseButton);
verticalLayout->addWidget(mTitlebarWidget);
verticalLayout->addWidget(mMainWindow);
QWidget *centralWidget = new QWidget(this);
centralWidget->setObjectName("centralWidget");
centralWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
centralWidget->setLayout(verticalLayout);
setCentralWidget(centralWidget);
}
void BorderlessMainWindow::mousePressEvent(QMouseEvent* event) {
if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
return;
if(event->button() == Qt::LeftButton) {
mMoving = true;
mLastMousePosition = event->pos();
}
}
void BorderlessMainWindow::mouseMoveEvent(QMouseEvent* event) {
if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
return;
if( event->buttons().testFlag(Qt::LeftButton) && mMoving) {
this->move(this->pos() + (event->pos() - mLastMousePosition));
}
}
void BorderlessMainWindow::mouseReleaseEvent(QMouseEvent* event) {
if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
return;
if(event->button() == Qt::LeftButton) {
mMoving = false;
}
}
void BorderlessMainWindow::mouseDoubleClickEvent(QMouseEvent *event) {
Q_UNUSED(event);
if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
return;
mMaximized = !mMaximized;
if (mMaximized) {
slot_maximized();
} else {
slot_restored();
}
}
void BorderlessMainWindow::slot_minimized() {
setWindowState(Qt::WindowMinimized);
}
void BorderlessMainWindow::slot_restored() {
mRestoreButton->setVisible(false);
mMaximizeButton->setVisible(true);
setWindowState(Qt::WindowNoState);
setStyleSheet("#borderlessMainWindow{border:1px solid palette(highlight);}");
}
void BorderlessMainWindow::slot_maximized() {
mRestoreButton->setVisible(true);
mMaximizeButton->setVisible(false);
setWindowState(Qt::WindowMaximized);
setStyleSheet("#borderlessMainWindow{border:1px solid palette(base);}");
}
void BorderlessMainWindow::slot_closed() {
close();
}
/*
MainWindow class: put all your code here
*/
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent, Qt::FramelessWindowHint), ui(new Ui::MainWindow) {
ui->setupUi(this);
statusBar()->setSizeGripEnabled(true);
}
MainWindow::~MainWindow() {
delete ui;
}

OriginalL'auteur Jorgen