simple MainWindow class implementation with frameless window and custom dark style.

It adds also support for titlebar and buttons (minimize, maximize, close)

Look is based on the VS2013 application window (flat and frameless window)

Screenshots
mac enabled	mac disabled

• tested with Qt5.5.0, Qt5.9.0 and Qt5.10.0
• tested on Windows 7, Windows 10,MacOSX 10.12.5 and MacOS 10.13.2

Here is an unofficial Python port of my implementation.

• add additional include plath to framelesswindow
• add resources framelesswindow.qrc and darkstyle.qrc
• add #include "framelesswindow.h" into main.cpp, create window FramelessWindow framelessWindow; and assign your mainwindow object as content framelessWindow.setContent(mainWindow); and show it framelessWindow.show();
• add #include "DarkStyle.h" into main.cpp and call a.setStyle(new DarkStyle);

#include <QApplication>
#include "DarkStyle.h"
#include "framelesswindow.h"
#include "mainwindow.h"

int main(int argc, char *argv[])
{
  QApplication a(argc, argv);

  // style our application with custom dark style
  a.setStyle(new DarkStyle);

  // create frameless window (and set windowState or title)
  FramelessWindow framelessWindow;
  //framelessWindow.setWindowState(Qt::WindowMaximized);
  //framelessWindow.setWindowTitle("test title");
  //framelessWindow.setWindowIcon(a.style()->standardIcon(QStyle::SP_DesktopIcon));
  
  // create our mainwindow instance
  MainWindow *mainWindow = new MainWindow;

  // add the mainwindow to our custom frameless window
  framelessWindow.setContent(mainWindow);
  framelessWindow.show();

  return a.exec();
}

• frameless window
• custom dark style (based on Fusion style with dark palette and custom stylesheets)
• title bar
• buttons (minimize | restore | maximize | close)
• move window by drag the title bar
• dobule click title bar to toggle between window styte (maximize and normal)
• use of native events, like minimizing or system menu

• resize window on each corner [#1] (some work done by notecola 👍)
• snap on screen edges [#3]

Many thanks goes to the Qt Forum and especially to Chris Kawa for pointing me to some usual issues and hints of great must have features.

The MIT License

Copyright (c) 2018, Juergen Skrotzky (https://github.com/Jorgen-VikingGod, JorgenVikingGod@gmail.com)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.