How to implement a VS-like window manager (floating tabs) with Qt?

Question

I'm developing on a project that needs an interface with support of floating tabs similar to the ones in Visual Studio (as is shown below).

The interface is expected to provide the following features:

• Several sub-windows are in the main window and can be added, removed or moved to another place;
• When several sub-windows occupy the same space, they appear as several tabs;
• Users can drag & drop the sub-windows (tabs) to move them to another place;
• As the sub-windows are dragged beside one of the sides of the main window, they can be automatically docked to the side;
• When a sub-window (tab) is not docked to any of the sides, it appears as a standalone window and can be located out of the range of the main window (to support multiple monitors).

So how can I implement such a VS-like window manager (if it is called so)? I am familiar with C++ and Qt and plan to implement such features with Qt.

I've tried two of the choices Qt provides to me, but both in vain:

1. I tried building a MDI application with Qt. I tried the official MDI example and found some problems:
   • The sub-windows are not automatically docked;
   • The sub-windows are not turning to tabs when they occupy the same space;
   • The sub-windows cannot be located out of the range of the main window.
2. I also tried using the dock widgets (mainly QDockWidget). I tried the official dock widgets example and also found some problems:
   • The central widget is useless, but once it is removed (programmatically, with answer in this question) the auto-docking feature seems broken;
   • The sub-windows can only be docked to one of the sides. For example, I cannot create 4x4 sub-windows in a main window.

So how can I implement such features with Qt and C++? Is there a handy solution provided by Qt, or do I have to implement these manually (by listening to the mouse events and set the correpsonding sub-windows)?

Thanks in advance!

Answer 1

I think I have had the answer.

The answer is: there's no easy way to do this with pure Qt. And QDockWidget is nearest to the perfect solution. If you would like to implement such features, you have to do so by yourself.

However, fortunately, there are implementations of such features by others, which can be found by searching through the Web. For example, by searching through GitHub, I have found 2 repositories that contain implementations of such features:

• mfreiholz/Qt-Advanced-Docking-System
• JackyDing/QtFlex5 (works on windows platform with DWM on only, according to its README)