Introducing KDDockWidgets An advanced docking framework for Qt
04.11.2019
KDDockWidgets is an effort by KDAB to provide an advanced docking system for Qt.
Throughout the years KDAB has contributed and funded QDockWidget development. Sadly, this wasn’t without pain: each change took many days to implement and an equal amount of time to fix regressions.
QDockWidgetmixes GUI code with logic/state in a spaghetti manner, making it
very hard to move forward. In hindsight, what caused this complexity was the
combinatorial explosion of options it supports (which seem unneeded to me, as
most people just want to use all the features). That, times 3 platforms, which
have different nuances, times 2, since code behaves drastically different if
you have animations enabled or not.
KDDockWidgets was born from my need to preserve sanity after having worked in two projects that needed extensive customization. One where we tried to work directly upstream but the regression rate ended up being too much. And another one where I took the route of using private API, fake mouse events and event filters, which seemed like a good idea at first, but ended up being a world of pain. Furthermore, our customers were getting more creative with their requests, so it was clear we needed a better docking framework.
Say hello to KDDockWidgets
The immediate differences you can spot are the very precise docking indicators and the total freedom in terms of docking areas.
Here’s a comprehensive list:
- You can now dock into the center or simply remove the concept of “central widget”
- You can have tabs in the center
- Nesting dock widgets in a floating window and docking that group back to main window works (Olivier Goffart from Woboq in collaboration with KDAB implemented the nesting part in
QDockWidgetfor Qt 5.10, but dropping the floating window back to main window was too difficult to finish.) - Docking to any main window. The main window is no longer the “owner” of a dock widget
- Separated GUI code from logic, so we can easily provide a QtQuick backend
- Exposes inner helper widgets so the user can customize them or provide his own
- 140+ tests, including some which send fake mouse events to test GUI DnD operations
- A fuzzer to help find bugs
- Allows the user to implement different types of docking indicators
- Eventually: QtQuick support
Moreover, it intends to be a framework, so you can easily override interfaces to provide custom behaviour and appearance.
KDDockWidgets is Open Source (GPLv2 & GPLv3). Alternatively contact KDAB for other licensing options if you need it in proprietary software.
What’s next ?
In the last months we’ve been having fun using KDDockWidgets in a couple of customer projects already, incorporating valuable feedback into the API. The next step is getting official documentation and source/binary-compat guarantees, in preparation for the 1.0 release. I also hope to gather feature requests from the community, so feel free to comment here or drop me an e-mail.
Yes, widgets are still alive and kicking. In the many years we have worked with them, we have gathered quite a number of tips and tricks that we’d love to share with you.
GridLayout in Qt Designer
Populating a Combobox from Qt Designer
Sessions in Qt Creator
Using Clang-Format to Ensure Style Guidelines
Un-sorting Headers in QTableView
Using GammaRay to Find the Class of an UI Element
Understanding Contents Margins in Qt Layouts
Starting the Application in GammaRay from Qt Creator
Spell Checking in Qt Creator
Communicating between a View/Delegate and a Model
Visualizing the Model Stack in GammaRay
Traversing Proxy Models to Get to the Source Model at the Bottom
Changing the Font to Jetbrains Mono in Qt Creator
Using Custom Types with Model/View
Top 7 Shortcuts in Qt Creator
Avoiding QVariant::fromValue around your Own Types
Document Templates in Qt Creator - Part 1
Document Templates in Qt Creator - Part 2
Document Templates in Qt Creator - Part 3
Document Templates in Qt Creator - Part 4
Adapting Column Content to Size
Converting Enums to and from Strings
Qt Designer Plugins (Part 1) - Widgets Promotion
Qt Designer Plugins (Part 2) - Initializing Classes when Using Qt Designer
About KDAB
KDAB is a consulting company offering a wide variety of expert services in Qt, C++ and 3D/OpenGL and providing training courses in:
KDAB believes that it is critical for our business to contribute to the Qt framework and C++ thinking, to keep pushing these technologies forward to ensure they remain competitive.
What about other Qt licences, at least GPL 3?
Might have been an oversight, GPLv3 should be possible, will check.
Great start! It would be nice to have such framework as part of Qt in the future. Do you have the plans?
Hi Dzmitry,
As Sergio explained in the blog, we actually tried to improve QDockWidget, but reached a dead-end at some point, that’s the whole reason for this external library.
We don’t plan on pushing this library upstream in Qt.
Hi Dzmitry,
if you look for an alternative advanced docking system implementation, then you could also consider this one:
https://github.com/githubuser0xFFFF
So, is it possible to use it in close-source software?
Hi Alex,
It is possible to use it in a close-source software, the library is dual license GPL/Commercial.
If you are interested, please contact us at info@kdab.com
Thank you
Wow, a really cool docking framework for Qt – I like it. Great work guys. It looks like advanced docking is something that the people really need because this is already the 3rd advanced docking framework for Qt. ;o)
If someone prefers LGPL2.1 license, then this one might be a nice alternative that I have written in Qt and that we already use in a commercial software:
https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System
And here is another nice commercial offering for an advanced Qt docking system:
https://www.devmachines.com/qtitandocking-overview.html
The cool thing about KDDockWidgets is the possibility to provide a future QtQuick backend. In my Qt Advanced Docking System I focused completely on QWidgets.
Anyway, great to see nice docking solutions for Qt.
Hi,
cool framework. Is it possible to highlight the widget/frame which has currently the focus?
I cant see it in the demo above.
Kind regards
Hannes
Are you talking about keyboard focus ? Usually only widgets accepting input should have focus, I don’t see much value with highlighting a certain dock widget.
Unless you want to make it easier to see that some line edit inside it has focus ?
Anyway, it’s possible by sub-classing from the frame class, and do your custom painting there.
Yes i meant the one with the keyboard focus. Sorry for my late reply