Developing a Beautiful and Performant Block Editor in Qt C++ and QML

I also think Qt/QML is a very underrated technology. I have been developing a handwritten notes for Linux/Windows using Qt Quick for quite some time [0]. The experience has been a mixed bag though.

I've encountered tons of bugs (many of them still unfixed) that I had to find very ugly workarounds for. Also, while a declarative style UI language can have a lot of benefits, it does have a lot of limitations. For example, in my application I required a (infinite) canvas to rendering the ink strokes and which would be a perfect job for QGraphicsView, but there is no equivalent in Qt Quick. So I had to roll out my own component (which uses Skia under the hood), but that was quite painful. Since Qt 6, the Qt Quick scenegraph is rendered with a custom RHI backend (abstracting over Vulkan, Metal, OpenGL and DirectX) which I had a lot of trouble integrating with third party engines (I really wish they had a WebGPU backend).

[0] https://scrivanolabs.github.io

Great write-up! It would be useful if various PKMs would settle on a similar format for recording (nested) tasks, dates and metadata, as it seems to have become the standard way to store kanban boards and similar 'enhanced' views. Currently there exist various strategies ranging from embedding JSON as comments to esoteric (non-markdown) formats, often trailing at the end of each task. This makes the source look cluttered and difficult to edit/navigate.

IMO, metadata (such as date ranges) could instead be stored as empty links leading each task (or by showing a custom placeholder symbol such as '@'), paving the way for a 'linked' data format while resulting in a same-width list for easy lookups and editing:

  - [x] [@](/2025/12/30..31.md (15:30:21)) task 1
  - [ ] [@](/2025/12/29..30.md (16:20:31)) task 2
  - [ ] [@](/2025/12/28..28.md (14:20:31)) same day task
    - [ ] undated nested task

In an ideal world, the task marker could hold a custom symbol and linked metadata itself, but would result in non-standard (GFM) markdown:

  - [@](/2025/12/30..31.md (15:30:21)) task 1
  - [ ](/2025/12/29..30.md (16:20:31)) task 2
    - [ ] undated nested task

This is brilliant work and I love the Qt ecosystem. Can’t help but imagine the things we could’ve had if Apple wasn’t pushing the horror of Swift down everyone’s throat by blocking alternatives in so many tiny ways.

Looks great, and it has some features and polish that I would love Logseq to have natively, but overall I prefer the customisation potential of logseq with tags, templates, block refs etc.

This could have been based on KDE's KTextEditor https://github.com/KDE/ktexteditor

I've worked with QtWidgets and I have mixed feelings about the extensive (1) documentation about integrating C++ with QML and QtQuick.

Here's a quick history lesson (as I understand it):

- QtWidgets the original C++ QT graphics library.

- Around 2008 or something, they introduced QML and QtQuick. This was basically declarative UI + javascript for logic.

- QtWidgets is considered 'done' and all new features and dev is basically happening in QML / QtQuick.

- ...as described in this post, the current recommended 'best practice' is to avoid writing a pile of javascript spaghetti and bridge between C++ for logic and QML for UI.

So, long story short: We've moved from a robust C++ framework, to a javascript backed framework to 'appeal to the masses', but it's kind of hard to build a whole application that way, and so 'best practice' is to go back and write your logic in C++.

Does that seem weird to anyone else?

> While powerful, Qt Widgets lack some essential modern features, in my opinion, such as declarative UI, bindings, behaviors, anchors, and more. These features enable the creation of beautiful, animated UIs simply and quickly, as seen in QML.

Hum. QML is certainly declarative.

I'd love to see a breakdown of specifically what features you can't do with widgets, and why having a js <-> c++ bridge is better than not having one.

Don't get me wrong; if you want to write a 100% javascript QML application, that's cool. Go for it... but when you're writing a C++ application and choosing, deliberately, to implement you UI in another language and communicate with that UI via a bridge...

...well, let's just say, if you had another option (eg. just use C++), wouldn't that make sense?

Couldn't you do the the same thing with react native components and logic in C++? (You could) Why is this any better than just writing a react native UI? Or a flutter UI?

You could do any kind of UI, even fully native, if you're implementing the application is c++ and then just doing cross language <-> to the ui.

Right?

[1] - https://doc.qt.io/qt-6/qtqml-cppintegration-overview.html