Category: Rant

The Quest for the Ultimate GUI Framework

I love Graphical User Interfaces, especially the good ones 🙂 Some people feel more comfortable with a terminal and command line arguments – I prefer a graphical representation, especially when visualization of information can be much more effective than text (even if colorful).

Most of the tools I write are GUI tools; I like colors and graphics – computers are capable of so much graphic and visualization power – why not see it in all its glory? GUIs are not a silver bullet by any means. Sometimes bad GUIs are encountered, which might send the user to the command terminal. I’m not going to discuss here what makes up a good GUI. This post is about technologies to create GUIs.

Disclaimer: much of the rest of this post is subjective – my experience with Windows GUIs. I’m also not discussing web UI – not really in the same scope. I’m interested in taking advantage of the machine, not being constrained or affected by some browser or HTML/CSS/JS engine. The discussion is not exhaustive, either; there is a limit to a post 🙂

In the old days, the Win32 User Interface reined supreme. It was created in the days where memory was scarce, colors were few, hardware acceleration did not exist, and consistency was the name of the game. Modern GUIs were just starting to come up.

Windows supports all the standard controls (widgets) a typical GUI application would need. From buttons and menus, to list views and tree views, to edit controls, the standard set of typical application usage was covered. The basis of the Win32 GUI model was (and still is) the might Handle to Window (HWND). This entity represented the surface on which the window (typically a control) would render its graphical representation and handle its interaction logic. This worked fairly well throughout the 1990s and early 2000s.

The model was not perfect, but any means. Customizing controls was difficult, and in some cases downright impossible. Built-in customization was minimal, any substantial customization required subclassing – essentially taking control of handling some window messages differently in the hope of not breaking integration with the default message processing. It was a lot of work at best, and imperfect or impossible at worse. Messages like WM_PAINT and WM_ERASEBKGND were commonly overridden, but also mouse and keyboard-related messages. In some cases, there was no good option for customization and full blown control had to be written from scratch.

Here is a simple example: say you want to change the background color of a button. This should in theory be simple – change some property and you’re done. Not so easy with the Win32 button – it had to be owner-drawn or custom-drawn (WM_CUSTOMDRAW) in later versions of Windows. And that’s really a simple example.

Layout didn’t really exist. Controls were placed at an (x,y) coordinate measured from the top-left corner of the parent window – in pixels, mind you – with a specified width and height. There were no “panels” to handle more complex layout, in a grid for example, horizontally, or vertically, etc.

From a programmatic perspective, working directly with the Windows GUI API was no picnic either. Microsoft realized this, and developed The Microsoft Foundation Classes (MFC) library in the early 1990s to make working with Win32 GUI somewhat easier, by wrapping some of the functionality in C++ classes, and adding some nice features like docking windows. MFC was very popular at the time, as it was easier to use when getting started with building GUIs. It didn’t solve anything fundamental, as it was just using the Win32 GUI API under the covers. Several third-party libraries were written on top of MFC to provide even more functionality out of the box. MFC can still be used today, with Visual Studio still providing wizards and other helpers for MFC developers.

MFC wasn’t perfect of course. Beyond the obvious usage of the Win32 UI controls, it was fairly bloated, dragging with it a large DLL or adding a big static chunk if linked statically. Another library came out, the Windows Template Library (WTL), that provided a thin layer around the Windows GUI API, based on template classes, meaning that there was no “runtime” in the same sense as MFC – no library to link with – just whatever is compiled directly.

Personally, I like WTL a lot. In fact, my tools in recent years use WTL exclusively. It’s much more flexible than MFC, and doesn’t impose a particular way of working as MFC strongly did. The downside is that WTL wasn’t an official Microsoft library, mostly developed by good people inside the company in their spare time. Visual Studio has no special support for WTL. That said, WTL is still being maintained, and had some incremental features added throughout the years.

At the same time as MFC and WTL were used by C++ developers, another might tool entered the scene: Visual Basic. This environment was super successful for primary two reasons:

  • The programming language was based on BASIC, which many people had at least acquaintance with, as it was the most common programming language for personal computers in the 1980s and early 1990s.
  • The “Visual” aspect of Visual Basic was new and compelling. Just drag controls from a toolbox onto a surface, change properties in the designer and/or at runtime, connect to events easily, and you’re good to go.

To this day, I sometimes encounter customers and applications still built with Visual Basic 6, even though its official support date is long gone.

The .NET Era

At around 2002, .NET and C# were introduced by Microsoft as a response to the Java language and ecosystem that came out in 1995. With .NET, the Windows Forms (WinForms) library was provided, which was very similar to the Visual Basic experience, but with the more modern and powerful .NET Framework. And with .NET 2 in 2005, where .NET really kicked in (generics and other important features released), Windows Forms was the go-to UI framework while Visual Basic’s popularity somewhat waning.

However, WinForms was still based around the Win32 GUI model – HWNDs, no easy customization, etc. However, Microsoft did a lot of work to make WinForms more customizable than pure Win32 or MFC by subclassing many of the existing controls and adding functionality available with simple properties. Support was added to customize menus with colors and icons, buttons with images and custom colors, and more. The drag-n-drop experience from Visual Basic was available as well, making it relatively easy to migrate from Visual Basic.

.NET 3 and WPF

The true revolution came in 2006 when .NET 3 was released. .NET 3 had 3 new technologies that were greatly advertised:

WCF was hugely successful, and took over older technologies as it unified all types of communications, whether based on remoting, HTTP, sockets, or whatever. WF had only moderate success.

WPF was the new UI framework, and it was revolutionary. WPF ditched the Win32 UI model – a WPF “main” window still had an HWND – you can’t get away with that – but all the controls were drawn by WPF – the Win32 UI controls were not used. From Win32’s perspective there was just one HWND. Compare that to Win32 UI model, where every control is an HWND – buttons, list boxes, list views, toolbars, etc.

With the HWND restrictions gone, WPF used DirectX for rendering purposes, compared to the aging Graphics Device Interface (GDI) API used by Win32 GUIs. Without the artificial boundaries of HWNDs, WPF could do anything – combine anything – 2D, 3D, animation, media, unlimited customization – without any issues, as the entire HWND surface belonged to WPF.

I remember when I was introduced to WPF (at that time code name “Avalon”) – I was blown away. It was a far cry from the old, predictable, non-customizable model of Win32 GUIs.

WPF wasn’t just about the graphics and visuals. It also provided powerful data binding, much more powerful than the limited model supported by WinForms. I would even go so far as say it’s one of the most important of WPF’s features. WPF introduced XAML – an XML based language to declaratively build UIs, with object creation, properties, and even declarative data binding. Customizing controls could be done in several ways, including existing properties, control templates and data templates. WPF was raw power.

So, is WPF the ultimate GUI framework? It certainly looked like a prime candidate.

WPF made progress, ironing out issues, adding some features in .NET 3.5 and .NET 4. But then it seemed to have grinded to a halt. WPF barely made some minor improvements in .NET 4.5. One can say that it was pretty complete, so perhaps nothing much to add?

One aspect of WPF not dealt with well was performance. WPF could be bogged down by many control with complex data bindings – data bindings were mostly implemented with Reflection – a flexible but relatively slow .NET mechanism. There was certainly opportunities for improvement. Additionally, some controls were inherently slow, most notable the DataGrid, which was useful, but problematic as it was painfully slow. Third party libraries came in to the rescue and provided improved Data Grids of their own (most not free).

WPF had a strong following, with community created controls, and other goodies. Microsoft, however, seemed to have lost interest in WPF, the reason perhaps being the “Metro” revolution of 2012.

“Metro” and Going Universal

Windows 8 was a major release for Microsoft where UI is concerned. The “Metro” minimal language was all the rage at the time. Touch devices started to appear and Microsoft did not want to lose the battle. I noticed that Microsoft tends to move from one extreme to another, finally settling somewhere in the middle – but that usually takes years. Windows 8 is a perfect example. Metro applications (as they were called at the time) were always full screen – even on desktops with big displays. A new framework was built, based around the Windows Runtime – a new library based on the old but trusty Component Object Model (COM), with metadata used with the .NET metadata format.

The Windows Runtime UI model was built on similar principles as WPF – XAML (not the same one, mind you; that would be too easy), data binding, control templates, and other similar (but simplified) concepts from WPF. The Windows Runtime was internally built in C++, with “convenient” language projections provided out of the box for C++ (C++/CX at the time), .NET (C# and VB), and even JavaScript.

Generally, Windows 8 and the Universal applications (as they were later renamed) were pretty terrible. The “Metro design language”, with its monochromatic simplistic icons and graphics was ridiculous. Colors were gone. I felt like I’m sliding back to the 1980s when colors were limited. This “Metro” style spread everywhere as far as Microsoft is concerned. For example, Visual Studio 2012 that was out at the time was monochromatic – all icons in black only! It was a nightmare. Microsoft’s explanation was “to focus the developer attention to the code, remove distractions”. In actually, it failed miserably. I remember the control toolbox for WinForms and WPF in VS 2012 – all icons were gray – there was just no way to distinguish between them at a glance – which destroys the point of having icons in the first place. Microsoft boasted that their designers managed to make all these once colorful icons with a single color! What an achievement.

With Visual Studio 2013, they started to bring some colors back… the whole thing was so ridiculous.

The “Universal” model was created at least to address the problem of creating applications with the same code for Windows 8 and Windows Phone 8. To that end, it was successful, as the Win32 GUI was not implemented on Windows Phone, presumably because it was outdated, with lots and lots of code that is not well-suited for a small, much less powerful, form factor like the phone and other small devices.

Working with Universal applications (now called Universal Windows Platform applications) was similar to WPF to some extent, but the controls were geared towards touch devices, where fingers are mostly used. Controls were big, list views were scrolling smoothly but had very few lines of content. For desktop applications, it was a nightmare. Not to mention that Windows 7 (still very popular at the time) was not supported.

WPF was still the best option in the Microsoft space at the time, even though it stagnated. At least it worked on Windows 7, and its default control rendering was suited to desktop applications.

Windows 8.1 made some improvements in Universal apps – at least a minimize button was added! Windows 10 fixed the Universal fiasco by allowing windows to be resized normally like in the “old” days. There was a joke at the time saying that “Windows 10 returned windows to Windows. Before that it was Window – singular”.

That being said, Windows 10’s own UI was heavily influenced by Metro. The settings up use monochrome icons – how can anyone think this is better than colorful icons for easy recognition. This trend continues with Windows 11 where various classic windows are “converted” to the new “design language”. At least the settings app uses somewhat colorful icons on Windows 11.

The Universal apps could only run with a single instance, something that has since changed, but still employed. For example, the settings app in Windows 10 and 11 is single instance. Why on earth should it be in an OS named “Windows”? Give me more than one Settings window at a time!

Current State of Affairs

WPF is not moving forward. With the introduction of .NET Core (later renamed to simply .NET), WPF was open sourced, and is available in .NET 5+. It’s not cross platform, as most of the other .NET 5+ pieces.

UWP is a failure, even Microsoft admits that. It’s written in C++ (it’s based on the Windows Runtime after all), which should give it good performance not bogged down by .NET’s garbage collector and such. But its projections for C++ is awful, and in my opinion unusable. If you create a new UWP application with C++ in Visual Studio, you’ll get plenty of files, including IDL (Interface Definition Language), some generated files, and all that for a single button in a window. I tried writing something more complex, and gave up. It’s too slow and convoluted. The only real option is to use .NET – something I may not want to do with all its dependencies and overhead.

Regardless, the controls default look and feel is geared towards touch devices. I don’t care about the little animations – I want to be able to use a proper list view. For example, the Windows 11 new Task Manager that is built with the new WinUI technology (described next) uses the Win32 classic list view – because it’s fast and appropriate for this kind of tool. The rest is WinUI – the tabs are gone, there are monochromatic icons – it’s just ridiculous. The WinUI adds nothing except a dark theme option.

Task manager in Windows 11

The WinUI technology is similar to UWP in concept and implementation. The current state of UI affairs is messy – there is WinUI, UWP, .NET Maui (to replace Xamarin for mobile devices but not just) – what are people supposed to use?

All these UI libraries don’t really cater for desktop apps. This is why I’m still using WTL (which is wrapping the Win32 classic GUI API). There is no good alternative from Microsoft.

But perhaps not all is lost – Avalonia is a fairly new library attempting to bring WPF style UI and capabilities to more than just Windows. But it’s not a Microsoft library, but built by people in the community as open source – there is no telling if at some point it will stop being supported. On the other hand, WPF – a Microsoft library – stopped being supported.

Other Libraries

At this point you may be wondering why use a Microsoft library at all for desktop GUI – Microsoft has dropped the ball, as they continue to make a mess. Maybe use Blazor on the desktop? Out of scope for this post.

There are other options. many GUI libraries that use C or C++ exist – wxWidgets, GTK, and Qt, to name a few. wxWidgets supports Windows fairly well. Installing GTK successfully is a nightmare. Qt is very powerful and takes control of drawing everything, similar to the WPF model. It has powerful tools for designing GUIs, with its own declarative language based on JavaScript. With Qt you also have to use its own classes for non-UI stuff, like strings and lists. It’s also pricey for closed source.

Another alternative which has a lot of promise (some of which is already delivered) is Dear ImGui. This library is different from most others, as it’s Immediate Mode GUI, rather than Retained Mode which most other are. It’s cross platform, very flexible and fast. Just look at some of the GUIs built with it – truly impressive.

I’ll probably migrate to using ImGui. Is it the ultimate GUI framework? Not yet, but I feel it’s the closest to attain that goal. A couple of years back I implemented a mini-Process Explorer like tool with ImGui. Its list view is flexible and rich, and the library in general gets better all the time. It has great support from the authors and the community. It’s not perfect yet, there are still rough edges, and in some cases you have to work harder because of its cross-platform nature.

I should also mention Uno Platform, another cross-platform UI framework built on top of .NET, that made great strides in recent years.

What’s Next?

Microsoft has dropped the ball on desktop apps. The Win32 classic model is not being maintained. Just try to create a “dark mode” UI. I did that to some extent for the Sysinternals tools at the time. It was hard. Some things I just couldn’t do right – the scrollbars that are attached to list views and tree views, for example.

Prior to common controls version 6 (Vista), Microsoft had a “flat scroll bars” feature that allowed customization of scrollbars fairly easily (colors, for example). But surprisingly, common controls version 6 dropped this feature! Flat scroll bars are no longer supported. I had to go through hoops to implement dark scroll bars for Sysinternals – and even that was imperfect.

In my own tools, I created a theme engine as well – implemented differently – and I decided to forgo customizing scroll bars. Let them remain as is – it’s just too difficult and fragile.

I do hope Microsoft changes something in the way they look at desktop apps. This is where most Windows users are! Give us WPF in C++. Or enhance the Win32 model. The current UI mess is not helping, either.

I’m going to set some time to work on building some tools that use Dear ImGui – I feel it has the most bang for the buck.