Enhancing Accessibility and Creative Tools in KDE Plasma Wayland

Wayland is a cornerstone of the modern Linux display stack. The transition from X11 to Wayland has implications for many aspects of desktop usage. At KDAB, we are excited to share the progress made in enhancing accessibility and creative tool configurability in the Wayland session of KDE Plasma. With support from NLnet, we’ve been able to address long-standing gaps, improve user experience, and lay the groundwork for a more inclusive and adaptable Linux ecosystem.

Improving Accessibility on Wayland

Accessibility is a crucial aspect of any modern operating system. Some users struggle to enter key sequences like Ctrl + C due to motor impairments, such as limited finger dexterity. To accommodate these users a feature called "Sticky Keys" is used. It allows users to enter key sequences one-by-one, eliminating the need for complex hand movements. While KDE Plasma 6.0 introduced initial support for accessibility features like Sticky Keys in Wayland, this implementation lacked certain refinements present in the traditional X11 session.

We have not only closed these gaps but also enhanced the overall experience, making Wayland more accessible than ever. One aspect that was lacking in the Wayland session is feedback about when Sticky Keys are active. Key improvements include:

• Popup Notifications: The Plasma system settings application allows to enable notifications when certain key events occur. This does not only include information about using Sticky Keys but generally about modifier keys being active or inactive. With our work these notifications consistently work on Wayland.
• System Bell: Another accessibility-related concept is the system bell. It allows applications to issue an abstract notification to the system to inform the user about something that has happened. This event can be represented in different ways. Typically, it will produce a sound, but to accommodate deaf / hard of hearing users it can also be represented visually by flashing the screen or window. Wayland recently gained a protocol to let applications issue such bells, however, there was no complete implementation of it in Plasma yet. We added a new visual bell implementation in KWin, KDE's Wayland compositor (and X11 window manager). Not only does this enable using a visual bell on Wayland, it also greatly improves the presentation of it on X11, especially with multiple or high-DPI displays. This system bell infrastructure can also be used to inform the user about key state changes instead of notifications.

• System Tray Indicator: Based on user feedback we also devised a novel way to communicate the sticky state to the user. For a long time, Plasma showed in the system tray area when the Caps Lock key was active. We extended this to also indicate the sticky state for modifier keys, providing an unintrusive yet visible way to see the state of the keys. This is a good example where the Wayland session is not only on par with but exceeding the X11 session.

Expanding Drawing Tablet Support for Artists

Another aspect that has shifted in the Wayland transition is drawing tablet support. A lot of configuration software was built around an X11 system that doesn't work on Wayland. Artists who prefer Linux and free software for their job still need X11, where tablet support is more mature.

KDE Plasma has already had some drawing tablet support and configuration in the Wayland session for years, so we could focus on adding onto the feature-set that was already present:

• Customizable Tablet Areas: Limit the usable area of the tablet surface, which may be desired when you have a large tablet. Limiting the usable area to a smaller fraction is desired for its better ergonomics.

• Pressure Curve Adjustment: Change the pressure curve of the stylus pen. Some artists prefer a certain curve to emulate a certain style, or to work around hardware issues with older tablet pens. This is configured by changing the points of a Bézier curve, a similar interface found in other configuration tools and art software.

• Configurable Stylus Buttons: Rebind stylus pen buttons to mouse button clicks. These buttons could already be configured to emulate a key press, but that's not the only input used in digital art software. You can now bind a pen button to the middle mouse to pan a canvas, or by right-clicking to open a color palette. Additionally, unused stylus pen buttons can now be disabled, which could be desired depending on the ergonomics of your stylus.

A Step Forward for Inclusivity and Creativity

The work funded by NLnet underscores the potential of open-source collaboration to make computing more inclusive and adaptable. By enhancing accessibility tools or expanding support for creative hardware, these updates reaffirm KDE Plasma's commitment to serving diverse user needs.