Design patterns for semi-transparent and overlaid UI elements
The current .osd style gets used for a whole bunch of different things - basically anything where we want the UI to be semi-transparent. This creates issues - the .osd style isn't always appropriate, and there are cases where we don't provide clear design patterns (see GNOME/libadwaita#335).
We likely want to set out a number of design patterns where the UI is semi-transparent and/or floating over other content. Some cases to consider:
- Standalone floating buttons (can be used in conjunction with other floating bars or not)
- Bars which are disconnected from the window edge
- Bars that are attached to the window edge
- Touch text entry/editing controls
- Full screen mode
Some things to consider:
- How to handle the light and dark UI styles, as well as high contrast mode
- Button and bar sizing
- Spacing of controls within bars
- When to use transparency and when not
- Reveal/hide behavior for controls which aren't permanently displayed (and possibly the a11y implications of this)
Edited by Allan Day