Goal
Ensure that canvas elements are available to keyboard-only users (as well as everyone else who uses a keyboard).
Why this matters
Many people with Physical and Motor Disabilities can’t use a mouse. Use of a mouse shouldn’t be required for someone to use our websites. Most assistive technology mimics the inputs of a keyboard, so if something is keyboard accessible, it’s accessible to a much higher number of people with disabilities than if it isn’t.
See Using <canvas> accessibly for the many accessibility issues that the canvas element currently contains. Keyboard accessibility must be added to this component manually.
How to Implement
See the Keyboard section of Canvas by Paul J Adam for example Javascript implementation of keyboard events on a canvas.
How to test
Using only your keyboard, try to accomplish all of the tasks a user is able to accomplish with the mouse. If anything fails, this test fails.