Web develop - Touch and interactions
Ensure that the user keeps control over interactions, particularly tactile ones
Allow zooming #
Target: everyone especially the visually impaired.
When: during development.
Description:
The site must not prohibit or limit the use of the zoom (especially on mobiles).
Allow to cancel the triggering of gestural interactions #
Target: Everyone, especially people with motor or visual disabilities and mobility.
When: during development.
Description:
During a single-point gesture interaction, at least one condition is true:
- the down event of the pointer (MouseDown) is not used to perform part of the function
- Abort or cancel, the function is terminated on the up event (MouseUp) and a mechanism is available to abort the function before the end or to cancel the function when finished
- Ability on the up event to reverse any result of the previous down event
- Finish the function on the event is essential. Note: Functions that emulate a keyboard or numeric keypad are considered as essential.
Reference WCAG :
Provide an alternative to complex gestures #
Target: Everyone, especially people with motor or visual disabilities and mobility.
When: during design and development.
Description:
- For each complex gesture interaction or path-based interaction ( swipe, drag, pinch </ span> ...), an alternative must be available (for example a non-gestural or simplified alternative) unless this gesture or this trajectory is essential (eg signature).
- In the same way, for the interactions requiring a change of orientation of the apparatus or a movement of the user (tilting, rotation, shaking ...), this functionality can be deactivated and must have an alternative in the interface.
Complex gesture: any multi-pointer gesture (requiring several fingers), and / or path-bases gesture.
Simplified gesture: an alternative requiring a single pointer (one finger) without path-based gesture.
Reference WCAG :
Provide an alternative to dragging movement #
Target : everyone, in particular people with motor or visual disability and mobility.
When : during design and development.
Description :
For each drag-and-drop interaction, verify that an accessible alternative is available and does not require a dragging movement.
This criterion only concerns movements where only the starting and end points are taken into account without path-based gesture.
Dragging movement: Action of clicking on a starting point, then holding contact during movement, then releasing the pointer to the final position.
Do :
For example, if you can drag and drop values into different columns, a sufficient alternative would be a button that allows you to select the column to move the value to.
Exception :
The dragging movement functionality is:
- essential (dexterity games)
- controlled by the user agent and not modified
Référence WCAG :
Give access to the content regardless of the orientation of the screen #
Target: Everyone, especially people with motor or visual disabilities and mobility.
When: during design and development.
Description:
Access to the content must not depend on the orientation of the screen (portrait and landscape) unless a specific display orientation is essential (e.g. serious game).
Reference WCAG :