Bug 249223 - preventDefault() doesn't block selection on iOS
Summary: preventDefault() doesn't block selection on iOS
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: UI Events (show other bugs)
Version: Safari 16
Hardware: Unspecified iOS 16
: P2 Normal
Assignee: Nobody
Keywords: InRadar
Depends on:
Reported: 2022-12-13 07:17 PST by Pierre Ossman
Modified: 2022-12-20 07:17 PST (History)
4 users (show)

See Also:


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Description Pierre Ossman 2022-12-13 07:17:00 PST
This issue is specific to Safari on iOS. It doesn't happen in Safari on macOS, nor in other browsers.

We (noVNC) have a canvas where we grab all UI events (keyboard, mouse, touch), pass them on to the remote system, and call preventDefault() to avoid both a local and remote action.

For the most part, this works well, but not for selections on iOS. There are two primary cases we've seen:

 * Pressing Cmd+A
 * Double-clicking

In these cases, we get a local selection in Safari as well, which means we get a blue overlay annoying the user.

We're trying to work around most of it by using -webkit-user-select, but it is difficult to handle all cases.
Comment 1 Radar WebKit Bug Importer 2022-12-20 07:17:15 PST