Add support for Clipboard API
Add clipboard manual test
Also includes these fixes:
- improve clipboard use for chrome browser
- make QClipboard::setText work
- html copy and paste
- image copy/paste
Chrome browser supports text, html and png
To use the Clipboard API, apps need to be served from
a secure context (https). There is a fallback in the
case of non secure context (http)
- Firefox requires dom.events.asyncClipboard.read,
dom.events.asyncClipboard.clipboardItem and
dom.events.asyncClipboard.dataTransfer to be
set from about:config, in order to support the
Clipboard API.
Change-Id: Ie4cb1bbb1dfc77e9655090a30967632780d15dd9
Fixes: QTBUG-74504
Fixes: QTBUG-93619
Fixes: QTBUG-79365
Fixes: QTBUG-86169
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
