Please note that this is an X11 Linux issue. Windows only supports one clipboard. X11 supports four. The Secondary Clipboard is what the Windows style clipboard is called in Windows.
This problem is with the Primary Clipboard, which is mouse highlight to copy and center mouse click to paste.
Bug: in onlyoffice-desktopeditors-8.0.0-99.el7.x86_64 Spreadsheet and Document, copying to the Primary Clipboard is not supported. Note: pasting is supported.
To reproduce: open a spreadsheet or document in OnlyOffice, mouse highlight some populated cells or in a document highlight some text, open a text only editor such as leafpad or gedit or similar, then center click to paste.
The Primary Clipboard is supported in libreoffice7.6-7.6.5.2-2.x86_64, as is this window. (I used the Primary Clipboard to paste several thing to this window.)
Are you using any additional software for clipboard?
Newer version of Desktop Editors is available. Please update your app and additionally check the behavior. By the way, it is installed as DEB/RPM package, isn’t it?
if I have 2 apps, let’s say google chrome + OnlyOffice
all traditional [ctr]+[c] / [ctr]+[v] do work
all traditional [right-click]+[copy] / [right-click]+[paste] do work
if I do a simple [mouse-select-text] in google-chrome and then [mouse-wheel-click] inside OnlyOffice, the selected text is pasted
IF I do a simple [mouse-select-text]IN OnlyOffice and then [mouse-wheel-click]STILL INSIDE OnlyOffice, the selected text is NOT pasted, but the previous [ctr]+[c]</kbd copied text
Am I right? I have replicated those cases. I hope it helps clarify the issue.
Thank you @Todd for reporting the issue and @str for providing additional details. We were able to reproduce the issue and based on received data we have registered a bug on inability to use Primary Clipboard when selecting data inside the editor and attempting to paste it in any other resource.