Bug 348012

In this case I am currently talking about "kate", but this actually applies to almost any application that might be activated by a URL or associated with a specific file mime type (e.g. web browsers or applications for specific file formats, aso.).

So, the problem is that it always depends in which Activity an application has been started first, which will then be re-used when opening files (e.g. a text file for Kate from within Dolphin) or URL's (e.g. clicking a link for Firefox from e.g. Quassel).

A specific example:
I have 3 Activities:
1. "Casual" - for general browsing, mails and other home stuff
2. "Development" - for development purposes incl. IDEs, Kate, various IRC channels with Quassel
3. "Management" - for local and remote management applications and tasks

Let's consider I start the day by starting the computer and login. This usually brings me to the first Activity, in which the following applications get opened automatically (assuming that this works):
* Firefox
* Dolphin
* Thunderbird
* Okular containing some ebook

At some point while reading some mails, I want to open an attachment which is a text file. But oops, instead of opening an instance of Kate inside the Activity I am currently operating in I get myself switched into the "Development" Activity and cannot read the rest of the mail, because Thudnerbird still is on Activity "Casual", of course. So, I close the document inside the Kate in the "Development" Activity, switch back to the "Casual" Activity, open a second instance of Kate and click again on the mail attachment: whooosh! On Activity "Development" again... closing document, switch back to "Casual", now trying to drag'n'drop the attachment from Thunderbird to the Kate instance: errrh.... "Malformed URL %001%008%006%001%004."??? OK... taking a deep breath, clicking the attachment, clicking "Save File...", navigating to /tmp/ to save it, inside Kate saying "File" > "Open...", navigating to /tmp/ and open the file. Wow! Finally...

After drinking the morning coffee I am going to do something productive, so I switch to the "Development" Activity, which has the following applications opened:
* IDE
* Kate containing some source files
* Quassel logs into some IRC channels
* Konsole

After some time of coding, I need to get some more information from the net, so I open a new Firefox instance for it. Then, I see an interesting link in one the IRC channels, which makes me click the URL. And guess what? Yes, I am back to Activity "Casual", because that's where the first instance of Firefox was started. So closing that page, back to "Development", copying the URL from the IRC channel, opening a new tab the the Firefox instance, pasting the URL and viola! I can read where I expected to (within the context of the IRC channel discussion).

Some time later, I need to prepare some VM's for some upcoming tasks, so I switch to the "Management" Activity and start setting up those. While getting into application specific setups, I need to get some further information which is available to me with a PDF file. You'll get it! Yes, while opening the PDF file from within a Dolphin instance in the "Management" Activity, I see myself being switched to the "Casual" Activity where the first instance of Okular is running.

...and this continues all day long...

So, I initially thought that the KDE Activities where supposed to present customizable working areas, as I read out from the following places conceptually:
* https://userbase.kde.org/Glossary#Activities
* https://userbase.kde.org/Plasma#Activities

Apparently, it turns out that Activities are not really useful in any way to separate activity as it seems to only separate things like desktop settings and its widgets, so pretty much like the virtual desktops with individual widgets in KDE SC 4.

Reproducible: Always

Steps to Reproduce:
1. create two activities
2. start Kate in activity #2
3. open a text file associated with Kate inside activity #1

Actual Results:  
1. see yourself being switched to activity #2
2. context information (that made you open the text file in the first place) is lost

Expected Results:  
1. new instance of Kate created inside activity #1 or already existing instance re-used
2. activities are never switched automatically