I really like & use this middle click paste feature in linux/kde a lot.
However often where I want to paste stuff, I want to replace other text (90% of the time this is the firefox URL / search bar). If I select it to erase it in one move, of course my middle click paste is then overridden.

So I was wondering, if it is possible to configure a grace time, i.e. if something is selected for less than 2 seconds, don't add it to Klipper.
Or
Even smarter would be if I select "sometext" and then hit middle click just on that "sometext", don't insert again "sometext" - as this is very unlikely to be the user choice.

Or how do other solve this?

you can set Klipper to not synchronize contents of the clipboard and the selection in Kilipper settings

google01103 wrote:you can set Klipper to not synchronize contents of the clipboard and the selection in Kilipper settings

What setting do you actual mean? And can I then still select and paste text with middle mouse click?

by not synchronizing the selection of text (highlighting) and the clipboard (ctrl+C or right click copy) you in effect have different buffers and you should have the functionality you desire as long as you copy to fill the clipboard

I do what google01103 suggests - Ctrl+C some text, select some other text, Ctrl+V to paste. Or I use Ctrl+L or Ctrl+K to select the location bar and search bar in Firefox, respectively, and hit backspace/delete to erase it.

In KDE applications you will often notice that there is an icon (usually looks something like this: <x|) to the right in some text boxes. You can click on it to erase the contents of the text box - most people know this. But did you know that you can also middle click on it to erase the contents and replace it with the clipboard contents?

Hans wrote:<snip>. But did you know that you can also middle click on it to erase the contents and replace it with the clipboard contents?

I did not know and unfortunately I will probably forget but still that is pretty cool

google01103 wrote:by not synchronizing the selection of text (highlighting) and the clipboard (ctrl+C or right click copy) you in effect have different buffers and you should have the functionality you desire as long as you copy to fill the clipboard

Ah, ok I see now. Well this wasn't enabled here (by default).
So yes, I know I can just use the usual keyboard shortcuts, but I was looking for a solution only with middle mouse click.

Hans wrote:I do what google01103 suggests - Ctrl+C some text, select some other text, Ctrl+V to paste. Or I use Ctrl+L or Ctrl+K to select the location bar and search bar in Firefox, respectively, and hit backspace/delete to erase it.

In KDE applications you will often notice that there is an icon (usually looks something like this: <x|) to the right in some text boxes. You can click on it to erase the contents of the text box - most people know this. But did you know that you can also middle click on it to erase the contents and replace it with the clipboard contents?

Yes, I already noticed & used this <x, but as you say this is only available in KDE apps... Still good to know you can also just use middle click.

You can get the <x| buttons in Firefox using e.g. Oxygen KDE. Unfortunately middle-clicking on them doesn't seem to paste anything, so you would have to click twice.

In some applications (e.g. Chrome) you can middle click on the new tab button to paste the clipboard content and open the URL in a new tab. Not sure about Firefox since I have heavily customized my Firefox. You can also customize Firefox so that when you middle click somewhere on the page, it'll paste the clipboard contents and open the URL in the current page (I believe you have to go to about:config for that setting).