How does this service menu work?

[chimak111]

I have this service menu: /home/chimak/.local/share/kservices5/ServiceMenus/meld-menu.desktop highly simplified from those in the KDE Store. It works only with files in the same folder.

[Desktop Entry]
Type=Service
ServiceTypes=KonqPopupMenu/Plugin
MimeType=inode/directory;application/octet-stream;
Actions=meld
X-KDE-Priority=TopLevel

[Desktop Action meld]
Icon=page-2sides
Exec=meld %U
Name=Meld

When I

• [1]left-click on one file
  [2]ctrl+left-click on a second file and
  [3]right-click to choose "meld" from the context menu

Meld opens and I can see where the two files differ.

(I can do the same thing in the terminal with meld /path/to/filename1 path/to/filename2.)

My question is this: it looks like the names of the file left-clicked in [1] and the file ctrl+left-clicked in [2] are somehow stored for use in [3] but where?

[Snowhog]

In memory or some tmp file (to be deleted after the function is closed)?

[chimak111]

In memory or some tmp file (to be deleted after the function is closed)?

In this meld service menu (modified from https://www.pling.com/p/998366), ~/tmp is used in the Exec= line:

[Desktop Entry]
Type=Service
ServiceTypes=KonqPopupMenu/Plugin
MimeType=inode/directory;application/octet-stream;
Icon=meld
Actions=setArg1;diff;_SEPARATOR_;selected;
X-KDE-Priority=TopLevel
X-KDE-StartupNotify=false
X-KDE-Submenu=Meld menu

[Desktop Action setArg1]
Icon=arrow-left
Exec=echo "%U" > /tmp/meld-menu-arg1
Name=Set file/folder

[Desktop Action diff]
Icon=arrow-right
Exec=ARG1=$(cat /tmp/meld-menu-arg1);meld "$ARG1" %U; rm /tmp/meld-menu-arg1;
Name=Compare with file/folder

[Desktop Action selected]
Icon=page-2sides
Exec=meld %U; rm /tmp/meld-menu-arg1;
Name=Compare selected files/folder

But in the one I posted, the Exec= line is simpler.

[vinnywright]

check "man meld" it may state what it dose .

VINNY

[oshunluvr]

Not really a mystery, just basic Dolphin service menu stuff:

%U = multiple URLs.

The first left-click selects the first file, the second left-click using CTRL selects the second file without de-selecting the first file, thus when you select the Meld action from the menu, it chooses all the files in the URL list - the two you selected.

[chimak111]

...
The first left-click selects the first file, the second left-click using CTRL selects the second file without de-selecting the first file, thus when you select the Meld action from the menu, it chooses all the files in the URL list - the two you selected.

Could it be a bit more complex than that?

Consider two files, .bashrc and .bashrc.bak both in my home folder. In a "non-split" Dolphin window, meld works as expected (first image) but if I split Dolphin's window, both open to my home folder, meld fails if I select .bashrc from the left side and .bashrc.bak from the right side: it seems to compare only the second file to itself (second image).

[vinnywright]

when working in dolphin , only the "active" pane is ? well active .

just try to delete files in both panes at once , only the files in the active pane will be worked on .

VINNY

[oshunluvr]

Could it be a bit more complex than that?

Well actually, no. In your original post you asked how it worked the way it did, which I think I explained correctly. Vinny's answer explains the why your test above didn't work.

In you above test you got the results you saw because of exactly how I and Vinny explained: In short, once you switched panes in Dolphin, the file URL list changed, so only the one selected file URL (the one in the current pane) was sent to Meld.

If you're looking to modify the behavior of the Service Menu you'd need to write a whole new one that works totally differently. It could be done, but it would function in a totally different way.