Version:           unspecified (using KDE 4.4.5) 
OS:                Linux

Using actions or open with on many selected files at once can easily grind your machine to a halt. In many common cases requiring a hard reset resulting in loss of data.

Even for a small number of files selected the results are not as expected ( starting 5 separate instances of qwenview etc ).


Reproducible: Always

Steps to Reproduce:
Purpose: Recompress JPEGS (worst case). Other operations similar.

Open dolphin.

navigate to a directory containing about 50 jpegs.

Select all of the jpg's. Use the right mouse button on one of the selected files to select Actions->"convert to"->JPEG.

Actual Results:  
Your machine becomes unusable. Leave for 1 hour. Try getting to console to kill processes etc.  Unplug machine.  Loss of data.

Expected Results:  
Warn user of potential impending avalanche of running programs. 
or
Open a batch processing dialogue and run applications serially allowing user to cancel.
or
disabled action and "open with" menus for more than 3 items.

 

My interface guess:

Allow custom settings for each service:
 Group-by to allow multiple files to be fed to application at a time.
 x files in a group
 settings for 1 group, < n groups and  > n groups.

for example,

 convert jpg
 1 files in group  ( ie files=groups - change reference of groups to files in dialog)
 1 group setting - no batch window, start action automatically
 groups <=10  - show batch window, start action auto
 groups >10 - show batch window, wait user start

 open using diff3
 3 files in group
 n=1
 groups<=1 - nobatch, start auto
 groups >1 - show batch window, wait user start  
 - allows diff3 to decide what to do for 1,2 or 3 files.