Development/Tutorials/Plasma4/PythonRunner

In this example, we're going to be writing a sample KRunner plugin, that will just display the entered text in a messagebox. Then we'll test it and finally package it up for distribution.

Building

First and foremost, make sure you have Python support enabled.

Next, you need to setup your plasmoid's development environment. For this example, our package will be called 'runner_msgbox'. Make a directory to put everything in. Plasma expects a certain set of files and directories to exist when loading a plasmoid package:

• / - The root of the package
  • metadata.desktop - Metadata about the plasmoid
  • contents/ - The directory plasma looks in for all your resources
    • code/ - 'code' type resources
      • main.py - The plugin's code. You can change this in metadata.desktop.

The metadata.desktop file

First, edit the metadata.desktop file, to look simlar to this:

[Desktop Entry]

Name=Msgbox runner Comment=Sample python krunner plugin, that will show the entered text in a messagebox Type=Service Icon=dialog-information ServiceTypes=Plasma/Runner X-Plasma-API=python X-Plasma-MainScript=code/main.py X-KDE-PluginInfo-Author=<your name> X-KDE-PluginInfo-Email=<your email> X-KDE-PluginInfo-Name=msgbox_runner X-KDE-PluginInfo-Version=0.1 X-KDE-PluginInfo-Website=http://plasma.kde.org/ X-KDE-PluginInfo-License=LGPLv3 X-KDE-PluginInfo-EnabledByDefault=true

The last line is not strictly nessecary, but convenient. Notice the ServiceType, which differs from other Plasma objects.

Code

The runner is a python class, and additionally you must provide a method for Plasma to create an instance.

from PyKDE4 import plasmascript

from PyKDE4.plasma import Plasma from PyKDE4.kdeui import KIcon, KMessageBox

class MsgBoxRunner(plasmascript.Runner):

   def init(self)
       # tell the user how to use this runner
       self.addSyntax(Plasma.RunnerSyntax("msg :q:", "Display :q: in a messagebox"))
       
   def match(self, context):
       # called by krunner to let us add actions for the user
       if not context.isValid():
           return
       
       q = context.query()

       # look for our keyword 'msg'
       if not q.startsWith("msg "):
            return

       # ignore less than 3 characters
       if q.length < 7:
           return
       
       # strip the keyword and leading space
       q = q[3:]
       q = q.trimmed()

       # now create an action for the user, and send it to krunner
       m = Plasma.QueryMatch(self.runner)
       m.setText("Message: '%s'" % q)
       m.setType(Plasma.QueryMatch.ExactMatch)
       m.setIcon(KIcon("dialog-information"))
       m.setData(q)
       context.addMatch(q, m)
       
   def run(self, context, match):
       # called by KRunner when the user selects our action,        
       # so lets keep our promise
       KMessageBox.messageBox(None, KMessageBox.Information, match.data().toString())

def CreateRunner(parent):

   return MsgBoxRunner(parent)

It is as simple as that. Note that the CreateRunner function must be present, and return an instance of your runner class.

This code is about minimal. Plasmascript. Runner is a Plasma.AbstractRunner

Test the plugin

Now you should be ready to test the plugin, to install it, simply run

$ plasmapkg --type runner --install <directory>

Now press ALT + F2 and type 'something', and you should see the command "Message 'something' in the match list, and if you run it, a messagebox should show, telling you "something"

I have learned that krunner should be restarted between updates, so if you change your script and reinstall it, restart krunner:

$ plasmapkg --type runner --upgrade <directory>
$ kquitapp krunner
$ # wait a moment
$ krunner

Distributing the plugin

Should you want to distribute your plugin, it is practical to pack it in a zip file that users can download:

$ zip -r runner_msgbox runner_msgbox

The zip archive can be installed with plasmapkg, just as the directory:

$ plasmapkg -t runner -i runner_msgbox.zip

That's all, happy coding :-)