Embedding in Python Applications

vncdotool is built with the Twisted framework, as such it best intergrates with other Twisted Applications Rewriting your application to use Twisted may not be an option, so vncdotool provides a compatability layer. It uses a seperate thread to run the Twisted reactor and communitcates with the main program using a threadsafe Queue.

To use the syncronous API you can do the following:

from vncdotool import api
client = api.connect('vnchost:display', password=None)

You can then call any of the methods available on vncdotool.client.VNCDoToolClient and they will block until completion. For example:

client.captureScreen('screenshot.png')
client.keyPress('enter')
client.expectScreen('login_success.png', maxrms=10)

It is possible to set a per-client timeout in seconds to prevent calls from blocking indefinitely.

client.timeout = 10
try:
    client.captureScreen('screenshot.png')
except TimeoutError:
    print('Timeout when capturing screen')

In case of too many timeout errors, it is recommended to reset the client connection via the disconnect and connect methods.

The vncdotool.client.VNCDoToolClient supports the context manager protocol.

with api.connect('vnchost:display') as client:
    client.captureScreen('screenshot.png')

The syncronous API can be used to automate the starting of a Virtual Machine or other application:

vmtool.start('myvirtualmachine.img')
client.connect('vmaddress::5950')
client.expectScreen('booted.png')
for k in 'username':
    client.keyPress(k)
client.keyPress('enter')
for k in 'password':
    client.keyPress(k)
client.keyPress('enter')
client.expectScreen('loggedin.png')
client.disconnect()

# continue with your testing session or other work