def selectDevice(self, context, key=None):
"""Select a device in our current context."""
if not len(self.devices):
raise errors.NoDevicesAvailableError()
if key is None:
# use the first device
key = sorted(self.devices.keys())[0]
try:
dev = self.devices[key]
except KeyError:
raise errors.NoSuchDeviceError()
if not dev.accessibleFrom(context.ID):
raise DeviceLockedError()
if 'device' in context:
if context['device'] != dev.guid:
try:
oldDev = self.devices[context['device']]
except KeyError:
pass
else:
# we're trying to select a new device.
# make sure to unlock previously selected device
if oldDev.lockedInContext(context.ID):
oldDev.unlock(context.ID)
oldDev.deselect(context)
context['device'] = dev.guid
dev.select(context)
else:
context['device'] = dev.guid
dev.select(context)
return dev
def getDevice(self, context, key=None):
if not len(self.devices):
raise errors.NoDevicesAvailableError()
if key is None:
# use the first device
key = sorted(self.devices.keys())[0]
try:
dev = self.devices[key]
except KeyError:
raise errors.NoSuchDeviceError()
if not dev.accessibleFrom(context.ID):
raise DeviceLockedError()
return dev
def selectedDevice(self, context):
"""Get the selected device from the given context."""
if not len(self.devices):
raise errors.NoDevicesAvailableError()
try:
key = context['device']
except KeyError:
raise errors.DeviceNotSelectedError()
try:
dev = self.devices[key]
except KeyError:
raise errors.NoSuchDeviceError()
if not dev.accessibleFrom(context.ID):
raise DeviceLockedError()
return dev