This enumeration determines the device event.

Values:

IG_TW_DE_CHECKAUTOMATICCAPTURE	The automatic capture settings on the device have been changed by the user.
IG_TW_DE_CHECKBATTERY	The status of the battery has changed.
IG_TW_DE_CHECKDEVICEONLINE	The device has been turned off and on.
IG_TW_DE_CHECKFLASH	The flash setting on the device has been changed by the user.
IG_TW_DE_CHECKPOWERSUPPLY	The power supply has been changed.
IG_TW_DE_CHECKRESOLUTION	The x/y resolution setting on the device has been changed by the user.
IG_TW_DE_CUSTOMEVENTS	Baseline for events specific to a given Source.
IG_TW_DE_DEVICEADDED	The user has added a device (for instance a memory card in a digital camera).
IG_TW_DE_DEVICEOFFLINE	A device has become unavailable, but has not been removed.
IG_TW_DE_DEVICEREADY	The device is ready to capture an image.
IG_TW_DE_DEVICEREMOVED	The user has removed a device.
IG_TW_DE_IMAGECAPTURED	The user has captured an image to the device's internal storage.
IG_TW_DE_IMAGEDELETED	The user has removed an image from the device's internal storage.
IG_TW_DE_LAMPFAILURE	The device's light source has failed.
IG_TW_DE_PAPERDOUBLEFEED	Two or more sheets of paper have been fed together.
IG_TW_DE_PAPERJAM	The device's document feeder has jammed.
IG_TW_DE_POWERSAVE	The device has powered down to save energy.
IG_TW_DE_POWERSAVENOTIFY	The device is about to power down to save energy.