26
CONTENTS
Figure 9: wxPropView - Device setting start procedure
• Please note that each setting location step in the figure from above internally contains two search steps. First
the framework will try to locate a setting with user scope and if this can't be located, the same setting will be
searched with global (system-wide) scope. Under Windows® this e.g. will access either the
HKEY_CURR
←
-
ENT_USER
or (in the second step) the
HKEY_LOCAL_MACHINE
branch in the Registry.
• Whenever storing a product specific setting, the device specific setting of the device used for storing will be
deleted (if existing). So when the user is currently working with a device 'VD000001' belonging to the product
group 'VirtualDevice' and there is a setting exclusively for this device storing a product specific setting now will
automatically delete the setting for 'VD000001'. Otherwise a product specific setting would never be loaded
as a device specific setting will always be found first.
• The very same thing will also happen when opening a device from any other application!
wxPropView
(p. 48)
does not behave in a special way but only acts as an arbitrary user application.
• Whenever storing a device family specific setting, the device specific or product specific setting of the device
used for storing will be deleted (if existing). See above to find out why.
• Under Windows® the driver will
not
look for a matching XML file during start-up automatically as the native
storage location for settings is the Windows® Registry. This must be loaded explicitly by the user by using
the appropriate API function offered by the SDK. However, under
Linux
XML files are the only setting formats
understood by the driver framework thus here the driver will also look for them at start-up. The device specific
setting will be an XML file with the serial number of the device as the file name, the product specific setting
will be an XML file with the product string as the filename, the device family specific setting will be an XML
file with the device family name as the file name. All other XML files containing settings will be ignored!
• Only the data contained in the lists displayed as
"Image Setting"
,
"Digital I/O"
and
"Device
Specific Data"
under
wxPropView
(p. 48) will be stored in these settings!
• Restoring of settings previously stored works in a similar way. After a device has been opened the settings
will be loaded automatically as described above.
• A detailed description of the individual properties offered by a device will
not
be provided here but can be
found in the C++ API reference, where descriptions for all properties relevant for the user (grouped together in
classes sorted by topic) can be found. As
wxPropView
(p. 48) doesn't introduce new functionality but simply
evaluates the list of features offered by the device driver and lists them any modification made using the GUI
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