Comtrol eCos - Manual (Page 783)

Writing New Devices - host
set message ""
if { ![synth::filter_parse_options $console_appearance parsed_options message] } {
synth::report_error \
"Invalid entry in target definition file $synth::target_definition\
\n synth_device \"console\", entry \"appearance\"\n$message"
} else {
synth::filter_add_parsed "console" parsed_options
}
On success parsed_options will be updated with an internal representation of the desired appearance, which can
then be used in a call to synth::filter_add_parsed. On failure message will be updated with details of the parsing
error that occurred.
The Graphical Interface
When the I/O auxiliary is running in graphical mode, many scripts will want to update the user interface in some
way. This may be as simple as adding another entry to the help menu for the device, or adding a new button to the
toolbar. It may also involve adding new subwindows, or even creating entire new toplevel windows. These may
be simple monitor windows, displaying additional information about what is going on in the system in a graphical
format. Alternatively they may emulate actual I/O operations, for example button widgets could be used to emulate
real physical buttons.
The I/O auxiliary does not provide many procedures related to the graphical interface. Instead it is expected that
scripts will just update the widget hierarchy directly.
So adding a new item to the Help menu involves a .menubar.help add operation with suitable arguments. Adding
a new button to the toolbar involves creating a child window in .toolbar and packing it appropriately. Scripts can
create their own subwindows and then pack it into one of .main.nw , .main.n , .main.ne , .main.w , .main.e ,
.main.sw , .main.s or .main.se . Normally the user should be allowed to control this via the target definition
file. The central window .main.centre should normally be left alone by other scripts since it gets used for text
output.
The following graphics-related utilities may be found useful:
synth::load_image < image name > < filename >
synth::register_ballon_help < widget > < message >
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