External pages with DRCS definitions can be loaded using the options in the
"DRCS pages" submenu within the "View" menu. Two DRCS pages can be loaded,
one for Global DRCS definitions and the other for Normal DRCS definitions.
Level 2.5 mode 0 PTUs are fully supported.
Partial support for Level 3.5 mode 1, 2 and 3 PTUs. DCLUTs defined in X/28/1
on the main page are not yet implemented; the characters currently appear in
the default DCLUTs described in D.1.6 and D.2.2 of the ETSI spec.
A document is first loaded as a generic PageBase before being converted to
level one pages afterwards.
This is preparation for loading pages of other types such as DRCS and Public
Object Pages. The latter will need further work as the non-TTI file loaders
blindly assume X/1 to X/25 are 7-bit odd parity coded.
This also reverts 0a1c018 putting back the copy constructor that allows
a PageBase to be converted to a LevelOnePage.
"Metadata" is data which is stored in a teletext file format but is not part
of the page itself, such as DE description and CT cycle time in the TTI file
format.
The saving code has been refactored into one class per format with common
methods for each part of the saving process. This should make it easier to
add further formats, and inheriting a format class can allow implementing a
different format that is largely based on an existing format.
The loading code is also in one class per format but is largely the same as
what it was before.
Both classes have the ability to warn the user if any issues or errors are
or will be encountered when loading or saving.
TTI files are now written with CR/LF line endings on all platforms as a
result of using binary file writing for all formats, previously Linux builds
would save TTI files with just LF line endings. TTI files are still loaded
with readLine() and trimmed() which can cope with either type of line ending.
Experimental support for loading and exporting EP1 and HMS SD-Teletext htt
formats has been added. The htt format inherits from the t42 format as the
format appears to be largely the same except for the bits being reversed
within each byte and the clock run-in and framing code added before each
packet.
This removes the character array from the LevelOnePage class and stores the
characters in packets 0 to 24 natively, adding a packet when a character is
first added to a row and removing a packet when a row becomes space
characters.
