This is long overdue. A bit of historical context. The grid API
is losely somewhat based on the old `radical` module, but was
heavily improved by @getzze. That version had row_span and col_span.
This made the way the previous implementation coded the border
incompatible. I spent some time back then trying to bolt it back on,
but the complexity is quite high and never made it work right.
This commit goes in another direction. Rather than draw the border,
it creates a mask where the border should *not* be, then bucket fill
the widget. This is the equivalent of CSS `border-collapse`.
It also support custom borders. This allows dashed lines and partial
borders.
The main use case will be to add border support to the calendar. It
was previously possible to partially do it using custom cell painters,
but was pretty hacky. Now that the calendar will deprecate the custom
painters in favor of `widget_template`s, a more robust alternative was
required.
The drawback of this commit is obviously the added complexity to the
most complex layout. This is why it adds many tests to cover the various
corner cases.
This allows to figure out if a test will generate an image without
having to run it. The long term plan for this is to run the tests during
compiling ("make") and not during configuring ("cmake"). Since the list
of files to e.g. install needs to be known during configuring, this
commit is a necessary step in that direction.
Signed-off-by: Uli Schlachter <psychon@znc.in>
Emmanuel Lepage Vallee
Uli Schlachter
getzze