...problem is, I actually don't know much about what kinds of markers
we'll get, and how we handle them. Thus introducing a marker kind
is just a wild guess, in order to get *any* tangible attribute
Phew, convoluted.
And I was doubtful that we need to support multiple typed child collection
Well, we get three such collections already in the first real world example...
...it occurred to me that very likely a casual reader of the code
will encounter here the first instance of such a diff binding function.
I am well aware this looks intimidating (and it is a tricky technical detail)
Even more so, if what you expect is just some access to a shared data model,
you might be completely puzzled by this code and nor recognise its importance.
...because of questionable utility
And it turned out to be quite a liability when it comes to implementing
the building blocks for binding tree implementation data structures
this is a tricky problem and a tough decision.
After quite some pondering I choose to enforce mandatory fields
through the ctor, and not to allow myself cheating my way around it
it occurred to me that effectively we abandoned the use of
a business facade and proxy model in the UI. The connection
becomes entirely message based now.
To put that into context, the originally intended architecture
never came to life. The UI development stalled before this could
happen; possibly it was also hampered by the "impedance mismatch"
between our intentions in the core and such a classical, model centric
architecture. Joel several times complained that he felt blocked; but
I did not really understand this issue. Only recently, when I came to
adapting the timeline display to GTK-3, I realised the model centric
approach can not possibly work with such an open model as intended
in our case. It would lead to endless cascades of introspection.
...shows again why its not adwisable to use wildcard namespace include.
Well, the old timeline code is going away soon, and for the rewritten new one,
we'll learn from such structural problems
these are just empty class files, but writing a basic description
for each made me flesh out a lot of organisational aspects of what
I am about to build now
...it seemed first that we'd might run into a very fundamental problem;
but after some consideration it turns out the interspersed display manager
and the decoupling between model/presenter and widget happens to mitigate
this problem as well.
BoUML was close sourced by its author and consequently dropped
from Debian. We use UML as a drawing and documentation tool,
and thus we'll just start over with the /obvious/ choice,
which is the Umbrello tool.
the content of the "GuiTimelineWidgetStructure" tiddler is
actually related to architecture questions related to custom widgets
in general, plus working notes regarding an investigation of the
Gtk::Layout widget.
bottom line
- seems we need to do that manually
- must wait until in the on_draw() callback
- use Container::foreach() to visit all child widgets
- Layout::set_size()
I am still suspicious the cleanup mechanism for child widgets works as expected...
But right now, we can't verify that, since on shutdown we get an assertion failure
from ld.so "dl-close.c: 762: _dl_close: Assertion `map->l_init_called' failed!"
Seems we're loading the GUI plugin not properly
- define tasks to be addressed during investigation
- read documentation, identify problematic aspects
- prepare a child widget class to be placed on the canvas
My intention is to use this space for experiments first,
and then as a construction site for a rewrite of the
custom timeline widget.
We really need a rewrite here, in order to be properly
aligned to the standard way of writing such a custom widget,
and also to build our first connection to the UI-Bus and then
remove the old placeholder UI model
