Hi,
I�ve been experimenting
with the various Cairo bits and pieces trying to figure out how to get a
nice looking tree/UI � some interesting stuff! (thanks
for the previous pointers, everyone).
One of which is the Gizmo �
which on first impression I wondered what�s with all these pink
rectangles?
But delving deeper it looks
like a pretty cool open ended framework � I�ve been experimenting with
nesting and it sort of works, but not sure if I�m configuring it
correctly.
The Cairo Wrapper Kit is a
piece of art, but I�m struggling to get my head around it � wrapper
hell?
Anyway, I was wondering where
the �Doodle Layout Algorithm� came from? � all
I can find are references to a constraint based object visualization system
from the mid 90�s.
BTW, I know Smalltalk is
generally self documenting code, but some �big picture�
class/package documentation with these lovely experiments would make them a lot
more accessible!
Cheers,
Stewart
Gizmo>>layoutFromIndex: index
"**
The Doodle Layout Algorithm **
1) Use desiredLayoutBlock
to find out what we want as our bounds inside the availableExtent
given to us. Store this in @desired.
2) Figure out what extent we
want to offer our children based on our @desired
bounds. Store this in @offered.
@desired
may contain a width/height of BlockClosure. In this
case, we offer the
available space for that dimension to our children
3) Offer the @offered space
to each child, storing their @requested space
4) Keep a record of the
@maximum extent that our children reach inside us so that we can decide how to
clip correctly.
5) <pluggable>
Use our child layout algorithm to position and size the @requested space as the
@bounds of the child
6) Return our
@desired bounds to our parent as a requested space replacing any BlockClosure with details from our children's @maximum
extent.
."